How good are your IV fluids skills?

Re: How good are your IV fluids skills?

Martin Atkinson — Fri, 13 Dec 2013 09:56:35 GMT

[quote user="David Mills"]

[quote user="Neil Wheadon"]Hartmanns has potassium in it, 0.9% saline doesn't. Addisons are hyperkalaemic which is a touch more life threatening that hyponatraemia,[/quote]

I do find the debate about saline and Hartmann's interesting.

[/quote] The haemodilution effect of the fluids will reduce the potassium by more than the small amount of potassium in Hartmanns will increase it. Whilst I would not knowingly choose Hartmanns in an Addisonian crisis if it was all I had I would use it. I would equally not expect Hartmanns to help in cases of hypokalaemia and would need to add some potassium.

Re: How good are your IV fluids skills?

David Mills — Thu, 12 Dec 2013 23:09:13 GMT

[quote user="Neil Wheadon"]Hartmanns has potassium in it, 0.9% saline doesn't. Addisons are hyperkalaemic which is a touch more life threatening that hyponatraemia,[/quote]

I do find the debate about saline and Hartmann's interesting. In studies of blocked cats, Hartmann's normalises electrolyte abnormalities more quickly than saline despite the addition of a very small amount of potassium to the circulating blood volume. Indeed, in Addisonians, I suspect a significant part of the hyperkalaemia is due to a combination of hypovolaemia and reduced renal perfusion, which is partly rectified by dilution with large amounts of crystalloid (of whatever flavour). Of course, a lot of Addisons will also be moderately to severely acidaemic at presentation if in crisis, which saline is may make worse through dilutional effects.

I think if you're treating the underlying condition it probably matters little but, given Hartmann's ability to normalise electrolytes more quickly in other scenarios where hyperkalaemia occurs, I'd go with that. If you're that bothered about the hyperkalaemia - and this is an ECG diagnosis, not a biocehmical one as the two have very poor correlation - then dose up with calcium +/- dextrose while volume expanding.

Re: How good are your IV fluids skills?

Neil Wheadon — Thu, 12 Dec 2013 22:40:51 GMT

[quote user="Francisco Gomez"]Addison's is indeed one of the few cases where you should be using saline rather than hartmanns as far as I can remember...[/quote]

Hartmanns has potassium in it, 0.9% saline doesn't. Addisons are hyperkalaemic which is a touch more life threatening that hyponatraemia, hope that backs Clive up

Neil

Re: How good are your IV fluids skills?

Clive Ansell — Thu, 12 Dec 2013 19:41:45 GMT

[quote user="Martin Atkinson"]

[quote user="Clive Ansell"]I was berated by this colleague for using saline because she argued the Na+ was too high and could cause cerebral oedema if the suspected hyponatraemia was corrected too quickly, and that I should have used Hartman's, and I should have known that![/quote]Some people are rather anally retentive control freaks and pedantic over minutia and she was probably trying out-rank you or justify her own bad decision making. Ah...the joys of being sole charge (and doing sole charge locums in your case eh Clive)!?

[/quote]

Nothing wrong with healthy discussion over a difference of opinion over a case, but some are just so condesending and rude with the primadonna bullshit when there is no need. And there was me thinking we were all on the same side and pulling in the same direction -if only

Agree about the sole charge too.

Re: How good are your IV fluids skills?

Martin Atkinson — Thu, 12 Dec 2013 17:07:08 GMT

Re: How good are your IV fluids skills?

Clive Ansell — Thu, 12 Dec 2013 16:41:18 GMT

For anyone that may be interested there is some fluid therapy CPD available on Dechra's website; 6 hours small animal and 6 hours equine

Re: How good are your IV fluids skills?

Clive Ansell — Thu, 12 Dec 2013 16:38:14 GMT

[quote user="Evelyn Barbour-Hill"]

Umm, I don't think a nurse should be calculating rate at all, but if she does a veterinary surgeon should be checking.

(Actually, i don't think a nurse should be setting up a drip, without someone checking, at all. But let's not go there).

[/quote]

RVN's and VN's routinely do almost all of the IV drip work in 2 of my regular practices, and I would expect any competent one to do so. They are very good at it and I leave them to it and would trust them 100%. We do however discuss cases, fluid types and flow rates. I check on things from a distance ( I know when a bag or burette should empty for example) but don't really need to.

[quote user="Evelyn Barbour-Hill"]

My only tip, from my ancient silly old dinosaur store, is to hang the bag from a spring balance. If you want to know how much has gone in,It's much easier to tell from that than from trying to judge the appeance of the bag.

[/quote]

Really good idea. I sometimes use some digital kitchen scales to determine what is left in a bag. I guess a digital hand held luggage balance would be a good idea too.

Re: How good are your IV fluids skills?

