Colloids

Re: Colloids

Kate Richardson — Mon, 19 Mar 2012 18:24:24 GMT

Thanks Chris. Saved me a lot of reading or at least will make more sense of the reading I have to do!

Wasn't a problem for me with my patient, colloids weren't indicated until about day 4 after referral, but just made me think that if referral hadn't been an option, what would I have used. Anyway despite referral and colloids, ended up ptsing the dog. Only really referred it cos it needed endoscopy and biopsies which we don't have facilities for, but then just as they were about to ga the dog for this, I got the faecal culture results back (already detected Isospora) and culture came back with salmonella! Managed to get hold of the clinician just in time, and after a lot of debate they deferred the endoscopy (from what I gather 50:50 in regards to whether to go ahead with it or not) but they elected to treat the salmonella first. But I/they think this dog had something else underlying it (either really severe IBD or lymphoma)- dog was on long term pred for skin issues (Westie!) prior to the PLE.

Anyway, thanks again to all who posted

Re: Colloids

Christopher Saul — Mon, 19 Mar 2012 17:11:40 GMT

Hi Kate

Please bear in mind I'm not an anaesthetist or critical careist, so maybe others may be more qualified to answer on this point.

I think venofundin and voluven may actually be tetrastarches. The main thing is that tetrastarches and pentastarches are smaller molecules than hetastarches.... and the larger the molecule the more profound the effect upon coagulation times. Hence tetrastarches and pentastarches are potentially less dangerous from this point of view.

As far as I'm aware, there's very little evidence that colloids offer any real benfit over crytalloids. Much of what evidence there is is anecdotal. In the overwhelming majority of cases if you use crystalloids alone then no one would be able to say you're doing the wrong thing

The rationale behind colloids is that they will sit wihin the vascular space and improve colloid oncotic pressure (COP), retaining fluid within the vasculature. Another theory is that they could be of use in cases of reduced vascular permiability, such as vasculitis or DIC, by sort of plugging the holes in the vasculature.

With regards to their use in increased vascular permiability, the risk is that colloids will increase hydrostatic pressure within the vasculature and this increased hydrostatic pressure will make the leaky vessels leak even more. Whether the this effect outweighs the benefit of the molecules plugging the holes, who knows?

With regards to your hypoalbuminaemic patient, I think there is a slightly better arguement for using a colloid, though even so it is still equivocal and by no means negligent not to use colloids. In answer to whether to use plasma or tetrastarch, not an easy question to answer. In theory hypoalbuminaemic patients will be low in antithrombin, and plama may help replenish this. However I heard somewhere that the ammount of plasma you would need to give in order to make any difference is impractical, and plasma is not particularly good at raising COP. So to answer your question, I'd probhably have given venofundin, with the hope that even though it prob won't have much effect on COP in itself, it may slow the rate at which COP falls. I really don't think you should beat yourself up about not using it though.

Of course there is one reason to keep a unit of plasma in - or at least know how you can get hold of a unit in a hurry ( pet blood bank) - and that is for coagulopathies such as rat poisoning. Plasma is an excellent source of clottting factors....

I'll wait while someone more qualified comes along to correct me though...

Chris

Re: Colloids

Kate Richardson — Mon, 19 Mar 2012 13:36:51 GMT

So are Venofundin and Volvulen both pentastarches? I had a dog recently with severe hypoalbuminaemia secondary to PLE, and it clinically it didn't require a colloid whilst with us, but I wasn't sure what would have been best for it should it have needed some. Would plasma be better in such a case or would you go with a pentastarch? The dog was referred (Bristol) and did end up on colloids as it went on to develop sc oedema. It's not often it is needed but I would like to make sure we have something in stock should it be necessary.

Re: Colloids

Christopher Saul — Sun, 18 Mar 2012 23:59:02 GMT

Generally speaking starches have a better duration of action than the gelatins, which are out of circulation within an hour or two. The main problem with the older/larger hetastarch types was the potential for side effects both in terms of the potential effect on coagulation times and volume overload, hence the colloids most commonly stocked nowadays would be the pentastarch derivatives........

The brand we stock is venofundin, though I believe voluven is very similar. They are more forgiving from the point of view of potential side effects and are the synthetic colloids of choice for most referral centres I believe.

[quote user="Michael Woodhouse"]We chose not to stock it after kept going out of date. Acute bleeding in people I am reliably informed they usually use crystalloids. I can collect blood if needs be.[/quote]

Micheal has a fair point... crystalloids are absolutely fine for the VAST majority of fluid resusitation scenarios.

Hope this helps

Chris

Re: Colloids

Michael Woodhouse — Sun, 18 Mar 2012 23:40:35 GMT

We chose not to stock it after kept going out of date. Acute bleeding in people I am reliably informed they usually use crystalloids. I can collect blood if needs be.

Re: Colloids

Lucy K — Sun, 18 Mar 2012 20:27:02 GMT

Our uni clinic uses HAES from Fresnius.

Re: Colloids

Clive Ansell — Sun, 18 Mar 2012 20:26:19 GMT

[quote user="Martin Atkinson"]

[quote user="Clive Ansell"]

Most practices I work in have Haemaccel and a few have Gelofusine in stock, although quite often it is out of date when one comes to use it. Some practices have no colloids at all.

[/quote]

Wasn't my practice was it Clive? I had a splenic rupture a couple of weeks ago and the Gelofusine was 2 years out of date, worked well though. Maybe not best practice but given the choice of that or nothing so long as it hasn't gone cloudy I'd choose that. Re-ordered stock now in date.

[/quote]

No.

I've used out of date colloids too with no problems. As you say, if it is that or nothing, then it is a case of doing what you can with what you've got.

I have seen Oxyglobin ordered in one emergency OOH clinic, only for it to out of date an be disposed of. That stuff is megabucks.

Re: Colloids

Martin Atkinson — Sun, 18 Mar 2012 19:34:20 GMT

[quote user="Clive Ansell"]

Most practices I work in have Haemaccel and a few have Gelofusine in stock, although quite often it is out of date when one comes to use it. Some practices have no colloids at all.

[/quote]

Re: Colloids

Rob Loxley — Fri, 16 Mar 2012 17:28:53 GMT

http://www.vetsurgeon.org/forums/p/9949/50016.aspx

Re: Colloids

Clive Ansell — Fri, 16 Mar 2012 16:21:30 GMT

Most practices I work in have Haemaccel and a few have Gelofusine in stock, although quite often it is out of date when one comes to use it. Some practices have no colloids at all.