December 15, 2023
How often do we, as Emergency Medicine clinicians, have to do a surgical airway aka cric? Is that number changing with time? We attempt to answer these questions with a review of some current literature.
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Hello everybody and welcome to SimKit and our conversation today, the uncommon cric. What we’re going to be talking about is incidence really related to the surgical airway? Collectively, I want to open with just sort of a thought experiment, a little meta cognitive thing that I’ve been kind of rolling over and I like to sort of frame this conversation around. We at SimKit, we teach procedural skills, procedural skill maintenance, procedural readiness in high acuity, low occurrence Halo procedures. And so I’ve been thinking recently and sort of in prepping for this podcast- the question “how rare would a procedural need have to be for you to deem it not worth you or your team’s time to having your armamentarium?” how uncommon then would a procedural need be for it to not be worth it because our time, our knowledge, our resources are not infinite, right? They are finite and so we do have some point in time we say it’s just probably not worth it to maintain a skill in it, to maintain the equipment in it, to train our team in it. Again, this is metacognitive. I don’t think that there is necessarily a procedure in emergency medicine that meets that threshold. And of course, there are questions and caveats that go with that broad based question. What is the procedure preventing? Is it limb loss? Is it vision loss? Is it life loss? How involved is the maintenance of the skill? What equipment is needed for that procedure? How often does that equipment expire? How trained up to your nurses and your techs n addition to your physicians have to be? There’s a lot of questions that go into that specific question, but I think it’s a worthwhile question to ask ourselves. I personally have not found a procedure that we train ourselves for that has met that threshold criteria of not really being worth it, mostly because the procedures we train in in these Halo circumstances are usually lifesaving, so the degree of rarity is hard to quantify in terms of when it would no longer be valuable for your team to train up in, but I just wanted to open with that question. Just to get your cerebral juices flowing as we talk about and think about Cricothyrotomy and its incidence and how often we have to do it. How ready we have to be for it.
So background for this. Obviously Cricothyrotomy is the endpoint in most failed airway algorithms. We go through the vortex or we go down the options. It depends on how you set up your failed airway algorithm, but at the bottom of it. It is usually involving cutting the neck. The incidence or the amount of times we would have to do that is evolving, right? It’s evolving for many reasons. I like to think it’s evolving because of our skill in intubation, but also technology is advancing.
We’re going to look at a specific article here in the American Journal of Emergency Medicine. It is by Offenbacher at all called “incidence of rescue airways after attempted orotracheal intubation in the emergency department, a national emergency airway registry or near study.” This was published again in American Journal of Emergency Medicine in June 2023. And in the introduction of the paper, they framed it similar to the introduction to this podcast. We have a general idea, you may or may not know the numbers for how common cricothyrotomy has been in sort of medical history, but what is the actual incidence today, as our skills and technology evolve? The current incidence they state of surgical Airways in the ED is not unknown, but prior work has demonstrated that a rescue surgical airway would occur in about .3 to 1.1% of general emergency department intubations so .3 to 1.1% is what’s in the quoted literature up to this date.
So with that frame, let’s dive into what they went into this paper. Now caveat, we are not going to be talking about this paper in the way we have broken down other articles in the past where we have their population, their primary outcome, their secondary outcomes, their methods, their results, etcetera. Not the way we do a typical scientific review because really we’re just looking for a number here. Right? The goal of this article is to say how common is cricothyrotomy now? So what did they do to answer this question, it is again a near registry database data set, so this is looking at intubations done in 25 centers across the country and looking retrospectively and getting information about how we practice and the incidences of different things here they’re talking about rescue surgical airway.
So I do want to put a quick caveat to. What they are trying to find is how many oral tracheal intubation attempts lead to a surgical airway, lead to Cricothyrotomy. That is a slightly different question than how many cricothyrotomies do we do on patients in the emergency department. And the reason why this is slightly different is probably very rare or pretty uncommon that cricothyrotomy would be our first move in securing the airway, but this data is looking at when someone’s going for an oral tracheal intubation and they do not succeed. How often do they have to go, you know, to a surgical airway or how many attempts at oral tracheal intubation lead to that? Now you can imagine someone with profound oral trauma, their jaw is wired shut. They have laryngeal or other cancer that makes it impossible. Maybe they have angioedema, ludwigs angina and you have no access to fiberoptics. There are other times when a surgical airway may be your first move, which is actually going to increase the numbers compared to what we’re talking about today.
