Anectine/Propofol for LMA insertion

rn29306 · Jul 9, 2006

Has anyone else seen this done? Just curious, because some docs & CRNAs at my site mix 1 mL of anectine in with their propofol stick for induction prior to LMA insertion. Those that don't have VERY STRONG OPINIONS on the practice, yet those that do have just as strong opinions and, as always, I'm in the middle. Any observations? Thoughts?
Z

I for one have never heard of this and for the life of me can't figure out how 20 mg of anectine is honestly going to make that much difference in LMA insertion. The risk / benefit in this situation doesn't add up. It seems as if you are entertaining all or at least the majority of the risks of anectine administration and recuping little benefit.

You are exposing them to the most potent trigger for MH. (Yes, I realize they are about to be exposed to a volatile agent, but anectine is still the most potent.) Also, you have to consider the possibility of pseudocholinesterase deficiency as well, after failure of regaining respirations, now you have to manage the airway and intubate the patient intra-op. The list goes on and on.

People might say statistically, MH and enzyme deficiency are exceedingly rare, but I've had both happen to me while in school. NOT FUN.

I've seen alot of knee-jerk practices in anesthesia, but this one seems to take the cake.

If a person needs additional deepening of anesthesia after a stick of propofol, either give the patient another dose or breathe them down with sevo after the propofol. That seems to be the safest way.

To me, you are just asking for a mishap here. My two cents.

Focker, CRNA · Jul 9, 2006

I have not heard of using succ with LMA before, and the reasons not to do it that RN29306 gave sound right on the money to me. One of the senior students at our school talked in journal club about a preceptor that she had that used mivacurium when putting in an LMA, so you lose the MH trigger, but gain histamine release (though probably inconsiquential since im sure it is a small dose). I've only put in two LMAs myself, so Im no expert, but it doesnt seem like muscle relaxant should be necessary.

louloubell1 · Jul 9, 2006

I have seen this in my clinical rotations as well, and though sometimes I have had to do it because the CRNA or MDA that I'm with wanted it, I don't think it makes much sense, nor have I noticed that it really makes a difference on the ease of insertion of the LMA. I've also spent some time recently with an MDA who uses a full intubating dose of mivacron for LMA insertion, the reason being completely anecdotal. On days when I am free to carry out induction as I see fit, I don't use any MR for LMAs, but rather induce with propofol and then breathe down on sevo. I've never found it difficult to insert the LMA doing just that, so I don't see the benefit of adding a paralytic to the mix.

jwk · Jul 9, 2006

No reason to give any NMB for LMA's as a matter of routine. None.

soliant12 · Jul 9, 2006

Was doing a TURP on an 84 year old patient the other day via LMA extensive cardiac history and just about anything else you can think of. Induced with 20mg of etomidate placed a #4 LMA and was giving Sevoflurane (exp about 2.1%) . Nurses went to put patient in stirrups and he was not relaxed enough so the MDA ordered 1cc (20mg) of anectine. It worked great, but I was worried about giving it.

susswood · Jul 9, 2006

I have had an MD recommend 20mg of Anectine for LMA insertion if they have a tight jaw. Seems to me this is a substitute for putting in an LMA early on a patient who is probably not adequately anesthetized. I would just mask 'em with gas, get 'em deep and pop it in.

p.s. Abbott has stopped making Mivacron

jwk · Jul 9, 2006

Was doing a TURP on an 84 year old patient the other day via LMA extensive cardiac history and just about anything else you can think of. Induced with 20mg of etomidate placed a #4 LMA and was giving Sevoflurane (exp about 2.1%) . Nurses went to put patient in stirrups and he was not relaxed enough so the MDA ordered 1cc (20mg) of anectine. It worked great, but I was worried about giving it.

That's called not being deep enough - it has absolutely nothing to do with relaxation.

This is why some people have issues with anesthesia awareness - they mask a light anesthetic with NMB's.

gaspassah · Jul 9, 2006

i first concider the use of an lma to be no different than using a mask. the risks are the same as the airway is not protected. therefore my use of the lma is for spontaneously breathing patients. i never use nmb for lma, we have an attending that will put proseal lma's in trauma pts, put them in prone cases etc. when i am staffing his room, we have had words on this practice, i tell him to get another crna cause i wont do it.

the point of this story is if you are just starting in anesthesia, these are the times when you begin to develop your own practice and decide how you will practice in the future. you will hear alot of anecdotal evidence that is hardly ever backed up with hard science. if it sounds fishy and smells fishy it probably is fishy.

now more directly to the point, nmb agents should not be needed for lma insertion, you can intubate patients if they are deep enough without nmb. give some prop and mask with sevo.

soliant12 · Jul 9, 2006

I agree he wasn't deep enough yet but the MDA and or surgeon doesn't want to wait around for them to get deeper. It does have to do with relaxation once the succ was onboard there wasn't a problem getting his legs in the stirrups he was well past an amnestic MAC so I there would be no issue with awareness.

That's called not being deep enough - it has absolutely nothing to do with relaxation.
This is why some people have issues with anesthesia awareness - they mask a light anesthetic with NMB's.

jwk · Jul 10, 2006

I agree he wasn't deep enough yet but the MDA and or surgeon doesn't want to wait around for them to get deeper. It does have to do with relaxation once the succ was onboard there wasn't a problem getting his legs in the stirrups he was well past an amnestic MAC so I there would be no issue with awareness.

As inhalation agents are taken up, alveolar concentration > blood concentration > brain concentration. Blowing 2.1% sevo means nothing a minute or two into the case - the brain concentration, where all the action's at, is far less. I can crank the sevo up to 6% and they'll be blowing 2.1% out on the 3rd breath - do you really think they've got enough agent on board at that point? Nope.

As far as awareness, I was speaking in general terms, not necessarily about this case, however, my statement is correct. Look at some of the case reports about anesthesia awareness. Many patients got more NMB's, when what they really needed was more anesthesia.

Your OR nurses should wait until you're ready - or at least ask - before putting the patient in stirrups. There was no clinical indication to give sux to this patient. I realize you're not in much position to argue with the docs at this point, but giving a drug unnecessarily to placate an impatient surgeon is not optimum care.

apaisRN, RN, CRNA · Jul 10, 2006

MAC is an ED50. Some patients need more, some less. I wouldn't want to assume adequate anesthesia/amnesia in the face of contradictory evidence.

I have never seen NMBs given for LMAs. Generally I've been taught to go light on the fentanyl, if any, and heavy on the propofol, and use some gas if they're still too light. It seems like a bizarre practice which defeats the whole point of an LMA.