Airway management is one of the hallmark skills of an emergency physician, but to call it a single skill does not give enough credit to the complexity of the task. It is actually a long sequence of micro-skills and decisions. Fortunately, airway skills and equipment have improved, and it is relatively rare to face a true “can't intubate, can't ventilate” scenario. At every step along the airway algorithm, however, are small branch points that offer opportunities for incremental improvement and better patient outcomes.
Which steps can be taken before, during, and after intubation to elevate airway management from simply securing the airway to a well-choreographed routine that sidesteps potential complications? Here we discuss 10 airway techniques—before, during, and after intubation—that you can start using today. Some of these have robust evidence; others are based on physiology and expert opinion.
Before: Optimize Conditions
1. The Checklist: It is the rare ED airway case that requires truly emergent intervention. All the rest give you at least a few minutes to plan ahead. Make the most of any planning time you have by employing a checklist and a verbal timeout. We get used to working with a rotating cast of nurses, respiratory therapists, technicians, and residents every shift. A checklist accompanied by a short verbalization of the plan cognitively unloads the to-do list, unifies everyone's efforts, and provides a shared mental model. Airway checklist use in the ED has been found to improve adherence to recognized safety measures and to reduce complications. (Acad Emerg Med 2015;22:989, http://bit.ly/2Kgjoso.) (See the checklist we use at the University of New Mexico.)
2. Resuscitation Before Intubation: Your airway checklist should also include reminders that will help steer you away from peri-intubation hypoxia or hypotension, which can contribute to secondary injury in fragile brain. More and more, FOAMed leaders have been reframing RSI as resuscitation (not rapid) sequence intubation. Our checklist has a single line—“Fluids? Blood? Pressors? CPAP?”—to remind us to resuscitate before we intubate.
It is worth delaying the intubation for a few minutes in many cases to optimize the patient's physiology. This may be as simple as starting blood or hanging an infusion of norepinephrine. The intent is to mitigate the physiological changes associated with the reduced sympathetic tone from medications and paralysis as well as reduced venous return from positive pressure ventilation to decrease the chance of decompensation.
3. Preoxygenation: Make the Most of Position and Equipment: Lying flat promotes posterior atelectasis, and the pressure of the abdominal contents on the diaphragm reduces the functional residual capacity of the lungs, so keep patients as upright as possible until it is time to intubate. Sniffing or ramped positioning will facilitate preoxygenation and intubation.
Ideal preoxygenation takes at least three minutes of the highest flow possible delivered with the addition of PEEP to replace nitrogen with oxygen, effectively creating an oxygen reserve to extend the time before desaturation after paralysis. A standard partial nonrebreather will suffice in many cases, using what is now referred to as flush rate oxygen: Simply turn the wall oxygen up as high as it will go; this will typically give about 50 L/min. Multiple studies have shown that flush rate oxygen with a nonrebreather (NRB) mask is not inferior to bag-valve-mask (BVM) for spontaneously breathing patients. (Ann Emerg Med 2017;69:1, http://bit.ly/2tJTodU; Ann Emerg Med 2018;71:381, http://bit.ly/2Kuchso.) NRB mask is technically much easier than BVM, and you don't need to worry about mask leak.
Be wary if patients are still saturating ≤93% despite sitting up with a nonrebreather. They are teetering on the edge of the steep part of the oxygen desaturation curve. (Ann Emerg Med 2016;67:389, http://bit.ly/2Kpd9yA; Prehosp Emerg Care 2008;12:46.) Time to desaturation will be measured in seconds, not minutes, at this point on the curve. It might be necessary to provide positive pressure with CPAP or BPAP for these patients. Do not forget to put the nasal cannula for apneic oxygenation on first.
We were all taught never to provide positive pressure during RSI to avoid the risk of insufflating air into the stomach, which can increase the risk for aspiration. We have found, however, that the risk of hypoxemia is often greater than the risk of aspiration, especially when hypoxemia leads to frantic bagging later in the procedure. It is better to provide gentle positive pressure up front than desperate bagging after hypoxemia ensues.
We also learned to avoid nasal intermittent positive pressure ventilation (NIPPV) in patients with altered mental status, but we use this liberally as long as the patient is attending one-to-one. Sedation may be required to facilitate NIPPV in some cases, though this can be fraught with danger in high-risk patients. Options are to titrate benzodiazepines carefully or use delayed sequence intubation (DSI) with ketamine. (Ann Emerg Med 2015;65:349, http://bit.ly/2yNbNwt.)
Another nice trick is to apply the NIPPV using a ventilator with a back-up rate rather than a standalone CPAP/BPAP device. One can transition seamlessly from NIPPV to full-mask ventilation (with breaths delivered by the machine rather than a self-inflating bag in this case) without breaking the seal and losing the built-up PEEP. (See table for suggested vent settings.)
During: Laryngoscope in Hand
4. Videoscope. Every Time: Multiple video laryngoscopes are currently on the market that utilize standard geometry (similar to a direct laryngoscope curved blade) and hyperangulated geometry blades to improve the glottic view. The video laryngoscopy technique with standard geometry blades is similar to direct laryngoscopy while the technique for hyperangulated blades is quite different.