So with that caveat in mind, let’s take a look at their data set and their numbers. As I said in the beginning we’re trying to get a sense of the current incidence, the current likelihood of an intubation leading to cricothyrotomy. Let’s recognize then that we are looking at the NEAR data set and their data. Their subjects are from January 1st, 2016 to December 31st, 2018. So nearly five years old already. It’s still more current than that prior sighted incidence of .3 to 1.1%, but we’re we’re not dealing with quote unquote current data. Specifically at best, we got about five years old. So with that in mind, they had in that time frame from 2016 to the end of year 2018, 19,071 intubations. If you have the paper in front of you, take a look at figure 1 and it sort of does that sort of flow down to their total numbers. They start out with 19,000 and change. Very importantly, as I mentioned, there is an exclusion. They exclude 315 surgical airways as first attempt intubation of existing tracheostomy or tube exchange. Now I went into the supplemental data here to see if they broke those numbers down even further. Most importantly, trying to find the number of surgical Airways as first attempt, and unfortunately they do not do that. Their goal again is to see when we’re going for an intubation- How often are we going to actually have to do a surgical airway? Different than how many total surgical airways are we going to have to do? Either way, they excluded those, they got to 17,720 patients from those. Thankfully, the vast majority did not require a rescue surgical airway and in the end we saw 49 subjects requiring cricothyrotomy. So out of 17,720, they had 49 surgical airways creating an incidence of 2.8 cases per thousand or .28%. Saying that another way, when we go to intubate someone about one in 350 will result in a cricothyrotomy. And just to say those numbers again for you, because we went through them kind of quick, they started with 19,000 and change they got to 17,720 that were undergoing intubation, 49 of which required a surgical airway that was 2.8 cases per thousand. 0.28% of intubation cases. One in 350 that required a surgical rescue airway.
Of course, as you’re given these numbers, you have to ask yourself certain questions, right? Who were these people? Who were the intubators? We know the NEAR database. The NEAR centers are Large academic tertiary centers and yes, they had learners, but they also had a lot of the bells and whistles. If we look at table 2, we see that direct laryngoscopy obviously was there video laryngoscopy was available there as well and actually they had bronchoscopy assisted intubations as well. So they had the modern technology at their disposal. There are pros and cons, obviously, in the debate about the safety and execution of an intubation in an academic tertiary center versus elsewhere. But modern technology video laryngoscopy available bronchoscopy assisted intubations available leads to that number one in 350.
Speaking again to the centers in which this data was collected, we see the indications and the amount of cases that required cricothyrotomy very interesting, about half of them were trauma cases. 25 of the 49 leaving 24 of the 49 as medical cases. So pretty high incidence of trauma as the indication leading to a cricothyrotomy. And these people were sick, sick, sick, sick. 14 of the 49 were in arrest at the time of the initial oral tracheal intubation. The average number of attempts before moving to the surgical airway was two. And of course, as you might imagine, the likelihood of doing the cricothyrotomy in a patient in arrest increased with the number of attempts before converting to surgical airway. The more we mess around trying to get the airway, not wanting to cross that line in the sand, the more likely the patient was to decompensate.
Now coming back to that question of how often do we as emergency medicine providers have to do a cricothyrotomy versus how often does an intubation attempt lead to a rescue surgical airway which are only subtly different. Obviously the vast majority of our crics are going to be down the failed airway attempt. But as I mentioned in the beginning, there are some other reasons just trying to dive into that a little bit more, get a little bit more clarity there. we’re coming again back to that figure 1, that 315 exclude patients. Unfortunately the supplemental data does not give us much more in that. But this is again the NEAR data set. There are other articles published on this same cohort of 19,071 patients. The one that I went to was the “extragalactic device use is rare during emergency airway management, A NEAR study” with the primary author Michael April. In this article they cite that there were 65 total surgical Airways out of the 19,071. That’s of course more than our 49 and maybe helps clarify a little bit of that exclusion that we see in Figure 1, not the 315. I bet you a lot of those are tube exchanges or intubating through tracheostomies or what have you, but maybe 65 instead of 49 for the total cohort, that doesn’t really change our incidence that much. It goes from 2.8 cases per thousand to three cases per thousand, or, 0.3% versus .28%. Raw numbers. Still roughly the same. We’re looking at roughly one in 350, maybe one in 325 airway attempts are going to be done or completed through a surgical airway. Again, this is a little extrapolation. It’s just a little bit of sleuthing, detective work I did to try to figure out more about maybe the patients that got surgical airway first.
But I don’t want the forest to be lost for the trees. Collectively, we’re seeing our incidence is on that smaller side of the reference range. If you remember in the beginning we said .3 to 1.1% was what was cited in prior literature. With our improvement in our medical training, our residency programs and of course of course, of course the technology at our disposal with video laryngoscopy nasal fiberoptic options, all the things that we have, bells and whistle, why’s the incidence of cricothyrotomy is likely dropped. Now one in 350 makes me feel better about our skills as intubators, our ability to secure the airway by less aggressive means. But coming back to that first metacognitive question, it does not give me ease or pause to say I don’t really need to maintain my skill in crioothyrotomy. Obviously you don’t know in that one in 350 when you are going to be drawing the short straw and getting that one instead of that 349. We gotta be ready. We gotta be skilled at it. I love this data. I like having this in my mind as we go through our airway algorithms and think about patients and I want you to have that for yourself as well. Know your numbers, know your likelihood of this, but always of course, be ready to perform when the time arises.
