Re: Blood pressure

Nick Shackleton — Thu, 26 Aug 2010 10:19:18 GMT

This is taken from an SOP I wrote for my previous practice, hope it helps:

Hypotension: Low blood pressure

Hypertension: High blood pressure

Systolic: Blood pressure measured at time of ventricular contraction

Diastolic: Blood pressure measured at time of ventricular relaxation

Mean: Average pressure over one cardiac cycle. Can approx. worked out using the following equation:

MAP = DP + 1/3 (SP – DP)

Hypovolaemia: Low circulating blood volume

Normal Ranges:

Dogs: Cats:

SP: 110-190mmHg SP: 120-170mmHg

MAP: 60-120mmHg MAP: 60-120mmHg

DP: 55-110mmHg DP: 70-120mmHg

Measurement:

Oscillometric: Non-invasive. Although considered inaccurate. Less reliable on smaller patients. This form gives you systolic, diastolic and mean

Doppler: The use of ultrasound waves to create an audible sound of the pulse rate. A cuff is then used to occlude the vessel and then as the sound returns gives you the patients’ systolic blood pressure. In smaller patients it is considered to be more in line with mean arterial pressure.

Direct Arterial blood pressure: Invasive blood pressure monitoring, but considered gold standard of BP monitoring. A transducer is used which detects the pulse waves in the fluid filled tubing connected to the catheter. It then converts this into a digital signal and then gives u a reading.

Central Venous Pressure: Also considered gold standard when monitoring BP. CVP is measured in mmH2O and not mmHg. Normal ranges are: 0-5cmH2O. You can either use the transducer like with DABP or a fluid bag and 3 way tap plus a extension set attached to a ruler. The three way tap/transducer should be placed rough at the base of the heart.

(I know it's a human, not gone mad just couldn't find a picture)

When CVP is >10cmH2O this indicates that the patient has become over infused and fluid therapy should be stopped until back down within normal ranges.

When the patients MAP is <60mmHg this indicates that the patient is hypotension and also renal perfusion may start to be compromised.

Dealing with Hypotension

Check the correct pressure cuff is being used for the patient, ensure that the cuff is either at the level of the heart base or lower.

Check depth of anaesthesia? Reduce inhalation agent % as required.

Some drugs can also cause hypotension such as induction agents and some antibiotics. Monitor for trends rather than one off lows.

Also hypothermia will also cause hypotension so keep the patient warm using the relevant means

I think my favourite Non-invasive BP monitoring equipment has to be the parks Doppler

http://www.aasmedical.co.uk/index.php?id=45

Re: Blood pressure

Sal the 1st — Thu, 26 Aug 2010 10:15:00 GMT

I like the CAT doppler. Dont go for memoprint - its rubbish!

Re: Blood pressure

Sophie Bedford RVN CertVNECC — Thu, 26 Aug 2010 10:09:31 GMT

We use the doppler one, it works pretty well, as long as the animal stays still enough for you to find a pulse! lol

Re: Blood pressure

Charlotte Fitzgerald — Thu, 26 Aug 2010 10:02:06 GMT

Are you thinking along the lines of doppler or oscilometric