Randomized Trial of Apneic Oxygenation during Endotracheal Intubation of the Critically Ill

Abstract

Rationale: Hypoxemia is common during endotracheal intubation of critically ill patients and may predispose to cardiac arrest and death. Administration of supplemental oxygen during laryngoscopy (apneic oxygenation) may prevent hypoxemia.

Objectives: To determine if apneic oxygenation increases the lowest arterial oxygen saturation experienced by patients undergoing endotracheal intubation in the intensive care unit.

Methods: This was a randomized, open-label, pragmatic trial in which 150 adults undergoing endotracheal intubation in a medical intensive care unit were randomized to receive 15 L/min of 100% oxygen via high-flow nasal cannula during laryngoscopy (apneic oxygenation) or no supplemental oxygen during laryngoscopy (usual care). The primary outcome was lowest arterial oxygen saturation between induction and 2 minutes after completion of endotracheal intubation.

Measurements and main results: Median lowest arterial oxygen saturation was 92% with apneic oxygenation versus 90% with usual care (95% confidence interval for the difference, -1.6 to 7.4%; P = 0.16). There was no difference between apneic oxygenation and usual care in incidence of oxygen saturation less than 90% (44.7 vs. 47.2%; P = 0.87), oxygen saturation less than 80% (15.8 vs. 25.0%; P = 0.22), or decrease in oxygen saturation greater than 3% (53.9 vs. 55.6%; P = 0.87). Duration of mechanical ventilation, intensive care unit length of stay, and in-hospital mortality were similar between study groups.

Conclusions: Apneic oxygenation does not seem to increase lowest arterial oxygen saturation during endotracheal intubation of critically ill patients compared with usual care. These findings do not support routine use of apneic oxygenation during endotracheal intubation of critically ill adults. Clinical trial registered with www.clinicaltrials.gov (NCT 02051816).

Trial registration: ClinicalTrials.gov NCT02051816.

Keywords: airway management; intratracheal intubation; pulmonary ventilation.

Figures

Figure 1.

Enrollment, randomization, intervention, and analysis. Of 196 adults intubated by pulmonary and critical care medicine fellows during the study period, 46 were excluded and 150 were randomized, followed, and included in the intention-to-treat analysis.

Figure 2.

Lowest arterial oxygen saturation by study group. (A) The primary outcome of lowest arterial oxygen saturation between induction and 2 minutes after completion of endotracheal intubation (lowest oxygen saturation) is displayed for patients randomized to apneic oxygenation (squares) and usual care (circles). Horizontal bars represent median and interquartile range. (B) The relationship between oxygen saturation at induction and lowest oxygen saturation is displayed for each patient in the usual care (left) and apneic oxygenation (right) groups.

Figure 3.

Subgroup analyses. The mean difference in lowest arterial oxygen saturation (%) between apneic oxygenation and usual care is given for patients in prespecified subgroups present at the time of induction (circles) and arising after procedure initiation (squares). Vertical bars represent the 95% confidence interval around the mean difference. BMI = body mass index in kg/m2; FiO2 in 6 hours prior = the highest fraction of inspired oxygen in the 6 hours before the intubation; time to intubation = time from induction until successful endotracheal intubation.