Noninvasive Ventilation for Preoxygenation during Emergency Intubation

Introduction: Among critically ill adults undergoing tracheal intubation, hypoxemia increases the risk of cardiac arrest and death. The effect of preoxygenation with noninvasive ventilation, as compared to preoxygenation with an oxygen mask, on the incidence of hypoxemia during tracheal intubation is uncertain.

Methods: In a multicenter, randomized trial conducted in 24 emergency departments and intensive care units in the United States, we randomly assigned critically ill adults undergoing tracheal intubation to receive preoxygenation using noninvasive ventilation or an oxygen mask. The primary outcome was the incidence of hypoxemia during intubation, defined as an oxygen saturation less than 85% during the interval between induction and 2 minutes after tracheal intubation.

Results: Among the 1,301 patients enrolled, hypoxemia occurred in 57 of the 624 patients (9.1%) in the noninvasive ventilation group and 118 of the 637 patients (18.5%) in the oxygen mask group (absolute risk difference, -9.4 percentage points; 95% confidence interval, -13.2 to -5.6; P value < 0.001). Cardiac arrest occurred in one patient (0.2%) in the noninvasive ventilation group and 7 patients (1.1%) in the oxygen mask group (absolute risk difference, -0.9 percentage points; 95% confidence interval, -1.8 to -0.1). Aspiration occurred in 6 patients (0.9%) in the noninvasive ventilation group and 9 patients (1.4%) in the oxygen mask group (absolute risk difference, -0.4 percentage points; 95% confidence interval, -1.6 to 0.7).

Discussion: In this multicenter randomized trial of critically ill adults undergoing tracheal intubation, preoxygenation with noninvasive ventilation lowered the incidence of hypoxemia by 9.4% compared to preoxygenation with an oxygen mask and did not appear to increase the risk of aspiration. Additionally, preoxygenation with noninvasive ventilation was associated with a lower risk of cardiac arrest. Although the small number of events precludes firm conclusions, this finding may suggest that, by preventing hypoxemia during intubation, preoxygenation with noninvasive ventilation could potentially reduce the incidence of downstream outcomes such as cardiac arrest and death.

Conclusion: Among critically ill adults undergoing tracheal intubation, preoxygenation with noninvasive ventilation significantly decreases the incidence of hypoxemia during intubation compared to preoxygenation with an oxygen mask. (Funded by the U.S. Department of Defense; PREOXI ClinicalTrials.gov number, NCT05267652)