Mivacron and RSI

[maturner]

AS with many others, I would like to see more clinical type discussions on this board.

I was speaking with a mivacron rep last week and he was telling me that you can reliably get a block in 90 sec with miv. if you give .25 mg/kg in divided doses. (i.e. induction agent, .15 mg/kg miv, wait 30 sec, .10 mg/kg miv, and 60 seconds later have a complete block) Per the rep, divided doses are preferred to minimize histamine release.

Out of curiousity, I asked if they had heard of anyone using miv as an RSI drug? He replied that it is not labeled for rsi, but people have used it as such. I left it at that, but was curious if anyone has seen miv used in RSI situations?

I can't really think of a situation where the R&B of miv would outweigh the R&B of SUX or roc and be the preferred RSI drug.

What do you guys think?

[athomas91]

a few of the docs i have worked w/ also like it in kids for ultra short procedures - it seems to work fine for that - but i agree otherwise - not really used much.

[Athlein1]

I tried it once for a rapid intubation, though it was not a true RSI. Despite divided doses, patient flushed red as a beet within just a few seconds. BP in toilet, impressive tachycardia. Healthy adult, fortunately. Took quite a bit of neo to get it resolved, as I remember. By the time I was done treating the hemodynamic changes, the patient was bucking.

I have used miv successfully a few times for T&As PSR, and it came in handy when I switched from a private practice clinical setting back to a teaching hospital. During the few days it took me to readjust to looonnnnng closures, I used it for relaxation after the intermediate agent wore off and before extubation (nimbex + miv).

I can also attest to the foolhardiness of mixing benzylisoquinoliniums and aminosteroids. Did this with vec + mivacurium as described above. Pt was significantly weak for over an hour! Caution!

[gaspassah]

i like miv in cases of when the surgeon is rolling his eyes cause he cant close the fascia on a lap case (not that he cant, it's just easier) and the roc or vec has worn off (like i wanted) so i give a little dose of miv, lasts about 15min then it's gone.

d

[air]

this is just from my experience.

We learned about mivacron sometime last fall.

I never saw that drug until this summer, at a clinical site in new york.

I used it steady for a solid three weeks.

The CRNA that introduced the drug to me in clinicals was trying to facilate rapid induction without need for reversal and to accomodate fast surgeons without subjecting patients to apparent delayed muscle pain that comes with anectine use(from my post-op reviews, i have not had a patient complaint of this pain that we sometimes hear about)

Three times with LMA's for femoral hernia repairs when the surgeon working with residents all of a sudden decided that he could use some relaxation(until this time, i had never given NMB to patient with LMA's).

I learned the trick is to push it slow.

We gave a fraction of the STP or propi. dose then mivacron, then the remainder of the STP or propi. We allowed the patients to breath 100% pure oxygen by mask. (program rules:CRNA or MDA must be present for induction and emergence of general anesthesia) I was allowed sometimes to bag the patients once to confirm "able to ventilate" sometimes the mivacron worked faster expected. For inductions we always used 0.2-0.3mg/kg dose.

I have to admit twice when i used mivacron followed by ZEM for TAH, I found it difficult to extubate, because these patients were too weak despite reversal. WE had the uneviable task of ambu-bagging the patients to PACU, then placing them on a respirator for a little while with 1-2mg of IV versed(usually less than 15-20mins).

We avoided your typical COPD patients and those with questionable pulmonary status. We did not attach serious attention to their CV status. I used alot of it on kids. sweet drug.

[jwk]

this is just from my experience.

We learned about mivacron sometime last fall.

I never saw that drug until this summer, at a clinical site in new york.

I used it steady for a solid three weeks.

The CRNA that introduced the drug to me in clinicals was trying to facilate rapid induction without need for reversal and to accomodate fast surgeons without subjecting patients to apparent delayed muscle pain that comes with anectine use(from my post-op reviews, i have not had a patient complaint of this pain that we sometimes hear about)

Three times with LMA's for femoral hernia repairs when the surgeon working with residents all of a sudden decided that he could use some relaxation(until this time, i had never given NMB to patient with LMA's).

I learned the trick is to push it slow.

We gave a fraction of the STP or propi. dose then mivacron, then the remainder of the STP or propi. We allowed the patients to breath 100% pure oxygen by mask. (program rules:CRNA or MDA must be present for induction and emergence of general anesthesia) I was allowed sometimes to bag the patients once to confirm "able to ventilate" sometimes the mivacron worked faster expected. For inductions we always used 0.2-0.3mg/kg dose.

I have to admit twice when i used mivacron followed by ZEM for TAH, I found it difficult to extubate, because these patients were too weak despite reversal. WE had the uneviable task of ambu-bagging the patients to PACU, then placing them on a respirator for a little while with 1-2mg of IV versed(usually less than 15-20mins).

We avoided your typical COPD patients and those with questionable pulmonary status. We did not attach serious attention to their CV status. I used alot of it on kids. sweet drug.

Why use mivacron then roc? Why not just roc all the way?

