What's the right airway to use? - Ed Bauter
What’s the right airway to use?
We’ve all been there. The cardiac arrest that may or may not have a positive outcome depending on what we do as providers. We know that walking into an arrest, our goal is to help the patient in any way that we can, and to get them to walk out of the hospital and home to their family. On paper, this is an easy thing to do. Hell, it’s our job. It’s what we do every day. But with the mountain of data that’s been coming out over the past year or so, it can be difficult to know what “the right thing” actually is. Sure, we always tryto do the right thing, but how can we be sure? What if I intubate someone and find out a week later that it wasn’t the right intervention? When do we use an endotracheal tube, or a supraglottic airway? What about a BVM? Should I RSI this patient? What about a DSI? If I do either of those and I fail, what’s my back up? These are all questions that are certainly valid and worth exploring. Let’s dive in.
ETI vs. SGA
Earlier this year, the AIRWAYS2 trial came out and everyone on social media was all a tizzy about it. Finally, we had a randomized, multicenter study that might give us some information about whether we were doing the right thing. And, it turns out, we may not be. The AIRWAYS2 trial included four separate ambulance services in the UK, and is the largest data set we have available thus far. It enrolled over 9,000 patients, with over 4,000 patients in each group that received either ETI or SGA. But, did it really show us anything that we don’t already know?
AIRWAYS2 showed that “first ventilation” success with SGA was 10% higher than ETI. So, stop the presses, right? First pass success is the goal, so naturally we’ve proven that SGA is superior to ETI. Not quite.
The design of the study allowed the paramedics to use discretion when placing an airway in the patients that were introduced to the study. This is of course a good thing, as we don’t want medics to be prioritizing a study over quality of care. However, it introduces a variable that is very difficult to control for. Simply put, in an unknown amount of cases, sicker patients may have received an SGA if the medic knew the patient was going to be a difficult intubation, or for any other number of reasons. The choice of providers for this study is also important to consider. We’ve previously discussed on the show that in order to be proficient at any skill, you must practice the skill. The paramedics that were involved in the AIRWAYS2 trial were volunteers, and while they were trained on the protocols for the study prior to deployment, this also lends to an availability bias and may not reflect how medics actually act in the field. It certainly is not representative of paramedic on the whole.
This is not to say that AIRWAYS2 doesn’t provide any useful data. It certainly lets us know that there’s better things that we can doing to provide for patients in cardiac arrest. But we must also keep in mind that survival to discharge in the study was 8.2%, and there was no statistical different in neurologic outcome.
What does all this mean? The study is good. Very good, in fact. It’s everything you’d look for on a wish list of “good studies”. It’s randomized, multi-center, etc… But as far as applicability is concerned, it may only be good as a reference for future studies and may not translate to providers in the United States or around the globe.
But even with all that said, either intervention is probably preferable to using a BVM and nothing else.
Yeah, but I like my ETI. What about me?
We all do. There are few better feelings than passing that tube on the first try, eh? Drop that laryngoscope and get a nice Cormack-Lehane 1 view. We all know the feeling. So, you’ve decided that you want to stick with ETI as your airway management of choice. Cool, I get that. But you want to be able to pass the tube on the first shot every time. Especially if you have a preceptor or a chief looking over your shoulder. Turns out there’s a way you can do that too.
Gum Elastic Bougies are cheap, easy to use, and will improve your intubation success. You’ll hear more seasoned medics discuss bougies in the same way people talk about the Yankees when they were good. But, we actually have data to support the use of Bougies. There’s no data supporting the support of the Yankees.
In 2017, a retrospective, observational study was performed to determine if first-pass success was improved by the use of a bougie in the ED. It turns out that first pass success was improved with the use of this simple device. But, as with everything else, this does not mean that we should abandon all of our tools and move on to bougies.
The study randomized 534 intubations. The sample size is good, but keep in mind that all retrospective studies have to be taken with a grain of salt. Another pretty significant limitation is that was a single center study and was not prospective or randomized. While the study didshow increased first pass success, it also showed increased time to intubation on the first pass, which can potentially increase hypoxia, and the patients were intubated with a video laryngoscope, which may not be something that your shop has.
The gum elastic bougie is a cheap alternative to other rescue airway equipment, but it is still a piece of rescue airway equipment. A practitioner who is not seasoned or experienced using the tool may not find the same success as the study.
RSI vs DSI
These techniques have been used in the ED for a long time, but may be relatively new to your shop. RSI, or rapid sequence induction is a process of chemically sedating and paralyzing a patient before introducing an endotracheal tube to maintain the airway. DSI or delayed sequence induction is a process of sedating and pre-oxygenating the patient prior to the introduction of an ETI.
So, who gets what? Again, this is something that is largely up to provider judgement. There is a standard patient that get RSI, for example a closed head trauma with a clenched jaw. But you may have patients that have fulminant pulmonary edema that require advanced airway management, and your only option may be RSI. If either of these are the case, it has been shown that RSI is more effective than non-RSI in these situations.
DSI, on the other hand would likely be more effective if the patient is combative. See, our head trauma from right up above? He’s the tame one. That’s the patient that you secure the airway before they lose it. DSI, on the other hand is more about sedating and pre-oxygenating prior to the intubation attempt. Both of these methods are generally effective when controlling the airway, you just have to know your patient and know which avenue might be better to pursue.
So what do I do?
In the end, to maintain an airway you’re going to have to know your strengths. Use clinical judgement to evaluate the patient before performing any airway management. You have to know your environment before you approach it. Think of it as establishing scene safety, but for an airway. Keep in mind, that your provider judgement may be that the patient would better benefit from a non-rebreathing mask, or CPAP as opposed to RSI or intubation.
Before you decide that you have to change your practice based off of one study, you have to take a look at the preponderance of data. There are a million journals out there, and they all need to publish. Take the time to read through the studies and really understand what they’re talking about. Listen to experts discuss the study before you bring it to your practice. Talk to your clinical people and see what they think. No matter what intervention you’re looking at, always make sure that the patient comes first and do your best you can for them.
And don’t use a BVM.