Well, we're going to talk about some airway emergencies, and I might just talk a little fast to get through some of these. Again, I'm Dr. Sarah Kekoma from Rush University Medical Center. I have no disclosures to report. The objectives today, we're going to identify signs and symptoms of an airway emergency, recognize a patient who's at risk for an airway emergency, and use accepted algorithms for team management of such emergencies. So before we begin, let's take a moment to talk about the airway management outside of the operating room. In this setting, intubation is often emergent. You have less time to organize all of the appropriate resources, so it's important to be well-prepared. You're often intubating for respiratory failure, where the desaturation is going to be faster. The airway is more likely to be difficult, and there may be more airway edema than you might expect from prior intubations or intubation attempts. Also, you know, in the operating room, we often have the option to wake a patient up if you can't intubate, and in the ICU, you might also lack additional resources for help. So there are lots of different indications for getting intubated. I kind of highlighted the three main ones here, airway protection, respiratory failure, and circulatory failure. So airway protection comes down to depressed level of consciousness, a requirement for deep sedation, or a compromised airway anatomy. Alternatively, it could be intubated for respiratory failure, which would include inadequate oxygenation or ventilation or excessive respiratory workload. And then, obviously, if you're in shock or having a cardiopulmonary arrest, you would need to get intubated as well. I don't believe you have, you know, voting buttons for these questions, but just in consideration of time, I'm going to kind of go through some of these questions. So question number one, what should a clinician do if the first attempt to intubate an unstable critically ill patient fails? Number one, try three times before getting help. Number two, get help. Three, change the type of laryngoscope blade being used. Four, wake the patient up. Or five, try video laryngoscopy. Get help. I'm a huge fan of help. Just call early and often. So just a good airway philosophy is an awake airway is always the best and safest. If first attempt fails, get help right then and there. Again, the desaturation is going to happen faster in the ICU compared to the operating room. If you can't intubate, use bag mask ventilation plus an alternate airway. And if you cannot intubate, cannot ventilate, call for help plus think about how to do a cricothyroidomy. In general, have a complete plan before you're going to intubate somebody. So think about their general medical assessment, their hemodynamics, their comorbidities, their potassium level, weight. Think about what position you want them in, kind of in a sniffing position, which lines up all the accesses, the oral pharyngeal and laryngeal accesses. Are you going to use a ramp or a shoulder roll behind their shoulders? Do you need to hold manual inline stabilization if their C-spine is unstable? Are you going to use cricoid pressure? What kind of induction agent are you going to use? Are you going to use a neuromuscular blockade agent? And then think about your equipment too. Are you going to do direct laryngoscopy or use a video laryngoscope? And then if you cannot intubate, cannot ventilate, what is your backup plan? So going through some risk factors for difficult mask ventilation, there's lots listed here. We're going to go through Malampati's score in just a second. We'll show you some pictures of that. But any sort of limited jaw protrusion, if you kind of look at a patient and have a really short chin, that's a short thyromental distance. Not to pick on the gentleman with beards, but not only do beards not give you a good seal where you can really mask ventilate the patient, but lots of times, gentlemen wear beards to kind of hide a shorter chin or not so strong chin. So keep in mind, they might be really anterior, thick neck, high BMI. And if they're a dentalist, once those dentures are out, they lose a lot of structure in their face. Here's just an overview of the Malampati score we use all the time in the operating room. So class one, if you have a patient open up their mouth, stick their tongue out, you can see pretty much everything, complete picture of their uvula. Gets worse as you go down to class four with barely able to see the uvula at all in class four. A lot of the risk factors for difficult mask ventilation are the same for difficult intubation. Just a couple more on here, though. Any sort of history of difficult intubation, obviously, if they have any sort of tracheal stenosis, it might be easy to get a view and everything, but passing that tube might be difficult. Pregnancy can offer a lot of airway edema, just kind of all congested in there and they desaturate very fast. And then any history of oropharyngeal cancer, especially those treated with radiation. Where tissues can become, you know, like wood, very hard. So question number two, failure to use capnography or capnometry in ventilated patients contributes to what percentage of death from airway complications? 