Clive Ansell — Thu, 12 Dec 2013 16:30:38 GMT

[quote user="Stephen Courtney"]

As far as Addisons goes, while Saline is the best fluid, even Hartmanns is adequate, the overall amount of potassium in Hartmanns isn't going to make a noticeable impact, and there is plenty of Na in Hartmans! Volume resuscitation is the real issue so I wouldn't hesitate to use Hartmanns if that was all I had.

[/quote]

I was berated by this colleague for using saline because she argued the Na+ was too high and could cause cerebral oedema if the suspected hyponatraemia was corrected too quickly, and that I should have used Hartman's, and I should have known that!

Normal saline contains 150 mmol Na+ and 150mMol Cl-, and Hartman's 131 mMol/L Na+ and 111 mMol Cl- , and I stick with my original choice given that Na+ and cl- were very very low, and k+ was +++ high.

Re: How good are your IV fluids skills?

Mark Holmes — Thu, 12 Dec 2013 15:43:33 GMT

Evelyn, would you expect a Vet to set up a drip without someone checking? If not what is it about a drip which makes it beyond the wit of a nurse and within that of a vet?

Re: How good are your IV fluids skills?

Evelyn Barbour-Hill — Thu, 12 Dec 2013 15:40:46 GMT

[quote user="An On MRCVS"]Recently had an elderly cat in for surgery. Nurse set up on drip and having calculated the rate, programmed the drip pump. Unfortunately calculated 24 hour requirement rather than hourly - Only noticed once cat had had 180ml in first hour, developed pulmonary oedema and died. Don't be gung-ho with fluids in cats, do be careful when programming pumps....[/quote]

Sort of a good argument for counting drops per minute instead – easier to get an instant feeling that "something's wrong here".

Umm, I don't think a nurse should be calculating rate at all, but if she does a veterinary surgeon should be checking.

(Actually, i don't think a nurse should be setting up a drip, without someone checking, at all. But let's not go there).

Re: How good are your IV fluids skills?

Martin Atkinson — Thu, 12 Dec 2013 15:34:21 GMT

[quote user="An On MRCVS"]Only noticed once cat had had 180ml in first hour, developed pulmonary oedema and died.[/quote] I quite frequently give cats up to 200ml in an hour and 500ml in a working day and rarely if ever have a problem. Indeed the only cat I've ever had that developed pulmonary oedema on a drip was one with total anuria/renal failure and that survived the oedema (not the renal failure). I would question the decisons made for the fluid needs of your cat if you killed it with 180ml! This is not to say of course that one should not be careful but monitoring is everything and a fluid chart that is filled in every 5-15 minutes is a must.

Re: How good are your IV fluids skills?

Stephen Courtney — Thu, 12 Dec 2013 15:06:27 GMT

I can remember the hassle of keeping a drip running on a cat or dog, with or without a burette, only to discover the drip had stopped because the animal moved its leg, or worse still, a cat that got 500ml in an hour . It was fine but i have had other cats on normal flow rates develop pleural effusions - they do need to be monitored, and if you don't have a pump your monitoring needs to be a lot more vigilant.

If you need to spike fluids with potassium, be very very careful if you don't have a pump.

Their biggest value outside of using CRI set ups is knowing that the fluids keep going at the same rate regardless of the animal's limb position

Re: How good are your IV fluids skills?

An On MRCVS — Thu, 12 Dec 2013 15:00:35 GMT

[quote user="Martin Atkinson"][quote user="Neil Wheadon"] I have seen a bag of fluids run into cats pretty quickly with no ill effect and honestly can't recall the last case I saw with pulmonary oedema as a result.[/quote] I agree with that and this a reason why no-one should be scared of the IV route in cats but I stand by the above statement.[/quote]

Recently had an elderly cat in for surgery. Nurse set up on drip and having calculated the rate, programmed the drip pump. Unfortunately calculated 24 hour requirement rather than hourly - Only noticed once cat had had 180ml in first hour, developed pulmonary oedema and died. Don't be gung-ho with fluids in cats, do be careful when programming pumps....

PS Sorry for anon - wanted to alert others to potential danger, but not fair to discuss somebody else's mistake on public forum.

Re: How good are your IV fluids skills?

Francisco Gomez — Thu, 12 Dec 2013 13:49:05 GMT

[quote user="Clive Ansell"]

Choice of fluids is equally guesswork unless one has electrolytes and blood gas results to hand. I was recently admonished by a colleague for using saline at shock rates in a collapsed addisonian dog when (I was told/shouted at) that I should of used hartmans. When the blood results were back later I was vindicated as Na+ was very low, and K+ dangerously high.