Being able to see the cords does not guarantee that intubation will be successful, but why not practice with it every time if you have a tool that routinely provides a better view? Having unfamiliar equipment as a rescue device during difficult airways only invites fumbling and equipment problems at the time you can least afford it, so use it on all the easy cases too. This is especially critical for hyperangulated blades where the technique may not be intuitive initially. Anyone who has worked with residents or other learners in the ED setting will attest that a screen has the valuable second benefit of allowing you to see what the learner is seeing.
5. ELM, A Helping Hand: External manipulation of the larynx (ELM) may improve visualization and intubation success for some airway anatomy. This isn't traditional cricoid pressure but rather a guided maneuver to actively bring the cords into view. This is most efficient with an assistant: Have him place his fingers directly on the thyroid cartilage and then place your hand over his, so you can let go once you have optimally aligned the airway while he maintains the view. (Photo.) This technique is simple and costs nothing, yet is still vastly underutilized. (Amer J Emerg Med 2013;31:32, http://bit.ly/2IuC7Lp.)
6. Use the Bougie: The bougie is worth more than it costs—less than $10 each! It is an incredibly handy tool that many of us have available in case we run into difficulty with direct laryngoscopy, but does it have a role in video laryngoscopy and should it be used routinely? Our EM colleagues at Hennepin County Medical Center in Minneapolis compared using the bougie in place of stylet for every intubation in a recent randomized, controlled trial. They used it as a rescue device only in patients being intubated with a standard geometry video laryngoscope.
The first-attempt intubation success was significantly higher with bougie in patients with difficult airway characteristics (absolute between-group difference: 14%). The first-attempt success was also higher with bougie among all patients. (JAMA 2018;319:2179.) As with video laryngoscopy, using this every time will also improve proficiency for the rare difficult case when you really need it.
After: High Fives All Around
7. Skip Colormetric Confirmation: Qualitative detectors have become ubiquitous for ET tube confirmation, but we now skip this step and go directly to continuous waveform capnography, which we require for continuous monitoring of tube placement and to avoid hyperventilation, which has been shown to be devastating for our neuro patients. We were using the intermediate step of the color-based detectors, but it seemed to take forever to get the continuous monitors hooked up. Now everyone knows to have them ready before the intubation.
8. Turn Down That Oxygen: Leading up to sedation, preparation has been all about finding ways to provide more supplemental oxygen and increase the patient's oxygen reserves to give as much time as possible before desaturation. Now, however, get the patient settled on the ventilator, and flip your mindset to figuring out how little oxygen is actually necessary to maintain acceptable saturations. Hyperoxia has been linked with worsened outcomes in acute MI, stroke, and cardiac arrest in the ICU.
Even relatively brief hyperoxia in the ED has been associated with increased mortality. (Crit Care 2018;22:9, http://bit.ly/2yP1aJf.) This is best done with a blood gas, but you can start by targeting a saturation less than 100%. We usually aim for 94-98%. Sometimes it is remarkable how far you can turn down the FiO2 before the saturation drops from 100% to 99%.
9. Avoid Benzodiazepines for Post-Intubation Sedation: The sedative and depth of sedation started in the ED may carry forward into the ICU, so consider both carefully. Benzodiazepine pushes can be helpful for managing acute anxiety, but long-term benzodiazepine infusions have been associated with prolonged intubation in the ICU. All benzodiazepines are also metabolized by the liver, and midazolam and lorazepam have renally-cleared active metabolites, so critically-ill patients with organ dysfunction may accumulate both.
Patients with seizures or alcohol withdrawal may benefit from benzodiazepines, but propofol offers better ability to titrate while giving the same benefits for the intubated patient. Sedatives like propofol won't relieve pain, so target pain first with, for example, fentanyl. Then use a short-acting sedative like propofol to permit rapid titration to goal sedation if there is agitation unrelated to pain. (Crit Care Med 2013;41:263, http://bit.ly/2N3fvVy.)
10. Elevate the Head of the Bed: Last but not least, elevating the head of the bed is an extremely easy and effective way to prevent ventilator-associated pneumonia. A recent review paper of 759 patients from eight randomized, controlled trials showed that you can decrease the risk of pneumonia more than 25 percent by just elevating the head of the bed to a semirecumbent position (30% to 60%) from the supine position. (Cochrane Database Syst Rev 2016:8;:CD009946, http://bit.ly/2N5TEg7.) Elevating the head of the bed also lowers intracranial pressure in patients with TBI. Consider the reverse Trendelenburg position if elevating the head of the bed is contraindicated.
Reducing Risk: Confident management of the difficult and emergent airway is a daily part of work in the emergency department, but every case still carries risk. Incremental improvement at every stage of airway management can reduce the risk and immediate and long-term complications. Routinely using these tips will hopefully help you and your patients breathe easier whenever the next challenging intubation comes through the doors.