Diploma

Case 1. Pancarpal arthrodesis

Sam Young RVN MBVNA — Thu, 23 Sep 2010 15:46:37 GMT

Current revision posted to Diploma by Sam Young RVN MBVNA on 23/09/2010 16:46:37

Case 1. Pancarpal arthrodesis

Pancarpal Arthrodesis Using Bone Graft From Proximal Humerus

OWNER:	FIELD	ANIMAL:	MAX
SPECIES:	DOG	BREED:	BORDER COLLIE
AGE:	6 YEARS	SEX:	MALE
WEIGHT:	25.6 KG	CONDITION:	GOOD

Clinical History

Max was presented unable to weightbear on the right foreleg, having jumped over a wall. The right carpus was swollen and painful on palpation. Radiographs were taken the following day, under general anaesthesia. Nothing abnormal was detected on the radiographs (see right) but on palpation it was found that the right carpus was unstable.

A dressing with gutter splints was applied for a total of 8 weeks. This proved to be unsuccessful and the dog still had a severe plantigrade stance at the end of this period. The options were discussed with the owners and it was decided that a pancarpal arthrodesis would be the best course of action. The owner was warned of the risks associated with general anaesthesiaanaesthesia..

On 13/5/98 the dog was admitted for surgery, having been starved overnight with access to water until 3 hours prior to surgery. A pre-anaesthetic clinical examination revealed no cardiovascular or thoracic abnormalities. Temperature was 38.1 C, pulse 127, respiration 27 per minute.

The owner signed a consent form and premedication was given with 1mg acepromazine (ACP, C Vet) by subcutaneous route 35 minutes prior to general anaesthesia. Analgesia and antibiotics were also given at this time, with 4mg morphine sulphate (Evans) by intra- muscular route, 100mg carprofen (Zenecarp, C Vet) and 450mg ampicillin (Duphacillin, Solvay Duphar Vet) by subcutaneous route. A 19 gauge intra-venous catheter was placed aseptically into the left cephalic vein and a slow infusion of 1 litre of compound sodium lactate (Hartmann's, Intraven) was started.

Anaesthesia was induced using 300 mg thiopentone sodium 2.5% (Intraval Sodium, Rhone Merieux) by intra-venous route, followed by intubation with a 12 cuffed endotracheal tube. A parallel semi-closed Lack circuit with 4L nitrous oxide, 2L oxygen and halothane was used to maintain anaesthesia.

Pre-surgical preparation
The dog was placed in left lateral recumbency and the whole of the right foreleg, including shoulder, right of sternum and brisket was clipped as in the first paragraph of Appendix 1. The dog was moved to theatre and placed in left lateral recumbency, where preparation of the skin around the right proximal humerus was completed, as in the second paragraph of Appendix 1. Four drapes were applied in a quadrant, leaving access to the right lateral proximal humerus only, the rest of the dog being covered by the drapes.

A standard kit, as listed in Appendix 2, was laid out with additional instruments as listed in Appendix 3.

Surgical procedure - harvest of the bone graft
An incision was made across the lateral approach to the greater tubercle of the right humerus through the skin and fascia. The deltoideus muscle was retracted to expose the area of bone just distal to the greater tubercle. An electric drill, fitted with a 4.5 mm bit, was used to drill a hole into the cancellous bone. A Volkmann scoop was used to harvest the graft bone. A total of ten scoops were put onto a saline soaked swab, which was carefully wrapped and put to one side in a sterile bowl.

The wound was closed using 3.5m chromic catgut (Ethicon) in a simple continuous suture pattern for both the muscle and subcutaneous tissue, and the skin was closed with simple interrupted sutures using 3m multifilament polyamide (Supramid, BK Vet Products).

The dog was then placed in ventral recumbency with a large cradle supporting the thorax. The right leg was tied, by the digits, to a drip stand and the skin from the bandage on the digits to the proximal radius and ulna was prepared as in Appendix 1. The surgeon and assistant changed surgical gloves. A new size 10 scalpel blade and new swabs were exchanged for the contaminated ones. A nurse released the leg from the drip stand (only holding the bandaged digits) and then held the leg proximal to the elbow to allow the surgeon to wrap the digits with a sterile bandage.

A large drape was placed under the right leg covering all parts of the dog caudal to the right axilla, including all of the left leg. A second drape was placed overlapping the first on the left side and laying over the dorsal aspect of the proximal radius and ulna on the right side. A third drape was laid to overlap both the other drapes on the right side, forming a triangle through which the right leg protruded. The last drape was laid approaching from the cranial direction and wrapping round the proximal radius and ulna. All drapes were secured with towel clips. The only part of the dog left exposed was the right leg (distal to the proximal radius and ulna), which lay, dorsal aspect uppermost, on the drapes covering the ventral abdomen. This was followed by a fenestrated barrier drape through which the limb was passed. See Figure 1.

The surgeon instructed the theatre nurse to apply a tourniquet to the distal humerus and the time was noted, as the surgeon requested that the tourniquet should only remain in place for 20 minutes.

Surgical procedure - pancarpal arthrodesis

An incision through the skin and fascia was made on the mid-dorsal surface from the distal third of the radius, across the carpus to the distal third of metacarpal III. The incision was made lateral to the accessory vein, following the vein. Gelpi retractors were used to retract the accessory vein and the common digital extensor tendon. The joint was then exposed by incising through the deep fascia. At this time a scalpel was used to sever the proximal insertions of the tendons of the extensor carpi radialis at metacarpals II and III, and the tendon of the abductor pollicis longus muscle. The joint capsule was then cut using a scalpel. The carpus was then held in the flexed position to locate the joint spaces between the radiocarpal joint; middle carpal joint and the carpometacarpal joints. An osteotome was used to debride the articular cartilages in order to provide space for the bone graft material to be inserted. Holes were then drilled in the distal radius to promote vascularisation of the area.

The plate was placed in position for a trial fitting. The fifth hole (of the nine holes) was located over the radial carpal bone. The carpus joint was proud and therefore only the end of the plate was in contact with the metacarpal. Plate benders were used to bend the plate midway along it's length. Rongeurs were also used to debride tissue from the dorsal carpus. On a second fitting the plate made contact with bone along the entire length of the plate. NOTE - at this time the tourniquet was removed.

The plate was positioned and the first hole to be drilled was into the radial carpal bone as this was the smallest bone. A 2.7 mm bit was used and 3.5 mm x15 mm Sherman screws were used for holding the plate in place. The order in which the screws were fitted is as shown in Diagram 1. After the first three screws had been placed the bone graft material was packed in the joint spaces.

The ninth hole was left unscrewed, as it appeared that it was aligned over the carpo- metacarpal joint space. The incision was then closed using 3m Supramid with simple interrupted sutures. Post-operative radiographs were then taken to check the alignment of the plate, (see radiograph pictured left). These were satisfactory - See discussion.

Post-operative management.
A short palmar moulded cast was applied to the leg. This was achieved by applying a sterile, nonadherent dressing to the wound, followed by a layer of conforming bandage, a layer of cotton wool and a further layer of conforming bandage. Delta-lite 7.5 cm casting tape was used to form a cast from the mid radius/ulna to claws. The cast had set after 8 minutes and was then split medially and laterally with an oscillating saw. The dressing was then re-applied with cotton wool padding in between all the toes, (including dew claw), using the caudal half of the cast as a splint. Care was taken to ensure adequate padding was in place under all edges of the cast to avoid tissue damage.

Recovery from anaesthesia was uneventful. The dog seemed uncomfortable during the post-operative period and the morphine was repeated after four hours. The dog went home the following day with Zenecarp 50mg tablets, to be given one twice daily with food.

The tubercle graft site wound healed well after initial swelling and a small amount of serous discharge. The dressing on the carpus was changed every 3 days initially, followed by weekly changes and was taken off after four weeks due to the skin around the dew claw being sore, despite padding.

Five weeks after surgery some swelling appeared over the carpus and the dog appeared to be in pain. A subsequent radiograph showed osteolysis around the proximal screw. See radiograph no. 3 pictured right.

A five week course of clindamycin 150mg (Antirobe, Upjohn), one twice daily, resolved the infection and the dog was walking well. The plate was expected to stay in place for approximately one year, until complete fusion of the joint had taken place. Ten months after surgery the dog became lame again and was admitted for radiography, followed by removal of the plate. Radiography showed complete fusion of the carpometacarpal joint and partial fusion of the radiocarpal joint. See Radiograph no. 4 pictured above. On removal of the plate it was noted that the distal 5 screws were loose. A post-operative Robert Jones support dressing was applied for 3 weeks. The dog is walking well now and the carpus has remained stable.

Discussion
In this case, after failure to respond to conservative treatment, surgery was indicated to restore the dog's mobility and to alleviate pain. This was achieved and can therefore be considered as successful surgery.

Hamish R Denny FRCVS (JSAP 32:329, 1991) suggests that the skin incision should be made down the medial side of the leg, curving laterally over the distal metacarpals. This ensures that the skin closure does not occur over the plate. However, in this case healing of the wound did not appear to be compromised despite being located directly over the plate. He also stated that the tourniquet could be left in place for one hour.

Packing of the joint spaces with graft material, after placement of the plate, proved difficult as the plate obstructed access. Hamish Denny recommends packing the joint spaces before fitting of the plate, while the carpus is partially flexed. This would have enabled more material to be inserted throughout all the joint spaces, and could account for incomplete fusion of the joint. A barrier drape is essential during orthopaedic surgery to prevent bacterial strike through ocurring, due to wet drapes.

An attempt could possibly have been made to drill and screw the last hole as the post-operative radiograph showed that the hole was, in fact, aligned over the proximal end of the metatarsal, although this could have resulted in the screw working loose if there wasn't adequate bone present. External post-operative support is essential to protect the plate from excessive bending forces until fusion has begun, and the gutter splint dressing should have ideally stayed on for 6 - 8 weeks.

When the post-operative infection round the proximal screw was diagnosed, ideally a swab could have been taken for a bacterial culture and sensitivity test to ensure that an effective antibiotic was prescribed. However, Antirobe was selected and did prove to be effective in eliminating the infection.

The combination of Zenecarp and morphine was an adequate choice of analgesia for this procedure, as orthopaedic surgery is extremely painful. Morphine is an opiate and therefore a potent analgesic, especially useful during anaesthesia to reduce the amount of halothane used. It also provides good analgesia in the immediate post-operative period, which is very important when using thiopentone as it has an ant-analgesic effect for up to 7 hours (the elimination half-life of the drug in the dog). Morphine lasts only 4 hours and therefore had to be repeated. Zenecarp is a non steroidal anti-inflammatory drug (NSAID), and therefore not as potent as morphine, but is considered to be the most potent of the NSAID's and a good choice as a post-operative analgesic for the following reasons: Zenecarp injectionable lasts for 24 hours, is the only NSAID considered safe to be given peri-operatively as it does not reduce the body's production of prostaglandins (which play a part in the protection of the GI tract and inadequate perfusion within the kidneys), and Zenecarp tablets enable the owner to continue administering analgesia at home.

Post-operative nursing of this case involved 8 dressing changes, management of the leg to avoid sores, initial wound management to avoid infection, observation of the leg, checking temperature and general health of the dog and advice to the client on restriction of exercise, care of the dressing and suitable post-operative diet.

The role of the owner is extremely important in a case where long-term post-operative management is needed and this commitment must be fully understood by the client before this type of surgery is carried out. In this case, despite our best efforts, the owner did not follow our advice and during the first eight weeks after the initial injury the dog was presented every 3 to 4 days with a broken gutter splint due to the dog being allowed to run free with no restriction of exercise. Had the owner followed our repeated advice surgery may not have been necessary. Unfortunately, this attitude continued into the post-operative period and the consequence of this could well have been amputation. However, despite not presenting the dog at the correct time for dressing changes and not restricting exercise the leg eventually healed.

References:
Brinker, Piermattei; Small Animal Orthopedics & Fracture Treatment, W B Saunders & Co, 2nd Ed, p 530 - 535, 1990.
Journal Small Animal Practice, 32:329, 1991.
BSAVA Manual of Anaesthesia, 3rd Rev Ed, p 53, 1992.
Small Animal Surgery, Fossum, Mosby, p938 - 942, 1997.

Case 1. Pancarpal arthrodesis

sabira mali — Fri, 24 Jul 2009 16:07:26 GMT
Revision 6 posted to Diploma by sabira mali on 24/07/2009 17:07:26

Case 1. Pancarpal arthrodesis

Pancarpal Arthrodesis Using Bone Graft From Proximal Humerus

OWNER: FIELD ANIMAL: MAX

SPECIES: DOG BREED: BORDER COLLIE

AGE: 6 YEARS SEX: MALE

WEIGHT: 25.6 KG CONDITION: GOOD

Clinical History
Max was presented unable to weightbear on the right foreleg, having jumped over a wall. The right carpus was swollen and painful on palpation. Radiographs were taken the following day, under general anaesthesia. Nothing abnormal was detected on the radiographs (see right) but on palpation it was found that the right carpus was unstable.

A dressing with gutter splints was applied for a total of 8 weeks. This proved to be unsuccessful and the dog still had a severe plantigrade stance at the end of this period. The options were discussed with the owners and it was decided that a pancarpal arthrodesis would be the best course of action. The owner was warned of the risks associated with general anaesthesia.

On 13/5/98 the dog was admitted for surgery, having been starved overnight with access to water until 3 hours prior to surgery. A pre-anaesthetic clinical examination revealed no cardiovascular or thoracic abnormalities. Temperature was 38.1 C, pulse 127, respiration 27 per minute.

The owner signed a consent form and premedication was given with 1mg acepromazine (ACP, C Vet) by subcutaneous route 35 minutes prior to general anaesthesia. Analgesia and antibiotics were also given at this time, with 4mg morphine sulphate (Evans) by intra- muscular route, 100mg carprofen (Zenecarp, C Vet) and 450mg ampicillin (Duphacillin, Solvay Duphar Vet) by subcutaneous route. A 19 gauge intra-venous catheter was placed aseptically into the left cephalic vein and a slow infusion of 1 litre of compound sodium lactate (Hartmann's, Intraven) was started.

Anaesthesia was induced using 300 mg thiopentone sodium 2.5% (Intraval Sodium, Rhone Merieux) by intra-venous route, followed by intubation with a 12 cuffed endotracheal tube. A parallel semi-closed Lack circuit with 4L nitrous oxide, 2L oxygen and halothane was used to maintain anaesthesia.

Pre-surgical preparation
The dog was placed in left lateral recumbency and the whole of the right foreleg, including shoulder, right of sternum and brisket was clipped as in the first paragraph of Appendix 1. The dog was moved to theatre and placed in left lateral recumbency, where preparation of the skin around the right proximal humerus was completed, as in the second paragraph of Appendix 1. Four drapes were applied in a quadrant, leaving access to the right lateral proximal humerus only, the rest of the dog being covered by the drapes.

A standard kit, as listed in Appendix 2, was laid out with additional instruments as listed in Appendix 3.

Surgical procedure - harvest of the bone graft
An incision was made across the lateral approach to the greater tubercle of the right humerus through the skin and fascia. The deltoideus muscle was retracted to expose the area of bone just distal to the greater tubercle. An electric drill, fitted with a 4.5 mm bit, was used to drill a hole into the cancellous bone. A Volkmann scoop was used to harvest the graft bone. A total of ten scoops were put onto a saline soaked swab, which was carefully wrapped and put to one side in a sterile bowl.

The wound was closed using 3.5m chromic catgut (Ethicon) in a simple continuous suture pattern for both the muscle and subcutaneous tissue, and the skin was closed with simple interrupted sutures using 3m multifilament polyamide (Supramid, BK Vet Products).

The dog was then placed in ventral recumbency with a large cradle supporting the thorax. The right leg was tied, by the digits, to a drip stand and the skin from the bandage on the digits to the proximal radius and ulna was prepared as in Appendix 1. The surgeon and assistant changed surgical gloves. A new size 10 scalpel blade and new swabs were exchanged for the contaminated ones. A nurse released the leg from the drip stand (only holding the bandaged digits) and then held the leg proximal to the elbow to allow the surgeon to wrap the digits with a sterile bandage.

A large drape was placed under the right leg covering all parts of the dog caudal to the right axilla, including all of the left leg. A second drape was placed overlapping the first on the left side and laying over the dorsal aspect of the proximal radius and ulna on the right side. A third drape was laid to overlap both the other drapes on the right side, forming a triangle through which the right leg protruded. The last drape was laid approaching from the cranial direction and wrapping round the proximal radius and ulna. All drapes were secured with towel clips. The only part of the dog left exposed was the right leg (distal to the proximal radius and ulna), which lay, dorsal aspect uppermost, on the drapes covering the ventral abdomen. This was followed by a fenestrated barrier drape through which the limb was passed. See Figure 1.

The surgeon instructed the theatre nurse to apply a tourniquet to the distal humerus and the time was noted, as the surgeon requested that the tourniquet should only remain in place for 20 minutes.

Surgical procedure - pancarpal arthrodesis
An incision through the skin and fascia was made on the mid-dorsal surface from the distal third of the radius, across the carpus to the distal third of metacarpal III. The incision was made lateral to the accessory vein, following the vein. Gelpi retractors were used to retract the accessory vein and the common digital extensor tendon. The joint was then exposed by incising through the deep fascia. At this time a scalpel was used to sever the proximal insertions of the tendons of the extensor carpi radialis at metacarpals II and III, and the tendon of the abductor pollicis longus muscle. The joint capsule was then cut using a scalpel. The carpus was then held in the flexed position to locate the joint spaces between the radiocarpal joint; middle carpal joint and the carpometacarpal joints. An osteotome was used to debride the articular cartilages in order to provide space for the bone graft material to be inserted. Holes were then drilled in the distal radius to promote vascularisation of the area.

The plate was placed in position for a trial fitting. The fifth hole (of the nine holes) was located over the radial carpal bone. The carpus joint was proud and therefore only the end of the plate was in contact with the metacarpal. Plate benders were used to bend the plate midway along it's length. Rongeurs were also used to debride tissue from the dorsal carpus. On a second fitting the plate made contact with bone along the entire length of the plate. NOTE - at this time the tourniquet was removed.

The plate was positioned and the first hole to be drilled was into the radial carpal bone as this was the smallest bone. A 2.7 mm bit was used and 3.5 mm x15 mm Sherman screws were used for holding the plate in place. The order in which the screws were fitted is as shown in Diagram 1. After the first three screws had been placed the bone graft material was packed in the joint spaces.

The ninth hole was left unscrewed, as it appeared that it was aligned over the carpo- metacarpal joint space. The incision was then closed using 3m Supramid with simple interrupted sutures. Post-operative radiographs were then taken to check the alignment of the plate, (see radiograph pictured left). These were satisfactory - See discussion.

Post-operative management.
A short palmar moulded cast was applied to the leg. This was achieved by applying a sterile, nonadherent dressing to the wound, followed by a layer of conforming bandage, a layer of cotton wool and a further layer of conforming bandage. Delta-lite 7.5 cm casting tape was used to form a cast from the mid radius/ulna to claws. The cast had set after 8 minutes and was then split medially and laterally with an oscillating saw. The dressing was then re-applied with cotton wool padding in between all the toes, (including dew claw), using the caudal half of the cast as a splint. Care was taken to ensure adequate padding was in place under all edges of the cast to avoid tissue damage.

Recovery from anaesthesia was uneventful. The dog seemed uncomfortable during the post-operative period and the morphine was repeated after four hours. The dog went home the following day with Zenecarp 50mg tablets, to be given one twice daily with food.

The tubercle graft site wound healed well after initial swelling and a small amount of serous discharge. The dressing on the carpus was changed every 3 days initially, followed by weekly changes and was taken off after four weeks due to the skin around the dew claw being sore, despite padding.

Five weeks after surgery some swelling appeared over the carpus and the dog appeared to be in pain. A subsequent radiograph showed osteolysis around the proximal screw. See radiograph no. 3 pictured right.

A five week course of clindamycin 150mg (Antirobe, Upjohn), one twice daily, resolved the infection and the dog was walking well. The plate was expected to stay in place for approximately one year, until complete fusion of the joint had taken place. Ten months after surgery the dog became lame again and was admitted for radiography, followed by removal of the plate. Radiography showed complete fusion of the carpometacarpal joint and partial fusion of the radiocarpal joint. See Radiograph no. 4 pictured above. On removal of the plate it was noted that the distal 5 screws were loose. A post-operative Robert Jones support dressing was applied for 3 weeks. The dog is walking well now and the carpus has remained stable.

Discussion
In this case, after failure to respond to conservative treatment, surgery was indicated to restore the dog's mobility and to alleviate pain. This was achieved and can therefore be considered as successful surgery.

Hamish R Denny FRCVS (JSAP 32:329, 1991) suggests that the skin incision should be made down the medial side of the leg, curving laterally over the distal metacarpals. This ensures that the skin closure does not occur over the plate. However, in this case healing of the wound did not appear to be compromised despite being located directly over the plate. He also stated that the tourniquet could be left in place for one hour.

Packing of the joint spaces with graft material, after placement of the plate, proved difficult as the plate obstructed access. Hamish Denny recommends packing the joint spaces before fitting of the plate, while the carpus is partially flexed. This would have enabled more material to be inserted throughout all the joint spaces, and could account for incomplete fusion of the joint. A barrier drape is essential during orthopaedic surgery to prevent bacterial strike through ocurring, due to wet drapes.

An attempt could possibly have been made to drill and screw the last hole as the post-operative radiograph showed that the hole was, in fact, aligned over the proximal end of the metatarsal, although this could have resulted in the screw working loose if there wasn't adequate bone present. External post-operative support is essential to protect the plate from excessive bending forces until fusion has begun, and the gutter splint dressing should have ideally stayed on for 6 - 8 weeks.

When the post-operative infection round the proximal screw was diagnosed, ideally a swab could have been taken for a bacterial culture and sensitivity test to ensure that an effective antibiotic was prescribed. However, Antirobe was selected and did prove to be effective in eliminating the infection.

The combination of Zenecarp and morphine was an adequate choice of analgesia for this procedure, as orthopaedic surgery is extremely painful. Morphine is an opiate and therefore a potent analgesic, especially useful during anaesthesia to reduce the amount of halothane used. It also provides good analgesia in the immediate post-operative period, which is very important when using thiopentone as it has an ant-analgesic effect for up to 7 hours (the elimination half-life of the drug in the dog). Morphine lasts only 4 hours and therefore had to be repeated. Zenecarp is a non steroidal anti-inflammatory drug (NSAID), and therefore not as potent as morphine, but is considered to be the most potent of the NSAID's and a good choice as a post-operative analgesic for the following reasons: Zenecarp injectionable lasts for 24 hours, is the only NSAID considered safe to be given peri-operatively as it does not reduce the body's production of prostaglandins (which play a part in the protection of the GI tract and inadequate perfusion within the kidneys), and Zenecarp tablets enable the owner to continue administering analgesia at home.

Post-operative nursing of this case involved 8 dressing changes, management of the leg to avoid sores, initial wound management to avoid infection, observation of the leg, checking temperature and general health of the dog and advice to the client on restriction of exercise, care of the dressing and suitable post-operative diet.

The role of the owner is extremely important in a case where long-term post-operative management is needed and this commitment must be fully understood by the client before this type of surgery is carried out. In this case, despite our best efforts, the owner did not follow our advice and during the first eight weeks after the initial injury the dog was presented every 3 to 4 days with a broken gutter splint due to the dog being allowed to run free with no restriction of exercise. Had the owner followed our repeated advice surgery may not have been necessary. Unfortunately, this attitude continued into the post-operative period and the consequence of this could well have been amputation. However, despite not presenting the dog at the correct time for dressing changes and not restricting exercise the leg eventually healed.

References:
Brinker, Piermattei; Small Animal Orthopedics & Fracture Treatment, W B Saunders & Co, 2nd Ed, p 530 - 535, 1990.
Journal Small Animal Practice, 32:329, 1991.
BSAVA Manual of Anaesthesia, 3rd Rev Ed, p 53, 1992.
Small Animal Surgery, Fossum, Mosby, p938 - 942, 1997.

Case 1. Pancarpal arthrodesis

Arlo Guthrie — Tue, 21 Apr 2009 15:50:58 GMT
Revision 5 posted to Diploma by Arlo Guthrie on 21/04/2009 16:50:58

Case 1. Pancarpal arthrodesis

Pancarpal Arthrodesis Using Bone Graft From Proximal Humerus

OWNER: FIELD ANIMAL: MAX

SPECIES: DOG BREED: BORDER COLLIE

AGE: 6 YEARS SEX: MALE

WEIGHT: 25.6 KG CONDITION: GOOD

Clinical History
Max was presented unable to weightbear on the right foreleg, having jumped over a wall. The right carpus was swollen and painful on palpation. Radiographs were taken the following day, under general anaesthesia. Nothing abnormal was detected on the radiographs (see right) but on palpation it was found that the right carpus was unstable.

A dressing with gutter splints was applied for a total of 8 weeks. This proved to be unsuccessful and the dog still had a severe plantigrade stance at the end of this period. The options were discussed with the owners and it was decided that a pancarpal arthrodesis would be the best course of action. The owner was warned of the risks associated with general anaesthesia.

On 13/5/98 the dog was admitted for surgery, having been starved overnight with access to water until 3 hours prior to surgery. A pre-anaesthetic clinical examination revealed no cardiovascular or thoracic abnormalities. Temperature was 38.1 C, pulse 127, respiration 27 per minute.

The owner signed a consent form and premedication was given with 1mg acepromazine (ACP, C Vet) by subcutaneous route 35 minutes prior to general anaesthesia. Analgesia and antibiotics were also given at this time, with 4mg morphine sulphate (Evans) by intra- muscular route, 100mg carprofen (Zenecarp, C Vet) and 450mg ampicillin (Duphacillin, Solvay Duphar Vet) by subcutaneous route. A 19 gauge intra-venous catheter was placed aseptically into the left cephalic vein and a slow infusion of 1 litre of compound sodium lactate (Hartmann's, Intraven) was started.

Anaesthesia was induced using 300 mg thiopentone sodium 2.5% (Intraval Sodium, Rhone Merieux) by intra-venous route, followed by intubation with a 12 cuffed endotracheal tube. A parallel semi-closed Lack circuit with 4L nitrous oxide, 2L oxygen and halothane was used to maintain anaesthesia.

Pre-surgical preparation
The dog was placed in left lateral recumbency and the whole of the right foreleg, including shoulder, right of sternum and brisket was clipped as in the first paragraph of Appendix 1. The dog was moved to theatre and placed in left lateral recumbency, where preparation of the skin around the right proximal humerus was completed, as in the second paragraph of Appendix 1. Four drapes were applied in a quadrant, leaving access to the right lateral proximal humerus only, the rest of the dog being covered by the drapes.

A standard kit, as listed in Appendix 2, was laid out with additional instruments as listed in Appendix 3.

Surgical procedure - harvest of the bone graft
An incision was made across the lateral approach to the greater tubercle of the right humerus through the skin and fascia. The deltoideus muscle was retracted to expose the area of bone just distal to the greater tubercle. An electric drill, fitted with a 4.5 mm bit, was used to drill a hole into the cancellous bone. A Volkmann scoop was used to harvest the graft bone. A total of ten scoops were put onto a saline soaked swab, which was carefully wrapped and put to one side in a sterile bowl.

The wound was closed using 3.5m chromic catgut (Ethicon) in a simple continuous suture pattern for both the muscle and subcutaneous tissue, and the skin was closed with simple interrupted sutures using 3m multifilament polyamide (Supramid, BK Vet Products).

The dog was then placed in ventral recumbency with a large cradle supporting the thorax. The right leg was tied, by the digits, to a drip stand and the skin from the bandage on the digits to the proximal radius and ulna was prepared as in Appendix 1. The surgeon and assistant changed surgical gloves. A new size 10 scalpel blade and new swabs were exchanged for the contaminated ones. A nurse released the leg from the drip stand (only holding the bandaged digits) and then held the leg proximal to the elbow to allow the surgeon to wrap the digits with a sterile bandage.

A large drape was placed under the right leg covering all parts of the dog caudal to the right axilla, including all of the left leg. A second drape was placed overlapping the first on the left side and laying over the dorsal aspect of the proximal radius and ulna on the right side. A third drape was laid to overlap both the other drapes on the right side, forming a triangle through which the right leg protruded. The last drape was laid approaching from the cranial direction and wrapping round the proximal radius and ulna. All drapes were secured with towel clips. The only part of the dog left exposed was the right leg (distal to the proximal radius and ulna), which lay, dorsal aspect uppermost, on the drapes covering the ventral abdomen. This was followed by a fenestrated barrier drape through which the limb was passed. See Figure 1.

The surgeon instructed the theatre nurse to apply a tourniquet to the distal humerus and the time was noted, as the surgeon requested that the tourniquet should only remain in place for 20 minutes.

The ninth hole was left unscrewed, as it appeared that it was aligned over the carpo- metacarpal joint space. The incision was then closed using 3m Supramid with simple interrupted sutures. Post-operative radiographs were then taken to check the alignment of the plate, (see radiograph pictured left). These were satisfactory - See discussion.

Post-operative management.
A short palmar moulded cast was applied to the leg. This was achieved by applying a sterile, nonadherent dressing to the wound, followed by a layer of conforming bandage, a layer of cotton wool and a further layer of conforming bandage. Delta-lite 7.5 cm casting tape was used to form a cast from the mid radius/ulna to claws. The cast had set after 8 minutes and was then split medially and laterally with an oscillating saw. The dressing was then re-applied with cotton wool padding in between all the toes, (including dew claw), using the caudal half of the cast as a splint. Care was taken to ensure adequate padding was in place under all edges of the cast to avoid tissue damage.

Discussion
In this case, after failure to respond to conservative treatment, surgery was indicated to restore the dog's mobility and to alleviate pain. This was achieved and can therefore be considered as successful surgery.

Hamish R Denny FRCVS (JSAP 32:329, 1991) suggests that the skin incision should be made down the medial side of the leg, curving laterally over the distal metacarpals. This ensures that the skin closure does not occur over the plate. However, in this case healing of the wound did not appear to be compromised despite being located directly over the plate. He also stated that the tourniquet could be left in place for one hour.

Packing of the joint spaces with graft material, after placement of the plate, proved difficult as the plate obstructed access. Hamish Denny recommends packing the joint spaces before fitting of the plate, while the carpus is partially flexed. This would have enabled more material to be inserted throughout all the joint spaces, and could account for incomplete fusion of the joint. A barrier drape is essential during orthopaedic surgery to prevent bacterial strike through ocurring, due to wet drapes.

An attempt could possibly have been made to drill and screw the last hole as the post-operative radiograph showed that the hole was, in fact, aligned over the proximal end of the metatarsal, although this could have resulted in the screw working loose if there wasn't adequate bone present. External post-operative support is essential to protect the plate from excessive bending forces until fusion has begun, and the gutter splint dressing should have ideally stayed on for 6 - 8 weeks.

When the post-operative infection round the proximal screw was diagnosed, ideally a swab could have been taken for a bacterial culture and sensitivity test to ensure that an effective antibiotic was prescribed. However, Antirobe was selected and did prove to be effective in eliminating the infection.

The combination of Zenecarp and morphine was an adequate choice of analgesia for this procedure, as orthopaedic surgery is extremely painful. Morphine is an opiate and therefore a potent analgesic, especially useful during anaesthesia to reduce the amount of halothane used. It also provides good analgesia in the immediate post-operative period, which is very important when using thiopentone as it has an ant-analgesic effect for up to 7 hours (the elimination half-life of the drug in the dog). Morphine lasts only 4 hours and therefore had to be repeated. Zenecarp is a non steroidal anti-inflammatory drug (NSAID), and therefore not as potent as morphine, but is considered to be the most potent of the NSAID's and a good choice as a post-operative analgesic for the following reasons: Zenecarp injectionable lasts for 24 hours, is the only NSAID considered safe to be given peri-operatively as it does not reduce the body's production of prostaglandins (which play a part in the protection of the GI tract and inadequate perfusion within the kidneys), and Zenecarp tablets enable the owner to continue administering analgesia at home.

