Calculations!!

Re: Calculations!!

Teh Fluffeh — Mon, 07 Mar 2011 17:14:35 GMT

[quote user="Phrin Vernon"]

for the lack and mini lack, the resistance is low, so circuit factors of 1-1.5

for the bain and t piece the resistance is relatively high, so circuit factors of 2.5-3

So once you have calculated the minute volume you are home free! Just multiply by the circuit factor, and you have your flow rate!

Have just read that back - it makes sense to me, but not sure it will make sense to anyone else

We were taught on my revision days that the mini lack is 1, lack is 1-1.5, t piece and bain are 2.5-3

Easy way to remember it is

A+B are 2.5-3 - say it out loud as it rhymes

[/quote]

Re: Calculations!!

Phrin Vernon RVN — Mon, 28 Feb 2011 21:16:04 GMT

[quote user="billikins"]

does anyone know a website i can get sample calculations to practice with? cant seem to find any anywhere.

bill

[/quote]

Hiya

Have you asked your tutor at college? Mine had reams of calculations for those that wanted extra practice!

Failing that, I'd ask your assessor, or colleagues at work to set you some.

Good Luck!

Re: Calculations!!

Sarah Southworth RVN CertVNECC — Mon, 28 Feb 2011 12:51:20 GMT

Hi Bilkins,

I have a book at home called The Complete Textbook Of Veterinary Nursing By Victoria Aspinall, it has all the calculations and examples in it (at the back i think), so you can test yourself. Its what i used for my exam and helped me alot.

good luck for exams.

Re: Calculations!!

billikins — Sun, 27 Feb 2011 23:37:36 GMT

does anyone know a website i can get sample calculations to practice with? cant seem to find any anywhere.

bill

Re: Calculations!!

Dot — Tue, 09 Nov 2010 21:42:08 GMT

I'am resitting my practicals for the 2nd time in Dec. Like the way to set out this example easy to follow. I hate calculations & get confused with them quickly :-(( I can never remember the range for tidal volume or pre ana resp rate. I no that these are both given to you in the exam, i'am doing lots of sample calculations. Can u help me with these range's

Thanks

Re: Calculations!!

Sal the 1st — Fri, 30 Apr 2010 21:22:50 GMT

no harm in asking is there?

Re: Calculations!!

FINNIGAN — Fri, 30 Apr 2010 21:11:37 GMT

ive asked for exam paper but all i got was the print out that the examiners tick off, an all it states is a fail on calculations, can i get one that states exactly where i went wrong?? i was originally told i couldnt.

Re: Calculations!!

Sal the 1st — Fri, 30 Apr 2010 19:51:51 GMT

[quote user="samz60020@hotmail.com"]

Hi fin it could be that you wrote ur 'units' wrong because they said id failed just because i supposedly didnt write litres when i so did!!!!!

[/quote]

request a copy of your exam paper

Re: Calculations!!

Sammyannieantha — Fri, 30 Apr 2010 19:34:35 GMT

Hi fin it could be that you wrote ur 'units' wrong because they said id failed just because i supposedly didnt write litres when i so did!!!!!

Re: Calculations!!

FINNIGAN — Thu, 29 Apr 2010 13:10:57 GMT

thanks guys i am doing it right, but wish theyd tell me what it is im doing wrong!!!

Re: Calculations!!

Phrin Vernon RVN — Tue, 27 Apr 2010 22:26:14 GMT

Sorry if I have made things worse! I think Sue Cox RVN has the best gas flow rate calc - see the revision thread.

Re: Calculations!!

Phrin Vernon RVN — Tue, 27 Apr 2010 22:10:14 GMT

For flow rates, just remember FGF (fresh gas flow) = MV (minute volume) x circuit factor

To get minute volume you need tidal volume

for tidal volume, think of the tide - the amount of water that can come into the beach depends on how big the beach is, so the amount of gas that can go into an animals lungs depends on how big they are;

15ml/kg for less than 10kg

10ml/kg for greater than 10kg

But you will be given the tidal volume ml/kg in your pracs, so don't worry about it too much- just remember TV is equal to size, so is to do with kg, and is not to do with time

Next is minute volume - MINUTE is the clue - minute volume is the tidal volume(size) x resp/min(time)

so the tidal volume per minute = minute volume

minute volume is how much O2 the animal needs per minute

if you are using a circuit that amount will be affected - basically because of resistance of the circuit - so you have to multiply the minute volume by the resistance factor.

for the lack and mini lack, the resistance is low, so circuit factors of 1-1.5

for the bain and t piece the resistance is relatively high, so circuit factors of 2.5-3

So once you have calculated the minute volume you are home free! Just multiply by the circuit factor, and you have your flow rate!

Have just read that back - it makes sense to me, but not sure it will make sense to anyone else

Re: Calculations!!

Honeybadger — Tue, 27 Apr 2010 21:46:06 GMT

Example anaesthetic calculation

The veterinary surgeon wants to anaesthetise an 4kg cat for ovariohysterectomy.

For this patient you are required to calculate:

a. Tidal volume (15 ml/kg)

b. Minute volume

c. Fresh gas flow per minute

The patient has a pre-anaesthetic respiration rate 10 breaths per minute

Answer:

4kg x 15ml = 60mls Tidal volume

60mls x 10 breaths per min = 600ml Minute volume

600mls x 3 (T piece circuit factor) = 1800mls Fresh gas flow rate

= 1.8 litres

Re: Calculations!!

Honeybadger — Tue, 27 Apr 2010 21:39:52 GMT

Example drip rate calculation:

2. The veterinary surgeon decides that a 15 kg patient should receive its total daily maintenance fluid requirement over a period of 12 hours.

For this patient you are required to calculate:

a) the total daily maintenance

b) ml per hour

c) the fluid administration rate (drops/min or seconds/drop)

Show all your workings including units

Maintenance rate calculations: 50 mls/kg/day

Drip factor: 20 drops/ml

Answer:

15kg x 50mls = 750mls total daily maintenance

750mls / 12 hours = 62.5mls per hour

62.5mls / 60 = 1.04 = 1mls per minute

1ml x 20 (drip factor) = 20 drops per minute

Re: Calculations!!

Sandra Taylor RVN, MBVNA — Mon, 26 Apr 2010 20:31:37 GMT

We use our own formulae at work for drip rates. One of the nurses came up with it a few yrs back

24x60x60/ divide by fluid amount/divide by your drip factor, that gives you your drops/second

fluid amount /divide by hours ie 24 that will give you your ml/hr

eg- 32 kg dog on maintenance

32x50=1600/divide by 24(hr)=66.6 ml hr

Now do your calculation for dps

24x60x60/1600/20(drip factor) =1 every 2.7

Re: Calculations!!

FINNIGAN — Mon, 26 Apr 2010 19:56:33 GMT

have got the calculations for vet nurses book, but have seen some of you doing it a bit differently so was a bit worried i may be doing it wrong.

Re: Calculations!!

Nick Shackleton — Mon, 26 Apr 2010 19:40:05 GMT

can you afford a book???

http://www.amazon.co.uk/Calculations-Veterinary-Nurses-Margaret-Moore/dp/0632054980/ref=sr_1_1?ie=UTF8&s=books&qid=1272307198&sr=8-1