[air]

Why use mivacron then roc? Why not just roc all the way?

sometimes, surgeons change their minds and require muscle relaxation. Efven though they may have previously said they would not require it throughout the case

[rn29306]

This is only my opinion, however small it may be, but mivacron sux quite literally. Who in their right mind would use this as RSI, you might as well not even call it RSI. Onset too long and S/E are terrible. Hey you might as well do Norcuron with cricoid pressure. Same onset, more predictable, and CV stable. Yeah, duration times are diffferent, but RSI's goal is to take from awake state to asleep with cuffed OETT in place as quickly as possible. We all know that so why even consider this stuff?

Mivacron, ie: mivacrap, movacron is just poo-poo.

Only potential place I see it (and I use potential very lightly) is PERHAPS peds outpatient ENT when requiring a tube to be placed. Me personally, I'd rather breathe the little boogers down with gas, get PIV access and not even fool with it.

[alansmith52]

we jokingly call it mivamove, but use it from time to time anyway. including RSI:

heres my explanation if anyone cares.

in my mind I do RSI for one of two reasons one umbrella is the full stomach umbrella, i.e. gerd, diabetes, pregancy ect.

the other situation is AIRWAY if I have a difficult airway. lets take a big fat guy with no chin who i also my think may have extrajuctional receptors or a K of 5.7. i want to intubate but on the off chance i cant ventilate or intubate i pray he will breath on his own soon right?

I dont want sux for the k issue. and i dont really want to use roc either cuz its gonna be too long before he breaths. I say miv is an option. you might argue if i have all these conditions i might opt for fiber optic or awake fiber optic or awake look, which i would probably do but hey we are talkiing about RSI right.

any way that is when i have used it and i havn't actually had a situation that i could not intubate or ventilate to test the theory that miv would ware off fast enough for the pt to breath spontaneously so its unproven at best.

word.

[jwk]

sometimes, surgeons change their minds and require muscle relaxation. Efven though they may have previously said they would not require it throughout the case

The example you used was mivacron then roc for a TAH. To me that makes no sense. You used two drugs where one would do fine, and you have the cost of two drugs instead of one, and in your two cases, got burned and had to leave your patient on a vent post-op.

Also, remember that mivacron is metabolized by pseudocholinesterase, so you have two drugs with two different elimination pathways as well.

And for pedi case requiring an ETT? Get em deep, give them some IV lidocaine, tube them with no muscle relaxants of any sort.

[maturner]

It has been interesting seeing everyone's opinion regarding the issue.

As the OP, It would be unsporting to not throw my hat in the ring.

I have used the drug a couple dozen times and had issues a couple of times and both were what I consider my own errors and not a problem with the drug. Both times have been at the 0.2mg/kg dose. The first was a musclebound guy in his midtwenties and I gave the 0.2mg/kg based on IBW, waited 2 minutes touched him with the larygoscope and sure enough he moved. I continued to bag for a minute with gas on and intubated a minute later with no problems. I should have dosed more in line with his actual body weight

The second time, I pushed the drug slowly on a woman at 0.2mg/kg and she relaxed slooowly. Tried to intubate at 1.5-2 minutes and sure enough she moved, she was Intubated a couple minutes later with no problems. I was to impatient and should have allowed more time.

After the second incident, I discussed miv with my attending and they suggested divided doses 30 secs apart and I have had no problems since.

Since speaking with the rep last week, I have had the opportunity to use the drug twice. Both times I used the 0.25 dose i/o 0.2 (0.15, waited 30 seconds, then 0.1) and both times I was able to intubate 90 seconds after the first dose with wide open cords and no movement.

Conclusive? No, but I was impressed. However, I did have sevo on at 3-4% which combined with the induction agent, versed, a touch of fentanyl and relaxant may have sped up the process...

As far as RSI, I think there m i g h t be a rare occasion where someone could justify its use. Such as a strong contraindication for succs and a clear problem with the duration of action of roc. Although, clearly only after other options prove impossible such as awake fiber optic, etc.

I think if one could get a reliable block in 90 seconds, it could be used in a "modified" rsi with someone holding cricoid as the patient is being bagged. Where the indication for RSI is there but marginal such as occasional reflux, etc. and the case is short with relaxation not required for the procedure itself.

anyway, thats my very humble opinion

[air]

The example you used was mivacron then roc for a TAH. To me that makes no sense. You used two drugs where one would do fine, and you have the cost of two drugs instead of one, and in your two cases, got burned and had to leave your patient on a vent post-op.

Also, remember that mivacron is metabolized by pseudocholinesterase, so you have two drugs with two different elimination pathways as well.

And for pedi case requiring an ETT? Get em deep, give them some IV lidocaine, tube them with no muscle relaxants of any sort.

The economics you talk about makes sense

Remember I am a student, economics usually does not come into play for me.

Most hospitals here in PA, require and MDA to be present for inductions, usually they want in and out in seconds, therefore you need a drug with rapid onset, then once after induction you can do what you please.

Anyway, during the TAH, that is what happened.

[jwk]

The economics you talk about makes sense

Remember I am a student, economics usually does not come into play for me.

Most hospitals here in PA, require and MDA to be present for inductions, usually they want in and out in seconds, therefore you need a drug with rapid onset, then once after induction you can do what you please.

Anyway, during the TAH, that is what happened.

I intubate on roc in less than a minute. You won't get good enough relaxation with mivacron to do that.