Post-operative nursing of this case involved 8 dressing changes, management of the leg to avoid sores, initial wound management to avoid infection, observation of the leg, checking temperature and general health of the dog and advice to the client on restriction of exercise, care of the dressing and suitable post-operative diet.

The role of the owner is extremely important in a case where long-term post-operative management is needed and this commitment must be fully understood by the client before this type of surgery is carried out. In this case, despite our best efforts, the owner did not follow our advice and during the first eight weeks after the initial injury the dog was presented every 3 to 4 days with a broken gutter splint due to the dog being allowed to run free with no restriction of exercise. Had the owner followed our repeated advice surgery may not have been necessary. Unfortunately, this attitude continued into the post-operative period and the consequence of this could well have been amputation. However, despite not presenting the dog at the correct time for dressing changes and not restricting exercise the leg eventually healed.

References:
Brinker, Piermattei; Small Animal Orthopedics & Fracture Treatment, W B Saunders & Co, 2nd Ed, p 530 - 535, 1990.
Journal Small Animal Practice, 32:329, 1991.
BSAVA Manual of Anaesthesia, 3rd Rev Ed, p 53, 1992.
Small Animal Surgery, Fossum, Mosby, p938 - 942, 1997.

Case 1. Pancarpal arthrodesis

Arlo Guthrie — Tue, 21 Apr 2009 15:47:28 GMT

Revision 4 posted to Diploma by Arlo Guthrie on 21/04/2009 16:47:28

Case 1. Pancarpal arthrodesis

Pancarpal Arthrodesis Using Bone Graft From Proximal Humerus

OWNER:	FIELD	ANIMAL:	MAX
SPECIES:	DOG	BREED:	BORDER COLLIE
AGE:	6 YEARS	SEX:	MALE
WEIGHT:	25.6 KG	CONDITION:	GOOD

Clinical History
Max was presented unable to weightbear on the right foreleg, having jumped over a wall. The right carpus was swollen and painful on palpation. Radiographs were taken the following day, under general anaesthesia. Nothing abnormal was detected on the radiographs (see right) but on palpation it was found that the right carpus was unstable.

On 13/5/98 the dog was admitted for surgery, having been starved overnight with access to water until 3 hours prior to surgery. A pre-anaesthetic clinical examination revealed no cardiovascular or thoracic abnormalities. Temperature was 38.1 C, pulse 127, respiration 27 per minute.

The owner signed a consent form and premedication was given with 1mg acepromazine (ACP, C Vet) by subcutaneous route 35 minutes prior to general anaesthesia. Analgesia and antibiotics were also given at this time, with 4mg morphine sulphate (Evans) by intra- muscular route, 100mg carprofen (Zenecarp, C Vet) and 450mg ampicillin (Duphacillin, Solvay Duphar Vet) by subcutaneous route. A 19 gauge intra-venous catheter was placed aseptically into the left cephalic vein and a slow infusion of 1 litre of compound sodium lactate (Hartmann's, Intraven) was started.

Anaesthesia was induced using 300 mg thiopentone sodium 2.5% (Intraval Sodium, Rhone Merieux) by intra-venous route, followed by intubation with a 12 cuffed endotracheal tube. A parallel semi-closed Lack circuit with 4L nitrous oxide, 2L oxygen and halothane was used to maintain anaesthesia.

Pre-surgical preparation
The dog was placed in left lateral recumbency and the whole of the right foreleg, including shoulder, right of sternum and brisket was clipped as in the first paragraph of Appendix 1. The dog was moved to theatre and placed in left lateral recumbency, where preparation of the skin around the right proximal humerus was completed, as in the second paragraph of Appendix 1. Four drapes were applied in a quadrant, leaving access to the right lateral proximal humerus only, the rest of the dog being covered by the drapes.

A standard kit, as listed in Appendix 2, was laid out with additional instruments as listed in Appendix 3.

Surgical procedure - harvest of the bone graft
An incision was made across the lateral approach to the greater tubercle of the right humerus through the skin and fascia. The deltoideus muscle was retracted to expose the area of bone just distal to the greater tubercle. An electric drill, fitted with a 4.5 mm bit, was used to drill a hole into the cancellous bone. A Volkmann scoop was used to harvest the graft bone. A total of ten scoops were put onto a saline soaked swab, which was carefully wrapped and put to one side in a sterile bowl.

The wound was closed using 3.5m chromic catgut (Ethicon) in a simple continuous suture pattern for both the muscle and subcutaneous tissue, and the skin was closed with simple interrupted sutures using 3m multifilament polyamide (Supramid, BK Vet Products).

The surgeon instructed the theatre nurse to apply a tourniquet to the distal humerus and the time was noted, as the surgeon requested that the tourniquet should only remain in place for 20 minutes.

References:

Brinker, Piermattei; Small Animal Orthopedics & Fracture Treatment,
W B Saunders & Co, 2nd Ed, p 530 - 535, 1990.

Journal Small Animal Practice, 32:329, 1991.

BSAVA Manual of Anaesthesia, 3rd Rev Ed, p 53, 1992.

Small Animal Surgery, Fossum, Mosby, p938 - 942, 1997.

Case 1. Pancarpal arthrodesis

Arlo Guthrie — Tue, 21 Apr 2009 15:43:27 GMT

Revision 3 posted to Diploma by Arlo Guthrie on 21/04/2009 16:43:27

Case 1. Pancarpal arthrodesis

Pancarpal Arthrodesis Using Bone Graft From Proximal Humerus

OWNER:	FIELD	ANIMAL:	MAX
SPECIES:	DOG	BREED:	BORDER COLLIE
AGE:	6 YEARS	SEX:	MALE
WEIGHT:	25.6 KG	CONDITION:	GOOD

Clinical History
Max was presented unable to weightbear on the right foreleg, having jumped over a wall. The right carpus was swollen and painful on palpation. Radiographs were taken the following day, under general anaesthesia. Nothing abnormal was detected on the radiographs (see right) but on palpation it was found that the right carpus was unstable.

A standard kit, as listed in Appendix 2, was laid out with additional instruments as listed in Appendix 3.

The surgeon instructed the theatre nurse to apply a tourniquet to the distal humerus and the time was noted, as the surgeon requested that the tourniquet should only remain in place for 20 minutes.

References:

Brinker, Piermattei; Small Animal Orthopedics & Fracture Treatment,
W B Saunders & Co, 2nd Ed, p 530 - 535, 1990.

Journal Small Animal Practice, 32:329, 1991.

BSAVA Manual of Anaesthesia, 3rd Rev Ed, p 53, 1992.

Small Animal Surgery, Fossum, Mosby, p938 - 942, 1997.

Case 1. Pancarpal arthrodesis

Arlo Guthrie — Tue, 21 Apr 2009 15:42:10 GMT

Revision 2 posted to Diploma by Arlo Guthrie on 21/04/2009 16:42:10

Case 1. Pancarpal arthrodesis

Pancarpal Arthrodesis Using Bone Graft From Proximal Humerus

OWNER:	FIELD	ANIMAL:	MAX
SPECIES:	DOG	BREED:	BORDER COLLIE
AGE:	6 YEARS	SEX:	MALE
WEIGHT:	25.6 KG	CONDITION:	GOOD

A standard kit, as listed in Appendix 2, was laid out with additional instruments as listed in Appendix 3.

The surgeon instructed the theatre nurse to apply a tourniquet to the distal humerus and the time was noted, as the surgeon requested that the tourniquet should only remain in place for 20 minutes.

References:

Brinker, Piermattei; Small Animal Orthopedics & Fracture Treatment,
W B Saunders & Co, 2nd Ed, p 530 - 535, 1990.

Journal Small Animal Practice, 32:329, 1991.

BSAVA Manual of Anaesthesia, 3rd Rev Ed, p 53, 1992.

Small Animal Surgery, Fossum, Mosby, p938 - 942, 1997.

Case 1. Pancarpal arthrodesis

Arlo Guthrie — Tue, 21 Apr 2009 15:34:14 GMT

Revision 1 posted to Diploma by Arlo Guthrie on 21/04/2009 16:34:14

Pancarpal Arthrodesis Using Bone Graft From Proximal Humerus

OWNER:	FIELD	ANIMAL:	MAX
SPECIES:	DOG	BREED:	BORDER COLLIE
AGE:	6 YEARS	SEX:	MALE
WEIGHT:	25.6 KG	CONDITION:	GOOD

Clinical History
Max was presented unable to weightbear on the right foreleg, having jumped over a wall. The right carpus was swollen and painful on palpation. Radiographs were taken the following day, under general anaesthesia. Nothing abnormal was detected on the radiographs (see right) but on palpation it was found that the right carpus was unstable.

A standard kit, as listed in Appendix 2, was laid out with additional instruments as listed in Appendix 3.

The surgeon instructed the theatre nurse to apply a tourniquet to the distal humerus and the time was noted, as the surgeon requested that the tourniquet should only remain in place for 20 minutes.

Surgical procedure - pancarpal arthrodesis
An incision through the skin and fascia was made on the mid-dorsal surface from the distal third of the radius, across the carpus to the distal third of metacarpal III. The incision was made lateral to the accessory vein, following the vein. Gelpi retractors were used to retract the accessory vein and the common digital extensor tendon. The joint was then exposed by incising through the deep fascia. At this time a scalpel was used to sever the proximal insertions of the tendons of the extensor carpi radialis at metacarpals II and III, and the tendon of the abductor pollicis longus muscle. The joint capsule was then cut using a scalpel. The carpus was then held in the flexed position to locate the joint spaces between the radiocarpal joint; middle carpal joint and the carpometacarpal joints. An osteotome was used to debride the articular cartilages in order to provide space for the bone graft material to be inserted. Holes were then drilled in the distal radius to promote vascularisation of the area.

References:

Brinker, Piermattei; Small Animal Orthopedics & Fracture Treatment,
W B Saunders & Co, 2nd Ed, p 530 - 535, 1990.

Journal Small Animal Practice, 32:329, 1991.

BSAVA Manual of Anaesthesia, 3rd Rev Ed, p 53, 1992.

Small Animal Surgery, Fossum, Mosby, p938 - 942, 1997.

Case 1. Splenectomy

Anne-Marie Lebis — Fri, 16 Apr 2010 19:45:17 GMT

Current revision posted to Diploma by Anne-Marie Lebis on 16/04/2010 20:45:17

Case 1. Splenectomy

OWNER	PIERCE	ANIMAL:	JASPER
SPECIES:	DOG	BREED:	XB
AGE:	10 YEARS	SEX:	MALE NEUTER
WEIGHT	29 KG OBESE	CONDITION:	BRIGHT

Clinical History.xxHistory.
The dog was first presented for anal adenomas which were subsequently removed under general anaesthesia. A routine palpation of the abdomen whilst the dog was under anaesthesia revealed a mass which was diagnosed as a splenic tumour. As the owners had not given consent for this surgery the dog was booked in for removal of the spleen 2 weeks later, as the dog was not showing any clinical symptoms consistent with a splenic tumour. A blood sample to measure packed cell volume was taken pre-operatively and this was recorded at 0.47 L/L, which was normal. The owners were warned of the risks associated with general anaesthesia of an old, obese dog undergoing a splenectomy and were required to sign a consent form to allow general anaesthesia and surgery.

Pre-anaesthetic clinical examination and premedication.
The dog was admitted for general anaesthesia having been starved for 12 hours with access to water until 2 hours prior to premedication. A clinical pre-operative check revealed no thoracic or cardiovascular abnormalities. Pulse was 92 per minute, respiration 34 per minute and temperature recorded at 38.8 C. Mucous membranes (m/m) were pink and capillary refill time (CRT) was just under 1 second. Premedication was given with 0.6 mg of acepromazine (ACP C Vet) by subcutaneous route and 7 mg of morphine (Morphine Sulphate, Evans) by intramuscular route. A 20 guage intravenous catheter was placed aseptically into the right cephalic vein and an infusion of Hartmanns crystalloid was started at a rate of 10 mls/kg/hour. One hour later the premedication seemed to have had no effect. The dog was still excitable and quite aggressive, needing to be muzzled in order to carry out induction, having already bitten someone without warning whilst being taken out of the kennel.

Induction.
Induction was achieved with 110 mg of propofol (Rapinovet, Schering-Plough) by slow intravenous injection given to effect through the catheter, and a cuffed 12 mm endo- tracheal tube was used to intubate the dog. A semi-closed parallel Lack circuit with a 4L resevoir bag was used with flow rates of 4L nitrous oxide and 2L oxygen, and halothane was used as the inhalation agent. Additional analgesia was given after induction with 125 mg carprofen (Rimadyl, Pfizer) by subcutaneous route. Antibiotic cover was provided with 225 mg ampicillin (Norobrittin, Norbrook) by subcutaneous route.

Radiography.
A radiograph of the thorax in right lateral recumbency was taken to ensure that no metastases had occurred. The radiograph revealed no visible abnormalities and the dog was prepared for surgery and a total splenectomy was performed.

Maintenance of anaesthesia.
For a detailed account of general anaesthesia see attached anaesthetic record. Duration of anaesthesia was 150 minutes with the dog able to walk 40 minutes after the end of anaesthesia.

After induction the dog was placed in dorsal recumbency and it was noticed after a few minutes that the pulse oximeter reading had fallen to 82% (hypoxaemia) and that the mucous membranes (m/m) were beginning to appear red. This indicated that the dog was hypoventilating. Neither a Bains circuit or a ventilator was available so the nitrous oxide was turned off and the oxygen increased to 8 L. Intermittent positive pressure ventilation (IPPV) was carried out and the pulse oximeter rose to 97% and the m/m returned to pink. At the time of the first incision the heart rate rose to 158 bpm in response to the surgical stimulation. The halothane was increased to 2% and the nitrous oxide was put back on at the previous flow rates, and IPPV was continued for the duration of anaesthesia 5 times a minute to assist with the dog's spontaneous respiration. This kept the pulse oximeter readings above 90% (the level at which hypoxaemia occurs). The heart rate continued to be quite erratic throughout the anaesthetic, although the ECG showed normal complexes and rhythm. The halothane remained at 2% for most of the duration of anaesthesia. The respiration remained fairly constant around 30 to 35 per minute. Extubation took place 5 minutes after cessation of anaesthesia.

Post-operative recovery.
The dog was very excitable on recovery and only received 700 mls of the Hartmann's as it continually tied the giving set in knots. The morphine was repeated after 4 hours. A PCV taken the following morning recorded at 0.36 L/L and the dog had slightly pale m/m's. However, it was eating and temp was normal so it was sent home with 10 Rimadyl 50 mg tablets to be given one twice daily with food, and 10 Ampicillin capsules also to be given one twice daily to start immediately. A post-operative check two days later revealed a PCV of 0.37 L/L and the dog was very bright and eating well. Sutures were removed at 10 days and the PCV was last recorded at 0.42 L/L.

Discussion.
Anaesthetic protocols should always be planned to suit the animal's condition at the time of surgery and the procedure to be performed. In this case the dog was not collapsed, as the spleen had not ruptured prior to surgery. However, a splenectomy can result in several complications under general anaesthesia and special consideration should be given to anaesthetic protocols to minimise the risks. In addition this dog was obese which also adds to the possible anaesthetic risk. Firstly, a pre-operative PCV was taken to be able to compare with post-operative PCV's, as anaemia can be a post-operative complication. Also, anaemia would preclude the use of nitrous oxide (if severe). Anaemia would also affect the accuracy of the pulse oximeter, as it measures the levels of oxygen saturation of the haemoglobin, not whether there are enough red cells to carry sufficient oxygen to the tissues. ACP was given as a premedication but it probably would have been wise not to use it for two reasons. Firstly, one side effect of ACP is to produce hypotension, which in itself could be one of the complications of removing a spleen which contains a large volume of blood. The second reason for not using ACP is that it is not usually an effective sedative for aggressive animals. In fact it can release the inhibtions that prevent a dog from biting, which is what appeared to happen in this case. However, as the dog did not give any indication of aggression prior to premedication and the owner made no mention of this behaviour this was totally unforeseen. One advantage of ACP is that it protects the heart from catecholamines. Choice of induction agent and maintenance agent is important for splenectomies as they are at risk from premature ventricular contractions (PVC) during general anaesthesia. PVC's can result from drugs, hypoventilation, hypoxaemia, pulmonary and myocardial contusions following trauma, and inadequate depth of anaesthesia.Thiopentone sensitises the myocardium to catecholamines which increases the risk of PVC's, and also depresses the respiratory and cardiovascular systems, so this agent should be avoided. Although propofol also depresses the respiratory and cardiovascular systems it does not sensitise the myocardium as much as thiopentone, and would be preferred to thiopentone. Diazepam (0.25 mg/kg) could be given intravenously before the propofol, which would reduce the amount of propofol needed for induction. Or ketamine (5 mg/kg) and diazepam (0.25 mg/kg) in the same syringe could have been given intravenously as an alternative induction agent. The advantage of using ketamine is that it does not produce as much cardiovascular depression. One third to one half of the dose should be given, followed by titration to effect after 30 seconds to allow intubation of the trachea. The disadvantage of using ketamine is that monitoring of depth of inhalation anaesthesia cannot be assessed using eye position, and monitoring instruments would be necessary to avoid overdose. Thiopentone (a barbiturate) also causes congestion of the spleen with blood, which would increase the risk of hypovolaemia and hypotension when the spleen was removed, so this agent is unsuitable for this procedure. A disadvantage of using propofol as an induction agent is that elimination of the drug can occur quite suddenly and consequently the depth of anaesthesia can change rapidly. This did occur with this dog just prior to the first incision and, as the record shows, increased respiration and pulse rate indicated that the depth of anaesthesia at this point was not adequate. The halothane was increased to take the dog back down to a suitable depth of anaesthesia. Halothane, which was used as the inhalation agent also sensitises the myocardium to catecholamines and it would have been better to use isoflurane which does not. However isoflurane is not available at this practice due to cost. Another problem encountered early in the anaesthetic was hypoventilation, caused by placing the animal in dorsal recumbency, which resulted in hypoxaemia, due to obesity. When an obese animal is placed on it's back the abdominal contents impede the diaphragm's movement. A Lack circuit is not designed for prolonged IPPV as rebreathing expired gases can occur. To try and overcome this the flow rate was turned up to 8 L. Neither a Bains circuit or ventilator was available at the time. The inspiratory phase was kept short (1 - 1.5 secs) as venous return is impeded during the inspiratory phase. The pulse oximeter rose to 97% and the m/m returned to pink. Nitrous oxide is an analgesic and is usually used at a ratio of 2:1 with oxygen. Ten minutes oxygen time must be used after cessation of nitrous oxide to avoid diffusion hypoxia. Turning off the nitrous oxide would have contributed to the dog showing a pain response to surgical stimulation, so the nitrous oxide was put back on at the previous flow rates and IPPV assistance continued 3 - 4 times a minute to assist the dog's spontaneous breathing. This kept the pulse oximeter reading above 90% for the duration of anaesthesia. Respiration rates remained quite fast throughout anaesthesia and this was attributed to obesity. Because of the risk of PVC's it was important to use the ECG to monitor the heart. Lignocaine at 1mg/kg was available to treat any PVC's if necessary, ie more than 2 in a row occuring or any PVC's in conjunction with low blood pressure. It would be necessary to ascertain the cause of the PVC's before treating with lignocaine, ie if caused by hypoxaemia or inadequate depth of anaesthesia then rectifying those problems should resolve the PVC's. Also, stopping the halothane and using isoflurane might rectify the problem. If neither of these work then a bolus of lignocaine can be tried. Close observation on depth of anaesthesia should be kept when using lignocaine (particularly if an infusion is used) as it is an anaesthetic and can lead to deepening of the anaesthetic level.

It might have been better to give the Rimadyl at the same time as the premedication as this would have ensured that it was effective at the time of the first incision. Research shows that Rimadyl has a synergistic effect when given in conjunction with morphine (a pure opioid acting on the mu receptors). Rimadyl is the only Non-Steroidal Anti-Inflammatory analgesic considered safe to use peri-operatively due to the fact that it does not inhibit the body's production of prostaglandins which play a role in protection of the gut and maintenance of renal function. Capillary refill time increased from 1 second to 1.5 seconds during ligation of the spleen and Haemaccel was substituted for Hartmann's to support the circulation volume, as the tumour was very friable and started to rupture.

Haemaccel is a gelatin used as a plasma expander which will remain in the circulation for about 5 hours. Hartmann's crystalloid was used at an initial rate of 10mls/kg/hr as this is the recommended fluid and rate of infusion for general intra-operative use. The rate of infusion of the Haemaccel was speeded up at this point and after 20 minutes the CRT returned to 1 second. Haemorrhage was not severe in this case, but if it had been it would have been better to give whole blood.If blood loss is to replaced by Hartmanns, three times the amount of blood lost should be given. However, for this procedure it is really important to provide intravenous fluids as it will be expected that removing a spleen which contains a fairly large amount of blood will have an effect on the cardiovascular system. Peripheral pulses, ie lingual and carpal were present throughout. This would indicate that, together with pink m/m's and reasonable CRT, that blood pressure remained reasonable during anaesthesia. Ideally it would be best to be able to monitor blood pressure with either direct measurement via an arterial catheter or indirectly with a cuff and Doppler or Dynamap type of measurement. None of these are available at this practice.

Temperature loss was minimal (1.2C) despite the age, duration of anaesthesia and an open abdomen. This was mainly due to having a heated operating table and using warmed fluids. This would have contributed to the quick recovery. Analgesia was suitable for this procedure and, although morphine is reported to delay recovery, it didn't in this case which was actually a disadvantage as fluid infusion had to be abandoned after recovery due to excitability of the dog.

Overall, this was a successful anaesthetic in view of the possible complications which could have occurred. The two features of the anaesthetic which were least successful were the inadequate depth of anaesthesia at the time of the first incision and management of the hypoventilation. Unfortunately some limitations are set by the equipment available, and although not ideal the pulse oximeter readings were kept above 90% (the level at which hypoxaemia occurs) for the duration of the anaesthetic after 1 minute below 90%. All complications were discussed prior to induction and relevant treatment protocols also prepared in order that the surgeon would not have to concentrate on surgical and anaesthetic emergencies simultaneously.

References:
Small Animal Surgery, T Fossum. Mosby. p 450 1997
Anasethesia of the Critical Patient, C Trim. BSAVA Congress 1999
Principles of Anaesthesia. Cont Ed Course. BSAVA March 1999 L Hughes & R McMurphy

Case 1. Splenectomy

Anne-Marie Lebis — Fri, 16 Apr 2010 19:44:54 GMT

Revision 4 posted to Diploma by Anne-Marie Lebis on 16/04/2010 20:44:54

Case 1. Splenectomy

OWNER	PIERCE	ANIMAL:	JASPER
SPECIES:	DOG	BREED:	XB
AGE:	10 YEARS	SEX:	MALE NEUTER
WEIGHT	29 KG OBESE	CONDITION:	BRIGHT

Clinical History.History.xx
The dog was first presented for anal adenomas which were subsequently removed under general anaesthesia. A routine palpation of the abdomen whilst the dog was under anaesthesia revealed a mass which was diagnosed as a splenic tumour. As the owners had not given consent for this surgery the dog was booked in for removal of the spleen 2 weeks later, as the dog was not showing any clinical symptoms consistent with a splenic tumour. A blood sample to measure packed cell volume was taken pre-operatively and this was recorded at 0.47 L/L, which was normal. The owners were warned of the risks associated with general anaesthesia of an old, obese dog undergoing a splenectomy and were required to sign a consent form to allow general anaesthesia and surgery.

Case 1. Splenectomy

sabira mali — Fri, 24 Jul 2009 16:01:16 GMT

Revision 3 posted to Diploma by sabira mali on 24/07/2009 17:01:16

Case 1. Splenectomy

OWNER	PIERCE	ANIMAL:	JASPER
SPECIES:	DOG	BREED:	XB
AGE:	10 YEARS	SEX:	MALE NEUTER
WEIGHT	29 KG OBESE	CONDITION:	BRIGHT

Clinical History.
The dog was first presented for anal adenomas which were subsequently removed under general anaesthesia. A routine palpation of the abdomen whilst the dog was under anaesthesia revealed a mass which was diagnosed as a splenic tumour. As the owners had not given consent for this surgery the dog was booked in for removal of the spleen 2 weeks later, as the dog was not showing any clinical symptoms consistent with a splenic tumour. A blood sample to measure packed cell volume was taken pre-operatively and this was recorded at 0.47 L/L, which was normal. The owners were warned of the risks associated with general anaesthesia of an old, obese dog undergoing a splenectomy and were required to sign a consent form to allow general anaesthesia and surgery.

Case 1. Splenectomy

Arlo Guthrie — Wed, 22 Apr 2009 10:25:42 GMT

Revision 2 posted to Diploma by Arlo Guthrie on 22/04/2009 11:25:42

Case 1. Splenectomy

OWNER	PIERCE	ANIMAL:	JASPER
SPECIES:	DOG	BREED:	XB
AGE:	10 YEARS	SEX:	MALE NEUTER
WEIGHT	29 KG OBESE	CONDITION:	BRIGHT

Clinical History.
The dog was first presented for anal adenomas which were subsequently removed under general anaesthesia. A routine palpation of the abdomen whilst the dog was under anaesthesia revealed a mass which was diagnosed as a splenic tumour. As the owners had not given consent for this surgery the dog was booked in for removal of the spleen 2 weeks later, as the dog was not showing any clinical symptoms consistent with a splenic tumour. A blood sample to measure packed cell volume was taken pre-operatively and this was recorded at 0.47 L/L, which was normal. The owners were warned of the risks associated with general anaesthesia of an old, obese dog undergoing a splenectomy and were required to sign a consent form to allow general anaesthesia and surgery.

Pre-anaesthetic clinical examination and premedication.
The dog was admitted for general anaesthesia having been starved for 12 hours with access to water until 2 hours prior to premedication. A clinical pre-operative check revealed no thoracic or cardiovascular abnormalities. Pulse was 92 per minute, respiration 34 per minute and temperature recorded at 38.8 C. Mucous membranes (m/m) were pink and capillary refill time (CRT) was just under 1 second. Premedication was given with 0.6 mg of acepromazine (ACP C Vet) by subcutaneous route and 7 mg of morphine (Morphine Sulphate, Evans) by intramuscular route. A 20 guage intravenous catheter was placed aseptically into the right cephalic vein and an infusion of Hartmanns crystalloid was started at a rate of 10 mls/kg/hour. One hour later the premedication seemed to have had no effect. The dog was still excitable and quite aggressive, needing to be muzzled in order to carry out induction, having already bitten someone without warning whilst being taken out of the kennel.

Induction.
Induction was achieved with 110 mg of propofol (Rapinovet, Schering-Plough) by slow intravenous injection given to effect through the catheter, and a cuffed 12 mm endo- tracheal tube was used to intubate the dog. A semi-closed parallel Lack circuit with a 4L resevoir bag was used with flow rates of 4L nitrous oxide and 2L oxygen, and halothane was used as the inhalation agent. Additional analgesia was given after induction with 125 mg carprofen (Rimadyl, Pfizer) by subcutaneous route. Antibiotic cover was provided with 225 mg ampicillin (Norobrittin, Norbrook) by subcutaneous route.

Radiography.
A radiograph of the thorax in right lateral recumbency was taken to ensure that no metastases had occurred. The radiograph revealed no visible abnormalities and the dog was prepared for surgery and a total splenectomy was performed.

Maintenance of anaesthesia.
For a detailed account of general anaesthesia see attached anaesthetic record. Duration of anaesthesia was 150 minutes with the dog able to walk 40 minutes after the end of anaesthesia.

Post-operative recovery.
The dog was very excitable on recovery and only received 700 mls of the Hartmann's as it continually tied the giving set in knots. The morphine was repeated after 4 hours. A PCV taken the following morning recorded at 0.36 L/L and the dog had slightly pale m/m's. However, it was eating and temp was normal so it was sent home with 10 Rimadyl 50 mg tablets to be given one twice daily with food, and 10 Ampicillin capsules also to be given one twice daily to start immediately. A post-operative check two days later revealed a PCV of 0.37 L/L and the dog was very bright and eating well. Sutures were removed at 10 days and the PCV was last recorded at 0.42 L/L.

Discussion.
Anaesthetic protocols should always be planned to suit the animal's condition at the time of surgery and the procedure to be performed. In this case the dog was not collapsed, as the spleen had not ruptured prior to surgery. However, a splenectomy can result in several complications under general anaesthesia and special consideration should be given to anaesthetic protocols to minimise the risks. In addition this dog was obese which also adds to the possible anaesthetic risk. Firstly, a pre-operative PCV was taken to be able to compare with post-operative PCV's, as anaemia can be a post-operative complication. Also, anaemia would preclude the use of nitrous oxide (if severe). Anaemia would also affect the accuracy of the pulse oximeter, as it measures the levels of oxygen saturation of the haemoglobin, not whether there are enough red cells to carry sufficient oxygen to the tissues. ACP was given as a premedication but it probably would have been wise not to use it for two reasons. Firstly, one side effect of ACP is to produce hypotension, which in itself could be one of the complications of removing a spleen which contains a large volume of blood. The second reason for not using ACP is that it is not usually an effective sedative for aggressive animals. In fact it can release the inhibtions that prevent a dog from biting, which is what appeared to happen in this case. However, as the dog did not give any indication of aggression prior to premedication and the owner made no mention of this behaviour this was totally unforeseen. One advantage of ACP is that it protects the heart from catecholamines. Choice of induction agent and maintenance agent is important for splenectomies as they are at risk from premature ventricular contractions (PVC) during general anaesthesia. PVC's can result from drugs, hypoventilation, hypoxaemia, pulmonary and myocardial contusions following trauma, and inadequate depth of anaesthesia.Thiopentone sensitises the myocardium to catecholamines which increases the risk of PVC's, and also depresses the respiratory and cardiovascular systems, so this agent should be avoided. Although propofol also depresses the respiratory and cardiovascular systems it does not sensitise the myocardium as much as thiopentone, and would be preferred to thiopentone. Diazepam (0.25 mg/kg) could be given intravenously before the propofol, which would reduce the amount of propofol needed for induction. Or ketamine (5 mg/kg) and diazepam (0.25 mg/kg) in the same syringe could have been given intravenously as an alternative induction agent. The advantage of using ketamine is that it does not produce as much cardiovascular depression. One third to one half of the dose should be given, followed by titration to effect after 30 seconds to allow intubation of the trachea. The disadvantage of using ketamine is that monitoring of depth of inhalation anaesthesia cannot be assessed using eye position, and monitoring instruments would be necessary to avoid overdose. Thiopentone (a barbiturate) also causes congestion of the spleen with blood, which would increase the risk of hypovolaemia and hypotension when the spleen was removed, so this agent is unsuitable for this procedure. A disadvantage of using propofol as an induction agent is that elimination of the drug can occur quite suddenly and consequently the depth of anaesthesia can change rapidly. This did occur with this dog just prior to the first incision and, as the record shows, increased respiration and pulse rate indicated that the depth of anaesthesia at this point was not adequate. The halothane was increased to take the dog back down to a suitable depth of anaesthesia. Halothane, which was used as the inhalation agent also sensitises the myocardium to catecholamines and it would have been better to use isoflurane which does not. However isoflurane is not available at this practice due to cost. Another problem encountered early in the anaesthetic was hypoventilation, caused by placing the animal in dorsal recumbency, which resulted in hypoxaemia, due to obesity. When an obese animal is placed on it's back the abdominal contents impede the diaphragm's movement. A Lack circuit is not designed for prolonged IPPV as rebreathing expired gases can occur. To try and overcome this the flow rate was turned up to 8 L. Neither a Bains circuit or ventilator was available at the time. The inspiratory phase was kept short (1 - 1.5 secs) as venous return is impeded during the inspiratory phase. The pulse oximeter rose to 97% and the m/m returned to pink. Nitrous oxide is an analgesic and is usually used at a ratio of 2:1 with oxygen. Ten minutes oxygen time must be used after cessation of nitrous oxide to avoid diffusion hypoxia. Turning off the nitrous oxide would have contributed to the dog showing a pain response to surgical stimulation, so the nitrous oxide was put back on at the previous flow rates and IPPV assistance continued 3 - 4 times a minute to assist the dog's spontaneous breathing. This kept the pulse oximeter reading above 90% for the duration of anaesthesia. Respiration rates remained quite fast throughout anaesthesia and this was attributed to obesity. Because of the risk of PVC's it was important to use the ECG to monitor the heart. Lignocaine at 1mg/kg was available to treat any PVC's if necessary, ie more than 2 in a row occuring or any PVC's in conjunction with low blood pressure. It would be necessary to ascertain the cause of the PVC's before treating with lignocaine, ie if caused by hypoxaemia or inadequate depth of anaesthesia then rectifying those problems should resolve the PVC's. Also, stopping the halothane and using isoflurane might rectify the problem. If neither of these work then a bolus of lignocaine can be tried. Close observation on depth of anaesthesia should be kept when using lignocaine (particularly if an infusion is used) as it is an anaesthetic and can lead to deepening of the anaesthetic level.

