Why Do You…
Williamson County EMS takes airway management seriously. We’ve learned the hard way that sometimes things don’t go the way we want them to. To avoid this, we’ve looked at every part of our airway management process, evaluating each step for ways to improve it. We do this by looking and collecting data on what works and what doesn’t work. We’ve published some of these efforts: We only use the King Video hyper-acute channeled laryngoscope1(there are no DL devices on our trucks) and we do not intubate hypoxic non-arrest patients.2We recently published an expanded discussion of the physiology and research behind our approach to avoiding peri-intubation hypoxia. Unfortunately, those papers don’t have the space to answer some of the more common questions about “why” we do some of these things. So, here is my rationale for why we do what we do. I’d greatly appreciate it if you read my reasoning before firing off the “I’ll stop intubating hypoxic patients when you pry my DL from my cold, dead fingers” tweet.
Why don’t we intubate hypoxic patients? Ever?
Wedo not intubate patients for whom we can’t achieve adequate pre-oxygenation despite our best efforts. Some patients are just not able to get their saturations up. This is obviously true. These patients will often need an endotracheal tube, but the question is when, where, and by whom should it be placed. Intubating hypoxic patients should be done as quickly as possible which means by the most skilled operator in the most controlled environment possible. This is almost never in the field. Placement of a blind-insertion device (BIAD), like an LMA or iGel, is faster, requires less skill, and can provide a degree of airway protection. The patient can then be better prepared and better pre-oxygenated by the time they arrive in the ED where they can ultimately undergo safer intubation. But a BIAD doesn’t protect against aspiration as well as an ET tube, you say. Maybe, but I feel the risks of peri-intubation hypoxia and cardiac arrest are larger than the theoretic risk of greater aspiration. I feel more strongly about this after seeing no difference in aspiration-related complications in two large, well-done, randomized controlled trials comparing ET and supraglottic airways.3, 4
Why do you use DSI on all patients, including those who are adequately pre-oxygenated?
From a physiology standpoint, DSI is unnecessary in these patients. From a logistics and training standpoint, however, I feel it is better to do every intubation the same way. Our system has limited opportunities for intubation outside of cardiac arrest. By using the same procedure every time, we maximize our experience and minimize the complexity of the process. This is important because it decreases the medic’s cognitive load and allows them to focus on the intubation. When I asked my medics about this, I got some very interesting comments. They like it because it gives them confidence knowing they don’t have to rush through an intubation in the mythical 30 seconds. They can take their time (as long as the patient doesn’t desaturate below 94%) and get the tube in on their first attempt. What was once a chaotic procedure is now a calm, quiet process because they are forced to slow down. The three minutes between ketamine and rocuronium, even in patients who are already pre-oxygenated, acts like nebulized Versed for everyone. I do this during my intubations in the ED, too. I feel exactly the same way. Seriously, who doesn’t like nebulized Versed?
Why don’t you allow the use of direct laryngoscopy?
Of all the things I’ve ever posted on Twitter, this seems to have generated the most angst. I might as well have separated children from their parents. First, let me try to convince you not to shoot me. If you have a 95% FPS with a direct laryngoscope, more power to you. Don’t change a thing. I will, however, tell you that you’re full of shit unless you can actually show some data. We all think we’re great but, unless we actually look at hard-cold numbers, we’re likely to be subject to an intense recall bias. We were absolutely amazing with direct laryngoscopy… right up until we looked at our data. I don’t call a 44% FPS amazing. That’s what our actual performance was. With VL exclusively, we now range between 88% and 100% FPS from month to month (we have relatively small numbers, so the rate is subject to wide swings). So, the answer as to why I took DL off our trucks? We were demonstrably better with VL than DL. I felt it would have been unethical to continue with something I knew we weren’t very good at.
“But, but… you could have been just as good with DL if you’d only tried”. Maybe. But, by the time we realized we were much better with VL we were already committed. Turning back at that point would have been silly.
Please, for the love of all that is holy, understand that I’m saying this works for us. If you’re like most EMS systems, I suspect it would work for you, too, but I’m not trying to tell you to give up DL. Keep at whatever you’re doing. I have faith that in 20 years, DL will be on the shelf right next to my beloved LifePak5, PASGs, and all those spine boards that haven’t yet been turned into station furniture.
Why don’t you intubate children (you monster)?
We don’t intubate children at all, for any reason. Instead, we use an iGel. We define a child, for this purpose, as anyone in whom the King Vision blade does not fit. If it fits, we intubate, regardless of age. If not, we use an iGel. I made this decision early on when I reviewed how often we were actually intubating children and, when we did, how successful we were. It was interesting. We weren’t any better at it than we were in adults and, on average, each of our medics would intubate a child once every two and a half careers. We just don’t do it very often. It’s not that our system doesn’t see these children, but we have to divide that by the 130 paramedics in our system. That’s a very, very small number. Skill dilution is real.
As I’m often told on Twitter, perhaps we could be as good with VL in children as we are in adults if we spent as much time training. Perhaps. In fact, I believe we would be. I have the privilege of working with outstanding paramedics. This isn’t a question of their skill. It’s one of priorities. The reality is that any time we spend training costs money. Since my system pays medics pretty well, it costs a lot of money. And, although our Court is very generous in their support, our training budget isn’t unlimited. Every hour of training on pediatric intubation comes at the expense of NOT spending that training hour on STEMI or stroke care. The pediatric airway training would very rarely be used but the STEMI or stroke care would be used very frequently. The value proposition (value of the training / cost of that training) is just not very high. On the other hand, the opportunity costs for pediatric airway training are high. That money is much better spent elsewhere.
So, that’s my quick and dirty rationale for doing what we do. Thanks for reading this. Now fire away… Seriously, I’d like to hear your thoughts.
1. Jarvis JL, McClure SF, Johns D. EMS Intubation Improves with King Vision Video Laryngoscopy. Prehosp Emerg Care. 2015; 19: 482-489.
2. Jarvis JL, Gonzales J, Johns D, Sager L. Implementation of a Clinical Bundle to Reduce Out-of-Hospital Peri-intubation Hypoxia. Annals of Emergency Medicine. 2018; 72: 272-279.
3. Benger JR, Kirby K, Black S, et A. Effect of a strategy of a supraglottic airway device vs tracheal intubation during out-of-hospital cardiac arrest on functional outcome: The airways-2 randomized clinical trial. JAMA. 2018; 320: 779-791.
4. Wang HE, Schmicker RH, Daya MR, et A. Effect of a strategy of initial laryngeal tube insertion vs endotracheal intubation on 72-hour survival in adults with out-of-hospital cardiac arrest: A randomized clinical trial. JAMA. 2018; 320: 769-778.