Evidence-based Emergency Tracheal Intubation

Abstract

Millions of critically ill adults undergo tracheal intubation in an emergency department or ICU each year, nearly 40% of whom experience hypoxemia, hypotension, or cardiac arrest during the procedure. Over the last two decades, a series of randomized trials have examined which of the tools, techniques, devices, and drugs used to perform emergency tracheal intubation improve outcomes and which are ineffective or harmful. Results of these trials have demonstrated that preoxygenation with noninvasive ventilation and administration of positive pressure ventilation between induction and laryngoscopy prevent hypoxemia during intubation, video laryngoscopy facilitates successful intubation on the first attempt and may prevent esophageal intubation, use of a stylet is superior to intubation with an endotracheal tube alone and is comparable with use of a bougie, and administration of a fluid bolus before induction does not prevent hypotension. Many additional decisions clinicians face during emergency tracheal intubation are not yet informed by rigorous evidence. Randomized trials must continue to examine systematically each aspect of this common and high-risk procedure to improve patient outcomes and bring forth an era of evidence-based emergency tracheal intubation.

Keywords: emergency tracheal intubation; induction medication; laryngoscopy; preoxygenation.

Figure 1.

Clinical decisions in each phase of emergency tracheal intubation may affect procedural and patient-centered outcomes. During the three phases of emergency tracheal intubation (preoxygenation, induction of anesthesia to initiation of laryngoscopy, and laryngoscopy and intubation of the trachea), clinicians make numerous treatment decisions regarding 1) the approach to administration of supplemental oxygen and positive pressure ventilation; 2) medications related to induction of anesthesia, neuromuscular blockade, and hemodynamic support; and 3) the tools and approach to laryngoscopy and intubation of the trachea. Conceptually, these choices may affect procedural outcomes (e.g., hypoxemia, hypotension, and failure to intubate on the first attempt), downstream short-term clinical outcomes (e.g., cardiac arrest), or long-term patient-centered outcomes (e.g., death, post-traumatic stress disorder). In the last two decades, how treatment choices during emergency tracheal intubation affect procedural and patient outcomes has been the focus of a series of randomized trials.

Figure 2.

Equipment used for laryngoscopy and intubation of the trachea. The figure shows a direct laryngoscope (upper left panel), a video laryngoscope (lower left panel), and endotracheal tube containing a flexible metal stylet (upper right panel) and an endotracheal tube introducer or gum elastic bougie (lower right panel). The images of the laryngoscopes were adapted from Reference . Copyright 2023 Massachusetts Medical Society. Reprinted with permission. The image of an endotracheal tube was adapted from Reference with the following license: https://creativecommons.org/licenses/by/4.0/.