References:
Small Animal Surgery, T Fossum. Mosby. p 450 1997
Anasethesia of the Critical Patient, C Trim. BSAVA Congress 1999
Principles of Anaesthesia. Cont Ed Course. BSAVA March 1999 L Hughes & R McMurphy

Case 1. Splenectomy

Arlo Guthrie — Wed, 22 Apr 2009 10:24:21 GMT

Revision 1 posted to Diploma by Arlo Guthrie on 22/04/2009 11:24:21

OWNER	PIERCE	ANIMAL:	JASPER
SPECIES:	DOG	BREED:	XB
AGE:	10 YEARS	SEX:	MALE NEUTER
WEIGHT	29 KG OBESE	CONDITION:	BRIGHT

Anaesthetic Cases - Appendix

sabira mali — Fri, 24 Jul 2009 16:15:10 GMT

Current revision posted to Diploma by sabira mali on 24/07/2009 17:15:10

Anaesthetic Cases - Appendix

Equipment available for anaesthesia

Piped gases from external bunker using 6800L Oxygen cylinders and 3400L Nitrous Oxide cylinders.
Active scavenging piped to outlet on roof.
Ex-hospital anaesthetic machines with low oxygen alarms, fitted with emergency E size oxygen cylinders and Fluotec Mark 3 vaporisers which are calibrated for use with Halothane.
Anaesthetic chamber, connected to scavenging system, for use with small animals.
ECG machine
Pulse oximeter
Respiration monitor (ap-Alert)
Heated operating table
Magill semi-closed circuit, used with various face masks.
Parallel Lack semi-closed circuits
Co-axial Bains semi-closed circuits
Ayre's T-Piece semi-closed circuits, all with Jackson Rees modification
Circle closed circuit
Oxygen tent for cats and small dogs
All sizes of cuffed and uncuffed endotracheal tubes
Laryngoscope
Oesophageal stethoscopes
Reservoir bags ranging from 2L to 5L

Drugs available for anaesthesia and premedication

Thiopentone Sodium (Intraval Sodium, Rhone Merieux) 2.5%
Propofol (Rapinovet, Coopers)
Halothane
Ketamine (Vetalar, Parke-Davis)
Pentobarbitone Sodium (Sagatal, RMB) - this is only used for fitting animals
Medetomidine (Domitor, SKB)
Atipamezole (Antisedan, SKB)
Xylazine (Rompun, Bayer)
Fentanyl/Fluanisone (Hypnorm, Janssen)
Atropine Sulphate 0.6 mg/ml (Atrocare, Animal Care)
Glycopyrrolate (Robinul, Robins)
Acepromazine 2mg/ml (ACP, C Vet)
Diazepam 10mg in 2mls (Valium, Roche)
Butorphanol 10mg/ml (Torbugesic, Willows Francis)
Morphine Sulphate 10mg/ml (Evans)
Pethidine 50mg/ml (CD)
Buprenorphine 0.3mg/ml (Temgesic, Reckitt & Coleman)
Adrenaline 1mg/ml (Phoenix)
Digoxin 0.5mg in 2mls (Lanoxin, Wellcome)
Naloxone hydrochloride (Narcan, Du Pont)
Doxapram hydrochloride 20mg/ml (Dopram V, Willows Francis)
Calcium gluconate 2.2 mmol/10mls (Phoenix)
Suxamethonium (Anectine, Wellcome)
Lidocaine hydrochloride 2% (Intubeaze, Arnolds) spray
Lidocaine hydrochloride 2% (Xylocaine Gel, Astra Pharm)
Dobutamine 12.5 mg/ml (Dobutrex)
Compound sodium lactate (Hartmanns)
Sodium chloride 0.9% (Saline)
Haemaccel 5L

Anaesthetic Cases - Appendix

Arlo Guthrie — Wed, 22 Apr 2009 10:38:58 GMT

Revision 1 posted to Diploma by Arlo Guthrie on 22/04/2009 11:38:58

Equipment available for anaesthesia

Piped gases from external bunker using 6800L Oxygen cylinders and 3400L Nitrous Oxide cylinders.
Active scavenging piped to outlet on roof.
Ex-hospital anaesthetic machines with low oxygen alarms, fitted with emergency E size oxygen cylinders and Fluotec Mark 3 vaporisers which are calibrated for use with Halothane.
Anaesthetic chamber, connected to scavenging system, for use with small animals.
ECG machine
Pulse oximeter
Respiration monitor (ap-Alert)
Heated operating table
Magill semi-closed circuit, used with various face masks.
Parallel Lack semi-closed circuits
Co-axial Bains semi-closed circuits
Ayre's T-Piece semi-closed circuits, all with Jackson Rees modification
Circle closed circuit
Oxygen tent for cats and small dogs
All sizes of cuffed and uncuffed endotracheal tubes
Laryngoscope
Oesophageal stethoscopes
Reservoir bags ranging from 2L to 5L

Drugs available for anaesthesia and premedication

Thiopentone Sodium (Intraval Sodium, Rhone Merieux) 2.5%
Propofol (Rapinovet, Coopers)
Halothane
Ketamine (Vetalar, Parke-Davis)
Pentobarbitone Sodium (Sagatal, RMB) - this is only used for fitting animals
Medetomidine (Domitor, SKB)
Atipamezole (Antisedan, SKB)
Xylazine (Rompun, Bayer)
Fentanyl/Fluanisone (Hypnorm, Janssen)
Atropine Sulphate 0.6 mg/ml (Atrocare, Animal Care)
Glycopyrrolate (Robinul, Robins)
Acepromazine 2mg/ml (ACP, C Vet)
Diazepam 10mg in 2mls (Valium, Roche)
Butorphanol 10mg/ml (Torbugesic, Willows Francis)
Morphine Sulphate 10mg/ml (Evans)
Pethidine 50mg/ml (CD)
Buprenorphine 0.3mg/ml (Temgesic, Reckitt & Coleman)
Adrenaline 1mg/ml (Phoenix)
Digoxin 0.5mg in 2mls (Lanoxin, Wellcome)
Naloxone hydrochloride (Narcan, Du Pont)
Doxapram hydrochloride 20mg/ml (Dopram V, Willows Francis)
Calcium gluconate 2.2 mmol/10mls (Phoenix)
Suxamethonium (Anectine, Wellcome)
Lidocaine hydrochloride 2% (Intubeaze, Arnolds) spray
Lidocaine hydrochloride 2% (Xylocaine Gel, Astra Pharm)
Dobutamine 12.5 mg/ml (Dobutrex)
Compound sodium lactate (Hartmanns)
Sodium chloride 0.9% (Saline)
Haemaccel 5L

Case 3. Bone marrow biopsy

sabira mali — Fri, 24 Jul 2009 16:14:23 GMT

Current revision posted to Diploma by sabira mali on 24/07/2009 17:14:23

Case 3. Bone marrow biopsy

OWNER	ABBOTT	ANIMAL:	CINDY
SPECIES:	DOG	BREED:	G RETRIEVER
AGE:	8 YEARS	SEX:	FEMALE NEUTER
WEIGHT	27.5 KG	CONDITION:	BRIGHT

Clinical History.
The dog was presented with a subcutaneous mass just cranial to the right proximal humerus. A needle aspiration biopsy was taken and the mass proved to be a mastcell tumour. Complete surgical removal was considered to be impossible due to it's infiltrative nature. So a bone marrow biopsy was arranged, to check for metastases before the dog underwent radio therapy. The dog was prescribed 36 mg prednisolone once daily until the general anaesthetic. The owners were warned of the risks of general anaesthesia and signed a form giving permission for a general anaesthetic and surgery.

Pre-anaesthetic examination.
Bloods were taken for haematology and biochemistry profiles, the results of which were unremarkable. See anaesthetic record. Auscultation of the pulmonary and cardiovascular systems did not reveal any abnormalities. Temperature was 38.4 C, heart rate 96 per min and respiration 24 per min. The dog had been starved for 10 hours with access to water until 2 hours prior to induction.

Premedication.
Premedication consisted of 0.28 mg of glycopyrrolate (Robinul, Robins), 8.25 mg of butorphanol (Phoenix) and 55 mg diphenhydramine (Abbott) all by intramuscular route. The premedication worked extremely well and the dog was very quiet and sedate at the time of induction 20 minutes later. Prior to induction an 18 guage intravenous catheter was placed aseptically into the right cephalic vein.

Induction.
Induction was achieved using 13.8 mg diazepam (Elkins-Sinn), followed by titration of 129 mg of 2.5 % thiopentone sodium (Phoenix), both via the intravenous catheter. Intubation was performed with an 11 mm cuffed endotracheal tube and positioned by palpation of the uninflated cuff at the thoracic inlet. The tube was connected to a circle circuit with 2 L of oxygen. The cuff of the endotracheal tube was slowly inflated whilst the reservoir bag was very gently squeezed with the valve closed, and inflation was stopped when sounds of gas passing round the tube were no longer heard. An ECG monitor was connected to the dog, the electrodes being placed just proximal to the stifles and olecranons. An area just distal to the stopper pad on the palmar aspect of the left forelimb was clipped and a Doppler sensor taped on, after application of conducting gel, in order to monitor blood pressure. The dog was placed on a water heated pad for the duration of anaesthesia. See picture right.

Maintenance of general anaesthesia.
The valve on the circuit was opened and maintenance of anaesthesia was achieved using 1 L oxygen with isoflurane at 2% reducing to 1.5 % after 45 minutes. Lactated Ringers crystalloid was given at a rate of 10mls/kg/hr for the duration of anaesthesia. For a detailed account of anaesthesia see attached record sheet. The heart rate was recorded at between 70 and 75 bpm for the first 20 minutes, and then began to decrease steadily over the next 10 minutes to 50 bpm. The systolic blood pressure (BP) had only fallen slightly, to 115 mm Hg. A bolus of 0.137 mg of glycopyrrolate (Robinul, Robins) was given at this time by intravenous route. The ECG trace showed a second degree AV heart block for a duration of approximately 1.5 minutes, before returning to normal complexes. The heart rate peaked at 120 bpm 2 minutes after administration of the glycopyrrolate and the systolic BP rose to 160 mm Hg. The heart rate fell gradually over the next 20 mins and was recorded at 88 bpm on extubation. The systolic BP fell to 115 mm Hg and was recorded at 130 mm Hg at extubation. Respiration was spontaneous throughout anaesthesia, with good chest excursion, and recorded at between 20 - 30 per min. It was not considered necessary to ventilate the dog. The dog did not lose any temperature during the course of general anaesthesia. Duration of anaesthesia was 57 minutes.

Post-operative period.
The dog was extubated 5 minutes after the end of anaesthesia and the pulse at this time was 96 per min, respiration 36 per min and temperature 38.1 C. The bladder was reasonably full and was manually expressed before the dog was put into a recovery kennel. Sternal recumbency was achieved 10 minutes after extubation and recovery was quiet. The dog went home the following morning, to return in 3 days for a post-operative check and 10 days for sutures out and the biopsy results. This case was conducted in the University of Georgia and I was no longer present when the biopsy results were received.

Discussion.
The condition, age of the animal and the type of surgery being performed are all important when deciding on a suitable general anaesthetic procedure and the possible complications which could arise. All of this should be discussed prior to anaesthesia so that a fast, suitable course of action can be taken if a crisis occurs, and hopefully selecting the most suitable agents will reduce the risk of such crises occurring. An animal should always be weighed prior to anaesthesia, as correct dosing of drugs can be critical, especially in older animals which may not even need the full calculated dose. This was suspected in this case and a note made prior to induction to titrate the thiopentone slowly in order to avoid overdose. There are differing views as to when an animal should be classed as a geriatric, and there is also the 'real' age of the animal to be considered, ie whether the animal's general condition would lead to an assumption that it is older or younger than it's birth age. In this case the University of Georgia state that a dog of this breed over 7 years old is classed as an old dog and this dog's 'real' age would be even older due to it's condition. This would mean that it is more likely to suffer from hypotension, hypothermia and hypoventilation under anaesthesia and would probably need reduced anaesthetic doses.

Premedication consisted of butorphanol (a partial agonist opioid), for both the sedative and analgesic components. Butorphanol has an onset of 10 minutes after intramuscular injection and lasts for 1 - 1.5 hours in the dog. In the US it is widely used as an analgesic but in this country the general opinion is that despite being an excellent sedative and anti-tussant, it's use as an analgesic is very limited as it appears to have very little analgesic effect. The author must agree with this opinion and perhaps a more potent opioid such as pethidine or morphine could have been used. Carprofen (a non steroidal anti-inflammatory drug) could not be used as it is contraindicated for use in conjunction with corticosteroids (prednisolone). There are differing views as to whether parasympathetic antagonists should be routinely used in premedication for several reasons. Firstly, in some cases it does dry up the salivary secretions and in others it makes them viscous and even more likely to block the endo- tracheal tube. It is contraindicated for use in animals with pre-existing tachycardia. Cats that have been given atropine often seem agitated and the pupillary dilation seems to upset them or cause them to panic. Atropine is said to prevent acid reflux from the stomach which can cause oesophagitis. The anticholinergic used in this case was glycopyrrolate as this is reported to be favourable for use in older animals. It has less occular effects than atropine and causes less tachycardia. Bradycardia (below 60 beats per min) did occur during the general anaesthesia, thought to be the result of the depressant effects of the anaesthetic agents, and glycopyrrolate was given intravenously to treat this. After adminstration the ECG trace showed heart block for approximately 1.5 minutes. This is 'normal' after giving the anticholinergic and should only be temporary. For a copy of the ECG trace showing the heart block (see below). After this initial heart block the heart rate did peak at 120 bpm and then gradually fell. It is important to ascertain that the cause of the bradycardia is not hypoventilation before giving glycopyrrolate and assisted ventilation should be under- taken first.

Diphenhydramine (an anti-histamine) was also included in the premedication, as mast cell tumours release histamines (which lower the blood pressure) when manipulated.This would appear to have been successful, as although the anaesthetic agents caused bradycardia, the systolic blood pressue did not fall below 110 mm Hg (80 mm Hg being considered as hypotension). Diazepam (a benzodiazepine) was given at induction prior to thiopentone in order to reduce the amount thiopentone needed. This is important in ill or elderly animals as thiopentone produces both respiratory and cardiovascular depression, whereas diazepam has little effect. It was very successful in this case, as 330 mg was the calculated dose of thiopentone needed and only 129 mg was given in order to allow intubation. Diazepam can also be used in this way with other induction agents.

Isoflurane was used as the maintenance agent as recovery from this agent is faster than halothane, as much less is retained in the body to be metabolised by the liver. It is very expensive and therefore often used in conjunction with a closed circuit, as low flow rates reduce the amount vapourised and wasted via the scavenging system. In this case the flow rate through the circuit was 1L per minute (minute volume), but it is possible to reduce the minute volume in a circle circuit to 500 mls, but it is advisable never to use as a totally closed circuit.

Old animals have difficulty in maintaining body temperature during general anaesthesia so the dog was placed on a water heated pad. This proved successful and the dog did not lose any temperature during the anaesthetic. If this had been a problem a warm air blower was available to blow warm air via a hose placed under a towel which covers the animal. Towels heated in the microwave are also used to pack around the animal if, say, abdominal surgery is performed. Hypothermia will delay recovery from anaesthesia and will increase the potency of anaesthetic drugs during anaesthesia, due to slowed metabolism of drugs. After long anaesthetics, where possible, bladders are manually expressed before recovery from anaesthesia. This ensures that the animal does not soil itself with urine during recovery when it is still recumbent. This is especially important if dressings have been used. Failure to express a bladder will be reported to the ICU staff, so that they can take appropriate measures to avoid this problem.

Hartmann's is the crystalloid of choice for general operative fluids and 10mls/kg/hr is the accepted rate of infusion. Intra-operative fluids are important to maintain good renal perfusion, particularly in older animals whose renal function is likely to impaired. Monitoring instruments are very useful in anaesthesia, as long as the anaesthetist is able to interpret them and also accepts that instruments can give inaccurate readings due to poor connections etc. Observation is still the most important skill of a good anaesthetist.

This anaesthetic was well managed and, as the other cases also show, changes in an animal's status can occur very quickly and one person should be dedicated only to monitoring the anaesthetic and not required to do anything else. Unfortunately this does not always happen in general practice, due to lack of staff.

References:
Veterinary Anaesthesia, Hall & Clarke, Saunders, 9th Ed 1991
Manual of Anaesthesia, BSAVA 1992
Prof C Trim, BSAVA Congress 1999
Prof C Trim 1999 - visit to University of Georgia, USA

Case 3. Bone marrow biopsy

Arlo Guthrie — Wed, 22 Apr 2009 10:35:37 GMT

Revision 1 posted to Diploma by Arlo Guthrie on 22/04/2009 11:35:37

OWNER	ABBOTT	ANIMAL:	CINDY
SPECIES:	DOG	BREED:	G RETRIEVER
AGE:	8 YEARS	SEX:	FEMALE NEUTER
WEIGHT	27.5 KG	CONDITION:	BRIGHT

Clinical History.
The dog was presented with a subcutaneous mass just cranial to the right proximal humerus. A needle aspiration biopsy was taken and the mass proved to be a mastcell tumour. Complete surgical removal was considered to be impossible due to it's infiltrative nature. So a bone marrow biopsy was arranged, to check for metastases before the dog underwent radio therapy. The dog was prescribed 36 mg prednisolone once daily until the general anaesthetic. The owners were warned of the risks of general anaesthesia and signed a form giving permission for a general anaesthetic and surgery.

Pre-anaesthetic examination.
Bloods were taken for haematology and biochemistry profiles, the results of which were unremarkable. See anaesthetic record. Auscultation of the pulmonary and cardiovascular systems did not reveal any abnormalities. Temperature was 38.4 C, heart rate 96 per min and respiration 24 per min. The dog had been starved for 10 hours with access to water until 2 hours prior to induction.

Premedication.
Premedication consisted of 0.28 mg of glycopyrrolate (Robinul, Robins), 8.25 mg of butorphanol (Phoenix) and 55 mg diphenhydramine (Abbott) all by intramuscular route. The premedication worked extremely well and the dog was very quiet and sedate at the time of induction 20 minutes later. Prior to induction an 18 guage intravenous catheter was placed aseptically into the right cephalic vein.

Induction.
Induction was achieved using 13.8 mg diazepam (Elkins-Sinn), followed by titration of 129 mg of 2.5 % thiopentone sodium (Phoenix), both via the intravenous catheter. Intubation was performed with an 11 mm cuffed endotracheal tube and positioned by palpation of the uninflated cuff at the thoracic inlet. The tube was connected to a circle circuit with 2 L of oxygen. The cuff of the endotracheal tube was slowly inflated whilst the reservoir bag was very gently squeezed with the valve closed, and inflation was stopped when sounds of gas passing round the tube were no longer heard. An ECG monitor was connected to the dog, the electrodes being placed just proximal to the stifles and olecranons. An area just distal to the stopper pad on the palmar aspect of the left forelimb was clipped and a Doppler sensor taped on, after application of conducting gel, in order to monitor blood pressure. The dog was placed on a water heated pad for the duration of anaesthesia. See picture right.

Maintenance of general anaesthesia.
The valve on the circuit was opened and maintenance of anaesthesia was achieved using 1 L oxygen with isoflurane at 2% reducing to 1.5 % after 45 minutes. Lactated Ringers crystalloid was given at a rate of 10mls/kg/hr for the duration of anaesthesia. For a detailed account of anaesthesia see attached record sheet. The heart rate was recorded at between 70 and 75 bpm for the first 20 minutes, and then began to decrease steadily over the next 10 minutes to 50 bpm. The systolic blood pressure (BP) had only fallen slightly, to 115 mm Hg. A bolus of 0.137 mg of glycopyrrolate (Robinul, Robins) was given at this time by intravenous route. The ECG trace showed a second degree AV heart block for a duration of approximately 1.5 minutes, before returning to normal complexes. The heart rate peaked at 120 bpm 2 minutes after administration of the glycopyrrolate and the systolic BP rose to 160 mm Hg. The heart rate fell gradually over the next 20 mins and was recorded at 88 bpm on extubation. The systolic BP fell to 115 mm Hg and was recorded at 130 mm Hg at extubation. Respiration was spontaneous throughout anaesthesia, with good chest excursion, and recorded at between 20 - 30 per min. It was not considered necessary to ventilate the dog. The dog did not lose any temperature during the course of general anaesthesia. Duration of anaesthesia was 57 minutes.

Post-operative period.
The dog was extubated 5 minutes after the end of anaesthesia and the pulse at this time was 96 per min, respiration 36 per min and temperature 38.1 C. The bladder was reasonably full and was manually expressed before the dog was put into a recovery kennel. Sternal recumbency was achieved 10 minutes after extubation and recovery was quiet. The dog went home the following morning, to return in 3 days for a post-operative check and 10 days for sutures out and the biopsy results. This case was conducted in the University of Georgia and I was no longer present when the biopsy results were received.

Discussion.
The condition, age of the animal and the type of surgery being performed are all important when deciding on a suitable general anaesthetic procedure and the possible complications which could arise. All of this should be discussed prior to anaesthesia so that a fast, suitable course of action can be taken if a crisis occurs, and hopefully selecting the most suitable agents will reduce the risk of such crises occurring. An animal should always be weighed prior to anaesthesia, as correct dosing of drugs can be critical, especially in older animals which may not even need the full calculated dose. This was suspected in this case and a note made prior to induction to titrate the thiopentone slowly in order to avoid overdose. There are differing views as to when an animal should be classed as a geriatric, and there is also the 'real' age of the animal to be considered, ie whether the animal's general condition would lead to an assumption that it is older or younger than it's birth age. In this case the University of Georgia state that a dog of this breed over 7 years old is classed as an old dog and this dog's 'real' age would be even older due to it's condition. This would mean that it is more likely to suffer from hypotension, hypothermia and hypoventilation under anaesthesia and would probably need reduced anaesthetic doses.

References:
Veterinary Anaesthesia, Hall & Clarke, Saunders, 9th Ed 1991
Manual of Anaesthesia, BSAVA 1992
Prof C Trim, BSAVA Congress 1999
Prof C Trim 1999 - visit to University of Georgia, USA

Case 2. Biopsy Mass

sabira mali — Fri, 24 Jul 2009 16:13:09 GMT

Current revision posted to Diploma by sabira mali on 24/07/2009 17:13:09

Case 2. Biopsy Mass

OWNER	TWIST	ANIMAL:	CRICKET
SPECIES:	DOG	BREED:	AMERICAN SPITZ
AGE:	11 YEARS	SEX:	FEMALE
WEIGHT	9.3 KG AVERAGE	CONDITION:	DYSPNOEA

Clinical History.
The dog was first brought in by the owner for respiratory distress. Stridor was evident on inspiration, visual examination revealed an intra-oral mass occluding the glottis and palpation of the neck revealed a mass present in the caudal oropharyngeal area over the larynx, dorsal to the trachea and about 5 cms in diameter. Exopthalamus was also noted. There were no other clinical symptoms. The owner reported that the dog had become increasingly more dyspnoeic over the last 2 months. A general anaesthetic for radiography and a biopsy was arranged for the following morning, the owner having been warned of the risks of general anaesthesia and having signed a consent form.

Pre-anaesthetic examination.
Blood samples were taken for both biochemistry and haematology profiles, the results of which were unremarkable. See anaesthetic record sheet. A clinical examination revealed temperature of 38 C, heart rate of 100 per min and respiration rate of 20. There were no apparent abnormalities of the cardiovascular or respiratory system, other than the mass. The dog was kept overnight in an oxygen cage in the intensive care unit (ICU) and starved from 10 pm with access to water until 8 am. The dog was given a class 3 anaesthetic risk, ie a patient with severe systemic disease that is not incapacitating.

Premedication.
Premedication consisted only of 0.37 mg atropine sulphate (Phoenix) given by intra- muscular route 30 minutes prior to induction. After premedication the dog was monitored constantly until induction.

Induction.
As difficulty of intubation was expected, due to the occlusion of the glottis, equipment was available for a tracheotomy and also an endoscope for assistance with intubation. Five minutes pre-oxygenisation was given via a mask before induction. The dog was quite calm prior to and during induction. A 20 g intravenous catheter was placed aseptically into the right cephalic vein. A smooth induction was achieved using 74 mg propofol (Diprivan, Zeneca) given slowly through the catheter. Intubation was performed successfully using a 6.5 mm cuffed endotracheal tube. Correct placing of the ET tube was carried out by palpating the thoracic inlet area with one hand whilst moving the tube in and out slightly in order to feel where the uninflated cuff was positioned. Correct inflation of the cuff was achieved by one person slowly inflating the cuff and listening by the mouth whilst a second person closed the valve on the circuit (which had been connected to the tube and 2 L oxygen turned on) and very gently squeezing the resevoir bag until no sounds of gas passing round the cuff could be heard and pressure was felt squeezing the bag. The dog had been connected to a circle circuit with oxygen flow of 2 L per min which was reduced to 1 L after 20 minutes. Isoflurane was used as the maintenance agent with initial settings of 2%, being reduced to 1% after 35 mins. An infusion of lactated ringers was started at a rate of 10ml/kg/hr. An area just distal to the stopper pad on the palmar surface of the left foreleg was clipped, conducting gel applied and a Doppler sensor attached with tape. A cuff was applied to the left proximal foreleg in order to measure blood pressure (BP). 0.465 mg of oxymorphone (Numorphan, Du Pont) was given by intravenous route.

Radiography.
The dog was radiographed which showed a mass consistent in size and position as described in the clinical examination. A biopsy was then taken through an incision in the right lateral neck.

Maintenance of anaesthesia.
For a detailed account of anaesthesia see attached anaesthetic record. Duration of anaesthesia was 60 minutes. General anaesthesia was unremarkable until 30 minutes into anaesthesia when a haemorrhage occurred at the incision site and the carotid artery was ligated. The systolic BP went up from 115 to 280 mm Hg. At this point the dog was connected to an ECG and within 1 minute premature ventricular contractions (PVC's) started intermittently. They then began to occur in ventricular bigeminy (every second complex was a PVC) and after a further 30 seconds were occurring in strings of 10 followed by one or two normal complexes. At this time a bolus of 9.3 mg of lidocaine (Abbott) was given by intravenous route. This had no effect and a further repeat bolus was given 1 minute later. At this time the isoflurane was reduced to 1%. See above right, where the PVCs can just be seen on the monitor. The PVC's then became intermittent again and a further 9.3 mg was given 10 minutes later, just before the cessation of anaesthesia. The systolic BP remained around 250 mm Hg and heart rate around 150 per minute. Little blood loss had occurred.

Recovery from anaesthesia.
Five minutes after cessation of isoflurane the larynx was swabbed, the oxygen had remained on and the ET tube was removed with the cuff partially inflated, and when the dog was in sternal recumbency. The dog initially seemed to have difficulty breathing and the tongue was extended and a pulse oximeter attached. The readings showed 72% (hypoxaemia) and an oxygen mask applied was immediately. The dog, at this time, became uncontrollable and disorientated, despite now being able to breath easily. It was impossible to maintain the oxygen mask over the face and the dog was taken straight through to the ICU where an intravenous bolus of 2.4 mg of diazepam (Elkins-Sinn) was given. This calmed the animal enough for telemetry pads to be attached whilst oxygen was administered and then the dog was put into an oxygen cage with the Doppler still attached. See the picture above, taken 15 minutes after being put in the oxygen cage. An hour later the dog was still showing signs of dyspnoea and had a systolic BP of 220 mm Hg, which was still high. The telemetry monitor showed that although the PVC's had stopped the T waves were large.

Post-operative progress.
Two hours after recovery the telemetry started showing abnormal traces and a cardiologist was called to interpret the trace. His recommendation was that the dog be monitored at all times, but that treatment was not necessary at this time. The dog remained in an oxygen cage for 48 hours, by which time the ECG trace had returned to normal and the dog was showing less dyspnoea than when it was first admitted. It was sent home the following day after being out for exercise and not showing any signs of dyspnoea. The owners were advised to restrict the dog to lead exercise and return in 3 days and 10 days for suture removal and biopsy results. It was not clear at this stage whether a tumour was present or whether the mass was in fact an aneurysm. If the results showed a tumour the dog would have radiotherapy as it was not possible to remove any more tissue. As this case was conducted in the University of Georgia, USA I was no longer present when the biopsy results came back.

Discussion.
The protocol for this general anaesthetic was discussed prior to induction and drugs were chosen to suit the animal's condition at the time of surgery. Possible complications were also discussed and provision made for dealing with these, ie the tracheotomy site was prepared and all equipment ready to use. This is very important as quick action needs to be taken and time is wasted making decisions after the crisis has occurred. The animal's life may also be at risk if necessary equipment is not at hand. However, this anaesthetic also proved that no matter how much planning takes place emergencies can always happen unexpectedly despite all possible precautions, ie the anaesthetic implications of ligating the carotid artery, which was also not expected. Only atropine was given as premedication, as there was concern that any sedative would cause further respiratory distress before an airway was secured. Atropine is an anticholinergic drug which was given to inhibit secretion of saliva and protect against bradycardia. Anticholinergics are standardly included in pre- medications in the University of Georgia, but other views held are that it should only be given if necessary, ie for bradycardia or if surgery might provoke a vagal response. Respiratory depression was also the reason that the oxymorphone was not given until after the dog was intubated, as although oxymorphone is ten times stronger than morphine, but has less effect as a depressant on the respiratory system, there is still some depression.

Oxymorphone can also be given quickly by intravenous route and has an onset time of about 3 minutes. When anaesthetising any dyspnoeic or very sick animal oxygen should always be given prior to induction so that the tissues are saturated, to cover the period of intubation when hypoxia can easily occur.

Propofol was used as the induction agent as recovery from this drug is rapid, which is very important when any surgery or problems with the upper respiratory tract are involved. This is because the swallow reflex and cough reflex need to present as soon as possible when consciousness returns, to avoid any aspiration or obstruction of the airway. Propofol would also be the choice of induction agent for otherwise healthy brachycephalic breeds, who anatomically have a predisposition for upper airway obstruction on recovery.

Correct placement of the ET tube is very important, and palpation of the cuff within the thoracic inlet ensures that the tube does not pass down into one bronchus which would be detrimental to the animal and would also mean difficulty in maintaining anaesthesia. Correct inflation of the cuff is also important, as it has to be inflated enough to provide a seal to stop wastage of gas and pollution by gases escaping into the theatre. Over inflation of the cuff can cause damage to the tissues with serious implications due to the nature of the site. The correct size of ET tube should, of course, be selected to suit the animal. The tube in this instance was placed correctly but could have been trimmed shorter, as the end of the tube should be by the nostrils, in order to keep the amount of mechanical dead space as small as possible. In this case the tube extended 5 cms beyond the nostrils. See the picture above, taken just prior to extubation.

