Premature ga recovery - any ideas why

RE: Premature ga recovery - any ideas why

PolkaDotty — Thu, 04 Aug 2016 13:36:25 GMT

We had a similar problem at my old practice. Had several cases 'coming round' before the end of the procedure, jaw tone and reflexes present. After having our vaporiser investigated it turn out this was our culprit. Although the dial was on 5% showing a large amount of isoflurane should be present, the engineer found only 1.25% was actually was actually being omitted. We ended up having a new vaporiser fitted and all was well with the world.

RE: Premature ga recovery - any ideas why

Jill Challis — Mon, 01 Aug 2016 21:46:06 GMT

I will try thr vapouriser test to make sure its ok, though its not long been serviced. Maybe the flow rate didnt suit this dog but its what we have used routinely with no problems. His temp was near to normal. We always use nerve blocks for extractions but in this instance didnt do it for the small epuli removal and the descale. Will push to use it for descales in future. Thanks for your thoughts

RE: Premature ga recovery - any ideas why

Jill Challis — Mon, 01 Aug 2016 21:35:34 GMT

Yes, it was premeded quite early and the acp may have started to wear off by the time we were finishing the procedure. Most things are given nsaids at premed as was this dog and it was just a routine scale, nothing to awful but may keep back up propofol on standby in future and hope I retire before it happens again! Thanks for your reply

RE: Premature ga recovery - any ideas why

Vicky Ford-Fennah — Mon, 01 Aug 2016 20:12:23 GMT

Hiya,

Just a couple of ideas in addition to previous points made

Is it a selecta tec vaporiser, have you checked for a leak in your back bar? (Set the FGF to 4L and occlude the common gas outlet just for a couple of seconds, the bobbin should dip, then repeat with the vaporiser switch on but set to 0%, you should still get a dip if there is a good seal)
where you using low flows on a circle, your inspired Iso conc may have dropped over time
What was the dogs temp? If it was hyperthermic, the dogs metabolic rate will have increased, thus requiring more iso
Pain, dental nerve blocks are fab and reduce the points of high stimuli

Hope that helps

Vicky

RE: Premature ga recovery - any ideas why

Susanna Taylor — Mon, 01 Aug 2016 16:06:56 GMT

1 of two things must of happened- either the dogs requirement of anaesthetic (iso) stayed the same and the iso dropped, OR the iso stayed the same and the dogs requirement increased The other comment covers causes of the first option, and from your reply sounds unlikely. So how about option two? What time was the dog premeditated? Could one or the other drug have worn off? I have seen this present as quite a sudden change, more commonly with alpha2s but ace/bup to. The fact the dog woke up so quickly and with dysphora also sounds like the acp might have gone. Was the arrousal after a painful bit? And this this can include scaling if bad gingivitis. Of course I'm not saying more iso would have been needed here (more analgesia would have been), but it could explain the arousal. A good tip is to always hang on to the left over propofol from the induction, and even top it up a bit so you have some handy for this sort of thing. Especially useful if having to move from one area to another. A prop stop up is less stressful and prob better cvs that high ISO levels. Hope provides a few more trains of thought. Well done and good job for asking!

RE: Premature ga recovery - any ideas why

Jill Challis — Fri, 29 Jul 2016 22:35:51 GMT

I was wonderkng if the fluotec was the problem too but the bad workmen blaming their tools sprang to mind! Certainly didnt run out of iso and dog was fine for 20 mins after turning and with regular checks on the tube (knowing what vets do to them during dentals), I dont think it was in or out to far.Nothing was disconnected or lose or leaking, I think our trainee would have noticed even if I failed to. Sadly, this practice does not have a capnograph as I agree it would have been invaluable. Will certainly request our fluotec and machine gets an additional service.

Thanks for your thoughts anyway.

RE: Premature ga recovery - any ideas why

sananbaz — Fri, 29 Jul 2016 22:22:36 GMT

The things I would consider:

Isoflurane ran out

Isotec had developed a fault

ET tube dislodged during turning

ET tube disconnected from circuit

Anaesthetic circuit disconnected somewhere

ET tube too far in and only providing gas to one lung

As the volatile agent is designed to wear off quickly, my guess is that the supply of gas/agent was disrupted by one of the ways above, and the patient woke up. You haven't mentioned it, but did you have a capnograph attached? That could give more evidence about any change in carbon dioxide measured or the percentage of volatile agent inspired.

Don't let this shake your confidence, the fact that you are reflecting on the incident shows that you will learn from this x (even if you only conclude that shit happens! )