Endotracheal Intubation vs. King LT

[systemet]

I know evidence outweighs opinion and experience but with the number of LMAs being used in the OR, I find it hard to believe that we haven't seen a problem, assuming one exists. You would think that something like this would be pretty easy to study. I would do it in a place with high survival rates the first time around and then if there is a difference, run the study in more average areas.

It seems like anesthesia occasionally uses the LMA for neurosurgical procedures, so you'd think if it decreased CPP, they'd noticed pretty quickly in someone with bolted with an a-line. Of course the corresponding pressures are much lower during CPR, and hardly resemble normal physiology. The newer devices, e.g. King, EGTA, iGel, etc. obviously have a smaller weight of evidence behind them, although I'm sure much of it is probably generalisable.

I said earlier the Hasegawa study had n = 65,000. It appears I was wrong, it was n= 650,000 : http://www.ncbi.nlm.nih.gov/pubmed/23321764

There's a good discussion of the relevant issues here: http://www.ncbi.nlm.nih.gov/pubmed/23519082

The problem here, is no one has run the RCT yet (for airway management in out of hospital cardiac arrest). There's a fair amount of retrospective data, but when you start seeing papers like Bobrow et al., where there's a survival benefit to apneic oxygenation (http://www.ncbi.nlm.nih.gov/pubmed/19660833), or this huge Hasegawa paper, it's clear that it needs to be done.

This is being looked at currently, although it's probably more of a 2020 guidelines issue:

http://www.clinicaltrials.gov/ct2/show/NCT02090218?term=cardiac+arrest+airway+management&rank=1

http://bmjopen.bmj.com/content/3/2/e002467.abstract

http://www.clinicaltrials.gov/ct2/show/NCT01718795?term=cardiac+arrest+airway+management&rank=8 (Looking at effectiveness versus survival)

[triemal04]

ROC has been kicking around doing a randomized study looking at ETI and supraglottic airways during cardiac arrest for awhile; from what I head a few months ago it may actually be in the works after the completion of ALPS. The problem is that there are a few ROC members who will catagorically refuse to be involved in this, including some that already have both high resuscitation rates, and high first pass success rates for ETI.

A true randomized study absolutely needs to be done, but as with all studies on paramedic ETI, it has to first use services that are truly competant at intubation before it's studied in the average service. Depending on the study design, that may be hard to do.

[systemet]

ROC has been kicking around doing a randomized study looking at ETI and supraglottic airways during cardiac arrest for awhile; from what I head a few months ago it may actually be in the works after the completion of ALPS. The problem is that there are a few ROC members who will catagorically refuse to be involved in this, including some that already have both high resuscitation rates, and high first pass success rates for ETI.

A true randomized study absolutely needs to be done, but as with all studies on paramedic ETI, it has to first use services that are truly competant at intubation before it's studied in the average service. Depending on the study design, that may be hard to do.

Yeah it's tough. I talked to one of the KCM1 medical directors at a conference earlier in the year, and it sounds like they're doing continuous asynchronous compressions with an OPA, then intubating at the 10 minute mark, in most of their patients. And when they're intubating, they're doing it without pausing compressions.

And it's working for them, clearly.

It's hard to expect them to turn around and go to standard ACLS, and attempt to capture the airway in the first few minutes of the code, or to use an SGA when they have a high intubation success rate and a strong QI/QA program.

The problem almost becomes, with services like that contributing large numbers of patients to ROC, is does their data really resemble the average system, with less motivated medical control, less experienced providers, weaker QI/QA, etc. At a certain point, you start wondering, can I really generalise this to other centers, because they don't have these things?

It's the same situation with some of the ETI versus SGA versus OPA resulsts, is do they reflect data from services with optimised resuscitation care? Because if there's clear basic steps that need to be taken for these services to start approaching Seattle rates, then these are the obvious first steps that should be taken.

Then again, how much of Seattle is demographics, PAD, citizen CPR training, and how much is targeted ALS -- because no one's really shown a benefit for ALS in an RCT environment yet.

[Edit: spelling, grammar, etc. -- got some, missed some.]

Edited December 3, 2014 by systemet

[triemal04]

I don't know that I'd call it a problem, just that the results from services like that encompass more than a simple "this is good or it isn't" answer. In all honesty, for the vast majority of paramedic services, paramedics shouldn't be intubating, and it's very likely that doing so really does more harm than good, or at best has zero benefit over a different type of airway. If you first focus on services that are proficient at it, the results would show that (assuming that was the outcome) intubation is good IF it's done by people who are good at it; then it would need to be replicated at the average type of service to see if there was a difference.