A circle circuit with the valve opened slightly was used to maintain anaesthesia. The advantage of this is to save money on gases and maintenance agents. Also, if intermittent positive pressure ventilation (IPPV) is needed, and no ventilator available, it is easier to do this on a circle than a semi-closed circuit such as the Bains. The subject of whether nitrous oxide should be used in a circle system is controversial. In this country, generally, there is concern that nitrous oxide will build up within the system to harmful levels and that it should not be used unless inspired oxygen levels can be measured. However, in the US it is used frequently, as after extensive monitoring at the University of Georgia they found that using 1L of oxygen and 1 L nitrous oxide to be quite safe to use with the valve partially open, but would not recommend any higher percentage of nitrous oxide to be used without monitoring devices. Isoflurane was used as the maintenance agent, as it does not sensitise the myocardium to catecholamines which can lead to PVC's, (as halothane does). So it was an advantage that isoflurane was used in this case as, although the dog suffered severe PVC's, it probably would have been more of a problem if halothane had been used. Recovery from isoflurane is faster than halothane as less is retained in the body for metabolism, which was also needed in this case for reasons previously explained. The disadvantage usually with isoflurane is that it lowers blood pressure more than halothane, (when used at the correct dosage). However, in this case this was a distinct advantage as hypertension was a problem. Propofol also has less of an effect on sensitising the myocardium than, say, thiopentone so again this was another advantage of using propofol. It was not known if hypertension existed prior to anaesthesia, as it was not measured, although exopthalmus was noted during the clinical examination.

The hypertension was thought to be partly the cause of the extreme hyperactivity of the dog after extubation, however it was decided not to use acepromazine to sedate the dog and reduce the blood pressure, as it was unclear at this time as to the cause of the hypertension and how long it might last and the concern was that if the BP were to return to normal suddenly the added effect of the acepromazine might take the BP too low too quickly for the body to compensate. This is why diazepam was selected, although in healthy dogs it can actually increase excitement. However, the dog did become calmer and less dyspnoeic. Excitement with struggling or distress in an already dyspnoeic animal can easily lead to death and should always be avoided if possible or treated with drugs. In this case dyspnoea and hypoxia were the main concern on extubation and all monitoring other than the telemetry and visual observation was suspended for one hour to allow the dog's oxygen status to improve.

The other important feature of this general anaesthesia were the PVC's which started to occur 30 minutes after induction when the carotid artery was ligated which affected the baroreceptors present in the artery. PVC's can also be caused by anaesthetic drugs, hypoxia, interfering with certain tumours or organs, such as the pancreas, which then release catecholamines, inadequate depth of anaesthesia leading to stimulation of the sympathetic nervous system, hypoventilation and pulmonary and myocardial contusions caused by trauma to the chest. All of the above sensitise the myocardium to the effects of catecholamines, which can result in PVC's occurring. PVC's should be treated with drugs if the cause is not attributed to hypoxia or inadequate depth of anaesthesia, (both of which can be corrected by appropriate actions), if changing from halothane which sensitises the heart to isoflurane (which does not) has no effect, if the PVC's occur in conjunction with low BP or occur more than two in a row. The drug of choice is lidocaine which can be given at 1 to 2 mg per kg as a bolus or as an infusion. In this case 3 boluses were used to control the PVC's and an infusion was not necessary. The isoflurane was turned down to 1% after administration of lidocaine, as it is an anaesthetic and can affect the depth of anaesthesia (more usually when using an infusion). However, it was important to monitor the heart post-operatively to ensure that they did not recur. Telemetry was used for this purpose as it has several advantages over normal ECG monitoring. Firstly it is impractical to have ECG electrodes connected to a conscious animal for obvious reasons of disconnection problems. Telemetry involves putting electrode pads on the animal and plugging them into a small transmitter box, which fits into a pouch and tied round the animal. The ECG trace is radio transmitted and picked up by an aerial in the ceiling and the trace is displayed on a central monitor visible from anywhere in the ICU. Up to 8 animals can be displayed at one time. Two hours into the post-operative period the ECG trace showed several irregularities and the consultant cardiologist was called. The large T waves were attributed to myocardial hypoxia and, on examination of the other abnormalities, it was stated that interference with, or ligation of the carotid artery will often cause the hypertension, PVC's and other abnor- malities seen on the ECG trace. Stimulation of the vagal nerve is also involved. This is of importance for the anaesthetist to be warned in advance by the surgeon of any surgery which will interfere with the carotid artery or which will involve ligation of the artery. Fossum, Small Animal Surgery, Mosby 1997 recommends ligation of the carotid artery during a maxillectomy, but there is no mention of the possible anaesthetic implications associated with this procedure. Human literature states that even temporary occlusion of the carotid artery can cause permanent brain damage due to lack of oxygen. This hypoxia (shown by the pulse oximeter and large T wave) may have been the cause of the disorientation displayed by the dog after extubation. As to whether permanent brain damage occurs in animals when the carotid artery is ligated, animals may not show this as readily as humans or owners may notice changes in the behaviour of the animal but not relate it to the anaesthesia, and therefore not mention it. The chemoreceptors and baroreceptors are also involved in the oxygen/carbon dioxide homeostasis of the body and it would be difficult to tell whether, in this case, the hypoxia was caused by the reaction to the ligation or the original upper respiratory obstruction. At the time that the hypertension started the dog's temperature also rose and finished a little higher than prior to induction. Respiration remained constant, apart from a period of panting which is common after administration of oxymorphone, with a good tidal volume and it was not judged necessary to ventilate the dog. Lactated Ringers (Hartmann's) is the preferred intra-operative crystalloid to use and was infused at the correct rate. Post-operative analgesics were withheld due to concern over any respiratory depression being detrimental. This is a view that widely differs within the veterinary profession. It is understandable to have concern about opioids and their sedative and repressive effect, but injectible carprofen (a NSAID) could possibly have been used, as it is considered safe to use peri-operatively, due to it's lack of inhibition of the body's prostaglandin production which plays a role in renal function and protection of the gut lining. Although this procedure would not seem to be one of the most painful surgeries it would be considered unacceptable to withdraw analgesia if this procedure were carried out on a human. Carprofen is still relatively new in the US and is not yet often used peri-operatively.

Overall, this was a complicated general anaesthetic which was well planned and managed, which demonstrated the usefulness of monitoring devices for identifying complications.

References:
Veterinary Anaesthesia, Hall & Clarke, 9th Ed, 1991
Manual of Anaesthesia, BSAVA 1992
Small Animal Surgery, T Fossum. Mosby 1997
Prof C Trim, Head of Sm & L An Anaes, University of Georgia, US. Aug 99
BSAVA Congress Anaesthesia Lectures, C Trim. 1999

Case 2. Biopsy Mass

Arlo Guthrie — Wed, 22 Apr 2009 10:31:21 GMT

Revision 2 posted to Diploma by Arlo Guthrie on 22/04/2009 11:31:21

Case 2. Buiopsy Biopsy Mass

OWNER	TWIST	ANIMAL:	CRICKET
SPECIES:	DOG	BREED:	AMERICAN SPITZ
AGE:	11 YEARS	SEX:	FEMALE
WEIGHT	9.3 KG AVERAGE	CONDITION:	DYSPNOEA

Clinical History.
The dog was first brought in by the owner for respiratory distress. Stridor was evident on inspiration, visual examination revealed an intra-oral mass occluding the glottis and palpation of the neck revealed a mass present in the caudal oropharyngeal area over the larynx, dorsal to the trachea and about 5 cms in diameter. Exopthalamus was also noted. There were no other clinical symptoms. The owner reported that the dog had become increasingly more dyspnoeic over the last 2 months. A general anaesthetic for radiography and a biopsy was arranged for the following morning, the owner having been warned of the risks of general anaesthesia and having signed a consent form.

Pre-anaesthetic examination.
Blood samples were taken for both biochemistry and haematology profiles, the results of which were unremarkable. See anaesthetic record sheet. A clinical examination revealed temperature of 38 C, heart rate of 100 per min and respiration rate of 20. There were no apparent abnormalities of the cardiovascular or respiratory system, other than the mass. The dog was kept overnight in an oxygen cage in the intensive care unit (ICU) and starved from 10 pm with access to water until 8 am. The dog was given a class 3 anaesthetic risk, ie a patient with severe systemic disease that is not incapacitating.

Premedication.
Premedication consisted only of 0.37 mg atropine sulphate (Phoenix) given by intra- muscular route 30 minutes prior to induction. After premedication the dog was monitored constantly until induction.

Induction.
As difficulty of intubation was expected, due to the occlusion of the glottis, equipment was available for a tracheotomy and also an endoscope for assistance with intubation. Five minutes pre-oxygenisation was given via a mask before induction. The dog was quite calm prior to and during induction. A 20 g intravenous catheter was placed aseptically into the right cephalic vein. A smooth induction was achieved using 74 mg propofol (Diprivan, Zeneca) given slowly through the catheter. Intubation was performed successfully using a 6.5 mm cuffed endotracheal tube. Correct placing of the ET tube was carried out by palpating the thoracic inlet area with one hand whilst moving the tube in and out slightly in order to feel where the uninflated cuff was positioned. Correct inflation of the cuff was achieved by one person slowly inflating the cuff and listening by the mouth whilst a second person closed the valve on the circuit (which had been connected to the tube and 2 L oxygen turned on) and very gently squeezing the resevoir bag until no sounds of gas passing round the cuff could be heard and pressure was felt squeezing the bag. The dog had been connected to a circle circuit with oxygen flow of 2 L per min which was reduced to 1 L after 20 minutes. Isoflurane was used as the maintenance agent with initial settings of 2%, being reduced to 1% after 35 mins. An infusion of lactated ringers was started at a rate of 10ml/kg/hr. An area just distal to the stopper pad on the palmar surface of the left foreleg was clipped, conducting gel applied and a Doppler sensor attached with tape. A cuff was applied to the left proximal foreleg in order to measure blood pressure (BP). 0.465 mg of oxymorphone (Numorphan, Du Pont) was given by intravenous route.

Radiography.
The dog was radiographed which showed a mass consistent in size and position as described in the clinical examination. A biopsy was then taken through an incision in the right lateral neck.

Post-operative progress.
Two hours after recovery the telemetry started showing abnormal traces and a cardiologist was called to interpret the trace. His recommendation was that the dog be monitored at all times, but that treatment was not necessary at this time. The dog remained in an oxygen cage for 48 hours, by which time the ECG trace had returned to normal and the dog was showing less dyspnoea than when it was first admitted. It was sent home the following day after being out for exercise and not showing any signs of dyspnoea. The owners were advised to restrict the dog to lead exercise and return in 3 days and 10 days for suture removal and biopsy results. It was not clear at this stage whether a tumour was present or whether the mass was in fact an aneurysm. If the results showed a tumour the dog would have radiotherapy as it was not possible to remove any more tissue. As this case was conducted in the University of Georgia, USA I was no longer present when the biopsy results came back.

Discussion.
The protocol for this general anaesthetic was discussed prior to induction and drugs were chosen to suit the animal's condition at the time of surgery. Possible complications were also discussed and provision made for dealing with these, ie the tracheotomy site was prepared and all equipment ready to use. This is very important as quick action needs to be taken and time is wasted making decisions after the crisis has occurred. The animal's life may also be at risk if necessary equipment is not at hand. However, this anaesthetic also proved that no matter how much planning takes place emergencies can always happen unexpectedly despite all possible precautions, ie the anaesthetic implications of ligating the carotid artery, which was also not expected. Only atropine was given as premedication, as there was concern that any sedative would cause further respiratory distress before an airway was secured. Atropine is an anticholinergic drug which was given to inhibit secretion of saliva and protect against bradycardia. Anticholinergics are standardly included in pre- medications in the University of Georgia, but other views held are that it should only be given if necessary, ie for bradycardia or if surgery might provoke a vagal response. Respiratory depression was also the reason that the oxymorphone was not given until after the dog was intubated, as although oxymorphone is ten times stronger than morphine, but has less effect as a depressant on the respiratory system, there is still some depression.

Overall, this was a complicated general anaesthetic which was well planned and managed, which demonstrated the usefulness of monitoring devices for identifying complications.

References:
Veterinary Anaesthesia, Hall & Clarke, 9th Ed, 1991
Manual of Anaesthesia, BSAVA 1992
Small Animal Surgery, T Fossum. Mosby 1997
Prof C Trim, Head of Sm & L An Anaes, University of Georgia, US. Aug 99
BSAVA Congress Anaesthesia Lectures, C Trim. 1999

Case 2. Buiopsy Mass

Arlo Guthrie — Wed, 22 Apr 2009 10:31:07 GMT

Revision 1 posted to Diploma by Arlo Guthrie on 22/04/2009 11:31:07

OWNER	TWIST	ANIMAL:	CRICKET
SPECIES:	DOG	BREED:	AMERICAN SPITZ
AGE:	11 YEARS	SEX:	FEMALE
WEIGHT	9.3 KG AVERAGE	CONDITION:	DYSPNOEA

Overall, this was a complicated general anaesthetic which was well planned and managed, which demonstrated the usefulness of monitoring devices for identifying complications.

Case 3. Excision arthroplasty of left hip

sabira mali — Fri, 24 Jul 2009 16:08:01 GMT

Current revision posted to Diploma by sabira mali on 24/07/2009 17:08:01

Case 3. Excision arthroplasty of left hip

OWNER	ALI	ANIMAL:	TOM
SPECIES:	CAT	BREED:	DSH
AGE:	1 YEAR	SEX:	MALE (N)
WEIGHT	4.1 KG	CONDITION:	GOOD

Clinical History
The cat was presented not able to weight bear on it's left hind leg, the owner having reported the cat coming in lame that morning. A clinical examination revealed a wound on the stifle, but palpation of the limb was not possible due to the cat's discomfort. A clinical examination of the cardiovascular and respiratory systems revealed no abnormalities and the cat was admitted for radiography under general anaesthesia. The cat had not eaten that morning, but the owners were warned of the risks of general anaesthesia and signed a consent form for general anaesthesia and possible surgery. The cat was premedicated with 0.16 mg acepromazine (ACP C VET) and 7.5 mg pethidine (Pethidine, Arnolds), both by intra- muscular route, 40 minutes prior to induction.

Radiography
Induction was achieved using 50 mg thiopentone sodium (Intraval, Rhone Merieux) by intra-venous route and an uncuffed 5 mm endo-tracheal tube used to intubate. Maintenance of anaesthesia was achieved using an Ayres T piece with flow rates of 2 L nitrous oxide and 1 L oxygen with halothane as the volatile agent. Antibiotic cover was provided with 100 mg ampicillin LA (Amfipen LA, Intervet) and additional analgesia with 15 mg carprofen (Rimadyl, Pfizer), both by subcutaneous route.

Radiographs of the pelvis were taken in both right lateral and ventrodorsal projections, and on examination the ventrodorsal projection showed that the left femoral neck had fractured with the femoral head remaining in the acetabulum. See Radiograph 1. The surgeon decided to perform an excision arthroplasty and the owners were contacted to advise them of the necessary surgical procedure.

Surgical preparation
A 22 g intra-venous catheter was placed aseptically into the right cephalic vein and an infusion of Hartmanns was started at a rate of 10mls/kg/hr. The left hind leg was clipped and prepared as in the first paragraph of Appendix 1, to include an area extending from the hock to the whole hip area, the incision site being over the greater trochanter of the femur. The cat was then moved to the theatre and final preparation of the skin took place as in the second paragraph of Appendix 1.

Surgery
The limb was lifted up by the nurse (holding the foot). The surgeon placed the first drape under the limb, lying along the ventral abdomen and left groin. A second drape was held under the limb and the nurse released the foot onto the drape. This drape was then wrapped around the distal limb and held in place with a towel clip. A third and fourth drape were placed to leave the proximal limb, including the hip exposed. See above.

The instruments used for this procedure included a standard kit, as described in Appendix 2. Additional instruments included Gelpi retractors, a Hohman retractor, an osteotome, an orthopaedic hammer and a disarticulator. Sterile saline was also used for flushing the surgical site.

An incision was made through the skin 5 cms in length over the greater trochanter, proximally just short of the dorsal midline and distally following the cranial border of the femur. The skin was undermined and retracted with the subcutaneous tissues. An incision was made in the superficial leaf of the of the fascia lata and the insertion of the tensor fascia lata muscle, following the cranial border of the biceps femoris muscle.

The biceps femoris was retracted caudally, and the fascia lata and tensor fascia lata retracted cranially, after separation of the tensor fascia lata from the middle gluteal muscle. Blunt dissection along the neck of the femur with the finger tip allowed visualisation of the deep gluteal muscle. The middle gluteal muscle was retracted caudally and partial tenotomy of the caudal two thirds of the deep gluteal muscle was performed. The joint capsule was incised and a Hohman retractor used to elevate the neck of the femur, whilst rotating the stifle outwards. An osteotome, with the orthopaedic hammer, was used to excise the neck of the femur. The excision site was checked to ensure that there were no sharp edges. The disarticulator was then used to sever the round ligament and remove the femoral head from the acetabulum. The area was flushed with sterile saline and the gluteal muscles coapted with 3 m chromic catgut (Ethicon) using mattress sutures. The fascia lata muscles were repaired as above and the subcutaneous tissues closed using 3 m catgut in a simple continuous pattern. The skin was closed using 2 m polyamide (Nylonamide, Animus) in a simple interrupted suture pattern. A total of 200 mls of Hartmanns was infused for maintenance, as no major haemorrhage had occurred. The endotracheal tube was removed within 3 minutes of the cessation of anaesthesia.

Post-operative progress.
The cat was in sternal recumbency within 15 minutes after extubation. Analgesia was repeated after 6 hours with 0.8 mg of morphine (Morphine Sulphate, Evans) by intra-muscular route.

The animal was sent home in the afternoon with instructions to the owner that the cat should be confined to house rest, and that revisits were necessary in 4 and 10 days for a post- operative check and sutures out. The cat was prescribed Rimadyl 20 mg tablets to be given half daily with food for 4 days, starting the following day, and Amfipen 50 mg tablets to be given one twice daily for 2 days, starting in two days.

The post-operative check was satisfactory - the cat was weight bearing on the limb, and sutures were removed after 10 days. Within 4 weeks the cat was using the limb normally.

Discussion
Excision arthroplasty is regarded as a salvage procedure to aleviate pain and restore a reasonable motility of the limb. Cats and small dogs, due to their light weight, seem to do well after the procedure and most have a wide range of movement of the limb. Large dogs (over 25 kg) can have problems with this treatment and other types of repair should be considered.

Complications that can occur from this procedure include damage to the sciatic nerve, resulting in possible paralysis, or chronic post-operative pain due to sharp edges being left on the femoral neck. There are several approaches to the hip joint, this one being considered to have the best exposure of the femoral neck. Post-operative care includes use of the limb, on a restrictive basis and active animals tend to have a quicker recovery than obese lethargic animals, as do animals that have suffered acute trauma (as in this case) rather than chronic conditions. It is particularly important to maintain the highest possible aseptic technique during any orthopaedic surgery. The drapes for this procedure did not quite cover the whole cat, and drapes of adequate size to cover the whole animal should always be provided, in order that the surgeon can give total concentration to the procedure without having to think about any risk of contamination. Ideally, a barrier drape should be used in order to avoid any bacterial strike through occurring when drapes get wet due to blood loss or flushing. On this occasion a drape, wrapped round and secured with a towel clip, was used to cover the distal limb. When manipulation of the limb during surgery is required a sterile bandage wrapped round and tied is probably less likely to slip, allowing contamination of the surgeon. Pethidine, an opiate, was chosen for the analgesic as the procedure was a painful one and inclusion in the premedication ensured that it was active at the time of the first incision. Carprofen, a non steroidal anti-inflammatory drug, was given after induction to ensure it was active during recovery which is very important when using thiopentone which has an antanalgesic effect during recovery. Pethidine is a short acting opioid, about 2 hrs in the cat, and analgesia was repeated after 2 hours using 0.8 mg of morphine by intra-muscular route. Morphine is a more potent analgesic than pethidine and also remains active for longer, ie 6 - 8 hours in the cat, so could have been used initially in the premedication instead of pethidine. However, analgesia was satisfactory for this procedure and the cat was comfortable post-operatively.

With regard to the use of suture materials, being a publicly funded clinic, cost will always play an important part in choice between any two suitable suture materials. Chromic catgut often causes an inflammatory tissue reaction and polyglactin 910 (Vicryl) could have been used as an alternative suture material. When catgut is used it should be rinsed in sterile saline after removal from the package, as the solution it is stored in is an irritant to tissues. Polyamide is the standard material used for skin closure at this practice, but monofilament nylon or Vicryl could have been used. Hartmanns was a good choice of fluids for general maintenance under anaesthesia. Plasma expanding fluids might have been necessary had there been haemorrhage during surgery. The owners were told to put an elizabethan collar on the cat to stop removal of sutures. However, generally speaking if an animal removes sutures it is usually because they are irritant, ie too tight, or underlying catgut is causing a tissue reaction. The sutures in this case were placed quite loosely to allow for any swelling of tissues and the owners stated that they found it unnecessary to use a collar.

References:
Atlas of Surg Approaches to Bones of Cat & Dog, Piermattei, Greeley. 2nd Ed Saunders 1979
Sm An Orthopaedics, Brinker, Piermattei, Flo. 2nd Ed. Saunders 1990
Sm An Surg Nursing, D Tracy, 2nd Ed. Mosby 1994

Case 3. Excision arthroplasty of left hip

Arlo Guthrie — Tue, 21 Apr 2009 16:08:21 GMT

Revision 2 posted to Diploma by Arlo Guthrie on 21/04/2009 17:08:21

Case 3. Excision arthroplasty of the left hip

OWNER	ALI	ANIMAL:	TOM
SPECIES:	CAT	BREED:	DSH
AGE:	1 YEAR	SEX:	MALE (N)
WEIGHT	4.1 KG	CONDITION:	GOOD

Clinical History
The cat was presented not able to weight bear on it's left hind leg, the owner having reported the cat coming in lame that morning. A clinical examination revealed a wound on the stifle, but palpation of the limb was not possible due to the cat's discomfort. A clinical examination of the cardiovascular and respiratory systems revealed no abnormalities and the cat was admitted for radiography under general anaesthesia. The cat had not eaten that morning, but the owners were warned of the risks of general anaesthesia and signed a consent form for general anaesthesia and possible surgery. The cat was premedicated with 0.16 mg acepromazine (ACP C VET) and 7.5 mg pethidine (Pethidine, Arnolds), both by intra- muscular route, 40 minutes prior to induction.

Radiography

Induction was achieved using 50 mg thiopentone sodium (Intraval, Rhone Merieux) by intra-venous route and an uncuffed 5 mm endo-tracheal tube used to intubate. Maintenance of anaesthesia was achieved using an Ayres T piece with flow rates of 2 L nitrous oxide and 1 L oxygen with halothane as the volatile agent. Antibiotic cover was provided with 100 mg ampicillin LA (Amfipen LA, Intervet) and additional analgesia with 15 mg carprofen (Rimadyl, Pfizer), both by subcutaneous route.

Surgical preparation
A 22 g intra-venous catheter was placed aseptically into the right cephalic vein and an infusion of Hartmanns was started at a rate of 10mls/kg/hr. The left hind leg was clipped and prepared as in the first paragraph of Appendix 1, to include an area extending from the hock to the whole hip area, the incision site being over the greater trochanter of the femur. The cat was then moved to the theatre and final preparation of the skin took place as in the second paragraph of Appendix 1.

Surgery

The limb was lifted up by the nurse (holding the foot). The surgeon placed the first drape under the limb, lying along the ventral abdomen and left groin. A second drape was held under the limb and the nurse released the foot onto the drape. This drape was then wrapped around the distal limb and held in place with a towel clip. A third and fourth drape were placed to leave the proximal limb, including the hip exposed. See above.

Post-operative progress.
The cat was in sternal recumbency within 15 minutes after extubation. Analgesia was repeated after 6 hours with 0.8 mg of morphine (Morphine Sulphate, Evans) by intra-muscular route.

The post-operative check was satisfactory - the cat was weight bearing on the limb, and sutures were removed after 10 days. Within 4 weeks the cat was using the limb normally.

Discussion
Excision arthroplasty is regarded as a salvage procedure to aleviate pain and restore a reasonable motility of the limb. Cats and small dogs, due to their light weight, seem to do well after the procedure and most have a wide range of movement of the limb. Large dogs (over 25 kg) can have problems with this treatment and other types of repair should be considered.

References:
Atlas of Surg Approaches to Bones of Cat & Dog, Piermattei, Greeley. 2nd Ed Saunders 1979
Sm An Orthopaedics, Brinker, Piermattei, Flo. 2nd Ed. Saunders 1990
Sm An Surg Nursing, D Tracy, 2nd Ed. Mosby 1994

Case 3. Excision arthroplasty of the left hip

Arlo Guthrie — Tue, 21 Apr 2009 16:04:47 GMT

Revision 1 posted to Diploma by Arlo Guthrie on 21/04/2009 17:04:47

OWNER	ALI	ANIMAL:	TOM
SPECIES:	CAT	BREED:	DSH
AGE:	1 YEAR	SEX:	MALE (N)
WEIGHT	4.1 KG	CONDITION:	GOOD

The post-operative check was satisfactory - the cat was weight bearing on the limb, and sutures were removed after 10 days. Within 4 weeks the cat was using the limb normally.

Case 4. Bilateral Thyroidectomy

sabira mali — Fri, 24 Jul 2009 16:06:52 GMT

Current revision posted to Diploma by sabira mali on 24/07/2009 17:06:52

Case 4. Bilateral Thyroidectomy

OWNER	THEOBALD	ANIMAL:	CANDY
SPECIES:	CAT	BREED:	DSH
AGE:	10 YEARS	SEX:	FEMALE
WEIGHT	3.4 KG	CONDITION:	FAIR

Clinical History
The cat was first presented for episodes of collapse and ataxia. An ECG revealed a heart rate of 260, sinustachycardia. A radiograph showed massive cardiomegaly. Systolic blood pressure measured at 178 - borderline hypertensive. The left thyroid was enlarged on palpation. Blood samples showed thyroxine > 300 nmol/l ( normal 19 - 65), elevated ALT and Alk Phos, and urea and creatinine normal. The cat was prescribed carbimazole 5 mg (NeoMercazole, Roche) one tab every 8 hrs, and propranolol 10 mg (Inderal, Zeneca), a quarter of a tablet three times daily.

The cat initially responded to medical treatment with a heart rate of 175 and systolic blood pressure falling to 142, and a weight gain of 0.1 kg in 3 weeks. However, the cat continued to be polyphagic and no further improvement was seen. In view of this and that the cat was only 10 years old it was decided to try surgical treatment. The cat was booked for a unilateral left thyroidectomy. The owners were warned of the risks of a general anaesthetic and of possible post-operative complications, and signed a consent form before surgery was undertaken.

Surgical preparation
Premedication consisted of 0.5 mg of morphine (Morphine Sulphate, Evans) by intramuscular route 1 hour prior to surgery. A 22 g intravenous catheter was placed aseptically into the right cephalic vein and an infusion of 200 mls of Hartmann's was started at a rate of 10mls/kg/hr. Induction was achieved using 1.5 mg diazemuls, followed by 20 mg propofol (Rapinovet, Schering Plough) given to effect, both by intravenous route.

The cat was intubated with a 5 mm uncuffed endotracheal tube and anaesthesia was maintained using a semi-closed Ayre's T piece with a Jackson Rees modification. Flow rates of 2L of nitrous oxide and 1L of oxygen were used, with halothane as the inhalation agent. Additional analgesia was given with 10 mg of carprofen (Rimadyl, Pfizer) by sub- cutaneous route and antibiotic cover was provided with 85 mg ampicllin LA (Amfipen LA). The ventral neck was clipped and prepared as in paragraph 1 of Appendix 1, extending caudally to the cranioventral thorax and cranially to include all the ventral neck.

The cat was moved to theatre and placed in dorsal recumbency with the abdomen supported in a bubble wrap lined cradle. The neck was extended and a sand bag placed underneath. The forelimbs were extended and tied caudally. The skin was then prepared as in paragraph 2 of Appendix 1. Four drapes were placed to leave a rectangular window, leaving the surgical site as the only part of the cat exposed. See figure 1 on the right. A standard kit was laid out as listed in Appendix 2. Additional instruments included iris scissors and fine rat tooth forceps.

Surgery
An incision through the skin was made from the larynx, on the ventral neck, extending for 5 cms. The sternohyoid and sternothyroid muscles were bluntly separated to expose the left thyroid gland. The right gland was not visible at this point as it was located behind the trachea, which explains why it was not clinically palpated despite also being large. A decision was made at this point to perform a bilateral thyroidectomy. Using iris scissors and fine rat toothed forceps the thyroid gland was removed from both the caudal and cranial parathyroid glands by careful sharp and blunt dissection. Both the cranial and caudal thyroid blood vessels were preserved and did not need ligating. All the visible thyroid tissue was removed from the parathyroids. The process was repeated with the left side and although no ligating was necessary there was suspicion that the caudal parathyroid might be damaged. The muscles were closed using 3 m chromic catgut (Ethicon) using a simple continuous suture pattern and the skin was closed with 2 m polyamide (Nylonamide, Animus) using simple interrupted sutures. The cat had an uneventful recovery and went home the same day, with instructions to the owner regarding post-operative complications. The cat was seen two days later and was eating well and had no signs of hypocalcaemia. Sutures were removed after 10 days and there were still no signs of hypocalcaemia. Three weeks after surgery the cat had increased it's weight by 0.3 kg and a further blood test showed T4 levels at 7.6 nmol/l (slightly low). Heart rate was 172 p min and systolic blood pressure down to 130.

Discussion
Hyperthyroidism usually occurs in cats over 8 years old, with an average age of 13 years. Symptoms can include weight loss, polyphagia, tachycardia, lethargy, rough coat, change of character, and it is often associated with cardiac abnormalities, hypertension and renal failure. Blood tests will show elevated T4 levels. The condition can be treated medically, surgically, or with Iodine 131. The type of treatment selected will depend on the renal function, age, cardiac function and owner preference. Owners need to be advised of the possible post-operative complication of hypocalcaemia, more commonly occurring when bilateral thyroidectomies have been performed. Removal or disruption of the parathyroids which are closely associated with the thyroids can result in an inability to increase calcium levels in the body, leading to ataxia, tremors, coma and death. This is likely to occur within the first few days and the cat should be kept inside for observation and the owners should phone immediately if symptoms appear, as the cat may need intravenous calcium gluconate. Other surgical complications include Horner's syndrome, hypothyroidism, laryngeal paralysis and recurrence of hyperthyroidism. The draping of this patient was good, with no possibility of contamination of the surgeon by any part of the cat. Analgesia was good in the choice of an opioid and non steroidal and the cat was quite comfortable post-operatively. Pre- operative use of drugs are important for this surgery. The Inderal is given to reduce the blood pressure and for management of sinustachycardia and the NeoMercazole is given to reduce the levels of T4 production. Both of these help reduce the risks of general anaesthesia whilst performing the surgery. There are two techniques for performing a thyroidectomy in the cat. The intracapsular technique and the modified extracapsular technique. In this case the surgeon used a slight variation on the modfied extracapsular method. The surgeon feels that each thyroidectomy is different and that the technique she chooses will depend on a visual inspection of the glands. The post-operative T4 levels were slightly low but this is usually transitory and does not need treatment. Removal of both thyroids can be undertaken unilaterally 6 weeks apart. This does result in the cat having two anaesthetics and if surgery is performed competently the risks of bilateral surgery should be minimal. With regard to the antibiotics used, there was no evident pre-existing infection so a single dose of antibiotics should be adequate. Ideally the antibiotics should be working at the time of surgery and could have been given with the premedication. Placement of a sandbag under the neck assists with the surgery by moving the glands into a more accessible position. Placing the cat in a bubblewrap lined cradle and giving warmed fluids helps to preserve body temperature during general anaesthesia, particularly as this procedure is usually performed on very thin cats with little or no body fat. Alternative suture materials could have been used for this procedure, such as polyglactin 910, but cost of materials is important in a charity clinic and the surgeon has never encountered a tissue reaction using catgut for this particular procedure or had a problem with polyamide in the skin, so feels that it is not imperative to use other suture materials when performing thyroidectomies.

