is it possible to run isoflurane through a ventilator?

[CCEMTP]

Hi everyone, I've got an interesting question on my hands I'm hoping y'all can help me with. I'm involved with a research project (on pigs, not humans) with limited equipment and funds and I'm trying to find a way to supply isoflurane anesthesia with a portable ventilator. I have an isoflurane machine and I have a portable ventilator (Impact 754), but I don't have a true anesthesia ventilator. I don't know how I could run the anesthesia gas through the ventilator, but is it possible to provide both anesthesia and ventilation with a T-piece in the ventilator tubing? Would that work or would that cause some sort of issue? Or do I really need to invest in an anesthesia machine to do this?

Sorry for my lack of knowledge of gaseous anesthesia, I'm familiar with ventilators but only recently discovered that y'all had your own special ventilators for supplying anesthesia. That's why I figured it was best to ask the experts at this stuff. Thank!

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[Wiscoblue]

Get an old seimens servo and you should be able to place a penfold ISO vaporizer on the breathing circuit. You can also add nitrous and a scavenger for venting spent gases.

 

[Wiscoblue]

The other option is to do a closed circuit with 150 cc gas flow and inject isoflurane with a syringe into the bag.

 

[CCEMTP]

Ya, I like what I've seen of the seimens servos, just haven't found one I can afford yet.

Sorry, I'm not sure I understand how to do a closed circuit like you're talking about. If I'm reading this correctly you're saying to basically have a bag with liquid isoflurane in it as part of the circuit?

Would there be a problem with having the vaporizer go into a t-piece on the ventilator tubing? I can wrap my feeble mind around how to do this, but I don't know if it would work.

Thanks for the quick replies!

 

[GhostTree]

I remembered reading about this before, please check out this link for a proprietary device. I have never used it and have no real knowledge about it or the cost. I just though it was an interesting concept.

http://www.sedanamedical.com/aboutanaconda_icu.php

 

[Wiscoblue]

Armed with knowledge of things like oxygen consumption per minute, body temperature, molecular wt of isoflurane, Basic gas laws, and advanced math you should be able to calculate how much ISO to inject manually into a breathing circuit to keep the animal asleep with a closed circuit. It's easier with spontaneous respiration because of lesser circuit leakage of gases.


If you decide to just add a vaporizer to your inspiration limb on the vent and avoid the math exercise, I would suggest that you will need a low resistance vaporizer like an OMV or the Oxford miniature vaporizer. You might be able to buy a used one. I have drager ISO vaporizer in my garage and I could give it to you for nothing but it won't work on your ventilator. You need an OMV or a penlon low resistance.

 

[Spinach Dip]

Hi everyone, I've got an interesting question on my hands I'm hoping y'all can help me with. I'm involved with a research project (on pigs, not humans) with limited equipment and funds and I'm trying to find a way to supply isoflurane anesthesia with a portable ventilator. I have an isoflurane machine and I have a portable ventilator (Impact 754), but I don't have a true anesthesia ventilator. I don't know how I could run the anesthesia gas through the ventilator, but is it possible to provide both anesthesia and ventilation with a T-piece in the ventilator tubing? Would that work or would that cause some sort of issue? Or do I really need to invest in an anesthesia machine to do this?

Sorry for my lack of knowledge of gaseous anesthesia, I'm familiar with ventilators but only recently discovered that y'all had your own special ventilators for supplying anesthesia. That's why I figured it was best to ask the experts at this stuff. Thank!

My brother! I do research on pigs also!

You should really REALLY invest in a real anesthesia machine IMO. It doesn't have to be new. (The ones in my lab were made in the 70's.) You could check vet offices/vet schools (I don't know where you are) and hospitals. Even if they aren't willing to sell, perhaps you can rent one.

I, personally, would not macgyver something together. I could, certainly, but I would not risk the lives of my girls in that way.

 

[Spinach Dip]

Now, if the question is whether or not it is possible, I would assume yes. Iso is about as chemically inert as possible.

 

[PonyUp]

Buy some intralipid. Combine with ISO. Inject IV at ED50. Use regular ventilator as intended. Profit?

http://www.ncbi.nlm.nih.gov/pubmed/16368817

 

[Spinach Dip]

Buy some intralipid. Combine with ISO. Inject IV at ED50. Use regular ventilator as intended. Profit?

http://www.ncbi.nlm.nih.gov/pubmed/16368817

Hasn't been tested in pigs AFAIK.

Second, what would the ED50 be? Or would you titrate to effect?

Third, no one has mentioned controlling waste gas in this thread (I assume that is because some sort of scavenging system goes without saying). IV iso is still eliminated via the lungs, so even if you did decide to go the IV route waste gas would need to be considered.

 

[CCEMTP]

Wow, thanks for all the info everyone! @Spinach Dip We currently do this in conjunction with a vet in their office on the weekends, but they only have a constant flow vaporizer machine (sorry don't know the correct name of it), not a full anesthesia ventilator. We've been using IV propofol but we could save A LOT of money, and with the blood pressure problems we've had with propofol we would probably be safer if we could keep using the gas after intubation. It sounds like what I was thinking of doing though would be macguyvering something up that may not work and may not be safe, which is what I was afraid of. Glad I asked y'all though. I'll start looking into an anesthesia machine. I've found a few drager narkomed's for kinda cheap, we will see what else comes up. If y'all know the name of an old machine to look for or to stay away from please let me know. Thanks again for all the help!

 

[scudrunner]

Closed circuit (cannot use t piece), inject ISO and oxygen into circuit. You would need a co2 absorber though, which I don't think portable vents have. Just go with TIVA.