This was sort of seen in the last study put out by, I think, Wang; he used ROC data (from PRIMED I think) and came to the conclusion that paramedic intubation was detrimental. BUT, at the end of the study there was a brief section that went over the fact that when the data from certain high performing subgroups was analyzed the opposite was true. That is what needs to be emphasized more than just a blanket "don't let paramedics intubate."

Granted, there are other confounders when you look at most high performing systems, but the best benefit of studying those systems would be to push others not to do the same skills, but to do the same skills at the same level of proficiency; that's what should be taken away from a study like that.

[BAYAMedic]

Doc,

Yes LMA have been used in OR a lot. But that is a far more controlled setting. Only after 6-8 hours fasting, with no history of reflux, when ETT has been used in less controlled airways for ages.

BayaMedic

[ERDoc]

I'm talking as far as the concerns for decreased cerebral flow with an LMA. You do bring up some concerning variables however. In the field, you have to deal with gastric distention from an overly aggressive firefighter bagging the pt before you got there. I still think an LMA is the best way to go in most situations until you get ROSC, then drop in the ET tube.

[BAYAMedic]

Ok it is late so I am shooting from the hip Doc. From what we know about apneic oxygenation from the dog labs and needle cricothyrotomy. And the results of NODESAT of high flow nasal cannulas utilizing saturation gradient apneic oxygenation during ETI/RSI. And the diminished venous return do to increased intrathorassic pressures with ET/SGA placement, to eliminate any Starling pressures possible, when do we say throw a NRB at 25LPM (or cannula with capnography to catch moment of ROSC), focus entirely on CPR and zip in an IO for EPI?

Its late, pardon the scattered thoughts.

BAYAMedic

[ERDoc]

You made my brain hurt and it's too early think. I don't think there are good answers to those questions (at least backed up by literature). My feeling is that we know the most important thing is to preserve coronary perfusion pressure, which means good, continuous CPR. If you have that going, anything else is icing on the cake.

[triemal04]

Ok it is late so I am shooting from the hip Doc. From what we know about apneic oxygenation from the dog labs and needle cricothyrotomy. And the results of NODESAT of high flow nasal cannulas utilizing saturation gradient apneic oxygenation during ETI/RSI. And the diminished venous return do to increased intrathorassic pressures with ET/SGA placement, to eliminate any Starling pressures possible, when do we say throw a NRB at 25LPM (or cannula with capnography to catch moment of ROSC), focus entirely on CPR and zip in an IO for EPI?

Its late, pardon the scattered thoughts.

BAYAMedic

That was the entire thinking behind what used to be called "cardio-cerebral resucitation," ie CCR; it may be called something else now, not really sure. It made a decent sized splash maybe 5-6 years ago, though probably not as big a one as it should have, but it did result in some departments changing how the run a CPR and to the deemphasize on intubation by the AHA.

[rock_shoes]

ROC has been kicking around doing a randomized study looking at ETI and supraglottic airways during cardiac arrest for awhile; from what I head a few months ago it may actually be in the works after the completion of ALPS. The problem is that there are a few ROC members who will catagorically refuse to be involved in this, including some that already have both high resuscitation rates, and high first pass success rates for ETI.

A true randomized study absolutely needs to be done, but as with all studies on paramedic ETI, it has to first use services that are truly competant at intubation before it's studied in the average service. Depending on the study design, that may be hard to do.

I work in one of the services you mention. I can absolutely confirm BC ALS providers will not buy into the proposed SGA versus ETI study. We have some of the best resuscitation and first pass ETI rates in Canada. I suspect the ETI success rate in BC is largely attributable to the fact an average ALS provider can expect to perform at minimum 20 to 30 intubations per year.

The damned if you do damned if you don't part of the whole thing is that the systems you need to play ball, like BCAS and Seattle King County, are the most likely to pack up their things and go home should such a study be dropped on them.

Possible reasons for these services success rates are numerous. Here are a few of the easily identifiable culprits for anyone not familiar with these services.

1) High level of intubation experience.

2) CPR continued and never stopped during intubation attempts (This is drilled in at every opportunity. CPR does not stop for intubation)

3) Regular Airway Management review/training (BCAS uses the AIMS program)

4) High levels of cardiac arrest management experience (ALS providers can expect to work at minimum 15 to 20 arrests per year)

5) Increased venous return as a result of eliminating intrinsic peep via intubation (something that does not happen using an EGD)

The number of variables are staggering when you really start to look at it. What is best in one service delivery model is not necessarily best in another.