[/quote] I appreciate that we don't always have a full diagnosis but if you have one or are close to one you should be using the appropriate fluids. Ie an acute hemorrhagic enteritis will most like to result in an acidotic patient and therefore you shouldn't be using an acidotic fluid (if you can help it). Btw, Addison's is indeed one of the few cases where you should be using saline rather than hartmanns as far as I can remember...

Re: How good are your IV fluids skills?

Mark Holmes — Thu, 12 Dec 2013 13:39:38 GMT

The most useful tip I have re fluids is noting when you expect the bag to finish - or if using a burette when the required volume to run in. It's very easy to set up a 500ml bag at 100ml/hr and find the bag 25% full 7 hours later.

Re: How good are your IV fluids skills?

Gillian Mostyn — Thu, 12 Dec 2013 12:46:44 GMT

[quote user="Clive Ansell"] I think continual monitoring and reassessing is far more important than precise calculations based on guesswork.[/quote]

It isn't an 'either/or' situation. Deficits should be calculated as accurately as we can (albeit it is always an estimate) AND the animal should be monitored.

[quote user="Clive Ansell"]I think fluid pumps are an expensive luxury, and just as good a job is possible with giving sets.[/quote]

Couldn't disagree more, especially if the animal isn't under continual supervision. As has been said, position of leg, patient, fluid bag etc will all affect the rate. Not to mention that you might not know the fluids have completely stopped until the animal is next checked....... how often are your patients checked...??? The it has completely blocked and you have to replace the canula.

[quote user="Clive Ansell"]When my Mother was an NHS nurse that used to give a litre saline in 4 hours or in 8 hours. Just the 2 rates regardless of whther the patient was a Twiggy 7 stone look alike or a 34 stone obese lard arse. That was fairly universal so I'm told, except for paediatrics and intensive care where rates were calculated. [/quote]

In the same way that large animal vets are unlikely to bother about giving a litre or two either way, but small animal vets (equivalent to paediatrics) need to be a bit more careful. It is all about weight and stability of the patient - no?

Re: How good are your IV fluids skills?

Martin Atkinson — Thu, 12 Dec 2013 12:36:16 GMT

[quote user="Neil Wheadon"]The S/C route is like spraying ringworm with purple spray, makes you feel better but does nothing useful[/quote] I think that is an unreasonable statement. I would use the IV route on a cat when possible/necessary, as in severe dehydration/shock as I would in a dog but giving 60ml saline S/C is tolerated well and perfectly effective in cases of mild dehydration or to prevent dehydration under GA or cats that are not drinking and it is churlish to suggest otherwise. The fact that cats given fluids this way have absorbed the fluid blip within minutes and are peeing an hour or so later proves it works.

[quote user="Neil Wheadon"] I have seen a bag of fluids run into cats pretty quickly with no ill effect and honestly can't recall the last case I saw with pulmonary oedema as a result.[/quote] I agree with that and this a reason why no-one should be scared of the IV route in cats but I stand by the above statement.

Re: How good are your IV fluids skills?

Clive Ansell — Thu, 12 Dec 2013 12:13:59 GMT

I agree with Michael and Martin. It is not an exact science by any means and any calculations are based on only guess work as to the % dehydrated and what may be lost through vomiting or diarrhoea. A 20 kg dog can be 5% dehydrated which is not, or barely, detectable on exam and have a deficit of 1kg = 1 litre. I think continual monitoring and reassessing is far more important than precise calculations based on guesswork.

I think fluid pumps are an expensive luxury, and just as good a job is possible with giving sets. In fact I have measured the throughput of a fluid pump (can't remember which one) and Millpledge Aniset dail-a-flow giving sets which I find very accurate, and in this case more so than the fluid pump.

I prefer paediatric sets or burettes for cats and small dogs, but if not available and with limited monitoring, say overnight, I will use standard sets with 100ml bags, or just half a 500ml bag.

When my Mother was an NHS nurse that used to give a litre saline in 4 hours or in 8 hours. Just the 2 rates regardless of whther the patient was a Twiggy 7 stone look alike or a 34 stone obese lard arse. That was fairly universal so I'm told, except for paediatrics and intensive care where rates were calculated. Probably different now I don't know?

Re: How good are your IV fluids skills?

Martin Atkinson — Thu, 12 Dec 2013 11:06:27 GMT

[quote user="Gillian Mostyn"]Martin - how can you get a 'feel' for doses when every animal has a different deficit/requirement and every animal weighs differently? [/quote] I think Michael explained this slightly better. This is the art of veterinary science, using common sense and observation rather than chasing numbers.

Re: How good are your IV fluids skills?

Michael Woodhouse — Wed, 11 Dec 2013 23:35:58 GMT

Neil - a pump is on the list! I do use IV in cats, just not that often. I suppose the majority of fluids I personally use in cats are supportive to other Tx and done s/c in the consulting room. If I get anything sickly and am giving NSAID I will usually give 100ml under the skin and it anecdotally seems to help and makes me feel better re kidneys!