5, 10, 20, 40, or 70%. So 70%, we love capnography, it's always good to make sure we're in the right place. When you're thinking about induction of patients, putting a patient to sleep before you intubate them, the goal is to facilitate safe intubating conditions. Think about their comorbidities, their mental status, their cardiopulmonary reserve. It may involve giving a sedative or a hypnotic, it may involve giving paralytics, it might involve giving nothing besides numbing up the airway. And we kind of talked about that sniffing position, it helps facilitate those alignments of those access. An RSI, a rapid sequence induction or intubation, here the goal is to minimize the time the airway is unprotected from induction until the tracheal intubation is confirmed. So it's indicated for all patients with an aspiration risk. I like to say that no one in the ICU peristalsis correctly, so just being critically ill does put you at risk for aspiration. Certainly anybody who has a small bowel obstruction, anybody who has ascites, kind of that increased intra-abdominal pressure pregnancy as well. Primary benefits from it include minimizing the time of apnea and therefore minimizing the risk of desaturation. And it should be more of the rule than the exception in the ICU. Got to think about whether you use cricoid pressure or not. The idea is that you would press down on the cricothyroid membrane or cricothyroid ring there and that kind of occludes the esophagus, so if they do start to regurgitate that you would shut that off. So the pro is that it would decrease your aspiration. It does reduce the diameter of the hypopharynx about 35%, but the cons of it, it can displace things laterally. It can make it more difficult to intubate. The conclusion is unclear in the literature, so we recommend going with your institutional standard. An awake intubation, like I said at the beginning, is definitely the safest option. Some things to think about if you're going to do this, it's advised to give some glycopyrrolate to help dry up those secretions so they have less saliva, which might get in your way with their fiber optic. You need to think about topicalization of the airway with either 4% lidocaine and an atomizer or nebulizer. So there's other concentrations, 5% of lidocaine ointment in the airway. You need to have some sort of bite block so the patient doesn't bite down on your fiber optic, therefore breaking your fiber optic. Alternatively, if you're really good with regional, you could think about doing glossopharyngeal, superior laryngeal, and transtracheal nerve blocks. My personal favorite. And think about how you're going to secure the tube afterwards as well. If you are going to induce the patient, here's a list of different medications that we would use for an induction. I'm going to talk about medications in another talk as well. Propofol, etomidate, ketamine, and midazolam are probably the most common ones that are used in the ICU setting. Different doses, different side effects listed here. Ketamine is often thought to have less respiratory depression. It's said to have less hemodynamic stability, but keep in mind critically ill patients can be depleted of catecholamine reserves, so sometimes it has just as much hypotension associated with it as propofol does. It does make people salivate more, so keep that in mind. Etomidate has more cardiovascular stability, but even one single dose can cause adrenocortical suppression. So keep that in mind if you're having shock that is not responsive. To give neuromuscular blockade or not. So neuromuscular blockade agents were introduced in 1942. They interrupt the nerve impulse transmission at the neuromuscular junction. They're primarily used by anesthesiologists, and they do improve first attempt success at intubation in the ICU. Question number four, which of the following is not a non-depolarizing agent? Rocuronium, atricurium, succinylcholine, currarine, vacuronium. Succinylcholine is a depolarizing agent. So succinylcholine is the only depolarizing neuromuscular blockade agent we use in clinical practice now. It's a rapid onset, short duration. It's hydrolyzed by plasma, butylcholine, and esterase, so it goes away quick. It does jump on the receptor and keep depolarizing, so you do get fasciculations after you give it. But downsides are, you know, it's difficult to use in renal failure, anybody who's had a burn because of the extrajunctional membrane receptors, and