Airway
Posted: August 17, 2011 Filed under: Podcasts 5 Comments »Today we are breaking from the usual format and doing something a little different. If your patient doesn’t have an adequate airway then we need to provide one. We are the experts in the emergent airway and there’s a lot more to it than shouting out “20 of etomidate and 100 of suxs” like they used to do on the TV show ER. This podcast will go over why we intubate patients, how to prepare for an intubation, the commonly used medications for RSI, tricks of the trade (and maybe a war story or two), and post-intubation management. This is the first topic podcast that is a lot longer than the usual podcasts but airway is our number one priority so it deserves a little extra time.
Also- for the first time ever- a bonus section on a common medical myth. Should you use the D-word for pain from cholecystitis…as in Demerol? Stay tuned after the airway podcast for why this may not be a great idea and why you should just strike Demerol from your memory.
Airway show notes (Word format)
Airway show notes (PDF format)
Carroll -
Solid lecture. If you don’t mind, I’m going to share some points of contention or food for thought…
1. I was a bit disappointed that you put sux in a good light – you are probably the only other person in our program that prefers roc like I do and I did not feel like you conveyed that as well as you do on shift. The onset of roc is really dose dependent with most rapid onset with doses of >1.4mg/kg of total body weight. I think part of the reason why people hate on roc so much is that it is usually mis-dosed – i.e. dosed on ideal body weight instead of total body weight. Additionally, sux has caused cardiac arrest even in those with a normal K+, it’s contraindicated in increased IOP, and it has been called into question in cases of increased ICP. Even if the issue of roc having slower onset – even if it’s only a few seconds – then you can just push your roc at time 0 and then push your sedative right after that. Then onset will be at the same time as your sedative.
2. What is the reason you do not like Versed so much? I think it is still under utilized – especially in the septic patients where our “preferred” induction agent has been called into question. Versed is really the “gold-standard” against which all other induction agents are compared in the literature. While one study has shown that etomidate for induction has no effect on 30-day all-cause mortality, I think that is a bit lofty for anything to demonstrate effects of. It is well-demonstrated that it causes adrenal suppression in the short-term, so why not use other induction agents that we know do not have this effect, i.e. Versed, ketamine, etc.? The only thing that has really been shown to have a change in 30-day outcomes is bug juice and water – so why are we using that as our outcome measure? If the hypotension is an issue then just have neosynephrine standing by. On that note, we like to talk about pressors and have debates about them, but pressors have never been shown to have effects on 30-day all-cause mortality so why are we comparing etomidate to such a standard (or using it as our excuse) – let’s base our usage of drugs on how well they do what they are supposed to do (or in the case of etomidate, not supposed to do). Also, the most recent literature on ketamine has down played the ICP issues, and even our governing body has removed it from the most recent policy statement. Multiple papers have demonstrated ketamine to actually have the opposite effect (i.e. lowers ICP) and to be neuroprotective in the case of head injury. I can provide those references if anyone wants them.
3. The GlideScope – this did not seem get much of your attention. I think that DL is really a dying art, the only place it has much use is for training and the austere environment (though the medics get taught cric’s as first line anyways). Is there a reason why you think that DL would be the method of choice in any RSI situation? In my opinion, there is really no indication for DL in the trauma patient if you have a videoscope available – that should be first line and only line. They have very well-engineered anti-fog and fluid-resistant lenses so I never bought into the BS that a bloody airway makes using DL the procedure of choice. On a side-note, while I am in the minority, the Mac has been shown to cause more C-spine movement than the Miller… and while Mac had more C-spine manipulation than the Miller, both of them did not keep C-spine immobilized. The GlideScope on the other hand removes most of the extension necessary for DL visualization.
I’ll look forward to hearing your thoughts on these topics and look forward to more podcasts.
Schauer
Hey Steve- first, as always, thanks for listening and commenting so I can make this better
1) Just like you, I would like to use Roc more but most attendings are most comfortable with suxs. It will probably take a major shift (like suggamadex finally getting approved) or a generation of “roc users” to rise to senior staff to get more people to use roc. Keep in mind that I’m making this for medical students and interns. If the average med student intern suggested roc to most attendings they wouldn’t go for it. What I tried to do is to present both sides of the argument so that people are aware of the debate, can talk intelligently about both sides, and can make their own decisions when the time comes. I agree with your concerns and I share most of them.