As times goes on I am doing less and less S/A surgery so my population is badly skewed by OOH sick cats.............

(I did once run about 400ml IV into a cat quite fast (changed position and drip suddenly sped up) and it was fine)

Re: How good are your IV fluids skills?

Neil Wheadon — Wed, 11 Dec 2013 23:11:33 GMT

Hi Michael If you were to invest in anything, get a fluid pump and use it on cats. The S/C route is like spraying ringworm with purple spray, makes you feel better but does nothing useful. You mention opening the burette right up to avoid blockages. In cats with lower fluid rates I/V it's a real help especially as you do your own on call and so will have these in overnight with moderate monitoring. Having a cat on 12ml/hour overnight without a pump is pretty tricky to judge. I fail to understand the fear in cats, yes you can overdo it, but it's pretty difficult and I have seen a bag of fluids run into cats pretty quickly with no ill effect and honestly can't recall the last case I saw with pulmonary oedema as a result. As a final general thought if you have a pump, don't forget to calibrate it once in a while. Simply put a bag on and set a rate and empty the fluid into a dish, you might be surprised at how inaccurate it has become. Neil

Re: How good are your IV fluids skills?

Michael Woodhouse — Wed, 11 Dec 2013 23:06:06 GMT

[quote user="CatherineThomas"]

isn't 5L the circulating blood volume of a 50kg dog?

[/quote]

I have 7-9% of bodyweight in the back of my mind for circulating volume, bigger animals have a lower percentage.

This is super basic stuff. We are talking about dehydration here. So deficit (ie level of dehydration or how much blood already on the floor) plus maintenance plus ongoing losses.

EG -

50KG dog. 10% dehydrated, maintenance is 50ml/kg/day. Lets say ongoing V/D losing another litre in total.

5 litres (deficit), maintenance is 2.5 litres and ongoing losses 1 litre - this dog (potentially) needs 8.5L of fluid.

If you give it at a steady rate (and obviously you wouldn't) that's 2 drops per second for 24 hours.

Remember that crystaloids are rapidly redistributed and after 1 hour only ~20% will remain in circulation. The blood volume is hardly relevant.

Re: How good are your IV fluids skills?

Gillian Mostyn — Wed, 11 Dec 2013 22:57:04 GMT

[quote user="Michael Woodhouse"]We could have the same 50kg dog in front of us[/quote]

OK.... 50kg dog....really? We see 5kg - 25kg dogs far more commonly at our practice!

[quote user="Michael Woodhouse"]you might put it at 8% dehydrated, I say it's 10% and Martin say 12%[/quote]

Well 2 of us are crap at estimating fluid deficit. As your chart shows, the differences are pretty obvious.

[quote user="Michael Woodhouse"] In cats I almost always use the s/c route for safety and they don't tolerate IV access as well as a dog.[/quote]

I think route of fluid administration should be based on clinical need. We use both routes for different reasons. An elderly cat undergoing a surgical procedure won't feel much benefit to its renal perfusion by having sub cut fluids pre-op!!! .

Re: How good are your IV fluids skills?

CatherineThomas — Wed, 11 Dec 2013 22:43:54 GMT

isn't 5L the circulating blood volume of a 50kg dog?

Re: How good are your IV fluids skills?

Michael Woodhouse — Wed, 11 Dec 2013 21:52:37 GMT

[quote user="James Laidlaw"]

2 Litres different?

How much circulating volume does a 50 Kg dog have that 4% difference in estimated dehydration equates to 2 Litres of difference? Or have I missed something?

[/quote]

50KG dog. Dehydration estimated as a percentage of bodyweight. So a 50kg dog 10% dehydrated requires (50X0.10)5 litres. For the same dog the deficit at an estimated 8% dehydrated gives you 4 litres and if you take 12% dehydrated you get a deficiency of 6 litres.

It's not unusual to see sickly dogs in the ~10% range is it:

< 5% dehydrated: No detectable clinical signs

5%-6% dehydrated: Subtle loss of skin elasticity

6%-8% dehydrated: Definite delay in return of skin to normal position (skin turgor), slight increase in capillary refill time, and eyes may be slightly sunken into orbits

10%-12% dehydrated: Extremely dry mucous membranes, complete loss of skin turgor, eyes sunken into orbits, dull eyes, possible signs of shock (tachycardia, cool extremities, and rapid and weak pulses), and possible alteration in consciousness

12%-15% dehydrated: Definite signs of shock; death is imminent if not corrected

Grabbed random reference off the net http://veterinaryteam.dvm360.com/firstline/article/articleDetail.jsp?id=655535