In summary, this was successful surgery as there were no post-operative complications and the aim of the surgery had been accomplished, ie the cat is no longer polyphagic or suffering weight loss and the T4 levels did return to the normal range after 2 months.

References:
Small Animal Surgery, T Fossum, Mosby. 1997

Case 4. Bilateral Thyroidectomy

Arlo Guthrie — Tue, 21 Apr 2009 16:11:41 GMT

Revision 2 posted to Diploma by Arlo Guthrie on 21/04/2009 17:11:41

Case 4. Bilateral Thyroidectomy

OWNER	THEOBALD	ANIMAL:	CANDY
SPECIES:	CAT	BREED:	DSH
AGE:	10 YEARS	SEX:	FEMALE
WEIGHT	3.4 KG	CONDITION:	FAIR

Clinical History
The cat was first presented for episodes of collapse and ataxia. An ECG revealed a heart rate of 260, sinustachycardia. A radiograph showed massive cardiomegaly. Systolic blood pressure measured at 178 - borderline hypertensive. The left thyroid was enlarged on palpation. Blood samples showed thyroxine > 300 nmol/l ( normal 19 - 65), elevated ALT and Alk Phos, and urea and creatinine normal. The cat was prescribed carbimazole 5 mg (NeoMercazole, Roche) one tab every 8 hrs, and propranolol 10 mg (Inderal, Zeneca), a quarter of a tablet three times daily.

Surgical preparation
Premedication consisted of 0.5 mg of morphine (Morphine Sulphate, Evans) by intramuscular route 1 hour prior to surgery. A 22 g intravenous catheter was placed aseptically into the right cephalic vein and an infusion of 200 mls of Hartmann's was started at a rate of 10mls/kg/hr. Induction was achieved using 1.5 mg diazemuls, followed by 20 mg propofol (Rapinovet, Schering Plough) given to effect, both by intravenous route.

Surgery
An incision through the skin was made from the larynx, on the ventral neck, extending for 5 cms. The sternohyoid and sternothyroid muscles were bluntly separated to expose the left thyroid gland. The right gland was not visible at this point as it was located behind the trachea, which explains why it was not clinically palpated despite also being large. A decision was made at this point to perform a bilateral thyroidectomy. Using iris scissors and fine rat toothed forceps the thyroid gland was removed from both the caudal and cranial parathyroid glands by careful sharp and blunt dissection. Both the cranial and caudal thyroid blood vessels were preserved and did not need ligating. All the visible thyroid tissue was removed from the parathyroids. The process was repeated with the left side and although no ligating was necessary there was suspicion that the caudal parathyroid might be damaged. The muscles were closed using 3 m chromic catgut (Ethicon) using a simple continuous suture pattern and the skin was closed with 2 m polyamide (Nylonamide, Animus) using simple interrupted sutures. The cat had an uneventful recovery and went home the same day, with instructions to the owner regarding post-operative complications. The cat was seen two days later and was eating well and had no signs of hypocalcaemia. Sutures were removed after 10 days and there were still no signs of hypocalcaemia. Three weeks after surgery the cat had increased it's weight by 0.3 kg and a further blood test showed T4 levels at 7.6 nmol/l (slightly low). Heart rate was 172 p min and systolic blood pressure down to 130.

Discussion
Hyperthyroidism usually occurs in cats over 8 years old, with an average age of 13 years. Symptoms can include weight loss, polyphagia, tachycardia, lethargy, rough coat, change of character, and it is often associated with cardiac abnormalities, hypertension and renal failure. Blood tests will show elevated T4 levels. The condition can be treated medically, surgically, or with Iodine 131. The type of treatment selected will depend on the renal function, age, cardiac function and owner preference. Owners need to be advised of the possible post-operative complication of hypocalcaemia, more commonly occurring when bilateral thyroidectomies have been performed. Removal or disruption of the parathyroids which are closely associated with the thyroids can result in an inability to increase calcium levels in the body, leading to ataxia, tremors, coma and death. This is likely to occur within the first few days and the cat should be kept inside for observation and the owners should phone immediately if symptoms appear, as the cat may need intravenous calcium gluconate. Other surgical complications include Horner's syndrome, hypothyroidism, laryngeal paralysis and recurrence of hyperthyroidism. The draping of this patient was good, with no possibility of contamination of the surgeon by any part of the cat. Analgesia was good in the choice of an opioid and non steroidal and the cat was quite comfortable post-operatively. Pre- operative use of drugs are important for this surgery. The Inderal is given to reduce the blood pressure and for management of sinustachycardia and the NeoMercazole is given to reduce the levels of T4 production. Both of these help reduce the risks of general anaesthesia whilst performing the surgery. There are two techniques for performing a thyroidectomy in the cat. The intracapsular technique and the modified extracapsular technique. In this case the surgeon used a slight variation on the modfied extracapsular method. The surgeon feels that each thyroidectomy is different and that the technique she chooses will depend on a visual inspection of the glands. The post-operative T4 levels were slightly low but this is usually transitory and does not need treatment. Removal of both thyroids can be undertaken unilaterally 6 weeks apart. This does result in the cat having two anaesthetics and if surgery is performed competently the risks of bilateral surgery should be minimal. With regard to the antibiotics used, there was no evident pre-existing infection so a single dose of antibiotics should be adequate. Ideally the antibiotics should be working at the time of surgery and could have been given with the premedication. Placement of a sandbag under the neck assists with the surgery by moving the glands into a more accessible position. Placing the cat in a bubblewrap lined cradle and giving warmed fluids helps to preserve body temperature during general anaesthesia, particularly as this procedure is usually performed on very thin cats with little or no body fat. Alternative suture materials could have been used for this procedure, such as polyglactin 910, but cost of materials is important in a charity clinic and the surgeon has never encountered a tissue reaction using catgut for this particular procedure or had a problem with polyamide in the skin, so feels that it is not imperative to use other suture materials when performing thyroidectomies.

References:
Small Animal Surgery, T Fossum, Mosby. 1997

Case 4. Bilateral Thyroidectomy

Arlo Guthrie — Tue, 21 Apr 2009 16:10:01 GMT

Revision 1 posted to Diploma by Arlo Guthrie on 21/04/2009 17:10:01

OWNER	THEOBALD	ANIMAL:	CANDY
SPECIES:	CAT	BREED:	DSH
AGE:	10 YEARS	SEX:	FEMALE
WEIGHT	3.4 KG	CONDITION:	FAIR

References:
Small Animal Surgery, T Fossum, Mosby. 1997

Case 5. Ovariohysterectomy due to pyometra

sabira mali — Fri, 24 Jul 2009 16:05:53 GMT

Current revision posted to Diploma by sabira mali on 24/07/2009 17:05:53

Case 5. Ovariohysterectomy due to pyometra

OWNER	LATHAM	ANIMAL:	CASSIE
SPECIES:	DOG	BREED:	BULL MASTIFF
AGE:	10 MONTHS	SEX:	FEMALE
WEIGHT	34 KG	CONDITION:	BRIGHT

Clinical History
The dog was presented with a purulent vaginal discharge which the owner reported had been present for 1 week, following the bitch's first oestrus. The dog was inappetant, not polydipsic, had no vomiting, recorded a temperature of 38.6 C, had pink mucous membranes and a capillary refill time of 1 second. Generally the dog was fairly bright. Nothing abnormal could be palpated in the abdomen and a white blood cell count showed a high count of 38.2 10 9/L. The dog was admitted and put on a slow infusion of 1 litre of compound sodium lactate (Hartmann's, Ivex) overnight, and given an antibiotic injection of 225 mg of ampicillin (Norobritten, Norbrook) by subcutaneous route. The owners signed a consent form for any necessary surgery and general anaesthesia. A pre-anaesthetic clinical check revealed no respiratory or cardiovascular abnormalities.

Radiography
The following morning the dog was sedated with 0.6 mg acepromazine (ACP, C VET) and 0.3 mg buphrenorphine (Temgesic, Schering Plough) by intramuscular route and a right lateral radiograph of the abdomen was taken under sedation. The radiograph confirmed the diagnosis of a pyometra. See radiograph 1 right.

The dog which had been starved overnight was started on a further infusion of Hartmann's, and one hour later was given a general anaesthetic in order to perform an ovario- hysterectomy.

Surgical preparation
General anaesthesia was induced with 180 mg propofol (Rapinovet, Schering Plough) by slow intravenous injection, given to effect. Endotracheal intubation was achieved using an 11 mm cuffed tube. The dog was connected to a semi-closed parallel Lack circuit with a 4L resevoir bag. Flow rates of 4L nitrous oxide and 2L oxygen were used, together with halothane as the inhalation agent, in order to maintain anaesthesia. Further analgesia was given with 13 mg of carprofen (Rimadyl, Pfizer) by subcutaneous route. The antibiotics were also repeated. The dog was placed in sternal recumbency and an area was prepared (as in the first paragraph of Appendix 1) extending from the vulva to the ziphisternum, and 4 cms lateral to the mammary glands on either side. The bladder was expressed manually and the dog was moved into theatre, where it was placed in dorsal recumbency with the thorax supported in a cradle. The hind legs were extended and tied caudally and the surgical site was prepared as in the second paragraph of Appendix 1. See Figure 1 above.

A standard kit (as listed in Appendix 2) was laid out, with 6 additional spey forceps and 8 additional swabs.

Surgery
The surgeon draped the surgical site using 4 drapes arranged to leave a rectangular area exposed, over the midline. A swab count was taken before surgery commenced and a written tally was recorded as 10 swabs. An incision through the skin and subcutaneous tissue was made along the midline just caudal to the umbilicus, extending cranially for approximately 9 cms. This exposed the linear alba, which was grasped and elevated whilst a stab incision was made through it into the abdomen. Blunt Mayo scissors were used to extend the incision to the length of the skin incision, exposing the abdominal contents. The bladder was lifted out of the abdomen and reflected caudally. Both horns and body of the uterus were then lifted out of the abdomen and the body reflected caudally. See Figure 2 above.

The suspensory ligament of the left ovarian pedicle was identified and carefully broken, to allow better exteriorization of the ovary. An assistant gently applied caudal and medial traction to the uterine horn in order to allow the surgeon to apply a ligature, using 4 m polyglactin 910 (Vicryl, Ethicon), 2 cms proximal to the ovary around the ovarian pedicle. A second ligature was placed 1 cm proximally to the first. Then 2 pairs of large spey forceps were used to clamp the ovarian pedicle, both placed distal to the ligatures but proximal to the ovary. The ovarian pedicle was then transected between the two forceps. The forcep remaining on the stump was left in place, and the uterine horn broken away from the remaining ligament and reflected caudally. The process was repeated with the right ovarian pedicle which lies further cranially resulting in the access to this pedicle being more restricted. Cranial traction was then applied to the body of the uterus and a transfixation ligature was placed cranial to the cervix around the body of the uterus. A second, circumferential, ligature was placed nearer to the cervix both with 4 m Vicryl. Two large forceps were placed cranial to the ligatures and the uterine body transected between the two clamps. All three stumps, in turn, had small artery forceps attached to the edge and the large clamps released so that any haemorrhage could be observed. All three had slight oozing and a third ligature was applied to each one. This proved satisfactory and all stumps were replaced into the abdomen. A swab count at this time only showed 9 swabs accounted for. After a recheck the abdomen was searched and the swab was found in the abdomen. The midline was closed with 3 m polydioxanone (PDS II, Ethicon) using interrupted cruciate sutures. The fascia and linear alba were included in the suture, but not the peritoneum. Subcutaneous tissue was closed with 3 m PDS using a simple continuous pattern. Skin was closed with 3 m polyproplene (Ethilon, Ethicon) using a continuous Ford Interlocking suture pattern. Both ovaries were examined after surgery and found to be enlarged, the left having cyst like structures present. Post-operative recovery was uneventful and the dog went home the same day with 10 Rimadyl 50 mg tablets to be given one twice daily with food and 20 Ampicillin 250 mg capsules to be given two twice daily, both to start the following day. If the owners are allergic to penicillin themselves they must wear gloves to administer the capsules.They were advised to get an Elizabethan collar and only to give lead exercise for 5 days. They were also warned to watch the dog's weight after the post-operative period as neutered dogs have a tendency to put on weight. A post-operative check two days later was satisfactory and the sutures were removed after 10 days.

Discussion
Pyometras usually occur in middle aged bitches, and 10 months is quite unusual for this condition. Pyometras can be either open (discharging from the vulva) or closed with no discharge. Generally the latter are usually more likely to be showing more severe symptoms. Medical treatment rarely works and surgery is the option for relieving this condition, which is fatal if left untreated. Although a very common surgical procedure there are several life threatening complications associated with the surgery, coupled with the fact that the animal is quite often very toxic and often collapsed. Incorrect placing of the ligatures on the uterus can lead to them slipping off post-operatively, leading to fatal haemorrhage. Quite often the tissues are very friable and can rupture when being handled, again either leading to serious haemorrhage or contamination of the abdomen with pus which can lead to peritonitis. The bladder was expressed prior to surgery to reduce it's size as much as possible to allow better access within the abdomen. A male dog would also have the risk of passing urine into the abdominal cavity.

With regard to choice of suture materials, despite correct placing of the ligatures all three stumps were oozing after ligation and had to have a third ligature placed on each. Discussion of this point with the surgeon revealed that this was a problem which sometimes occurred when using Vicryl, but not when using chromic catgut. This would imply that it is more difficult to tighten the ligature using Vicryl and that chromic catgut might be a more suitable ligature material. PDS was used to close the subcutaneous tissue in this case, which is more suitable than chromic catgut, as the catgut can provoke a tissue reaction. With regard to suture patterns, simple interrupted could have been used instead of cruciate sutures for the midline but cruciate sutures were considered quicker and are equally efficient. The skin was closed using a continuous Ford Interlocking pattern for speed, but the disadvantages of this type of suture pattern is that it is more difficult and therefore more stressful to remove them. Secondly, if the animal chews at the wound a break in any part of the suture pattern can result in the whole wound opening whereas if an interrupted suture is removed there will only be a small gap in wound closure. This is especially important in an abdominal wound. The importance of conducting a swab count was well demonstrated in this case. Had the number of swabs not been recorded the missing swab would have gone unnoticed and remained within the abdomen, with serious consequences post-operatively.

Draping was carried out with cloth drapes and ideally should have also had a barrier drape to prevent bacterial strike through occurring when the drapes got wet. Analgesia was adequate for the procedure by combining a partial agonist with a non steroidal, although the non steroidal could have been given at the time of premedication to achieve the maximum analgesia during surgery. Rimadyl was a good choice of post-operative analgesia as it can be continued at home and only needs to be given every 24 hours. It is important to warn owners that penicillin can be absorbed through the skin as they have testified, several times, that they have been quite ill after disregarding this advice. Penicillin would appear to be an adequate antibiotic for this procedure and rarely needs a further course to restore the animal to full health. The first injection was given 15 hours prior to surgery and was therefore active during surgery. The outcome of this surgery was successful and the dog did not need to revisit after suture removal.

References:
Anatomy of the Dog, Miller. Saunders 2nd Ed.
1979 Small Animal Surgery, T Fossum. Mosby. 1997

Case 5. Ovariohysterectomy due to pyometra

Arlo Guthrie — Tue, 21 Apr 2009 16:16:52 GMT

Revision 1 posted to Diploma by Arlo Guthrie on 21/04/2009 17:16:52

OWNER	LATHAM	ANIMAL:	CASSIE
SPECIES:	DOG	BREED:	BULL MASTIFF
AGE:	10 MONTHS	SEX:	FEMALE
WEIGHT	34 KG	CONDITION:	BRIGHT

Clinical History
The dog was presented with a purulent vaginal discharge which the owner reported had been present for 1 week, following the bitch's first oestrus. The dog was inappetant, not polydipsic, had no vomiting, recorded a temperature of 38.6 C, had pink mucous membranes and a capillary refill time of 1 second. Generally the dog was fairly bright. Nothing abnormal could be palpated in the abdomen and a white blood cell count showed a high count of 38.2 10 9/L. The dog was admitted and put on a slow infusion of 1 litre of compound sodium lactate (Hartmann's, Ivex) overnight, and given an antibiotic injection of 225 mg of ampicillin (Norobritten, Norbrook) by subcutaneous route. The owners signed a consent form for any necessary surgery and general anaesthesia. A pre-anaesthetic clinical check revealed no respiratory or cardiovascular abnormalities.

The dog which had been starved overnight was started on a further infusion of Hartmann's, and one hour later was given a general anaesthetic in order to perform an ovario- hysterectomy.

A standard kit (as listed in Appendix 2) was laid out, with 6 additional spey forceps and 8 additional swabs.

Discussion
Pyometras usually occur in middle aged bitches, and 10 months is quite unusual for this condition. Pyometras can be either open (discharging from the vulva) or closed with no discharge. Generally the latter are usually more likely to be showing more severe symptoms. Medical treatment rarely works and surgery is the option for relieving this condition, which is fatal if left untreated. Although a very common surgical procedure there are several life threatening complications associated with the surgery, coupled with the fact that the animal is quite often very toxic and often collapsed. Incorrect placing of the ligatures on the uterus can lead to them slipping off post-operatively, leading to fatal haemorrhage. Quite often the tissues are very friable and can rupture when being handled, again either leading to serious haemorrhage or contamination of the abdomen with pus which can lead to peritonitis. The bladder was expressed prior to surgery to reduce it's size as much as possible to allow better access within the abdomen. A male dog would also have the risk of passing urine into the abdominal cavity.

References:
Anatomy of the Dog, Miller. Saunders 2nd Ed.
1979 Small Animal Surgery, T Fossum. Mosby. 1997

Case 2. Cystotomy & removal of uroliths

sabira mali — Fri, 24 Jul 2009 16:03:52 GMT

Current revision posted to Diploma by sabira mali on 24/07/2009 17:03:52

Case 2. Cystotomy & removal of uroliths

OWNER	MERTENS	ANIMAL:	BECK
SPECIES:	DOG	BREED:	JACK RUSSELL
AGE:	7 YEARS	SEX:	FEMALE
WEIGHT	11 KG	CONDITION:	OBESE

Clinical History
The dog was presented with dysuria and haematuria for a duration of two weeks. On palpation of the bladder numerous stones could be felt. The owner was warned that surgery would be needed and the risks of general anaesthesia in an obese animal were explained. The dog was booked for radiography and surgery the following day and was given a course of tablets containing trimethroprim 80mg and sulphamethoxazole 400mg (Co-Trimoxazole, Regent), to be given half a tablet twice daily.

Radiography
On 23/12/98 the dog was admitted for a general anaesthetic, having been starved over night with access to water two hours prior to surgery. A pre-anaesthetic check revealed no thoracic or cardiovascular abnormalities. Temperature was 38.2 C, pulse 114 per minute and respiration 31 per minute. The owners signed a consent form and the dog was premedicated with 0.6 mg acepromazine (ACP, C VET) by subcutaneous route, 45 minutes prior to surgery.

Induction was achieved using 175 mg thiopentone sodium 2.5% (Intraval Sodium, Rhone Merieux) and a cuffed size 7.5 endo-tracheal was used to intubate. The dog was placed on a semi-closed parallel lack circuit with flow rates of 4 litres of nitrous oxide and 2 litres of oxygen and 1.5% halothane. A 23g intravenous catheter was placed aseptically into the cephalic vein and a slow infusion of 500 mls Hartmann's was started. Analgesia was given with 3 mg morphine sulphate by intra-muscular route. Antibiotic cover was provided with 165 mg trimethoprim-sulphadiazine 7.5% (Borgal, Hoescht Roussel) given intra-venously.

A radiograph of the abdomen in right lateral recumbency was taken to confirm the location of the uroliths, including the kidneys. The radiograph revealed that all the uroliths were located in the bladder. See radiograph 1 above.

Surgical preparation
The ventral abdomen was prepared, as in the first paragraph of Appendix 1, covering an area from the ziphisternum cranially to the vulva caudally, and laterally 10 cms either side of the midline. The dog was moved to theatre and placed in dorsal recumbency (supported by a cradle) with both hind legs extended and tied out. The ECG electrodes were attached on the limbs just proximal to the stifle and olecranon. Skin cleansing took place as described in the second paragraph of Appendix 1.

Surgery
The area of the incision site was then draped by the scrubbed surgeon using four barrier drapes arranged in a quadrant, leaving only the midline exposed. See figure 1 on the right.

The instruments in this procedure included two standard surgical kits, as described in Appendix 2. In addition to this a sterile bowl, two 20 ml syringes, a 23 g needle, sixteen swabs and 0.9 % saline were used.

An incision was made through the skin and subcutaneous tissue along the midline, starting 2 cms cranial to the pubic symphysis and extending for 10 cms. Blunt dissection revealed the abdominal wall which was grasped with rat toothed forceps and lifted. A stab incision was made through the tissue and blunt mayo scissors were used to lengthen the incision to the extent of the skin incision. The bladder was located and lifted out of the abdomen, reflected caudally and laid on swabs. A stay suture using 3 m monofilament nylon (Monilon, Arnolds) was placed in the cranial bladder. Other swabs were then packed in the abdominal wound to minimise contamination by the bladder contents. Cystocentesis was performed with a 20 ml syringe and 23 g needle to remove as much urine as possible. A 2 cm incision was made into the dorsal aspect of the bladder, taking care to avoid the visible blood vessels. Numerous uroliths, ranging from 1 mm to 1.4 cms, were removed from the bladder. See Figure 2 below.

The bladder was then flushed using a sterile 20 ml syringe and sterile saline to ensure all uroliths had been removed. The bladder was closed with 2 m polyglactin 910 (Vicryl, Ethicon) on a round bodied needle using a double layer of simple interrupted sutures, the first layer including the mucosa and submucosa and the second including the muscularis and serosa.

All used swabs were removed and counted, the bladder replaced within the abdomen and the abdominal cavity was flushed with 0.9% saline. At this time the surgeon changed surgical gloves and a fresh surgical kit was used to close the abdominal wound. The abdominal wall was closed using 3 m polydioxanone (PDS II, Ethicon) on a cutting needle with simple interrupted sutures. The subcutaneous tissue was closed with 3.5 m chromic catgut (Ethicon) on a cutting needle using a simple continuous suture. Skin was closed with 3 m polyamide (Nylonamide, Animus) on a cutting needle using horizontal mattress sutures.

Post-operative period.
Recovery was uneventful, the dog being in sternal recumbency within 30 minutes of the end of anaesthesia. On recovery the dog was given 24 mg of ketoprofen (Ketofen 1%, Rhone Merieux) by intramuscular route. The dog was sent home later in the day with 2 Ketofen 20 mg tablets, half to be given daily with food, to start the following day. The owners were advised to watch for urination and revisit in the morning if the dog could not urinate. They were also told to expect haematuria and that they should finish the course of antibiotics previously prescribed for the dog. The calculi were sent off for analysis to the Minnesota Urolith Centre, University of Minnesota, USA. The dog returned 3 days later for a satisfactory post-operative check and the sutures were removed after 10 days. The owners were then told to revisit when the results of the calculi analysis returned.

Discussion
There are many causes of urolithiasis, including genetics, diet, obesity, inactivity, infectious agents or systemic disease. Therefore surgical removal of uroliths is not a cure. The owner was warned that, as uroliths reform in 1 in 4 dogs, (Hills Pet Products Data Sheet), permanent dietary management would be necessary for the dog. In this particular case, despite the bladder being full of calculi, the radiograph showed none in the urethra and the bitch was still able to pass urine with difficulty. Male dogs are more susceptible to obstruction of the urethra by calculi due to natural constrictions in the urethra - the most important being at the site of the os penis.

Results from Minnesota showed that the chemical composition of the uroliths was comprised of both calcium phosphate and magnesium ammonium phosphate. Some types of calculi, eg struvite (magnesium ammonium phosphate) can be dissolved by dietary management and treatment with antibiotics of the urinary tract infection which usually precedes formation of struvites (Minnesota Urolith Centre).Therefore it would be advisable to send off a urine sample for bacterial culture to ensure the correct antibiotic was used. This type of treatment would be suitable for male cats after placement of a urinary catheter due to obstruction by calculi. Manufacturers, eg Hills, produce a diet called s/d which is low in protein, magnesium, phosphate, high in sodium and produces acid urine. This diet is intended for short term use for the dissolution of struvite calculi. Struvites form in alkaline urine but become highly soluble in acid urine below pH 6.4. Hills also produce a long term maintenance diet which is called c/d to maintain acidity of the urine, to prevent struvites reforming. Other diets are available for different types of calculi. There is no dissolution diet available for calcium phosphate. Dissolution was not an option in this dog's case due to amount and size of calculi and condition of the dog.

Complications of this type of surgery include contamination of the abdomen, which could result in peritonitis. Therefore great care has to be taken to avoid spillage of urine into the abdominal cavity. Another post-operative complication is failure to remove all calculi, resulting in further obstruction. Prior to closure of the bladder the urethra should be flushed with sterile saline to ensure removal of all calculi. Other considerations in this type of surgery which involves large amounts of flushing with saline involve bacterial strike through via wet drapes and hypothermia of the patient due to excessive wetting of the skin, causing temperature loss through evaporation. Barrier drapes are essential to avoid both of these from ocurring. Also, saline should be heated to body temperature before flushing as this will help preserve body temperature. Water heated pads are not available in this clinic but bubble wrap was used to wrap limbs prior to surgery in order to conserve body temperature.

With regard to analgesia, carprofen would have been the choice of non steroidal anti- inflammatory drug, as it is the only one of the group which is considered safe to use peri-operatively due to its lack of effect on the body's prostaglandin production. However, due to a manufacturing problem it was not available at the time of surgery and ketoprofen was used as the NSAID. This could not be administered peri-operatively due to its adverse effects on prostaglandin production, possibly causing renal failure or ulceration of the GI tract. Therefore morphine was selected for intra-operative use, in conjunction with nitrous oxide. It would have been preferable for the morphine to be given in the premedication to allow it to be active at the time of the first incision. The only disadvantage of giving morphine pre-operatively is that vomiting can occur shortly after administration - this is rarely a problem in a conscious animal.

A blood sample was taken to check the function of the parathyroid gland, as this is recommended in cases of calcium phosphate calculi, as excess levels of calcium are thought to be the precursor to these calculi. However, the results of the blood sample showed normal levels of calcium (2.4 mmol/l). Therefore the owner was told to feed Hills s/d exclusively for 2 months and then to change to Hills c/d diet permanently. The owner could also have been told to check the pH of the dog's urine daily and to revisit if the urine showed alkalinity for more than 2 days. (Manual of Canine and Feline Nephrology and Urology, BSAVA).

References:
Anatomy of the Dog, Miller, Saunders 2nd Ed 1979, Ch 9.
Current Techniques in Sm An Surg, Bojrab, 3rd Ed, Lea & Febiger 1990.
Clinical Management of Canine & Feline Urolithiasis, Hills 1991.
Minnesota Urolith Centre, Clinical Data Sheet Rev 1996.
Manual of Can & Fel Nephrology & Urology, BSAVA 1996, p 216,217.

Case 2. Cystotomy & removal of uroliths

Arlo Guthrie — Tue, 21 Apr 2009 16:08:37 GMT

Revision 3 posted to Diploma by Arlo Guthrie on 21/04/2009 17:08:37

Case 2. Cystotomy and & removal of uroliths

OWNER	MERTENS	ANIMAL:	BECK
SPECIES:	DOG	BREED:	JACK RUSSELL
AGE:	7 YEARS	SEX:	FEMALE
WEIGHT	11 KG	CONDITION:	OBESE

Clinical History
The dog was presented with dysuria and haematuria for a duration of two weeks. On palpation of the bladder numerous stones could be felt. The owner was warned that surgery would be needed and the risks of general anaesthesia in an obese animal were explained. The dog was booked for radiography and surgery the following day and was given a course of tablets containing trimethroprim 80mg and sulphamethoxazole 400mg (Co-Trimoxazole, Regent), to be given half a tablet twice daily.

Surgical preparation
The ventral abdomen was prepared, as in the first paragraph of Appendix 1, covering an area from the ziphisternum cranially to the vulva caudally, and laterally 10 cms either side of the midline. The dog was moved to theatre and placed in dorsal recumbency (supported by a cradle) with both hind legs extended and tied out. The ECG electrodes were attached on the limbs just proximal to the stifle and olecranon. Skin cleansing took place as described in the second paragraph of Appendix 1.

Surgery
The area of the incision site was then draped by the scrubbed surgeon using four barrier drapes arranged in a quadrant, leaving only the midline exposed. See figure 1 on the right.

Post-operative period.
Recovery was uneventful, the dog being in sternal recumbency within 30 minutes of the end of anaesthesia. On recovery the dog was given 24 mg of ketoprofen (Ketofen 1%, Rhone Merieux) by intramuscular route. The dog was sent home later in the day with 2 Ketofen 20 mg tablets, half to be given daily with food, to start the following day. The owners were advised to watch for urination and revisit in the morning if the dog could not urinate. They were also told to expect haematuria and that they should finish the course of antibiotics previously prescribed for the dog. The calculi were sent off for analysis to the Minnesota Urolith Centre, University of Minnesota, USA. The dog returned 3 days later for a satisfactory post-operative check and the sutures were removed after 10 days. The owners were then told to revisit when the results of the calculi analysis returned.

Discussion
There are many causes of urolithiasis, including genetics, diet, obesity, inactivity, infectious agents or systemic disease. Therefore surgical removal of uroliths is not a cure. The owner was warned that, as uroliths reform in 1 in 4 dogs, (Hills Pet Products Data Sheet), permanent dietary management would be necessary for the dog. In this particular case, despite the bladder being full of calculi, the radiograph showed none in the urethra and the bitch was still able to pass urine with difficulty. Male dogs are more susceptible to obstruction of the urethra by calculi due to natural constrictions in the urethra - the most important being at the site of the os penis.

References:
Anatomy of the Dog, Miller, Saunders 2nd Ed 1979, Ch 9.
Current Techniques in Sm An Surg, Bojrab, 3rd Ed, Lea & Febiger 1990.
Clinical Management of Canine & Feline Urolithiasis, Hills 1991.
Minnesota Urolith Centre, Clinical Data Sheet Rev 1996.
Manual of Can & Fel Nephrology & Urology, BSAVA 1996, p 216,217.

Case 2. Cystotomy and removal of uroliths

Arlo Guthrie — Tue, 21 Apr 2009 16:03:06 GMT

Revision 2 posted to Diploma by Arlo Guthrie on 21/04/2009 17:03:06

Case 2. Cystotomy and removal of uroliths

OWNER	MERTENS	ANIMAL:	BECK
SPECIES:	DOG	BREED:	JACK RUSSELL
AGE:	7 YEARS	SEX:	FEMALE
WEIGHT	11 KG	CONDITION:	OBESE

Radiography

On 23/12/98 the dog was admitted for a general anaesthetic, having been starved over night with access to water two hours prior to surgery. A pre-anaesthetic check revealed no thoracic or cardiovascular abnormalities. Temperature was 38.2 C, pulse 114 per minute and respiration 31 per minute. The owners signed a consent form and the dog was premedicated with 0.6 mg acepromazine (ACP, C VET) by subcutaneous route, 45 minutes prior to surgery.

