I have long questioned the utility of airway algorithms and their relevance to emergency airways. This notion that if we just memorize X, Y, and Z, we will magically perform better has not been borne out by my own efforts to improve my practice or made me more comfortable with my job.
Explore This IssueACEP Now: Vol 38 – No 11 – November 2019
In my opinion, airway algorithms add significant cognitive burden. The burden of multitasking procedural performance while simultaneously trying to remember a complex algorithm can imbalance the operator’s psyche, adding to the perceived demand of the situation. This precipitates increased operator stress and, in turn, degrades crisis performance. Ironically, in true crisis, the burden of trying to remember an algorithm—although intended to give cognitive assistance—can backfire dramatically. We know from clinical experience that real cases frequently do not fit neatly into the boxes and arrows. While we seek a guide, a hand to lead us through the challenge, as I see it, algorithms fail to light the way.
Watching clinicians for more than three decades and reflecting on my two decades of procedural education, I now recognize a common mindset of those who do well in crisis. I believe I have improved my own performance and become more comfortable with the challenging and humbling job of emergency physician by not focusing on comprehensive algorithms or the big picture.
I now entirely focus on the next step. That is the “secret.”
One Step at a Time
Master clinicians, who walk into complete chaos with a smile, maintain their cool, and inspire confidence from the team, do not worry about everything. They have insight into the priorities of the situation. They take small incremental steps, fixing one problem, then the next, until it’s clear they have command and control of the situation, making forward progress in the face of great challenge.
Operating “in the zone” is not about struggling to do everything at once; it is the exact opposite. A lightness of being, an unburdening of mental load, “just doing, not trying”—this is the inside secret of those in all areas of life who perform mightily in the face of enormous stress and terrific challenge.
We have all seen novice clinicians struggling in a crisis situation, overthinking and trying to figure out what is the right thing to do. Conversely, experienced clinicians calmly and with relaxed focus are able to just perform. Those with the least experience and knowledge are struggling with performance while assuming complex cognitive burden. Master clinicians, who have the most experience and knowledge, have no cognitive burden and just glide through performance.
In my prior columns I have enumerated an incrementalized approach to oxygenation, laryngoscopy, and surgical airways. All of these procedures are just assembled tiny little steps, deliberately engineered to be achievable and believable. The best clinicians engineer their practice—it is not just they are skilled and experienced. Having deliberately engineered their performance into small, simple, reproducible, and reliable steps, they have lowered the task complexity. This improves the balance of perceived ability to perceived demand, lowering stress and improving confidence and performance. Without the adrenaline surge flowing through their body, they can see and hear better. Their voice stays calm; their pulse, low. They have more situational awareness and think better. Master clinicians do better (especially in the most stressful of situations) because they have engineered their practice to actually be simpler and easier. Difficult tasks have been compartmentalized and incrementalized (and practiced over and over again). The small steps flow into a muscle-memorized, smooth process done without struggle or desperation.
The secret to procedural performance is compartmentalization, incrementalization, and repetitive practice.
But there is a big-picture component that master clinicians do have in mind. It is not an expansive detailed algorithm for every possible scenario—rather it is a clear insight into the fundamental priorities of the situation.
Oxygenation Is the Priority
The priorities in the airway game are 1) oxygenation and 2) avoidance of vomit and management of fluids. Avoidance of vomit and management of fluids are directly related to priority number one. On rare occasions, when patients have severe metabolic acidosis with a compensatory respiratory alkalosis, ventilation becomes critical. For almost all patients, however, it is hypoxia that kills quickly, and the frequent co-conspirator is fluid in the airway.
Taking an abstract overview of airway management, all airway emergencies are directly or indirectly oxygenation emergencies—immediate evidence of hypoxia or threatening of hypoxia.
The patients present upright, with their head forward relative to chest, straightening cervical and thoracic trachea, and breathing through their nose and out their mouth. All of this is to improve upper airway patency and also expand the area of gas absorption in the alveoli (ie, open the lower airway). In addition to positioning, breathing faster is the body’s main way to increase oxygen absorption. Pursed lips can add a small amount of native positive end-expiratory pressure (PEEP).
As clinicians, we should realize that our therapies should align with the patient’s effort. They want to live! We can instantly help by boosting FiO2, but we must be mindful that the route of oxygenation is via the nose and that the negative inspiratory flow in their trachea far exceeds the 15 lpm given by a non-rebreather mask. This is why they rip off their mask—it is not meeting inspiratory needs and forces them to rebreathe their exhaled CO2—actually lowering their FiO2.
The patient who is driving you crazy—pulling off their mask and holding it above their nose, uncovering their mouth—is actually delivering a higher FiO2 than they would achieve by having a non-rebreather over their face.
A standard nasal cannula opened up to “jet speed” (a loud audible hiss)—setting the manometer valve to flush—will blow nearly 70 lpm in most hospitals in the United States and Canada (not quite as high elsewhere around the world). End-tidal CO2 cannulas will not permit this flow (they pop off at 6 lpm due to their small aperture). Warm humidified special-purpose high-flow systems (Fisher & Paykel and Vapotherm) are great but often not immediately ready at the bedside. If pulse oximetry is not improving with high-flow nasal oxygen, we need to consider the need for PEEP and ventilatory assistance (noninvasive ventilation, or intubation).
All While Addressing the Underlying Problem
While immediately initiating oxygen administration and optimizing conditions for oxygen absorption (positioning, suctioning), we also face the simultaneous task of determining the cause of the patient’s respiratory distress or airway emergency.