As for suxs, I think the ICP/IOP concerns are overblown- sticking a blade in their throat is what causes the increased ICP/IOP, not the suxs. I agree that the “advantage” of sux’s quick recovery is BS- unless you are tubing a totally healthy trauma patient who is simply being rowdy- you aren’t going to recover a normal respiration pattern or oxygenation/ventilation- you are back to square one and then now what?
I went back to the show notes and I said the same onset for both suxs and roc based on a 1.5 mg/kg dose of either one. You’re right about the actual body weight- while I made sure to mention that that 200 kg patient needs 300mg of suxs, I didn’t stress actual vs. ideal body weight- point taken.
2) I think Versed is a crappy induction agent plain and simple. Its dosing is very unpredictable, it is not as hemodynamically stable as other agents, and the long length of onset (3-5+ minutes) doesn’t make it ideal. I want an agent that will reliably and quickly produce total unconsciousness and amnesia for the RSI. Yes, versed has the retrograde amnesia so even if the patient looks light they still may not remember it but I’d rather be sure- you really don’t want someone to be conscious when you push that paralytic.
I think the etomidate worries in sepsis totally unwarranted. These concerns started years ago in the era when patients would ride for days on etomidate drips in the ICU and they found increased mortality. This is hardly the same as a single dose for RSI. No one has ever proven that etommidate does anything bad to anyone’s satisfaction. Yeah, it changes some lab values but does it change any meaningful clinical outcomes? The best evidence says no. I like ketamine for sepsis as well- it even has its own built in pressor effect! So I have no problem with ketamine and I encourage it- once again, I just wanted to present both sides so people know both sides of the argument and can talk intelligently about it.
I do worry about maintaining stable BP during RSI because if you don’t then your patient will crash. Forget 30 day mortality- if they never make it up to the unit because they tanked from a dose of versed or propofol then you haven’t helped anything. Since etomidate is the most hemodynamically stable agent available I prefer it for RSI. I just don’t believe the adrenal suppression hype. So if you don’t like etomidate, use ketamine, not versed.
I agree- ketamine raising ICP is debunked. Once again, that’s not 100% out there yet and I go back to the average medical student/intern suggesting it to the average attending. So I’ll let people know what the best evidence shows but I have to temper that with the prevailing practice patterns. I don’t like having to do that but its the fairest thing to do for the target audience.
3) First- I agree, I short changed the glidescope. I tried putting in a section on using it and it really broke up the flow. After your suggestion, I’ll probably do a bonus section in the future with how to use the glidescope so thanks for the feedback.
However- I firmly disagree with you on this- to call DL a dying art is a dangerous thing. I believe that you need to be facile with every possible airway technique- from BVM bagging with a nasal/oral airway to DL to flexible fiberoptics to glidescope to the bougie to a surgical cric, etc. What happens when you are somewhere that has one glidescope available (or one of the two is broken- how often do we see that?) and it craps out on you? Are you going to cric someone because you never really learned how to DL someone? I have also had specific cases where the glidescope, in experienced hands, failed to provide an airway where DL succeeded. You can also have fluid resistant lenses as much as you want but I’ll tell you from my own experience that its hard to suction effectively when you are sticking in a suction catheter next to a glidescope instead of doing DL.
I wasn’t aware of the mac and miller data in c-spine injury but it makes sense. I’ll admit I could use more practice with a miller blade- I would probably need a month in the OR doing 30+ miller intubations but that’s a pipe dream because LMAs have taken over OR airway management and I would still have to fight for those tubes. I’ll probably go to Levitan’s course in Baltimore when I’m staff and have the money but until then I think I speak for most people when I say that mac blades are what we know and love. (Yes, I know this is the same crappy argument for using suxs instead of roc but you have to be honest about your own abilities and experience and mine says that I just don’t have enough practice with a miller)
Out of curiosity- how much more movement are we talking about? Is it truly clinically significant or is it just statistically significant? Obvious answering the clincial significance would take a huge trial that would never make it past an IRB but I’d be curious to know how big the difference is on a numerical/percentage basis.