Surgery

The area of the incision site was then draped by the scrubbed surgeon using four barrier drapes arranged in a quadrant, leaving only the midline exposed. See figure 1 on the right.

Case 2. Cystotomy and removal of uroliths

Arlo Guthrie — Tue, 21 Apr 2009 15:52:44 GMT

Revision 1 posted to Diploma by Arlo Guthrie on 21/04/2009 16:52:44

OWNER	MERTENS	ANIMAL:	BECK
SPECIES:	DOG	BREED:	JACK RUSSELL
AGE:	7 YEARS	SEX:	FEMALE
WEIGHT	11 KG	CONDITION:	OBESE

Surgery
The area of the incision site was then draped by the scrubbed surgeon using four barrier drapes arranged in a quadrant, leaving only the midline exposed. See figure 1 on the right.

Anaesthetic Case Reports

Arlo Guthrie — Wed, 22 Apr 2009 10:25:14 GMT

Current revision posted to Diploma by Arlo Guthrie on 22/04/2009 11:25:14

Please use the navigation on the right to navigate to the case reports.

Radiographic Diary

Arlo Guthrie — Wed, 22 Apr 2009 10:18:22 GMT

Current revision posted to Diploma by Arlo Guthrie on 22/04/2009 11:18:22

NB. The following excerpt is presented for the purpose of illustration.

DATE	30.4.99	30.4.99	-	30.4.99
REF NO	274w	106w	-	210w
SPECIES	DOG	DOG	-	CAT
OWNER	Francis	Grady	-	Dicredico
ANIMAL	Lady	Bomber	-	Lucky
WEIGHT OB/AV/TH	31.8kg Av	22.6 kg Av	-	3.9 kg Th
AGE	6 yrs	13 yrs	-	10 yrs
COND OF ANIMAL	Good	Good	-	Poor
CONS/ SED/GA	GA	GA	-	Sed
AREA	Thorax	Pelvis	Pelvis	Abdomen
VIEW	Right lateral	Right lateral	Ventro-dorsal	Right lateral
GRID	Parallel stationary	Parallel stationary	Parallel stationary	No
X-RAY MACHINE	Guardian 125	Guardian 125	Guardian 125	Guardian 125
FILM	CP-G PLUS	CP-G PLUS	CP-G PLUS	CP-G PLUS
SCREEN	Rare Earth	Rare Earth	Rare Earth	Rare Earth
EXP kV mAs	78:25	78:25	70:25	50:9
FFD	100 cms	100 cms	100 cms	100 cms
NO. OF FILMS	1	1	1	1
SPECIAL FEATURES	-	-	-	-
FILM QUALITY	4 unexposed film edges. Exposure good. Collimation too caudal, centred over diaphragm. Definition quite good. Diagnostic film.	4 unexposed film edges. Slightly overexposed. Collimation good. Centred over L7. Slightly rotated. Diagnostic film.	4 unexposed film edges. Exposure very good, with large range of densities. No rotation, patellae centrally located on femurs. Centred on pubic symph.	4 unexposed film edges. Contrast very good despite thin cat. Hind legs not fully extended. True lateral. Diagnostic film.
DIAGNOSIS	No metastasis from mammary tumours.	L7 vertebra collapsed with subsequent new bone growth.	See before.	Nothing abnormal detected.

Appendix

Arlo Guthrie — Wed, 22 Apr 2009 10:16:42 GMT

Current revision posted to Diploma by Arlo Guthrie on 22/04/2009 11:16:42

All personnel involved in radiography wear dosemeters at all times.
These are sent off every 3 months to check radiation received by personnel.
The X-ray machine is fixed in a room 4m x 3.5m, designated to radiography.
The radiography table measures 150cms x 90cms and is lead lined.
The control panel is situated out in the corridor.
The door to the room is lead lined and has a lead glass window.
All personnel must wear lead aprons in the room when the X-ray machine is turned on.
All personnel leave the room and the door closed before an exposure is made.
It is extremely rare for animals to be restrained manually whilst an exposure is made. If this is ever necessary lead gloves are worn and hands must remain outside the primary beam.

Case 5. Distal right hind

Arlo Guthrie — Wed, 22 Apr 2009 10:13:39 GMT

Current revision posted to Diploma by Arlo Guthrie on 22/04/2009 11:13:39

X RAY REF:	53	DATE:	15/10/99
SPECIES:	CAT	BREED:	DSH
OWNER:	CHANNER	ANIMAL:	GINGER
AGE:	13 YEARS	SEX:	FEMALE NEUTER
WEIGHT:	2.7 KG	BUILD:	AVERAGE

Clinical history
The cat was first presented for 'being off colour for the past few days'. On clinical exam- ination it was found that there was a solid mass on the right medial hock. On being questioned the owner reported that the mass had be growing over the last few months. Several lymph nodes were enlarged, but no other abnormal clinical symptoms were found. The mass appeared to be a tumour and the owner was advised that the cat would need radiography and a biopsy to determine the extent and type of tumour. The owner signed a consent form for a general anaesthetic, radiography and a biopsy. The cat was starved overnight with access to water until 2 hours prior to premedication.

Restraint for radiography
This was achieved with general anaesthesia.

Premedication:	0.6 mg morphine by intramuscular route. 0.2 mg acepromazine by subcutaneous route.
Induction:	50 mg thiopentone by intravenous route.
Maintenance:	2L nitrous oxide, 1L oxygen, 1% halothane.

Choice of film/screen/grid
Agfa CP B Blue 100 NIF film was used with calcium tungstate screens. This is a blue light sensitive film to compliment the blue light emitting screen. No grid was necessary as the tissue depth was not greater than 10 cms.

Positioning for RH distal limb
Lateral
The cat was laid in right lateral recumbency with the RH placed on the cassette. The left hind limb was abducted, pulled caudally and tied, to avoid superimposition of the left limb on the radiograph. The right limb was tied in partial extension. A visual check was made to ensure that the hock was not rotated. Sometimes a foam pad will be need to be used to bring the hock to the true lateral position. A right marker was placed next to the limb.

Craniocaudal
The cat was laid in dorsal recumbency with the right hind extended and placed on the unexposed part of the cassette. The right hind was extended and tied. The body is rotated axially until the hock is straight. Sand bags can be used along the body, and also one placed over the femur helps bring the hock parallel to the cassette. This is possible with cats but sometimes difficult with dogs to bring the hock down onto the cassette. A right marker was placed by the limb.

All safety precautions taken during radiography are described in Appendix 1.

Centering
An overall view of the distal limb was requested by the clinician, so the hock was used as the centring point for both projections.

Collimation
For both projections the collimation included the distal half of the tibia and fibula to the distal phalanges.

Exposures
The following exposures were used:

Lateral	50kV 75mA 0.04 secs
Craniocaudal	50kV 75mA 0.04 secs
FFD	85 cms

Radiographic appraisal
Positioning
Lateral The positioning of this projection is very nearly straight. The metatarsals are quite well superimposed. The hock is slightly rotated. The positioning is good enough in this case to enable a diagnosis.

Craniocaudal
This projection is slightly rotated - the metatarsals do not appear in true cranoicaudal projection. It is difficult when trying to position broken limbs, as the bones proximal to the fracture may be in true position but not distal to the fracture. Positioning was adequate to enable a diagnosis to be made.

The most prominent fault in positioning is that the cassette was not turned so that both projections were similarly distally/proximally aligned. This is distracting when viewing a radiograph, as one projection appears upside down and the radiograph has to be turned around to view each projection properly.

Centering
Lateral
An overall view of the distal limb was required so the primary beam was centred over the hock. In this projection the centre of the beam is at the level of the hock, just cranial to it. This could be improved by better palpation of the bones.

Craniocaudal
Again the distal limb was required so the beam was centred over the hock. In fact it is actually centred just lateral to the hock.

Collimation
Lateral
All four edges of the film are unexposed which demonstrates the extent of the primary beam. This is important for personal safety and to produce a better quality radiograph. The area of interest was actually the distal tibia and fibula. For normal projections of this area the collimation should be closer to the area of interest. In this case the whole of the distal limb was required, so collimation is acceptable.

Craniocaudal
As above.

Exposure
Both projections are slightly overexposed. Particularly in this case assessment of the soft tissues is important, although the soft tissue mass can be seen. Perhaps halving the time of the exposure would have produced a better result - too much mAs blackens the whole film, which is what appears to be happening here. Detail is reasonably good despite over exposure and the definition is also good. There is still a fairly large range of densities around the hock area. This is a diagnostic radiograph.

Processing
An automatic processor was used for this radiograph and it appears to be processed correctly. Labelling Labelling should be done at the time of exposure or before processing, with a light marker, to ensure permanent labelling and also to avoid radiographs being labelled with the wrong animal details. There are presently neither of these in use at this practice.

Artefacts
There are roller marks caused by the processor which do not respond to repeated cleaning of the rollers. There are also finger prints caused after processing during examination of the radiograph.

Diagnosis
The diagnosis in this case was osteosarcoma. The thorax was radiographed and examined under a bright light due to overexposure. No metastasis was evident but the owner was warned that metastasis could still have occurred. The owner opted for amputation of the limb and this has been done, despite advice that it might be better to put the cat to sleep.

General comments on radiography
Radiography was a good diagnostic tool in this case as it enabled sight of both soft tissue and bone, as a non evasive procedure. Heavy sedation and analgesia could probably have been used to obtain diagnostic radiographs rather than general anaesthesia, as the cat was quite ill. A radiograph of the right lateral thorax was also taken but not included as a case here. See Radiographic Case no. 4 with reference to radiography of the thorax.

References
Small Animal Diagnostic Imaging, BSAVA 1995
Diploma Notes 1999

Case 4. Thorax

Arlo Guthrie — Wed, 22 Apr 2009 10:09:53 GMT

Current revision posted to Diploma by Arlo Guthrie on 22/04/2009 11:09:53

X RAY REF:	20	DATE:	8/10/99
SPECIES:	DOG	BREED:	YORKIE
OWNER:	BLOWES	ANIMAL:	MAX
AGE:	12 YEARS	SEX:	MALE
WEIGHT:	4.3 KG	BUILD:	AVERAGE

Clinical history
Max had been on long term treatment for a grade VI heart murmur for 1 year, with frusemide 20 mg tablets quarter daily and lanoxin 0.0625 mg tablets half twice daily. He was stable on the medication and doing well. Then he was bitten by a dog and suffered a glenoid fracture of the right scapula. This was repaired and postoperatively the dog was doing well. Two months later the owner presented Max for coughing and wheezing which had been getting progressively worse for the last 3 weeks. Max was booked in for radiography and ultrasonography, the owner having signed a consent form for the procedures and general anaesthesia. The dog was starved from the night before with access to water until 2 hours prior to premedication.

Restraint for radiography
This was achieved with general anaesthesia.

Premedication:	None.
Induction:	20 mg propofol.
Maintenance:	3L oxygen, 1% halothane.

Choice of film/screen/grid
Agfa CP B Blue 100 NIF film was used with calcium tungstate screens. These screens emit blue light so a blue light sensitive film has to be used with them. No grid was used. The tissue depth was 10 cms which was borderline for use of a grid, although some sources state that when radiographing the thorax up to 15 cms can be radiographed without the use of a grid.

Positioning
Right Lateral
The dog was placed in right lateral recumbency with the thorax on the cassette. A foam pad was placed between the fore limbs and the forelegs were extended cranially and tied. A foam wedge was placed under the sternum to prevent axial rotation of the thorax. The neck was placed in a neutral position.

Dorsoventral
The dog was placed on it's sternum with the forelimbs drawn forwards and tied. The hind limbs were extended and drawn caudally. This is to help achieve a straight positioning. The spine should be straight and axial rotation should be avoided by extending both forelimbs equally and rotating the dog until the sternum is directly under the thoracic spine. A right marker was placed on the appropriate side of the animal.

All safety precautions taken during radiography are described in Appendix 1.

Centering
Lateral
The primary beam was centred just caudal to the caudal border of the scapula and midway between the thoracic spine and ventral thoracic wall.

Dorsoventral
As above.

Collimation
Lateral
The primary beam was collimated from a position just cranial to the manubrium to the last rib. It was also collimated from the spinous process of T12 to the ventral thoracic wall.

Dorsoventral
Laterally the primary beam was collimated just outside each thoracic wall and also from just cranial to the manubrium to the last rib.

Exposures
The following exposures were used:

Lateral	63kV 100mA 0.02 secs
Dorsoventral	70kV 100mA 0.02 secs
FFD	85 cms

Both exposures were taken on inspiration.

Radiographic appraisal
Choice of film and screen
The tungstate screens and blue light sensitive film are standard at this practice. Possibly a better detailed radiograph could have been obtained using a rare earth screen and green light sensitive film such as Agfa CP-G PLUS. Rare earth screens are more efficient at absorbing x-ray photons and converting them to visible light, resulting in smaller exposures being necessary and better quality films. As the tissue depth was on the border line for use of a grid, a slightly better quality radiograph might have been obtained by using one.

Positioning
Lateral
The forelegs are drawn well forward, out of the cranial thoracic field. There is a little axial rotation which can be seen where the ends of the ribs are not in alignment. Perhaps more time spent assessing the elevation of the sternum could have improved this. However, this dog had a barrel shaped thorax which makes visual assessment difficult.

Dorsoventral
This projection appears to be quite straight. It is difficult to see the sternum which would indicate that it is directly under the spine. The spine itself is reasonably straight and both forelegs appear to be equally extended.

Centering
Lateral
The primary beam is centred over the base of the heart. This would seem to be an acceptable centring point for the general view of the thorax. In some animals it is quite difficult to be accurate both with centring and collimation - correct collimation will leave the centring point slightly out of place and, similarly correct centring can sometimes make correct collimation impossible. This is because they are inter-linked, with the centre of the beam always falling within the centre of the field of collimation.

Dorsoventral
The primary beam is centred over the spine at the level of T8. This is a little caudal to the point mentioned in literature, which would appear to be at T6, if centred just caudal to the scapula. However, this is an example of the collimation/centring problem mentioned above. For the purposes of this radiograph the centring would probably be accurate enough.

Collimation
Good collimation is necessary for both film quality and personnel safety. All 4 film edges are unexposed which demonstrates the extent of the primary beam. Close collimation is required to reduce scatter from tissues which are not under investigation. This scatter will reduce the overall quality of the radiograph's detail. Both of these projections are collimated reasonably well. Both are collimated correctly, just cranial to the manubrium and to the last rib. Laterally the collimation is acceptable on the dorsoventral projection, and dorsally on the lateral projection the collimation is correct, as it is important to see the dorsocaudal lung fields.

Exposure
The exposure of these projections is reasonable. The thorax can be a difficult area to obtain good overall exposure. The lungs having a very low physical density and the heart having a high physical density. Therefore one or other organ will be under or overexposed. For this reason a high kV and low mAs are used - higher kV's produce less contrast between different physical densities of tissues. The other advantage of this technique is that exposure times can be shorter which helps with the problem of movement blur that occurs when radiographing the thorax. There is a large range of densities on both projections, and the definition (sharpness is reasonable). With regard to detail, the pulmonary vessels can be seen and the caudal vena cava is visible on the lateral projection. The aorta is not visible but that may be due to the heart enlargement.

On the dorsoventral projection the heart is well penetrated, allowing site of the bifurcation of the trachea (carina) at the level of T5 and the bronchi. Detail could be better with regard to the internal structures of the lungs. Perhaps manual inflation of the lungs to maintain maximum lung expansion without respiratory movement whilst the exposure is made might have improved detail. This is not possible at this practice, as no one is allowed in the room whilst an exposure is made.

The lateral projection was taken on inspiration. The caudal crura meet the vertebral column at T13. On inspiration there should also be a space between the heart and diaphragm. However, as this radiograph demonstrates, if the heart is enlarged it is not a reliable indicator of the respiratory cycle.

If the same premise can be applied to the dorsoventral projection the crura meet the vertebral column at the level of T12, so it could be assumed that this exposure was not taken at full inspiration.

Processing
This radiograph was put through an automatic processor and appears to have been processed correctly. Over development would result in blackening of the metal marker.

Artefacts
The processor rollers have left some marks over the length of the film. Despite fully dis- mantling and cleaning every week there still artefacts appearing on radiographs. This is very frustrating. The metal wire appearing on both projections is not a true artefact but the wire used for the repair of the fractured shoulder.

There are several fingerprints on the film, caused after processing. This is difficult to avoid as these are 'working' radiographs, and have been handled and examined by veterinary surgeons!

Labelling
The system of labelling radiographs as they emerge from the processor is not ideal and all radiographs should be labelled at the time of exposure to avoid the possibility of mis- labelling.

Diagnosis
The radiography enabled the size of the cardiac shadow to be assessed - in this case it is grossly enlarged. Pulmonary oedema was also seen within the lungs. With the results of both radiography and ultrasonography the treatment regime was changed to frusemide 40mg quarter twice daily, lanoxin pg 0.25 mls per os twice daily and Cardiovet 5mg quarter twice daily for 2 days then half twice daily.

General comments on radiography
In this case a complete diagnosis could not be made with radiography. Ultrasonography was also used prior to general anaesthesia to assess the physical condition of the heart. The results of which showed - a massive volume overload of the left atria and ventricle. The mitral valve is thickened and can actually be seen leaking when fully closed. See figure 1.

Figure 1 - Mitral valve insufficiency

References
Manual Sm An Diagnostic Imaging. BSAVA 1997
Radiographic Techniques - The Dog. Morgan, Duval, Samii. Schlutersche. 1998.

Case 3. Abdomen and pneumocystogram

Arlo Guthrie — Wed, 22 Apr 2009 10:05:12 GMT

Current revision posted to Diploma by Arlo Guthrie on 22/04/2009 11:05:12

Case 3. Abdomen and pneumocystogram

X RAY REF:	41	DATE:	13/10/99
SPECIES:	DOG	BREED:	XB
OWNER:	HUTCHINSON	ANIMAL:	DINO
AGE:	15 YEARS	SEX:	MALE
WEIGHT:	14 KG	BUILD:	THIN

Clinical history
The owner first presented the dog for dyschezia of one week's duration. On examination it was noted that the anus was sore and on rectal palpation the prostate seemed large. The dog also had many rotten teeth, was a little under weight, possibly due to old age and had no other remarkable clinical symptoms. The dog was booked in for radiography and possible castration, the owners' having signed a consent form. The dog was starved overnight with access to water until 2 hours prior to premedication.

Restraint for radiography
This was achieved with general anaesthesia.

Premedication:	2.8 mg morphine sulphate by subcutaneous route. 55 mg carprofen by subcutaneous route.
Induction:	4 mg diazepam intravenously. 30 mg propofol intravenously.
Maintenance:	2L oxygen, 4L nitrous oxide, 1% halothane. Hartmanns 10mls/kg/hr.

Choice of film/screen/grid
Agfa CP B Blue 100 NIF film was used as it is the standard general purpose film used at this clinic. Rare earth screens were used with a large cassette and a stationary parallel grid was used as the tissue depth was more than 10 cms.

Positioning
Two radiographs were taken, one plain and the other a pneumocystogram. Both were positioned in the same way in right lateral recumbency. This right lateral projection was achieved in the following way:

The dog was placed in right lateral recumbency with the abdomen on the cassette and grid.
A foam pad was placed between the hind legs in order to bring them parallel with each other and the table top. They were extended caudally and tied in position.
A foam wedge was placed under the abdomen to avoid axial rotation and the front legs were pulled cranially and tied.
A visual check was made to ensure there was no rotation.

All safety precautions taken during radiography are described in Appendix 1.

Collimation

Plain radiograph
The primary beam was collimated to include the caudal abdomen, ie L3 to caudal border of ischium. Dorsally the beam was collimated to the spinous process of L6 and ventrally to include the prepuce.

Pneumocystogram
This radiograph was collimated more to the caudal abdomen, ie L4 to the ischium. The dorsal/ventral collimation remained the same.

Centering
Plain radiograph The primary beam was centred over the bladder by palpation.

Pneumocystogram
Again the bladder was used as a centring point for the primary beam, by palpation.

Preparation for a negative contrast pneumocystogram
The contrast agent used for this study was room air. Filling of the bladder with air was achieved in the following way:

After the plain radiograph had been taken, an enexposed cassette had been replaced under the grid and the dog had been repositioned, an 8 fg dog urinary catheter was aseptically placed into the bladder and a three way tap attached to the end of the catheter, with a 20 ml syringe then also attached to the three way tap. Then 53 mls of urine was aspirated from the bladder into a kidney dish. Following this 110 mls of room air was syringed into the bladder using the three way tap to ensure that no air escaped. Sometimes air can leak around the catheter and it may be necessary to clamp the prepuce around the catheter to prevent this. In this case it was not necessary, which might be due to the fact that there was some resistance when passing the catheter through the urethra at the point of the prostate, indicating constriction of the urethra by the prostate which acted as a seal to stop air passing back down the urethra. The bladder is palpated whilst injecting the air, to give a guide as to how much will be needed to expand the bladder to a reasonable size. The amount of urine, compared with the size of the bladder on the plain radiograph can also give a guide as to how much air will be needed. Under inflation of the bladder will give the impression of thickened walls. Over inflation will have obvious disastrous con- sequences, as would pushing the catheter through the bladder wall. After taking the radiographs, and checking that they were satisfactory, the air was removed from the bladder by aspiration and the catheter taken out.

Exposures
The following exposures were used:

Plain radiograph	60kV 100mA 0.1 sec
Pneumocystogram	60kV 100mA 0.08 sec
FFD	85 cms

As with any radiograph of the abdomen the exposure should be taken at expiration when the abdomen is at it's largest, allowing organs to spread out.

Radiographic appraisal
Positioning
For both the radiographs the hind legs are not equally extended. This was because the left hip would not extend as far as the right, possibly due to arthritis. On the plain radiograph there is some slight axial rotation - the transverse processes of the vertebrae are not superimposed and neither is the pelvis. The pneumocystogram is virtually straight - the pelvis is nearly superimposed and there will always be some magnification of the side of the pelvis furthest from the cassette and also some distortion due to the pelvis being at the edge of the radiographic field, where the primary beam is at it's most divergent from 90 degrees.

Centering
Centring the primary beam is always linked to collimation, as the cross wires always remain in the centre of the collimation area. Therefore the centring should be done first and the extent of the beam altered afterwards. Both of these radiographs were centred over the bladder. In the plain radiograph this was probably the best place to centre the beam. In the pneumocystogram it probably would have been better to try and centre the beam more over the prostate as this was the centre of interest. This is important, as the centre of the primary beam is where the least distortion of structures takes place, due to the photons travelling at 90 degrees to the cassette at this point. One of the qualities required of a good radiograph is to represent the structures with the minimum distortion and magnification, ie as true to reality as possible.

Collimation
On both radiographs there are 4 unexposed film edges which demonstrates the extent of the primary beam. This is important both for safety of personnel and to reduce the amount of scatter which improves film quality. On the plain radiograph a general view of the caudal abdomen was required as well as the prostatic area and pelvis. Therefore the collimation was reasonably good. All of the pelvis was required in order to check for metastasis from any prostatic tumour. The large bowel also needed to be included in order to rule out any other reason for the dyschezia. The pneumocystogram could have been collimated a little closer as it was decided that the area of interest was now the bladder and prostate, although over collimation can lead to areas of interest being excluded from the field and radiographs needing to be repeated.

Choice of film/screen/grid
The film used for these radiographs is the standard film used at this clinic. A rare earth screen is used when a grid is required, in order to reduce the exposure time and mA. Rare earth screens are more efficient at turning x-ray photons into light, therefore fewer are needed to expose the film correctly. This will reduce the exposure time which reduces movement blur and increases image quality. The rare earth compound used in these screens is Lanthanum Oxybromide which is predominantly a blue light emitting compound. This allows the CP B Blue film to be used either with a rare earth screen or the calcium tungstate screens which are fitted in the other cassettes in use at this clinic, as calcium tungstate also emits blue light. Ideally, for better image quality green light sensitive film and the rare earth compound Gadolinium screen (predominanatly green light emitting) could be used. This is particularly noticable when radiographing joints which need good detail radiographs to reach a diagnosis. A stationary parallel grid was used for these radiographs, as the tissue was more than 10 cms in depth. As the primary beam is attenuated while passing through the tissues scatter is produced (photons which are of longer wave length than the primary beam and no longer follow the path of the primary beam). These photons blur the image and produce a fog which decreases contrast. The thicker the tissue the more scatter is produced. Also at higher kV's the scatter can be harmful to personnel. A grid absorbs photons that are divergent from the primary beam and only allows photons travelling in the same direction as the primary beam to pass through. As the grid is constructed of slats some of the useful beam will be absorbed by the slats, so increased mAs are needed to compensate for this. Back scatter produced when a photon reaches the table also decreases film quality and presents a hazard to personnel. The table used here has a lead mat on the table top to absorb any photons reaching it.

Exposure
Plain radiograph.
There are two reasons for taking a plain radiograph before commencing contrast studies. Firstly an overview of the area is necessary to see if any abnormalities can be seen which might enable a diagnosis to be made without the time, effort and expense of contrast studies. Some contrast studies, such as myelography, also increase the risk of complications for the patient. Having decided that contrast studies are necessary to making a diagnosis, the second reason for taking a plain radiograph first is to ensure that the optimum exposure for the area has been selected. In certain studies there is only one opportunity to take a radiograph after administration of the contrast agent, for example barium to study the oesophagus or intravenous urography. Therefore if a radiograph is not suitably exposed the whole study will have been wasted. In this case the plain radiograph had an overall increased density, indicating slight overexposure. However the main area of interest was the prostate which was lying under the hindleg muscles (which increased the tissue depth and exposure needed). This resulted in that particular area being exposed correctly. The general abdomen lacks really good contrast, ie does not have a large range of densities overall, making it harder to distinguish adjacent tissues. Above a certain point increasing the mAs does not improve contrast but blackens the whole radiograph, which is what appears to have happened here. Therefore the exposure time was reduced for the contrast radiograph which would also reduce movement blur a little.

Pneumocystogram radiograph
The reduction of length of exposure has improved the contrast of this radiograph - the range of densities has increased, enabling individual organs to be seen more clearly. The definition (sharpness) appears to be better on the plain radiograph than on the contrast one, when comparing the spleen for example. This would imply that the contrast radiograph was taken during a respiratory movement which has produced movement blur. Good detail relies on good contrast and definition so neither radiograph has the optimum detail possible. However, the detail was good enough to make a diagnosis in this case. As the physical densities of tissues within the abdomen are similar it is usually better to select a lower kV and higher mAs when examing an abdomen - as long as the kV is sufficient to penetrate the tissues. The rule of thumb is that either increasing or reducing the kV by 10 and either halving or doubling the mAs will result in the same overall exposure.

Preparation of the pneumocystogram
It is important to inflate the bladder with the correct amount of air. In this case it appears to be the correct amount. The bladder is well inflated but not over distended. The urinary catheter can just be seen lying against the cranial bladder wall. There is no distortion of the wall at this point, indicating that there is not undue pressure on the bladder wall, but it would have been better to have the catheter end slightly more caudal to reduce the risk of perforating the bladder. Perhaps more careful measuring by palpating the bladder and laying the catheter (within it's packet) along the line of the urethra outside the body could have avoided this. Occasionally air can travel up the ureters into the renal pelvis of the kidneys. There are no ureters visible on this radiograph. Overall the technique used for producing a suitable pneumocystogram seems to have been satisfactory.

Processing
This was achieved by automatic processor. The film appears to have been processed correctly, which is the advantage of using a processor when repeating exposures of radio- graphs, as the processor should always process consistently (unless broken). One of the disadvantages is damage to the film caused by the rollers. This is a problem with these radiographs and new rollers are currently on order.

Artefacts
Unfortunately there are several on these radiographs.

Firstly, grid lines can be seen on both radiographs. This is unavoidable when using a stationary grid.
There are roller scratches running the length of the films, caused by the processor. This is permanent damage and cleaning the rollers has no effect.
There are suspicious marks not within the emulsion, which appear dorsocranial to the bladder, a small circular area above the ischium and several around the prostate area. They appear to have been present at the time of exposure, possibly due to a dirty screen or grid - they appear in the same place on the film on both radiographs, but not in the same place anatomically. The screens and grid should be more frequently cleaned to avoid this, as a misdiagnosis can be made due to artefacts.

Labelling
This should have been done at the time of exposure using X-rite tape (or similar). It is not provided at this clinic, and a rule is adopted that radiographs are labelled as soon as they emerge from the printer. This is not entirely satisfactory, as it is still possible to forget to label a radiograph at the time.

Diagnosis
The radiographs showed an enlarged prostate which was constricting the rectum, which can be clearly seen. There was no metastasis to the pelvic bones. The dog was susequently castrated in order to help reduce the size of the prostate.

General comments on radiography
On plain radiographs it can sometimes be difficult to see an enlarged prostate or it can be confused with the bladder. A negative contrast pneumocystogram can aid in identifying a large prostate. It is difficult to tell the cause of enlargement from a radiograph. Ultrason- ography is very useful in assessing the prostate. It can also be performed on conscious animals, whereas a pneumocystogram needs to be performed under general anaesthesia. Boney changes in the pelvis could not be assessed by ultrasound, however, so there is a place for both radiography and ultrasonography in assessment of the prostate.

References:
Diagnostic Radiology, Kealy, Saunders 2nd Ed
Manual of Sm An Diagnostic Imaging, BSAVA 1995
Radiography Diploma Notes 1999

Case 3. Abdomen and pneumocystogram

Arlo Guthrie — Wed, 22 Apr 2009 10:01:17 GMT

Revision 1 posted to Diploma by Arlo Guthrie on 22/04/2009 11:01:17

X RAY REF:	41	DATE:	13/10/99
SPECIES:	DOG	BREED:	XB
OWNER:	HUTCHINSON	ANIMAL:	DINO
AGE:	15 YEARS	SEX:	MALE
WEIGHT:	14 KG	BUILD:	THIN

Restraint for radiography
This was achieved with general anaesthesia.

Premedication:	2.8 mg morphine sulphate by subcutaneous route. 55 mg carprofen by subcutaneous route.
Induction:	4 mg diazepam intravenously. 30 mg propofol intravenously.
Maintenance:	2L oxygen, 4L nitrous oxide, 1% halothane. Hartmanns 10mls/kg/hr.

The dog was placed in right lateral recumbency with the abdomen on the cassette and grid.
A foam pad was placed between the hind legs in order to bring them parallel with each other and the table top. They were extended caudally and tied in position.
A foam wedge was placed under the abdomen to avoid axial rotation and the front legs were pulled cranially and tied.
A visual check was made to ensure there was no rotation.

All safety precautions taken during radiography are described in Appendix 1.

Collimation

Pneumocystogram
This radiograph was collimated more to the caudal abdomen, ie L4 to the ischium. The dorsal/ventral collimation remained the same.

Centering
Plain radiograph The primary beam was centred over the bladder by palpation.

Pneumocystogram
Again the bladder was used as a centring point for the primary beam, by palpation.

Preparation for a negative contrast pneumocystogram
The contrast agent used for this study was room air. Filling of the bladder with air was achieved in the following way:

Exposures
The following exposures were used:

Plain radiograph	60kV 100mA 0.1 sec
Pneumocystogram	60kV 100mA 0.08 sec
FFD	85 cms

As with any radiograph of the abdomen the exposure should be taken at expiration when the abdomen is at it's largest, allowing organs to spread out.

Artefacts
Unfortunately there are several on these radiographs.

Firstly, grid lines can be seen on both radiographs. This is unavoidable when using a stationary grid.
There are roller scratches running the length of the films, caused by the processor. This is permanent damage and cleaning the rollers has no effect.
There are suspicious marks not within the emulsion, which appear dorsocranial to the bladder, a small circular area above the ischium and several around the prostate area. They appear to have been present at the time of exposure, possibly due to a dirty screen or grid - they appear in the same place on the film on both radiographs, but not in the same place anatomically. The screens and grid should be more frequently cleaned to avoid this, as a misdiagnosis can be made due to artefacts.