Emergency airways are, in fact, a minute-by-minute round-and-round of rapid assessment, oxygenation and optimization, and interventions. The very definition of “emergency” involves the component of time.
Experienced clinicians “thin-slice” the basics of patient presentation through sight, sound, and feel. We visually assess a patient’s breathing, respiratory rate, depth, body habitus, work of breathing, flaring of nostrils, patency of oropharynx and mouth opening, chest wall integrity, chest rise, diaphragmatic movement, swelling of the legs, diaphoresis, color, and appearance of the nail beds. We listen with our ears for stridor, upper airway noises, and grossly audible airway noise as well as with a stethoscope over the lungs, neck, and heart. We feel for crepitus, edema, and temperature.
Even prior to basic imaging and labs, we frequently instantly recognize the patterns and patient appearance of chronic obstructive pulmonary disease (COPD), asthma, congestive heart failure (CHF), pneumonia, pneumothorax, pulmonary embolus, and other common presentations.
After our immediate assessment, a relatively small group of imaging studies can be used to dial in our patient’s diagnosis. Ultrasound, stat portable X-rays, and endoscopy are the quickest to utilize at the bedside. CT scans take significantly longer and require patient transport but give us the best look at the lungs and upper airway (Ludwig’s angina, masses, hematomas, postoperative swelling, trauma, and the full array of pulmonary pathology). Unfortunately, patients who are severely compromised, either from poor pulmonary function or upper airway problems, do not tolerate the flat positioning that CT requires. Sometimes, the necessity for CT imaging triggers the decision point to manage the airway (ie, intubate the patient).
Airway interventions involve therapies that treat the underlying cause of the airway problem or involve plastic being placed into the mouth, neck, or chest. Pharmacological therapy includes things I consider “airway magic.” They work fast: naloxone for opioid overdose, epinephrine for anaphylaxis, nitroglycerin for CHF, nebulizers for COPD and asthma, and racemic epinephrine for stridor. While bradykinin and kallikrein inhibitors have revolutionized treating angioedema, they do not work instantly. Steroids and antibiotics are important and commonly used therapeutic interventions, but they take longer to work.
Let’s think about equipment. The fastest and simplest are supraglottic airways. Unfortunately, they work poorly when fluids are emerging from below. The chest can be rapidly decompressed (finger thoracostomy, chest tubes). Intubation requires more preparation, especially in unstable patients who should have intubation sequenced to their resuscitation (eg, those with high shock index, severe hypoxia, etc.). Intravenous fluids, blood, and pressors sometimes need to be initiated before the patient can safely undergo induction and positive pressure ventilation. Critically hypoxic patients should have preprocedural oxygenation maximized before intubation.
Putting It All Together
While there is an apparently large array of things involved in assessment, oxygenation, and interventions, in reality the trick is just to work from simplest and fastest to deploy to the more complicated.
All patients should have oxygenation optimized. We formulate our presumptive diagnosis as we deploy our “airway magic.” Next is the first tier of imaging studies (portable films, bedside ultrasound, endoscopy). We gauge the response to the airway magic interventions, which either solidifies our diagnostic impression or steers us in a different direction.
Labs may help influence management decisions (arterial blood gas, severe acidosis, lactic acid, etc.). Last in the diagnostic realm (requiring more time) is the need for and safety of obtaining CT imaging of neck or chest.
Thinking about the time—speed and simplicity—is tremendously useful for organizing our diagnostic studies and pharmacological interventions. It is also useful for considering the triggers to intubation. All patients should have oxygenation maximized through noninvasive maneuvers as needed (positioning, oxygen administration, PEEP with bag-valve-mask or bilevel positive airway pressure if not improving with supplemental oxygen alone).
Supraglottic airways can be temporarily useful in cardiac arrest situations on initial presentation. Ultimately, however, there is the decision to intubate and determining the necessity and safety of muscle relaxants. There are numerous triggers to intubate. Consider the timeline of the presumed diagnosis and the efficacy and responsiveness of the pathology to therapeutic interventions. Histamine-induced angioedema, pulmonary edema, opioid overdose, foreign bodies, most asthma presentations—these can correct very quickly. These are the pathologies where our airway magic may work.
Most airway emergencies are not immediately fixed, however—traumatic injuries (eg, head, face, chest), infectious processes (eg, epiglottitis, Ludwig’s, pneumonia), and severe lung disease. In considering the trigger to intubate, it’s useful to distinguish the difference between airway emergencies that are potentially quickly reversible and those that are not.
In my rural hospitals, major trauma cases all get transferred—and almost always require intubation simply for safe transport if not for airway protection and oxygenation. Patients with airway pathology not immediately reversible should not be transported with insecure airways. Examples include nonhistamine-induced angioedema, Ludwig’s, expanding neck hematomas and other masses, massive achalasia, and massive nasal bleeding. Critically ill patients with severe lung disease will eventually require intubation. Sooner intervention (after preprocedural optimization of oxygenation) is usually better.
In summary, although the entirety of the diagnostic and therapeutic interventions in the airway seems large, it is manageable mentally (and in practice) by simply working from the simplest and fastest to the more complicated and time-consuming. Consider the underlying pathology and potential responsiveness to airway magic and interventions.
Master clinicians look at the problem in front of them, accept the reality of the situation, understand the priorities, and act—one step at a time.