Thanks for listening
Steve
1. With regards to the adrenal suppression issue, I go back to what we decide are the goals that we are aiming to change. The goal of a drug, procedure, etc. should be to evaluate how well it does what it is intended to do or not to do. The etomidate has been evaluated for adrenal supression and the literature says just that – it causes adrenal suppression. In response to your statement: “Yeah, it changes some lab values but does it change any meaningful clinical outcomes?” – I would like to spin that back around to the use of pressors (since we all use them). There is no evidence that the use of pressors has any effect on mortality, so why is it that we will use the argument for continuing to use etomidate, but do not apply that same logic to pressors? Along the argument I am making, pressors have no effect on mortality – however, they do have effects on what we use them for – blood pressure (another number).
2. Why is it that you suggest an asthmatic be placed on 0 PEEP? That seems a bit low since that won’t even provide enough support to overcome the resistance of the tube, no?
3. The movement of the Miller vs Mac is really just a statistical matter without any real clinical significance. I just like to pull it out when people start hating on my Miller blade. In actuality, most of the worries about C-spine injury when intubating trauma patients is wayyyyy over-played. There is no data to support most of the griping. There was a recent paper published looking at all the closed claims filed with the major malpractice insurers for anesthesiologists and almost none of the major injuries were tied to trauma intubations; most of them were involving a patient for non-trauma surgery with known C-spine issues. I’ll list one of those articles below; the other one is on my other computer in San Antonio so I’ll have to post it when I get back. I really think that some recent literature in NEJM demonstrates that the fears of malpractice suits are probably over-blown.
Hindman et al. “Cervical Spinal Cord, Root and Bony Spine Injuries, A Closed Claims Analysis” Anesthesia, V 114, No 4
4. I didn’t mean to say that DL should no longer but taught. I was really referring to its use as being a dying art outside the realm of teaching purposes. By the time you and I are “senior staff” DL will go by the wayside, much like the DPL of previous generations. Once the technology that replaces it becomes more wide-spread its use will become obsolete.
5. On a side note, why did you design the program for interns? It’s a solid review for non-interns as well.
Hey Steve
1) I get what you are saying. I agree that the adrenal suppression exists but I just don’t think its clinically significant. In the end it comes down to this- I believe that either etomidate or ketamine are perfectly fine for RSI in sepsis or any other critically ill patient- they are both great agents that do what you want (rapid unconsciousness/dissociation) without clinically significant side effects- etomidate with adrenal suppression and ketamine with the increased ICP- both of which are probably not clinically significant (although after Friday’s grand rounds, I now understand that we should be talking more about increased cerebral blood flow- CBF- not ICP- another topic for another day)
2) So this is something that Scott Weingart of EmCrit advocates. The concern here is that any PEEP will cause breath stacking and that PEEP is not necessary in these patients. You want them to have a long amount of time for expiration and taking away the PEEP allows this to happen more effectively. From my memory- he does say that if you can’t handle seeing zero PEEP on the settings then you can do 2 or 3 to make everyone happy but NEVER higher than 5. I’d have to go back to the podcast (I think its called “How to dominate the vent) to quote exactly what he said about that 2 or 3 PEEP setting but he’s a big advocate of ZEEP. To me, it makes physiologic sense.
3) I gotcha on the miller vs. mac. I’ll never hate on someone using a miller blade if they tell me that is what they are the most comfortable and successful with. On the flip side, I wouldn’t tell someone who is most comfortable with a mac to stop using it in trauma patients because of a concern for increased c-spine movement that is probably not clinically significant. Go with what you are comfortable with. (Heck, we’ve never even proved that c-collars work, in fact in a large trauma data dredge, those who didn’t have a c-collar placed in the field had a lower overall mortality than those that did. It was most likely due to decreased transport times and not putting on the actual collar but it raised an interesting point).
4) Point taken- we should progress to new technologies- people didn’t stay with horses forever because cars may break down. I think we are in agreement that DL always needs to be taught. Since the learning curve for DL is a lot steeper than the glidescope I think we need to start with the basics by teaching DL and then progressing to the glidescope. I still think that my DL skills assist me in getting the best glidescope view because I understand the anatomy.
5) I’m glad that you think that it’s a solid review for upper levels as well. I just want everyone to know that is the level I am teaching to so they know what level of review to expect. I also want to make it clear that I’m not talking as an expert in the field with my own practice based opinions the same way EmCrit or similar podcasts do- I’m just doing a review of the basics because as a 3rd year resident, it’s what I’m qualified to do.
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