References:
Diagnostic Radiology, Kealy, Saunders 2nd Ed
Manual of Sm An Diagnostic Imaging, BSAVA 1995
Radiography Diploma Notes 1999

Case 2. Pelvis

Arlo Guthrie — Wed, 22 Apr 2009 09:58:36 GMT

Current revision posted to Diploma by Arlo Guthrie on 22/04/2009 10:58:36

Case 2. Pelvis

X RAY REF:	173W	DATE:	12/3/99
SPECIES:	DOG	BREED:	GSD
OWNER:	MERRYMAN	ANIMAL:	BONYA
AGE:	10 YEARS	SEX:	FEMALE
WEIGHT:	30.3 KG	BUILD:	AVERAGE

Clinical history.
The dog was first seen for chronic lameness of the right hind which had become progressively worse over the last two weeks. Manipulation of the limbs revealed right hip pain. The dog was booked in for radiography of the pelvis.

Restraint for radiography.
This was achieved by general anaesthesia.

Premedication:	0.6 mg acepromazine (ACP, C VET).
Induction:	250 mg thiopentone sodium (Intraval Sodium, Rhone Merieux) 2.5% i/v.
Maintenance:	8L oxygen, 1% halothane (Halothane, Rhone Merieux).

Choice of film/screen/grid.
Agfa CP-G Plus (30 cm x 40 cm) with a Curix rare earth screen. This is a standard green sensitive general purpose film.

A stationary parallel grid was used as the tissue depth was greater than 10 cms.

Positioning.
Ventro-dorsal pelvis.
Positioning for this projection was achieved by placing the dog in dorsal recumbency with the thorax supported in a cradle. Both stifles were inwardly rotated and secured with sellotape, and the patellae were palpated to ensure central location between the femoral condyles. Tapes were attached to both feet and the hind legs extended and tied to the table to ensure both femora were parallel to the table top. The dog was checked to ensure it was placed in a bilaterally symmetrical position. See picture right, showing positioning for the dorso-ventral projection of the pelvis. A metal right marker was placed on the grid.

Safety procedures undertaken during radiography are described in Appendix 1.

Centering and collimation.
The primary beam was centered on the cranial border of the pubic symphysis, and collimated to include the patellae and all the pelvis.

The following exposures were used:

kV 70

mAs 30

FFD 100 cms

Radiographic appraisal.

Positioning
The pelvis is slightly rotated to the left - the left wing of the ilium appears larger than the right and the sacro-iliac joint space is larger on the right. Usually the obturator foramen is smaller to the side of rotation but it is difficult to see on this radiograph. The spine is not quite straight and curves to the right. This dog proved difficult to position as the right hip would not extend fully, despite general anaesthesia - see Figure 1. This might account for the rotation. The patellae are both centrally located on the femora.

Centering
The primary beam was centered on the pubic symphysis approximately 3 cms caudal to the cranial border of the symphysis, whereas it should have been on the cranial border. This is a relatively small discrepancy but palpation of the femoral heads may have improved the accuracy of centering, as the femoral heads lie in line with the cranial border of the pubic symphysis.

Collimation
All four edges of the radiograph are unexposed, demonstrating the extent of the primary beam. Collimation could have been closer laterally. This could be improved by palpating the bones instead of relying on soft tissue for collimation of the area. It would be difficult to collimate any closer cranially and still retain centering and caudal collimation in the correct position.

Exposure
The exposure of this radiograph is satisfactory. The contrast is good, having a large range of well differentiated densities within the bones and the soft tissues can also be seen. Detail is also of a reasonably high quality on this radiograph. Fine detail relies both on good contrast and good definition. Several factors are involved in obtaining sharp definition. Restraint by general anaesthesia improves definition, as movement is reduced. Using a grid when tissue depth is over 10 cms (15 cms for the thorax), when higher kVs are required to penetrate tissue, will also help improve definition. This is due to the grid slats absorbing secondary radiation and only allowing X-ray photons which are travelling in the same direction as the primary beam to pass through the grid, resulting in a sharper image. Use of a lead mat or lead lined table to absorb X-ray photons will reduce back scatter and improve definition. Correct centering and close collimation will also have an effect on the sharpness of the image by reducing scatter and ensuring the area of interest has the smallest distortion possible - the centre of the primary beam has the least divergence of X-ray photons.

Artefacts
There are several on this film:

A grid artefact appears as a mottled area above the right ilium.
There are parallel scratch lines running the length of the film, caused by the rollers in the automatic processor. This could be resolved by either more frequent cleaning of the rollers or replacing them if they are damaged.
The grid lines are visible on the radiograph - this is usual when using a stationary grid.
There are several finger prints on the radiograph, caused after processing.

Processing
This radiograph was processed automatically, and is correctly developed - the background would be grey if under developed, unless grossly under exposed. If the radiograph had been over developed the metal marker would be grey instead of white. Note - there are grey areas on the marker but this is due to the marker not lying flat on the grid and, as a result, being partly exposed.

General comments
This is a diagnostic radiograph for the purpose it was intended. A diagnosis was made of osteoarthritis of the right hip, possibly secondary to hip dysplasia although it was noted that the left hip did not show any gross abnormalities which is unusual in cases of hip dysplasia, as the condition is usually bilateral. German Shepherds are the breed most susceptible to hip dysplasia.

The treatments available for this condition would be conservative or surgical - by performing an excision arthroplasty, total hip replacement or pelvic osteotomy. In this case the treatment chosen by the veterinary surgeon was conservative with phenylbutazone 200 mg tablets, one to be given twice daily with food. This decision was based on the weight being considered too heavy for successful excision arthroplasty, the cost of a hip prostheses being beyond the client's budget and the joint having too many degenerative changes for a pelvic osteotomy to be performed.

The purpose of this radiograph was to obtain a medical diagnosis, but this would be the required projection, positioning and collimation (including the patellae) necessary for a pelvic radiograph which was to be submitted for hip dysplasia certification. However, it would be necessary to record the date, left/right marker and dog's kennel club number using X-RITE tape, or similar, to appear permanently on the radiograph at the time of processing. Very accurate positioning is also necessary for hip scoring.

General assessment of radiography
Radiography was useful in this case for the following reasons:

It is a non invasive procedure, and diagnostic radiographs could probably have been achieved with sedation, although better positioning and definition can be obtained under general anaesthesia.
A radiograph enables sight of bone changes, which are not always apparent to the naked eye.

References:
Principles of Veterinary Radiography, Douglas, Herrtage & Williamson, Bailliere Tindall, 4th Ed. 1987 Ch 4, 7, 9.
Manual of Small Animal Diagnostic Imaging, BSAVA 2nd Ed 1995 Pg 124, 125, 183

Case 2. Pelvis

Arlo Guthrie — Wed, 22 Apr 2009 09:56:09 GMT

Revision 1 posted to Diploma by Arlo Guthrie on 22/04/2009 10:56:09

X RAY REF:	173W	DATE:	12/3/99
SPECIES:	DOG	BREED:	GSD
OWNER:	MERRYMAN	ANIMAL:	BONYA
AGE:	10 YEARS	SEX:	FEMALE
WEIGHT:	30.3 KG	BUILD:	AVERAGE

Restraint for radiography.
This was achieved by general anaesthesia.

Premedication:	0.6 mg acepromazine (ACP, C VET).
Induction:	250 mg thiopentone sodium (Intraval Sodium, Rhone Merieux) 2.5% i/v.
Maintenance:	8L oxygen, 1% halothane (Halothane, Rhone Merieux).

Choice of film/screen/grid.
Agfa CP-G Plus (30 cm x 40 cm) with a Curix rare earth screen. This is a standard green sensitive general purpose film.

A stationary parallel grid was used as the tissue depth was greater than 10 cms.

Safety procedures undertaken during radiography are described in Appendix 1.

Centering and collimation.
The primary beam was centered on the cranial border of the pubic symphysis, and collimated to include the patellae and all the pelvis.

The following exposures were used:

kV	70
mAs	30
FFD	100 cms

Radiographic appraisal.

Artefacts
There are several on this film:

A grid artefact appears as a mottled area above the right ilium.
There are parallel scratch lines running the length of the film, caused by the rollers in the automatic processor. This could be resolved by either more frequent cleaning of the rollers or replacing them if they are damaged.
The grid lines are visible on the radiograph - this is usual when using a stationary grid.
There are several finger prints on the radiograph, caused after processing.

General assessment of radiography
Radiography was useful in this case for the following reasons:

It is a non invasive procedure, and diagnostic radiographs could probably have been achieved with sedation, although better positioning and definition can be obtained under general anaesthesia.
A radiograph enables sight of bone changes, which are not always apparent to the naked eye.

Case 1. Dorsoventral intraoral nasal cavities

Arlo Guthrie — Wed, 22 Apr 2009 09:54:11 GMT

Current revision posted to Diploma by Arlo Guthrie on 22/04/2009 10:54:11

Case 1. Dorsoventral intraoral nasal cavities

X RAY REF:	162W	DATE:	10/3/99
OWNER:	PAGE	SPECIES:	CAT
BREED:	DSH	ANIMAL:	TC
AGE:	11 YEARS	SEX:	MALE NEUTER
WEIGHT:	6.0 KG	BUILD:	SL OBESE

Clinical history.
The cat was presented with a purulent left nasal discharge and sneezing. No other clinical symptoms were present. Two 10 day courses of oxytetracycline 50 mg (Oxycare, Animal Care) one twice daily were prescribed, but after completion of each course the discharge returned. A further course of ampicillin 25 mg/ml (Ampicillin, Kent) 2mls twice daily also failed to resolve the discharge and 5 weeks after treatment commenced the cat was booked for radiography of the nasal chambers.

Restraint for radiography.
This was achieved by general anaesthesia.

Premedication:	0.3 mg acepromazine (ACP, C Vet) by subcutaneous route.
Induction:	75 mg thiopentone sodium (Intraval Sodium, Rhone Merieux) 2.5% by intravenous route.
Maintenance:	4L oxygen, 1% halothane (Halothane, Rhone Merieux).

Choice of film/screen.
Agfa Dentus M2 5cm x 7cm non-screen dental film was selected, firstly for it's high definition which is necessary for examining any changes in the nasal turbinate bones. Secondly, this is a non-screen film which is supplied in a light proof plastic envelope, enabling it to be inserted into a cat's oral cavity.

No grid was necessary for this radiography as the tissue depth was not greater than 10cms.

Area radiographed and positioning.
Intra-oral dorso-ventral nasal chambers.

This projection was achieved by placing the cat in sternal recumbency. The head and neck were extended and the head placed on a foam pad, in order to bring the hard palate parallel to the table and perpendicular to the vertical primary beam, therefore minimising any distortion of structures on the radiograph. The forelegs were pulled caudally and positioning of the head along it's longtitudinal axis was checked in order to achieve a true dorso-ventral projection.

The envelope containing the film was carefully placed, one corner first, into the oral cavity dorsal to the endotracheal tube and pushed as far caudally as possible. This film, despite not being in a cassette, has a back and front and must have the front of the envelope presented to the primary beam.

A right marker, X-ray ref. no., animal/owner details and date were placed on the film using X-RITE tape.

All personnel safety precautions taken during radiography are described in Appendix 1.

Centering and collimation.
The primary beam was collimated to the edge of the film envelope and centred midway along the maxilla above the palatine fissure.

The following exposure was used:

kV	65
mAs	40
FFD	100 cms

Radiographic appraisal.

Positioning
This is not a true dorso-ventral projection, as the skull is slightly rotated to the right - the right nasal chamber appears slightly smaller than the left. This cat proved very difficult to position visually as the cat's head was not symmetrical, due to two previous road traffic accidents both involving injuries to the head. The first resulting in loss of teeth and left eye enucleation, the second resulting in loss of further teeth, fracture of the mandibular symphysis and luxation of the mandibular joints.

Care has to be taken when placing the film into the oral cavity as it is sensitive to pressure and teeth marks will result in unexposed lines across the radiograph.

Centering
The primary beam was actually centered rostrally over the left nasal chamber. Correct centering for this projection should have been on the midline of the dorsum nasi at the level of the third premolar. However, to include the markers and collimate only to the edge of the film it was necessary to centre to this position.

Collimation
When using film in cassettes collimation should always result in four film edges unexposed in order to demonstrate the extent of the primary beam. It is important to collimate as closely as possible to the area of interest, both for safety of personnel and maximum definition. Non-screen dental film radiography is an exception to this rule, as the size of the film and oral cavity necessitate collimating to the edge of the film in order to include as much of the nasal chambers as possible. However, the primary beam should never extend beyond the film edge and either a lead mat or, as in this case, a lead lined table should be used to absorb as many X-ray photons as possible. In this case the primary beam was collimated exactly to the film edge.

Exposure
As no intensifying screen is used with this film, exposure is entirely dependant on X-ray photons rather than by X-ray photons plus visible light emitted during fluorescence of the phosphor crystals in an intensifying screen (when exposed to X-ray photons). Therefore this film required greatly increased exposure factors. The overall exposure of this radiograph is good. Contrast is good, with a large range of well defined densities present within the bones. Soft tissues can also be seen. Detail is also good, due to the characteristics of this fine grained film, lack of movement blur and good contrast. This film has a wide latitude, and therefore a wide range of exposures would result in an image on the film, although to obtain the best definition the optimium exposure must be selected.

Processing
Non-screen dental film has a thicker emulsion layer than standard films and therefore needs longer developing and fixing times. For this reason it is not suitable to be put through an automatic processor. This film was developed manually in dishes with chemicals from the automatic processor, and was developed for 5 minutes at approximately 20 C, rinsed in water, fixed for 40 minutes and washed for 30 minutes. This film appears to be processed correctly. Under development would have resulted in grey background density, unless grossly under exposed. Gross over development would have an overall blackening effect on the film.

General Comments
Accurate positioning is extremely important when taking radiographs of the nasal chambers, as the slightest rotation can cause distortion of the structures which make it very difficult to see subtle changes within these structures. General anaesthesia or deep sedation is necessary for intra-oral radiography, both to enable good positioning and insertion of the film into the oral cavity.

Despite slight rotation this was a diagnostic radiograph showing patchy increased soft tissue densities in the mid left nasal chambers with loss of turbinate definition, consistent with chronic rhinitis. The cat was given a 3 week course of cephalexin syrup 25 mg/ml (Ceporex, Glaxol) to be given 2 mls twice daily orally. Ideally a swab could have been taken for bacterial culture. Two months later the discharge returned and the cat was re x-rayed. See radiograph 2. Note the same problems were encountered in positioning straight. There was little change seen and the cat was put back on Ceporex and prednisolone 5mg one every other day. The discharge and sneezing resolved and the cat has been free of symptoms for 7 months.

Dental film was used for this radiograph as non screen film is now unobtainable and there was no other alternative available within the practice at the time. However, thin flexible cassettes with ultra vision screens are now available (Sterling Diagnostic Imaging) which are suitable for this type of radiography and are now in use at this practice. The advantages are: smaller exposures are used (due to intensifying screens) and the film can be put through an automatic processor.

General Assessment of Radiography
Radiography was useful in this case for the following reasons:

It is a non-invasive procedure.
It enables sight of boney changes necessary for diagnosing nasal tumours which occur fairly commonly in cats.
This is not a radiographic procedure which could have been undertaken without heavy sedation or general anaesthesia.

References:
Atlas of Radiographic Anatomy of the Dog and Cat, Schebitz & Wilkens, 5th Ed, Paul Parey. 1985 p. 161 - 163
Principles of Veterinary Radiography, Douglas, Herrtage, Williamson, 4th Ed, Bailliere Tindall. 1987. Ch 3, 4

Case 1. Dorsoventral intraoral nasal cavities

Arlo Guthrie — Wed, 22 Apr 2009 09:51:17 GMT

Revision 1 posted to Diploma by Arlo Guthrie on 22/04/2009 10:51:17

X RAY REF:	162W	DATE:	10/3/99
OWNER:	PAGE	SPECIES:	CAT
BREED:	DSH	ANIMAL:	TC
AGE:	11 YEARS	SEX:	MALE NEUTER
WEIGHT:	6.0 KG	BUILD:	SL OBESE

Restraint for radiography.
This was achieved by general anaesthesia.

Premedication:	0.3 mg acepromazine (ACP, C Vet) by subcutaneous route.
Induction:	75 mg thiopentone sodium (Intraval Sodium, Rhone Merieux) 2.5% by intravenous route.
Maintenance:	4L oxygen, 1% halothane (Halothane, Rhone Merieux).

No grid was necessary for this radiography as the tissue depth was not greater than 10cms.

Area radiographed and positioning.
Intra-oral dorso-ventral nasal chambers.

A right marker, X-ray ref. no., animal/owner details and date were placed on the film using X-RITE tape.

All personnel safety precautions taken during radiography are described in Appendix 1.

Centering and collimation.
The primary beam was collimated to the edge of the film envelope and centred midway along the maxilla above the palatine fissure.

The following exposure was used:

kV	65
mAs	40
FFD	100 cms

Radiographic appraisal.

Care has to be taken when placing the film into the oral cavity as it is sensitive to pressure and teeth marks will result in unexposed lines across the radiograph.

General Assessment of Radiography
Radiography was useful in this case for the following reasons:

It is a non-invasive procedure.
It enables sight of boney changes necessary for diagnosing nasal tumours which occur fairly commonly in cats.
This is not a radiographic procedure which could have been undertaken without heavy sedation or general anaesthesia.

Radiographic Case Reports & Diary

Arlo Guthrie — Wed, 22 Apr 2009 09:48:53 GMT

Current revision posted to Diploma by Arlo Guthrie on 22/04/2009 10:48:53

Introduction
Radiography equipment available for use in this casebook

Clinic 1.

X-RAY MACHINE	Mullard Fixed Guardian 125. max kV 120, mA 200.
INTENSIFYING SCREENS	Small, medium and large Rare Earth.
GRID	Stationary Parallel. Unknown grid factor.
FILM	Ortho Agfa CP-G PLUS 100 NIF Green light sensitive. Agfa Dentus non screen film.
AUTOMATIC PROCESSOR	Gevamatic 60

Clinic 2.

X-RAY MACHINE	Mobile MX 4. Max kV 125, max mA 100.
INTENSIFYING SCREENS	Small, medium and large calcium tungstate. Large rare earth.
GRID	Stationary parallel. Grid factor unknown.
FILM	Agfa CP B Blue 100 NIF. Agfa Dentus non screen film.
AUTOMATIC PROCESSOR	Fuji RG11.

Case 2. Fall from 7th Floor Balcony

Arlo Guthrie — Wed, 22 Apr 2009 08:42:58 GMT

Current revision posted to Diploma by Arlo Guthrie on 22/04/2009 09:42:58

Case 2. Fall from 7th Floor Balcony

OWNER:	BROOKS	ADMISSION DATE:	10/10/99
SPECIES:	CAT	BREED:	DSH
SEX:	FEMALE	AGE:	2 YEAR
WEIGHT:	2.7 KG ON ADMITTANCE	ANIMAL NAME:	SABRINA

HISTORY
The cat was first seen as an emergency, having fallen off a 7th floor balcony sometime during the night. On admittance she had a temperature of 34.8°C, very pale mucous membranes, could not walk and was dyspnoeic. She was immediately treated for shock, hypothermia, pain, and dyspnoea. The following day she was given a short general anaesthetic and radiographed. The thoracic radiograph showed pneumothorax with pulmonary haemorrhage and haemothorax, no diaphragmatic line being visible. She had also suffered a fractured L ischium which was badly displaced. It was considered that this needed repair but the thoracic injuries were too severe for the cat to have a lengthy anaesthetic - she was very dyspnoeic under anaesthetic. She had also suffered fractures of all metatarsals on both hind legs, the left being badly displaced. The bladder was intact but the cat was not urinating and so the bladder was expressed manually until 5 days later when bladder function returned and she was able to urinate voluntarily. The thorax was radiographed 3 days later and showed an intact diaphragm and improvement in the lungs. See radiographs at end of case. By day 5 she was very bright, eating well, temperature normal and although still on 0.03mg buprenorphine (Temgesic, Rickett & Coleman) s/c twice daily and 10 mg carprofen orally once daily she was not considered a critical patient. On day 10 she didnt want to eat, had not passed faeces for 3 days, was a little depressed but had normal temperature and no vomitting. She was given i/v fluids and a packed red cell volume showed 20% (L/L), and was started on a course of 30mg ampicillin (Amfipen) s/c daily. Over the next 2 days she ate a tiny amount, had no vomitting, temperature normal, PCV remained at 20% (L/L). Palpation of the abdomen did not reveal any abnormalities. The following day she was very depressed and collapsed, despite daily fluid infusions, with very pale mucous membranes. Her weight at this time was 2.5kg, so she had lost 0.2kg since being admitted, and her temperature that morning was 36.2°C.

This is the point at which this intensive care case starts, as the author was not involved with the cat before this time.

AIMS OF INTENSIVE CARE IN THIS CASE

To identify reason for collapse 2.
Treat the above.
Support body systems to preserve life until animal able to make a recovery and maintain own body systems without external support.

CRITICAL PARAMETERS

TEMPERATURE, FLUIDS, NUTRITION, ANTIBIOTICS

Diagnosis
A conscious radiography in right lateral recumbency was taken of the abdomen. This showed a smudgy appearance to the intestines. This indicated possible ascites and abdocentesis was performed. This involved placing a 23g intravenous catheter aseptically into the abdomen just to the left of the umbilicus. Slightly viscous yellowish fluid was allowed to drip out and a smear was taken of the fluid and stained for microscopic analysis. Before placing the catheter it is important to make 2 fenestrations near the tip with a sterile scalpel blade. This decreases the chance of the catheter becoming blocked by omentum etc. It is also important not to aspirate with a syringe but just allow fluid to drip out, as aspiration encourages tissue to block the passage of fluid through the hole. (Professor Mike Willard, Head of Small Animal Medicine, Texas University). This technique allows small amounts of fluid present in the abdomen to be sampled. The stained sample showed both diplococci and streptococci to be present in large quantities. Therefore peritonitis was diagnosed and a decision made that an exploratory laparotomy had to be performed, in spite of the cat's very poor state of health at this time. The owners were contacted and advised that the prognosis for this cat was extremely poor.

Treatment
The cat had already been put on an infusion of 200mls colloids (Haemaccel, Hoechst Roussel) earlier in the morning, as the PCV had dropped to 18% (L/L) and blood urea was 6 mmol/l. Premedication was given with 0.5mg morphine, after which the cat vomited. Induction was achieved with 1mg diazemuls i/v followed by 10mg propofol i/v. No nitrous oxide was used, due to the anaemia and previous thoracic injuries. Depth of maintenance of anaesthesia was kept as light as possible to preserve blood pressure, which recorded at 79/81 systolic. During anaesthesia the ECG showed multiple single premature ventricular contractions and some other unidentified arrythmias with sinustachycardia at 250bpm. 300mls of purulent fluid was suctioned from the abdomen. A tear in the stomach near the pyloris was sutured, a tear in the liver which was healing, and previous haemorrhage from the right ovary were both noted. The abdomen was flushed with 3L of warm 0.9% saline before closure. Every effort was made to preserve temperature during the surgery.

For a full record of the intensive care that followed see attached inpatient sheets.

Post-operative care
As soon as the anaesthetic was turned off the cat, which was still on oxygen therapy, was dried with a towel. Then a hair drier was used to dry all the fur to stop any further heat loss by evaporation. The cat remained on the heated operating table while this was done. Then it was wrapped in bubble wrap and vet beds and put in an oxygen cage with 2 L oxygen run through a humidifier containing warm water. The oxygen cage was left on the heated operating table and the cat checked every 10 minutes for 2 hours.

INTENSIVE CARE TECHNIQUES USED
Oxygen therapy
This was very important for several reasons. Firstly the cat was anaemic and therefore had a lower oxygen carrying capacity. Secondly the cat was extremely ill and the sepsis requires higher metabolic requirements for the healing process to take place. Also the respiratory system is depressed under general anaesthesia and oxygen therapy is helpful until the animal is fully round. The oxygen was humidified to stop the upper respiratory tract drying. It was also run through warm water in order to heat it a little - oxygen coming from a remote bunker is very cold.

Temperature
This was one of the most critical parameters in this intensive care case. The cat, although adult, weighed only 2.5kg. So there was no fat at all to help insulate this animal, and these very thin cats are very difficult to maintain good temperature. Hourly checks were made on temperature for the first two days and a lot of effort put in to keep Sabrina's temperature up in the normal range. This involved covered hot water bottles, heated drips, bubblewrap, plenty of bedding, running the drip lines through bowls of warmed water and ensuring she kept free from urine contamination. Hypothermia in extremely ill animals post-operatively can make the difference between recovery and death. She also had a large area of the abdomen clipped and was still draining some saline from her wound, so bedding had to changed regularly. See picture above right, taken 6 hours post operatively and the cat is critically ill.

Temperature management was very successful during this case. One hour after the end of anaesthesia the temperature was 37.8°C which was 1°C higher than the pre-operative temperature.

Fluids
Supporting the cardiovascular system is very important in every intensive care patient. In this case it was a good choice to use a colloid as initial pre-operative fluids. In Sabrina's case she was both anaemic due to previous blood loss, and probably hypoprotanaemic due to her peritonitis. Hartmanns was the crystalloid of choice to use after colloids. As she wasn't eating or drinking and was losing fluid into the abdomen she needed daily fluid therapy. In an anaemic patient it is difficult to assess the fluid balance by measuring the PCV, and daily weighing, which is another method of fluid assessment, is also of no use when an animal is producing ascites as the weight will remain the same whilst the animal is becoming dehydrated.

Nutrition
Nutrition was very important in this case and probably could be considered to be one of the critical factors in the intensive care. The practice does not have any means of measuring potassium levels but it was suspected that the cat was hypokalaemic. Hypokalaemia can occur from anorexia, alkalosis, hypovolaemia, prolonged excessive fluid therapy and gastric losses all of which had occurred with Sabrina, bearing in mind her history over the previous 10 days. Hypokalaemia can cause the cardiac arrythmias she suffered from and it also causes muscle weakness. She became so weak post-operatively that she could not lift her head or chew food despite wanting to eat. If left untreated the animal will not usually make a recovery. The practice does not have an intravenous form of potassium, and it would be unwise to administer potassium in this form without any way of measuring the serum levels. Potassium can be absorbed by the body from food within 12 to 24 hours, so the following morning intensive hand feeding began with Hill's a/d which she was able to lick whilst in lateral recumbency. She was fed every hour during the day and evening in an effort to provide some potassium intake and also because, in order to recover from sepsis the energy requirements of the animal are approximately 1.5 times the normal intake requirements. Hill's a/d was chosen as it is specially formulated for critical patients, providing more than twice the nutritional value of normal catfood. It is also supplied as a paste which suitable for syringe and hand feeding. Intensive hand feeding continued until the cat was able to feed itself. See picture left, taken on day 4 when the cat had started to eat by itself.

Animals should be weighed daily to assess whether the feeding regime employed is adequate. Obviously, if the cat is losing weight then the food intake is insufficient. In this case Sabrina lost 0.3kg post-operatively because 300mls of ascites weighs approximately 0.3kg, which makes weighing inaccurate in animals that are losing fluid into a body cavity. After this she kept her weight and by Day 5 she had put on 0.1kg. This meant that nutrition was managed successfully.

Pulse and respiration
Pulse and respiration were monitored regularly. The heart rate on Day 2 seemed quite slow but an ECG confirmed that the arrythmias had ceased and a normal ECG trace was recorded. Respiration remained quite constant throughout.

Bedding and hygeine
This was important for comfort, warmth and keeping the cat dry. Being a female it was decided not to catheterise her, so bedding had to be changed regularly for the first 4 days to avoid urine contamination of the wound and also for temperature maintenance.

Positioning
As the cat was too weak to move for 3 days it was important to turn her every 2 hours to prevent hypostatic pneumonia from developing. At night an effort was made to try and prop her up on her sternum.

Antibiotics
Administration of these were obviously a vital part of Sabrina's intensive care. During and after surgery the cat was given 50mg metronidazole (Torgyl solution, Merial) intravenously in Hartmanns infusion. This was followed up with ampicillin50 mg (Amfipen, Intervet) tablets twice daily and spiramycin 46.9mg/metronidazole 25mg (Stomorgyl 2, Merial) tablets twice daily. These tablets proved very difficult to give and eventually had to be crushed and mixed with a small amount of a/d each time. Constant injections over the previous 10 days had left the cat's neck very bruised and giving injections became difficult.

Analgesia
This was an important part of intensive care as the pelvis was very painful, together with abdominal surgery. Good pain management is necessary for humanitarian reasons, to encourage eating and decrease depression. An animal in pain will have less chance of recovery. The analgesia consisted of 0.5mg morphine (Evans) s/c and 10mg carprofen (Rimadyl, Pfizer) s/c. After 3 days 0.02mg buprenorphine (Temgesic, Rickett & Coleman) was substituted for morphine.

Morale
Stroking, grooming and talking to the animal is a very important part of intensive care. This cat had already been through 10 days of treatment and cage confinement before the peritonitis occurred. Cats can become depressed and give up the will to live so care and attention is greatly needed. See picture right.

Progress
This cat was extremely ill and nobody expected it to survive the first night post-operatively. For the first day it was unable to lift it's head and could not stand until the fourth day when it managed to walk to it's food bowl and litter tray. See picture right. On the fifth day it was very bright and happy and no longer needed intensive care.

The following day it went home and seems to have made a full recovery from the peritonitis. It is walking reasonably well on the fractured pelvis and metatarsals and is passing faeces successfully.

GENERAL COMMENTS ON INTENSIVE CARE
Good intensive care requires a 100% committment on the part of the nurse, and good observation skills are necessary to spot subtle changes in the animal's condition. This case also illustrates that the unexpected can always happen and small changes in condition should always arouse suspicion. It is amazing that this cat could have eaten for 8 days, without vomiting, and was actually recovering from her thoracic injuries whilst she had a hole in her stomach. Fortunately she survived and the intensive care in this case could be considered successful, as the initial aims were achieved.

References
Trauma Management in the Dog and Cat, Houlton, Taylor 1989
Critical Care Nursing, Steve Haskins BSAVA Congress 1999
The Acute Abdomen, M Willard BSAVA Congress 1999

Case 2. Fall from 7th Floor Balcony

Arlo Guthrie — Tue, 21 Apr 2009 16:58:33 GMT

Revision 4 posted to Diploma by Arlo Guthrie on 21/04/2009 17:58:33

Case 2. Fall from 7th Floor Balcony

OWNER:	BROOKS	ADMISSION DATE:	10/10/99
SPECIES:	CAT	BREED:	DSH
SEX:	FEMALE	AGE:	2 YEAR
WEIGHT:	2.7 KG ON ADMITTANCE	ANIMAL NAME:	SABRINA

This is the point at which this intensive care case starts, as the author was not involved with the cat before this time.

AIMS OF INTENSIVE CARE IN THIS CASE

To identify reason for collapse 2.
Treat the above.
Support body systems to preserve life until animal able to make a recovery and maintain own body systems without external support.

CRITICAL PARAMETERS

TEMPERATURE, FLUIDS, NUTRITION, ANTIBIOTICS

For a full record of the intensive care that followed see attached inpatient sheets.

Temperature management was very successful during this case. One hour after the end of anaesthesia the temperature was 37.8°C which was 1°C higher than the pre-operative temperature.

The following day it went home and seems to have made a full recovery from the peritonitis. It is walking reasonably well on the fractured pelvis and metatarsals and is passing faeces successfully.