anybody who's been bed-bound. So lots of times in the ICU we're not able to use it. The other class of neuromuscular blockade agents are non-depolarizers, and then the non-depolarizers are broken up into two categories. So these are the benzyl-quinonium compounds. Always a tongue twister. So atricurium and cis-atricurium. These are not great agents for induction, meaning like a bolus that you're going to give to intubate, but they are typically what we use if we're going to do an infusion of neuromuscular blockade in the ICU, which hopefully you don't have to do that a ton. But both of them use Hoffman elimination, so they don't build up if you have renal or liver failure, which is great in the ICU. The other category of non-depolarizers are the aminosteroidals, and these are vacuoronium and rocuronium. Rocuronium is probably the most common one used as an induction agent because its profile can be similar to succinylcholine in the sense that you can do a rapid sequence induction with it. So the normal intubating dose is 0.6, but if you do a bigger dose of 1.2, you would have intubating conditions in about 60 seconds. And both of these are metabolized by the liver, so they do build up if you have liver and kidney failure. So neuromuscular blocker agents in general do have some side effects. They can cause the patient to appear to be asleep, but they can actually still be awake and have awareness, so you need to sedate them significantly with them. And then if they're given for a long period of time, they can lead to neuromuscular weakness, critical care myopathy, and neuropathy. And you need to monitor, if you are going to use them, you need to monitor your train of thought with a peripheral nerve stimulator. So to paralyze or to not, you're going to have good or excellent intubating conditions 35% of the time without atricurium, 95% with atricurium. There's a lower prevalence of hypoxemia with neuromuscular blockade agents used during intubation. So you're going to have a better first pass success there. Mass ventilation does not protect the airway. It's only a temporizing measure, but this skill can save lives. So I always recommend the residents and fellows to really get to know how to bag mask ventilate a patient. That is a life-saving technique. It requires minimal equipment and can be readily performed. When you are thinking about laryngoscopy, like I said, you could either do direct with a Mac or a Miller blade or a video laryngoscopy. So the difference between the Mac and the Miller blades are listed here. The McIntosh blade is kind of a larger, more curved blade. It gives you a better view, kind of moves excessive tissue out of the way, and it makes it easier to put in, you have a better view to put the tube in. The Miller blade is a smaller, straighter blade, a narrower view. Anybody who has a really large epiglottis, you can pick the epiglottis up with the Miller blade. So sometimes it does give you a better view. I just wanted to highlight this trial from, or this study that was published in New England Journal of Medicine in 2023. It looked at video versus direct laryngoscopy in critically ill adults. It's conducted over 17 emergency departments and ICUs and included about 1,400 patients. And those 1,400 patients were assigned to either video laryngoscopy or direct laryngoscopy. And the primary outcome was first attempt success. Secondary outcomes looked at things like severe hypoxemia and cardiac arrest. This study kind of just showed what we all thought, that you do have better first attempt success, about 85% in the video laryngoscopy group and 70% in the direct laryngoscopy group. So the video glidescope, as we probably more commonly know it, it does not require a straight line of sight. You have likely higher success rate, and everyone can kind of see the same view that you are when you're using it. However, some disadvantages are, you know, if somebody has to go get it, it's likely not right there. More and more in the world of anesthesia, it's kind of found in every operating room, but certainly not in every ICU room yet. And then if the patient's airway is bloody, you know, as soon as any blood gets on that, on the scope, you're not going to have a view. Blind nasal intubation is a very antiquated technique, but once in a while it works, especially if you have a big bloody airway, where it's just inserting an endotracheal tube into the nare and then kind of just going with their respiration and doing a shot into the vocal cords. You should, it should be avoided, those of you who work in a trauma center, avoid it in patients with any sort of basilar skull fracture that, you know, might have raccoon eyes or the battle sign, the hematoma behind the ears. If you are going to do a fibro-optic intubation, it is the gold standard for the difficult airway and entails the