So with all that said, let’s do a little summary and wrap up before we conclude today, we start with a metacognitive question of how infrequent would a procedure need to be for us to not feel like we have to maintain our skill in it, it is again not applicable to our case here, but something that we want to have in our minds. We then went in and started to talk about how often are we, or should we be expecting to be doing cricothyrotomy in the modern era? Prior data was 0.3 to 1.1% of Intubations. We’re looking at the NEAR data set which we’re calling quote unquote, modern era. Again, this data set is about 5 years old, but they found that in 17,720 intubation attempts, 49 required a rescue surgical airway. That’s 2.8 per thousand or one in 350 roughly. This gives us a sense of confidence in our ability to secure the airway by less aggressive means, but know that we may draw that short straw. We need to be ready and as we saw in this article, we do not want to delay crossing that line in the sand because worse patient outcomes happen with that and doing a cric while they’re doing compressions is certainly a lot worse then stepping across the line earlier and securing the airway before the patient decompensated.
Thank you so much for listening. And until next time.
Incidence of Cricothyrotomy in the Past
The likelihood of needing to preform a cricothyrotomy on a patient in the ED has been evolving with time. In some institutions where the C-spine was in question and an airway needed to be secured, cricothyrotomy was the go-to in the days of old. Of course that is not the case any longer.
In terms of intubations needing to progress to cric, the data has been varied but seems to fall somewhere between 0.3 and 1.1%, or 1 in every 100-325 intubations, as noted in the introduction of the article highlighted in this podcast .
The question we are looking to answer now is:
What is the current likelihood of having to preform a cricothyrotomy on an ED patient?
As you will note if you listen to the podcast, this is slightly different than the question being asked by Offenbacher et al. in their paper- who really asked “when going to intubate an ED patient, what is the probability of having to do a cric?” The subtle difference here lies in the notably few patients where cricothyrotomy is the first (or only) option for securing the airway- maybe bad facial trauma, angioedema, etc. This is a small difference that likely does not affect our overall numbers, but worth pointing out.
Notably though, the surgical airway/cric is the endpoint of most difficult intubation algorithms, as see in the Difficult Airway Societies flowchart below. What we are trying to find out of course is-
Are we going down this algorithm more or less frequently than we used to?
Incidence of Cricothyrotomy Today
In this NEAR registry data set, they started with 19,072 patient encounters, excluded 1036 for being <14 years old and 315 where surgical airways was the first attempt, they intubated through a trach, or did a tube exchange. Unfortunately, in the article and supplemental data they don’t separate these 315 patients out more.
They are left with 17,720 patients getting intubated, 49 of whom went on to get a cric. This gives an incidence of 0.28%, 2.8 per 1000 intubations, or
1 in ~350 intubation attempts progress to cricothyrotomy
A Little More Data Dissecting
A few other interesting elements to the data:
- Of the 49 crics done in this data set, a large percentage (25 of the 49 total cases) were in trauma patients.
- The providers had the modern bells and whistles. Table 2 shows the use of Direct Laryngoscopy as well as Video Laryngoscopy and Bronchoscopy-assisted intubation techniques.
- On average, there were two intubation attempts before progressing to cricothyrotomy.
Cricothyrotomy is seemingly becoming a less and less common procedure. This probably a result of increased Emergency Medicine clinician skill in intubating and improved technology to assist in intubation such as video laryngoscopy.
This should bring to us a sense of confidence in our intubation skills, but with 1 in 350 intubations requiring surgical rescue, this is a skill that absolutely needs to be maintained, so we avoid hesitation or delay when it is time to cut the neck.
- Offenbacher J, Nikolla DA, Carlson JN, Smith SW, Genes N, Boatright DH, Brown CA 3rd. Incidence of rescue surgical airways after attempted orotracheal intubation in the emergency department: A National Emergency Airway Registry (NEAR) Study. Am J Emerg Med. 2023 Jun;68:22-27. [pubmed]
- April MD, Driver B, Schauer SG, Carlson JN, Bridwell RE, Long B, Stang J, Farah S, De Lorenzo RA, Brown CA 3rd. Extraglottic device use is rare during emergency airway management: A National Emergency Airway Registry (NEAR) study. Am J Emerg Med. 2023 Oct;72:95-100. [pubmed]
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