How to save Isoflurane: upcoming supply problems

RE: How to save Isoflurane: upcoming supply problems

Sal the 1st — Sat, 29 Dec 2018 04:27:05 GMT

[quote user="apache"]

We should have enough to take us through to the end of March at least. Have added a few pounds onto the cost of each anesthetic but business as normal here.

[/quote]

yes this is what I am hearing from most people I ask now - that they have managed to source but at a vastly inflated price - and I am now wondering how genuine this shortage was and how much of it was 'created' through restricted supply. We have our regular Zoetis iso I am not doubting a manufacturing issue - just the way it has been dealt with. It certainly panicked people.

RE: How to save Isoflurane: upcoming supply problems

apache — Fri, 28 Dec 2018 23:10:30 GMT

We should have enough to take us through to the end of March at least. Have added a few pounds onto the cost of each anesthetic but business as normal here.

RE: How to save Isoflurane: upcoming supply problems

Sal the 1st — Fri, 28 Dec 2018 21:16:10 GMT

so how many practices are struggling and how many have managed to source elsewhere? ie is this still a problem or have people coughed up for bottles at 4-5 times the pre shortage price - nice little earner for those selling it.

RE: How to save Isoflurane: upcoming supply problems

Nichola231 — Fri, 28 Dec 2018 17:52:16 GMT

www.youtube.com/watch

This might help too!

RE: How to save Isoflurane: upcoming supply problems

Susanna Taylor — Sun, 16 Dec 2018 07:51:16 GMT

MEOW1950

Yes, as James says, the patient is always receiving the same percentage %; the flowmeter is just changing the volume of gas provided.

Imagine you make a jug of Gin and Tonic - and you pour some into a shot glass, and some in a tumbler. A sip from the shot glass OR the tumbler will have the same amount of alcohol in it.

When you are using circle systems in low flow, it is possible that the % of iso in the system may end up not being that same as % on the dial, due to the possible dilution (at the beginning, causing it to be lower) or the recycling of agent (after a long time at low flow, causing it to be higher). The key is to monitor the patients signs of depth closely and adjust in relation too that, dont get too hung up on numbers. And if you are worried, 5mins at high flow will bring %'s equal again.

now wheres that gin...

RE: How to save Isoflurane: upcoming supply problems

James Colver Cert. Ed, RVN — Fri, 14 Dec 2018 10:18:44 GMT

No, regardless of the flow rate, the percentage of anaesthetic is still the same.

If you had your dog on 2% iso with a flow rate of 2litres/min, and you turned it up to 3litres/min, whatever isn't used is just getting wasted through the scavenge.

RE: How to save Isoflurane: upcoming supply problems

Meow1950 — Fri, 14 Dec 2018 07:41:21 GMT

This has always been something I find it hard to wrap my head round so since we’re on the subject I may as well ask :)

So, technically speaking if I have my dog on 2% iso with a oxygen flow rate of 3, that dog is getting more anaesthesia than if I had my dog on 2% iso with an oxygen flow rate of 2?

How do I know when I’m actually getting the true amount of iso that I’ve set it to on the dial?

And what about when I have to turn my oxygen flow up? E.g rebreathing. Should I turn the iso down in this instance?

Not sure why I find this concept so confusing lol. Someone help my confused mind lol!

RE: How to save Isoflurane: upcoming supply problems

Susanna Taylor — Fri, 14 Dec 2018 03:06:09 GMT

Hi, you've misinterpreted my meaning, but I guess I didn't explain what I meant very well!

I was referring to the mLs of gas flowing through the vaporisation chamber, not the mLs of isoflurane used. So, when 2L/min flows into a vaporiser, 2% of it gets saturated with isoflurane, which is 40mls/min of saturated GAS (not mLs of isoflurane - if that were the case we'd be in a lot of bother!).

The overarching point is that the higher your flow rate, the more isoflurane is used even if the % on the dial remains the same.

Thanks for getting me to explain more clearly!

RE: How to save Isoflurane: upcoming supply problems

apache — Thu, 13 Dec 2018 20:48:27 GMT

[quote user="Susanna Taylor"]The higher the flow the more Iso is picked up. 2% of 1L/min is 20mLs, 2% of 4L/min is 80mL etc. [/quote]

So at 2 litres per minute you use 40ml of iso, therefore your 250ml bottle lasts 6.25 minutes.........

You are forgetting:

From 1ml of isoflurane liquid you get 195ml of isoflurane vapour.

250ml X 195ml = 48.75 litres

At 2% and 2 litres per minute that's 1219 minutes or just over 20 hours of operating from the 250ml bottle.

https://www.zora.uzh.ch/id/eprint/98532/7/VolatileCostsCalculationsZORA.pdf

RE: How to save Isoflurane: upcoming supply problems

James Colver Cert. Ed, RVN — Wed, 12 Dec 2018 19:37:01 GMT

Thank you Susanna.

Please could you advise regarding situations where TIVA might be contraindicated / ill-advised (we were having a discussion re. caesarians) i.e. would you be inclined to hold back a bottle of iso if available for any cases in particular?