least amount of neck movement if you have an unstable cervical spine, so it's a great option for that. Kind of similar to the video laryngoscopy or the glide scope, if you get any sort of blood or mucus on your scope, you're not going to have a view. Does require more equipment, you know, takes some time to set it all up, prep the airway. I think everybody should be comfortable with supraglottic airway devices. Some other names for this would be like an LMA or an iGel or an AirQ. LMAs kind of become the Kleenex of supraglottic airway devices. It is a brand name. But these are good things to be comfortable with inserting in moments when you cannot or you're not able to intubate right away and you're calling for help. You can, it might, you know, you can oxygenate and ventilate through them. And then just that horrible situation that we all dread, the can't intubate, can't ventilate situation. Most common risk factors for this are any sort of facial trauma, a bloodied airway, multiple laryngoscopy attempts, head and neck irradiation gives me nightmares still at night and any sort of burn to the airway. Certainly in this situation, as you call for more help, you could try to insert a supraglottic airway device or an LMA as a bridge to a definitive airway. But you know, think about the cricothyroidomy in this patient. Why do we use the cricothyroid membrane? It has a very superficial location. I think it's pretty easy to find in, you know, thin necks and thicker necks, it gets a little bit more difficult. But if you start at your sternal notch and go up to your first divot, that's your cricothyroid membrane. Oftentimes, there's no critical structures over it, so thyroid, nerves, vessels, things like that. There's less risk of esophageal perforation there. It's faster and easier to do than a trach. You might have a higher incidence of airway stenosis, but the patient will be alive to deal with that. So two types, you can do a needle cricothyroidomy or surgical cricothyroidomy. I think it's more common in ICUs to have a cric kit around. If it's kind of old school and you don't have a cric kit around, you can do a needle cricothyroidomy. You're going to extend the neck back. You're going to locate the cricothyroid membrane. You can take just an IV, like a 14-gauge IV, attach a syringe to it. Lots of times, we have safety lock IVs now, so sometimes it's hard to find the IVs that you can take the end off, but if you can, that's great. Put a little saline in that 10cc syringe. Advance the needle in the caudal direction while aspirating for bubbles. Once you get lots of bubbles, advance that catheter off into the airway and you can ventilate through that 14-gauge IV. Ventilation is tough, but you can certainly give oxygenation through that. You will get air trapping and barotrauma through that. You can get subcutaneous emphysema. If you do have a cric kit or some other tools to do a surgical cricothyroidomy, that's great. Kind of the same first steps. You're going to locate that cricothyroid membrane. If you have the kit, it's going to have a needle and a syringe in that. Put some saline in that syringe again, so once you pop through the cricothyroid membrane, you'll see copious amounts of bubbles. If you have the kit, insert a wire through that needle, and then there's a dilator with the cric that goes over that. If you don't have the kit, you can make a vertical incision there and then put an endotracheal through that incision. So just in general, recommendations from the National Audit Project of the Royal College of Anesthetists and Difficult Airway Society. Limit the number of intubation attempts to three. Cannot ventilate occurs. Waking the patient up is not an option. Give paralytics to give yourself a better view. Attempt to put a supraglottic airway device, and both surgical and needle cricothyroidomy should be taught and practiced. Some sage advice in just a bad situation. It's not the procedure, the cricothyroidomy that kills patient, but rather the delaying or not doing it that causes a harm. Keep in mind, too, no matter how you secure that airway, once you intubate the patient, they're always, more than likely in the ICU, going to have post-intubation hypotension. This is from positive pressure ventilation, loss of sympathetic drive, maybe they had a mild cardiac infarction, maybe tension pneumo, auto-peeping, all sorts of reasons, too. And then just a reminder, think everything through before you do it. Know who your help is. Go through all of these different. I always like to have plan A, B, C, and D ready, and think about who your backup is if you can't obtain the airway. I know I went through a lot in a short amount of time, but any burning questions?

airway emergencies

intubation techniques

ICU desaturation

airway management algorithms

cricothyroidotomy

post-intubation hypotension