References
Trauma Management in the Dog and Cat, Houlton, Taylor 1989
Critical Care Nursing, Steve Haskins BSAVA Congress 1999
The Acute Abdomen, M Willard BSAVA Congress 1999

Case 2. Fall from 7th Floor Balcony

Arlo Guthrie — Tue, 21 Apr 2009 16:56:54 GMT

Revision 3 posted to Diploma by Arlo Guthrie on 21/04/2009 17:56:54

Case 2. Fall from 7th Floor Balcony

OWNER:	BROOKS	ADMISSION DATE:	10/10/99
SPECIES:	CAT	BREED:	DSH
SEX:	FEMALE	AGE:	2 YEAR
WEIGHT:	2.7 KG ON ADMITTANCE	ANIMAL NAME:	SABRINA

This is the point at which this intensive care case starts, as the author was not involved with the cat before this time.

AIMS OF INTENSIVE CARE IN THIS CASE

To identify reason for collapse 2.
Treat the above.
Support body systems to preserve life until animal able to make a recovery and maintain own body systems without external support.

CRITICAL PARAMETERS

TEMPERATURE, FLUIDS, NUTRITION, ANTIBIOTICS

For a full record of the intensive care that followed see attached inpatient sheets.

Temperature management was very successful during this case. One hour after the end of anaesthesia the temperature was 37.8°C which was 1°C higher than the pre-operative temperature.

Progress

This cat was extremely ill and nobody expected it to survive the first night post-operatively. For the first day it was unable to lift it's head and could not stand until the fourth day when it managed to walk to it's food bowl and litter tray. See picture right. On the fifth day it was very bright and happy and no longer needed intensive care.

The following day it went home and seems to have made a full recovery from the peritonitis. It is walking reasonably well on the fractured pelvis and metatarsals and is passing faeces successfully.

References
Trauma Management in the Dog and Cat, Houlton, Taylor 1989
Critical Care Nursing, Steve Haskins BSAVA Congress 1999
The Acute Abdomen, M Willard BSAVA Congress 1999

Case 2. Fall from 7th Floor Balcony

Arlo Guthrie — Tue, 21 Apr 2009 16:55:58 GMT

Revision 2 posted to Diploma by Arlo Guthrie on 21/04/2009 17:55:58

Case 2. Fall from 7th Floor Balcony

OWNER:	BROOKS	ADMISSION DATE:	10/10/99
SPECIES:	CAT	BREED:	DSH
SEX:	FEMALE	AGE:	2 YEAR
WEIGHT:	2.7 KG ON ADMITTANCE	ANIMAL NAME:	SABRINA

This is the point at which this intensive care case starts, as the author was not involved with the cat before this time.

AIMS OF INTENSIVE CARE IN THIS CASE

To identify reason for collapse 2.
Treat the above.
Support body systems to preserve life until animal able to make a recovery and maintain own body systems without external support.

CRITICAL PARAMETERS

TEMPERATURE, FLUIDS, NUTRITION, ANTIBIOTICS

For a full record of the intensive care that followed see attached inpatient sheets.

Temperature

This was one of the most critical parameters in this intensive care case. The cat, although adult, weighed only 2.5kg. So there was no fat at all to help insulate this animal, and these very thin cats are very difficult to maintain good temperature. Hourly checks were made on temperature for the first two days and a lot of effort put in to keep Sabrina's temperature up in the normal range. This involved covered hot water bottles, heated drips, bubblewrap, plenty of bedding, running the drip lines through bowls of warmed water and ensuring she kept free from urine contamination. Hypothermia in extremely ill animals post-operatively can make the difference between recovery and death. She also had a large area of the abdomen clipped and was still draining some saline from her wound, so bedding had to changed regularly. See picture above right, taken 6 hours post operatively and the cat is critically ill.

Temperature management was very successful during this case. One hour after the end of anaesthesia the temperature was 37.8°C which was 1°C higher than the pre-operative temperature.

Analgesia

This was an important part of intensive care as the pelvis was very painful, together with abdominal surgery. Good pain management is necessary for humanitarian reasons, to encourage eating and decrease depression. An animal in pain will have less chance of recovery. The analgesia consisted of 0.5mg morphine (Evans) s/c and 10mg carprofen (Rimadyl, Pfizer) s/c. After 3 days 0.02mg buprenorphine (Temgesic, Rickett & Coleman) was substituted for morphine.

Progress

This cat was extremely ill and nobody expected it to survive the first night post-operatively. For the first day it was unable to lift it's head and could not stand until the fourth day when it managed to walk to it's food bowl and litter tray. See picture right. On the fifth day it was very bright and happy and no longer needed intensive care.

The following day it went home and seems to have made a full recovery from the peritonitis. It is walking reasonably well on the fractured pelvis and metatarsals and is passing faeces successfully.

References
Trauma Management in the Dog and Cat, Houlton, Taylor 1989
Critical Care Nursing, Steve Haskins BSAVA Congress 1999
The Acute Abdomen, M Willard BSAVA Congress 1999

Case 2. Fall from 7th Floor Balcony

Arlo Guthrie — Tue, 21 Apr 2009 16:47:52 GMT

Revision 1 posted to Diploma by Arlo Guthrie on 21/04/2009 17:47:52

OWNER:	BROOKS	ADMISSION DATE:	10/10/99
SPECIES:	CAT	BREED:	DSH
SEX:	FEMALE	AGE:	2 YEAR
WEIGHT:	2.7 KG ON ADMITTANCE	ANIMAL NAME:	SABRINA

This is the point at which this intensive care case starts, as the author was not involved with the cat before this time.

AIMS OF INTENSIVE CARE IN THIS CASE

To identify reason for collapse 2.
Treat the above.
Support body systems to preserve life until animal able to make a recovery and maintain own body systems without external support.

CRITICAL PARAMETERS

TEMPERATURE, FLUIDS, NUTRITION, ANTIBIOTICS

For a full record of the intensive care that followed see attached inpatient sheets.

Temperature management was very successful during this case. One hour after the end of anaesthesia the temperature was 37.8°C which was 1°C higher than the pre-operative temperature.

The following day it went home and seems to have made a full recovery from the peritonitis. It is walking reasonably well on the fractured pelvis and metatarsals and is passing faeces successfully.

References
Trauma Management in the Dog and Cat, Houlton, Taylor 1989
Critical Care Nursing, Steve Haskins BSAVA Congress 1999
The Acute Abdomen, M Willard BSAVA Congress 1999

Case 1. Fall from 4th Floor Window

Arlo Guthrie — Tue, 21 Apr 2009 16:45:30 GMT

Current revision posted to Diploma by Arlo Guthrie on 21/04/2009 17:45:30

Case 1. Fall from 4th Floor Window

OWNER:	KANTOROWSKI	ADMISSION DATE:	18/10/99
SPECIES:	CAT	BREED:	DSH
SEX:	MALE	AGE:	1 YEAR
WEIGHT:	5.0 KG	ANIMAL NAME:	SULEK

HISTORY
The cat arrived as an emergency; one of two cats that had been witnessed by the finder appearing to be thrown out of a 4th floor window. One cat died instantly and Sulek was brought in by the finder. On arrival the cat was in extreme pain with obvious severe injuries to both hind legs, suspected thoracic injuries due to the severe dyspnoea, very pale mucous membranes which were tinged with blue, cold extremities and collapsed veins - all indicative of shock. Intensive care started immediately and continued for 9 days before the cat was considered to be fit enough to survive the lengthy general anaesthetic required for the necessary major surgery needed to repair the injuries sustained during the fall. These included RH multiple comminution of the talus and compound collapse of the joint space with luxation of the the tibia, LH segmental fracture of the tibia and nondisplaced fracture of the talus, haemothorax and pulmonary haemorrhage with right lung collapse. See radiographs at end of case.

For a detailed account of the intensive care carried out on this cat please see the example day sheet by clicking here.

The general aims of intensive care in this case were as follows:

Preservation of life and relief from suffering - emergency treatment on admittance 2.
Maintenance of life - support of body systems not immediately life threatening but which were temporarily unable to function adequately, until such time that those systems were able to function without external support, to allow skeletal repair to be undertaken.

CRITICAL PARAMETERS

DYSPNOEA, CARDIOVASCULAR SUPPORT, TEMP
ASSESS INTACT UR SYSTEM, INTERNAL HAEMORRHAGE

INTENSIVE CARE TECHNIQUES USED

Oxygen therapy
Oxygen therapy was necessary on admittance and on several occasions during treatment, to support the respiratory system. A pulse oximeter reading taken from the ear (which was white) recording below 90% indicated hypoxaemia, and also observation of dyspnoea which occurred after handling the cat and general anaesthesia all resulted in oxygen therapy being adminstered. This was achieved by using cling film over the front of the cage and passing an oxygen line into the cage. It is necessary to humidify oxygen when using it for any length of time. This is done by passing the oxygen through water before it reaches the patient. If this is not done the animal's upper respiratory tract dries and they can easily become dehydrated. A humidifier was used in this case. See figure 1 above (Note the humidifier attached to cage below.).

Fluid therapy
Hypovolaemic shock can be fatal and fluid therapy was instituted immediately. The cat was showing signs of shock on admittance. See clinical history. Hartmanns crystalloid Ivex no.11 was infused by i/v route at a rate of 50mls/kg for the first hour and then slowed to 10mls/kg/hr. Hartmanns was the correct crystalloid to choose, but as only approximately 25% remains in the circulation after 30 mins it might have slightly better to start the infusion with a plasma replacement (colloid), such as Haemaccel, which has a half life of 2 to 5 hours before being excreted by the kidney. This would have been followed with Hartmanns. Haemodilution is greater when using crystalloids alone, but as long as the PCV does not fall below 20%(L/L) it is not a problem. The cat responded well to the fluid therapy and was sitting up 3 hours after commencing treatment. Haemaccel was used later in the day when the cat had an anaesthetic to allow dressings to be applied to the fractured legs, as the mucous membrane colour was very pale under general anaesthesia. Fluid therapy was continued for the next 2 days until the cat was eating, and able to maintain it's own cardiovascular system.

Analgesia
This is a vital part of intensive care as animals that are in pain are more likely to die than those with good pain management, and appropriate analgesia should always be given on humane grounds. Potent analgesia was given immediately, ie a combination of 15mg carprofen (Rimadyl, Pfizer) s/c and 1mg morphine (Evans) s/c. It is now generally accepted that in thoracic injuries the respiratory depression caused by pain is greater than the respiratory depression caused by morphine, therefore these were suitable analgesics to use. Unfortunately even this combination did not totally aleviate the cat's pain. There are other forms of analgesia, two of which were used in this case. Firstly, after the cat was admitted it was placed in a baker's bread delivery tray lined with vetbeds. This was an improvisation necessary due to lack of suitable equipment. See figure 2 above right. This enabled the cat to be moved from kennels to the treatment area without having to pick it up (which was causing great pain from both the chest injuries and unstable fractures of the hindlegs, despite analgesia). Secondly, support dressings on both fractured legs relieved pain, but this was only possible to do after the shock treatment was complete and a short general anaesthetic was considered safe.

Other medication
As the cat had an open fracture and other injuries, antibiotic cover was provided daily with 50mg of cephalexin (Ceporex, Schering-Plough) s/c. On Day 4 the cat's breathing became very wheezy and after assessment by the clinician, was given 70mg etamiphyline camsylate (Millophyline, Arnolds) s/c and 5mg frusemide (Lasix, Hoechst Roussel) i/v. On Day 6 the analgesics were changed to 0.05mg buprenorphine (Temgesic, Rickett & Coleman) s/c twice daily and 15mg carprofen once daily.

Monitoring pulse, respiration and temperature
Sometimes compromises have to be made depending on the patient's particular problems. This cat was of nervous temperament and severely dyspnoeic for the first 3 days. Cats often die if they are severely dyspnoeic and are subjected to any further stress. Monitoring was strictly limited to observation for the first few hours, due to dyspnoea. Oxygen therapy, analgesia and fluids were the priority and then the cat was placed in an oxygen cage, not to be handled unless apnoea occurred. A towel was placed over the cage and visual observation took place every 10 mins. Quite frequently over the next two days monitoring was abandoned due to dyspnoea. Pulse or heart rate was difficult to record, due to the dressings on the hindlegs and the haemothorax made listening to the heart difficult. Measuring capillary refill was difficult due to stress. Having one person looking after the cat helped in this case as it was so nervous, because animals become accustomed to one person after a couple of days and become less stressed. This became evident when someone else was asked to weigh him and he panicked, resulting in a severe attack of dyspnoea. Having one person assigned to an animal also allows subtle changes to be noticed because they get to know the animal's habits and character. Temperature is extremely important in critical patients. Every effort should be made to keep the temperature up in the normal range (assuming it is not high due to infection) as this can make the difference between recovery and death. In this case temperature was not the main concern except after each general anaesthetic when the temperature fell to 35°C - 36°C. Wrapped hot water bottles, vetbeds and bubble wrap were used on these occasions and the temperature was up again after 2 to 3 hours. Generally he probably kept reasonable temperature due to being fat and having the hindlimbs bandaged. His blood pressure was measured on the second day using an indirect doppler. The systolic recorded at 120 which was reasonable, as dopplers tend to record a little low on cats, and indicated that the shock had been managed adequately. Blood samples measuring the packed red cell volume and blood urea were taken on the first day to act as base samples for monitoring over the next few days. This could give an indication of the state of bleeding within the thorax and the blood urea was taken as a bladder could not be palpated initially. It was decided not to drain the haemothorax, as continued bleeding would have resulted in anaemia. Previous cases have shown that the blood is usually reabsorbed. The PCV fell from 38% (L/L) on admittance to 25% the following day. This was mostly due to haemodilution by the crystalloid infusions. The following day the PCV fell to 23%, which was just below the bottom of the normal range, but acceptable. The following day the PCV was recorded at 25% (L/L).

Radiography
This was an important adjunct to the intensive care nursing. Radiography was used to evaluate the extent of the injuries. See radiographs 1 to 9. This revealed the injuries described in the clinical history. The results from the radiographs showed that the cat had suffered right lung collapse, which was relevant information for subsequent intensive care. This meant that the cat should not be placed in left lateral recumbency, because the weight of the upper lung and heart always compromises the lower lung - so the good lung should never be placed under a dysfunctional one. This appeared to have quite a marked effect when the cat moved itself into left lateral recumbency, and dyspnoea increased within 2 to 3 minutes.

Nutrition
Nutrition is extremely important during intensive care. Water balance in the body can be maintained with i/v fluids but nutritional needs must be either met orally, with feeding tubes or parentally with specially prepared i/v solutions. These are very expensive and not available at this practice. In this case, although recumbent and inappetant, the cat would eat if coaxed and handfed. This is time consuming but a suitable amount of food can be given if fed often. The first 2 days proved to be difficult, but thereafter with a lot of effort he ate enough to maintain his bodyweight. Lack of nutrition will lead to a lowered immune system and the energy requirements of the body to repair tissues is greatly increased in this severity of trauma (1.5 to 1.7 times the maintenance energy requirement). Hills a/d diet was used in this case as it has a much higher nutritional value than normal catfood and is the diet formulated for post-operative care. The fact that this cat was overweight is of no consequence with regard to intensive care - if an animal moves into a catabolic state, healing of tissues will be much slower.

Bedding and hygiene
Ample bedding was used to cover all the area of the kennel, firstly because it is more comfortable than lying on newspaper only, and secondly to keep the cat warm. Vet beds were also used to cover the cat and, if needed, hot water bottles were placed under the vetbeds. These are not ideal, as close monitoring is necessary to ensure no burns occur. See figure 3 right. Ideally the cat should have had a urinary catheter placed and attached to an empty drip bag, both to stop soiling and to measure urine output. This was one area where the care could have been improved. However, the cat was being monitored closely and as soon as urine or faeces were produced the bedding was changed so the dressings did not get wet and the cat did not get soiled with faeces. Monitoring urine output will indicate whether the fluid therapy is adequate - for this cat urine output should be 5 to 10mls per hour.

As the cat progresses to moving around it is a good idea to allow the animal to choose the most comfortable position for itself, even if it looks very painful to us, rather than trying to reposition it to what we would assume to be a comfortable position. See figure 4 left.

It is also helpful to provide anything that might help with patient comfort. In this case a box was used to raise the food bowl up to a height where the cat could reach it from the position it found most comfortable to be in. See figure 5 below.

Morale
Often described as TLC, this is an extremely important part of nursing any critical patient. Cats, particularly, if depressed give up the will to live and need the comfort of being stroked, groomed and talked to. Morale visits should not be confined to treatment times, as when combined with painful treatments, will be of little benefit. Stroking etc. is also an important way to get inappetant cats to start eating.

Progress
The cat responded well to the initial shock therapy but severe dyspnoea was a problem for 2 days, necessating oxygen therapy. Thereafter, although still dyspnoeic there was some improvement and oxygen therapy was no longer needed. On Day 4 the breathing became audibly wheezy, was treated, and seemed to resolve by Day 6. The cat's thorax was radio-graphed on the first, second and third day and each day unfortunately showed more haemorrhage. By Day 4, the breathing became audibly noisy. After treatment the breathing improved and by Day 8 appeared normal. Radiography on the first day showed that the bladder was intact and the cat was able to urinate. The cat was comfortable with the dressings and generally very bright. On Day 9 it was declared fit for orthopaedic surgery and has been booked for repair of the left hind and assessment of the right, after radiography of the thorax showed confirmation of a diaphragmatic line and clearing of the lungs. The radiographs/photos of the radiographs are arranged in chronological order.

GENERAL COMMENTS ON INTENSIVE CARE
It is indisputable that intensive care increases the chances of survival in critical patients. However, good intensive care is only possible if the facilities, expertise, drugs and staff solely dedicated to intensive care are available. The advantage of this type of monitoring is that trends can be spotted and treated before they become critical. In this particular case the intensive care can be considered successful, as the intensive care aims had been achieved.

References
Trauma Management in the Dog and Cat, Houlton & Taylor. Wright 1987
Diploma Notes

Case 1. Fall from 4th Floor Window

Arlo Guthrie — Tue, 21 Apr 2009 16:42:10 GMT

Revision 3 posted to Diploma by Arlo Guthrie on 21/04/2009 17:42:10

Case 1. Fall from 4th Floor Window

OWNER:	KANTOROWSKI	ADMISSION DATE:	18/10/99
SPECIES:	CAT	BREED:	DSH
SEX:	MALE	AGE:	1 YEAR
WEIGHT:	5.0 KG	ANIMAL NAME:	SULEK

For a detailed account of the intensive care carried out on this cat please see the example day sheet by clicking here.

The general aims of intensive care in this case were as follows:

Preservation of life and relief from suffering - emergency treatment on admittance 2.
Maintenance of life - support of body systems not immediately life threatening but which were temporarily unable to function adequately, until such time that those systems were able to function without external support, to allow skeletal repair to be undertaken.

CRITICAL PARAMETERS

DYSPNOEA, CARDIOVASCULAR SUPPORT, TEMP
ASSESS INTACT UR SYSTEM, INTERNAL HAEMORRHAGE

INTENSIVE CARE TECHNIQUES USED

References
Trauma Management in the Dog and Cat, Houlton & Taylor. Wright 1987
Diploma Notes

Case 1. Fall from 4th Floor Window

Arlo Guthrie — Tue, 21 Apr 2009 16:40:03 GMT

Revision 2 posted to Diploma by Arlo Guthrie on 21/04/2009 17:40:03

Case 1. Fall from 4th Floor Window

OWNER:	KANTOROWSKI	ADMISSION DATE:	18/10/99
SPECIES:	CAT	BREED:	DSH
SEX:	MALE	AGE:	1 YEAR
WEIGHT:	5.0 KG	ANIMAL NAME:	SULEK

For a detailed account of the intensive care carried out on this cat please see the example day sheet by clicking here.

The general aims of intensive care in this case were as follows:

Preservation of life and relief from suffering - emergency treatment on admittance 2.
Maintenance of life - support of body systems not immediately life threatening but which were temporarily unable to function adequately, until such time that those systems were able to function without external support, to allow skeletal repair to be undertaken.

CRITICAL PARAMETERS

DYSPNOEA, CARDIOVASCULAR SUPPORT, TEMP
ASSESS INTACT UR SYSTEM, INTERNAL HAEMORRHAGE

INTENSIVE CARE TECHNIQUES USED

Oxygen therapy

Oxygen therapy was necessary on admittance and on several occasions during treatment, to support the respiratory system. A pulse oximeter reading taken from the ear (which was white) recording below 90% indicated hypoxaemia, and also observation of dyspnoea which occurred after handling the cat and general anaesthesia all resulted in oxygen therapy being adminstered. This was achieved by using cling film over the front of the cage and passing an oxygen line into the cage. It is necessary to humidify oxygen when using it for any length of time. This is done by passing the oxygen through water before it reaches the patient. If this is not done the animal's upper respiratory tract dries and they can easily become dehydrated. A humidifier was used in this case. See figure 1 above (Note the humidifier attached to cage below.).

Analgesia

This is a vital part of intensive care as animals that are in pain are more likely to die than those with good pain management, and appropriate analgesia should always be given on humane grounds. Potent analgesia was given immediately, ie a combination of 15mg carprofen (Rimadyl, Pfizer) s/c and 1mg morphine (Evans) s/c. It is now generally accepted that in thoracic injuries the respiratory depression caused by pain is greater than the respiratory depression caused by morphine, therefore these were suitable analgesics to use. Unfortunately even this combination did not totally aleviate the cat's pain. There are other forms of analgesia, two of which were used in this case. Firstly, after the cat was admitted it was placed in a baker's bread delivery tray lined with vetbeds. This was an improvisation necessary due to lack of suitable equipment. See figure 2 above right. This enabled the cat to be moved from kennels to the treatment area without having to pick it up (which was causing great pain from both the chest injuries and unstable fractures of the hindlegs, despite analgesia). Secondly, support dressings on both fractured legs relieved pain, but this was only possible to do after the shock treatment was complete and a short general anaesthetic was considered safe.

Bedding and hygiene

Ample bedding was used to cover all the area of the kennel, firstly because it is more comfortable than lying on newspaper only, and secondly to keep the cat warm. Vet beds were also used to cover the cat and, if needed, hot water bottles were placed under the vetbeds. These are not ideal, as close monitoring is necessary to ensure no burns occur. See figure 3 right. Ideally the cat should have had a urinary catheter placed and attached to an empty drip bag, both to stop soiling and to measure urine output. This was one area where the care could have been improved. However, the cat was being monitored closely and as soon as urine or faeces were produced the bedding was changed so the dressings did not get wet and the cat did not get soiled with faeces. Monitoring urine output will indicate whether the fluid therapy is adequate - for this cat urine output should be 5 to 10mls per hour.

Morale

Often described as TLC, this is an extremely important part of nursing any critical patient. Cats, particularly, if depressed give up the will to live and need the comfort of being stroked, groomed and talked to. Morale visits should not be confined to treatment times, as when combined with painful treatments, will be of little benefit. Stroking etc. is also an important way to get inappetant cats to start eating.

References
Trauma Management in the Dog and Cat, Houlton & Taylor. Wright 1987
Diploma Notes

Case 1. Fall from 4th Floor Window

Arlo Guthrie — Tue, 21 Apr 2009 16:26:25 GMT

Revision 1 posted to Diploma by Arlo Guthrie on 21/04/2009 17:26:25

OWNER:	KANTOROWSKI	ADMISSION DATE:	18/10/99
SPECIES:	CAT	BREED:	DSH
SEX:	MALE	AGE:	1 YEAR
WEIGHT:	5.0 KG	ANIMAL NAME:	SULEK

For a detailed account of the intensive care carried out on this cat please see the example day sheet by clicking here.

The general aims of intensive care in this case were as follows:

Preservation of life and relief from suffering - emergency treatment on admittance 2.
Maintenance of life - support of body systems not immediately life threatening but which were temporarily unable to function adequately, until such time that those systems were able to function without external support, to allow skeletal repair to be undertaken.

CRITICAL PARAMETERS

DYSPNOEA, CARDIOVASCULAR SUPPORT, TEMP
ASSESS INTACT UR SYSTEM, INTERNAL HAEMORRHAGE

INTENSIVE CARE TECHNIQUES USED

References
Trauma Management in the Dog and Cat, Houlton & Taylor. Wright 1987
Diploma Notes

Intensive Care Reports

Arlo Guthrie — Tue, 21 Apr 2009 16:24:14 GMT

Current revision posted to Diploma by Arlo Guthrie on 21/04/2009 17:24:14

Intensive Care Reports

Introduction
The two cases included in this casebook are both involving the same initial cause for injury, ie one cat fell from the 7th floor and the other was thrown (?) from the 4th floor. This casebook illustrates how the difference in physical build of the animal can influence the subsequent intensive care needs. Sulek was overweight and maintaining his temperature was not overly difficult. Sabrina, however, was very thin and needed constant effort to try and maintain her temperature - even left unattended for 2 hours resulted in a decrease in temperature in the early stages. Cats suffering 'high rise falls' are common in this clinic - there were 4 in the 10 days during the time these case studies were being conducted.

It must be pointed out that, unlike the vet schools, general practices usually do not have specialised intensive care facilities and improvisation is often necessary, due to lack of suitable equipment. Sabrina's temperature would have been managed quite easily if there had been a cage with underfloor and ambient temperature controls - hot water bottles are not the best way to heat an animal!

Intensive care is an area where nurses can practice their skills and knowledge, and good observation skills can frequently aid in identifying problems arising that will require treatment, as directed by the clinician.

Please click the links on the right to navigate to the individual case reports

Intensive Care Reports

Arlo Guthrie — Tue, 21 Apr 2009 16:23:01 GMT

Revision 2 posted to Diploma by Arlo Guthrie on 21/04/2009 17:23:01

Intensive Care Reports

Please use click the links on the right to navigate to the cases.individual case reports

Intensive Care Reports

Arlo Guthrie — Tue, 21 Apr 2009 16:22:44 GMT

Revision 1 posted to Diploma by Arlo Guthrie on 21/04/2009 17:22:44

Please use the links on the right to navigate to the cases.

Surgical Case Reports

Arlo Guthrie — Tue, 21 Apr 2009 16:21:41 GMT

Current revision posted to Diploma by Arlo Guthrie on 21/04/2009 17:21:41

Surgical Case Reports

[[diploma-nursing:Pancarpal arthrodesis|Case 1. Pancarpal arthrodesis]]

Please click the links on the right to navigate to the individual case reports

Surgical Case Reports

Arlo Guthrie — Tue, 21 Apr 2009 16:21:09 GMT

Revision 2 posted to Diploma by Arlo Guthrie on 21/04/2009 17:21:09

Surgical Case Reports

[[diploma-nursing:Pancarpal arthrodesis|Case 1. Pancarpal arthrodesis]] Please click the links on the right to navigate to the individual case reports

Surgical Case Reports

Arlo Guthrie — Tue, 21 Apr 2009 15:32:11 GMT

Revision 1 posted to Diploma by Arlo Guthrie on 21/04/2009 16:32:11

Please click the links on the right to navigate to the individual case reports

Appendix 3. Additional Equipment

Arlo Guthrie — Tue, 21 Apr 2009 16:19:42 GMT

Current revision posted to Diploma by Arlo Guthrie on 21/04/2009 17:19:42

APPENDIX 3 - EQUIPMENT & INSTRUMENTS USED IN ADDITION TO THE STANDARD SURGICAL KIT

Electric drill
Drill bits - sizes 2.7mm and 4.5mm
Gelpi retractors
Volkman's scoop
Bone rongeurs
Osteotome
Screw driver
Plate benders
Medium carpal arthrodesis plate - 9 holes
Sherman screws 3.5mm x 15mm
Oscillating saw
Ten swab

Appendix 2. Contents of Surgical Kit

Arlo Guthrie — Tue, 21 Apr 2009 16:18:48 GMT

Current revision posted to Diploma by Arlo Guthrie on 21/04/2009 17:18:48

Appendix 2. Contents of Surgical Kit

APPENDIX 2 - CONTENTS OF A STANDARD SURGICAL KIT

One hand towel
Two swabs
One scalpel handle (no 3 size)
One pair of Gillies (needle holders)
Two pairs of Allis Tissue Forceps
One pair blunt Mayo dissecting scissors
One pair sharp point straight scissors
One pair of dressing forceps (block end serrated)
One pair of dissecting forceps (Treves)
One pair Halsted mosquito artery forceps
One pair Cairns' curved artery forceps
One pair Cairns' straight artery forceps
One pair Spencer Wells straight artery forceps
Four towel clips (either cross action or Backhaus)
Selection of needle types and sizes
One scalpel blade no 10.

Appendix 2. Contents of Surgical Kit

Arlo Guthrie — Tue, 21 Apr 2009 16:18:48 GMT

Revision 1 posted to Diploma by Arlo Guthrie on 21/04/2009 17:18:48

APPENDIX 2 - CONTENTS OF A STANDARD SURGICAL KIT

One hand towel
Two swabs
One scalpel handle (no 3 size)
One pair of Gillies (needle holders)
Two pairs of Allis Tissue Forceps
One pair blunt Mayo dissecting scissors
One pair sharp point straight scissors
One pair of dressing forceps (block end serrated)
One pair of dissecting forceps (Treves)
One pair Halsted mosquito artery forceps
One pair Cairns' curved artery forceps
One pair Cairns' straight artery forceps
One pair Spencer Wells straight artery forceps
Four towel clips (either cross action or Backhaus)
Selection of needle types and sizes
One scalpel blade no 10.

Appendix 1. Skin Preparation

Arlo Guthrie — Tue, 21 Apr 2009 16:17:58 GMT

Current revision posted to Diploma by Arlo Guthrie on 21/04/2009 17:17:58

APPENDIX 1 - STANDARD SKIN PREPARATION OF SURGICAL PATIENT

The following procedures take place in the preparation room:

Fur around the surgical site is closely clipped, allowing a generous field round the prescribed incision site, using a size 40 blade.
All loose fur is vacuumed away from the clipped site and adjacent fur.
If feet need to be covered during limb surgery a bandage is applied to the foot.
The animal is moved to the theatre.

The following procedures take place in the theatre:

The animal is positioned for surgery.
If the surgical procedure involves a limb it is suspended by the foot and tied to a drip stand, to enable all aspects of the limb to be prepared without contamination taking place.
Iodine 0.75% w/v (Pevidine surgical scrub, C Vet) is used for initial skin cleansing at full strength, with just enough water to make a lather. This is applied with cotton wool using a circular motion, always working from the incision site outwards, discarding the cotton wool when the outer edge of the site has been reached. This is performed for 5 minutes, after which the excess scrub is rinsed away using surgical spirit. The area is then sprayed with 1% w/v iodine in spirit (Povidone Alcoholic Tincture, Vetasept) and left for 2 minutes prior to draping.

NOTE: If diathermy is to be used during the procedure no alcohol should be used, as this constitutes a fire risk.

Dip AVN Case Study

Arlo Guthrie — Tue, 21 Apr 2009 15:30:21 GMT

Current revision posted to Diploma by Arlo Guthrie on 21/04/2009 16:30:21

The Author
Geraldine Coles stumbled into the veterinary nursing profession, having previously trained as a geologist. She joined the PDSA as a trainee in 1994, qualifying as a VN in 1997. She gained the Diploma AVN in 2000, in the process winning the BVNA Award for the highest marks achieved in the examination. She currently works at the PDSA in Bow, where she enjoys the freedom that the charity gives her to practice her skills. In particular, she finds the extra responsibility, huge work load and variety both challenging and exciting.

Author's note
The following case studies are one example of the content and type of format acceptable to the examiners. There are, of course, other types of formats which are equally acceptable. Those that follow illustrate my own personal choice.

My own experience has shown me that it is not too advisable to write up all your cases too early, as you will probably find yourself re-writing them as your knowledge accumulates.

If you are like me though, you will probably rewrite them about five times anyway!

Good luck!

Publisher's Note
Please note that it has not been possible to reproduce the x-ray images that appear in the following case study to the same high standard as the originals. They are therefore for illustrative purposes only. We hope to be able to reproduce them more clearly in the future.

Our congratulations to Geraldine, and sincere thanks for allowing us to publish her work on this website.