N Engl J Med. 2019 Jun 20;380(25):2482

# Bag-Mask Ventilation during Tracheal Intubation of Critically Ill Adults. Reply.

Casey J, Rice T, Semler M

BACKGROUND: Hypoxemia is the most common complication during tracheal intubation of critically ill adults and may increase the risk of cardiac arrest and death. Whether positivepressure ventilation with a bag-mask device (bag-mask ventilation) during trachealintubation of critically ill adults prevents hypoxemia without increasing the risk ofaspiration remains controversial.

METHODS: In a multicenter, randomized trial conducted in seven intensive care units in theUnited States, we randomly assigned adults undergoing tracheal intubation to receiveeither ventilation with a bag-mask device or no ventilation between induction andlaryngoscopy. The primary outcome was the lowest oxygen saturation observed duringthe interval between induction and 2 minutes after tracheal intubation. The secondaryoutcome was the incidence of severe hypoxemia, defined as an oxygen saturation ofless than 80%.

RESULTS: Among the 401 patients enrolled, the median lowest oxygen saturation was 96% (interquartile range, 87 to 99) in the bag-mask ventilation group and 93% (interquartilerange, 81 to 99) in the no-ventilation group (P = 0.01). A total of 21 patients (10.9%)in the bag-mask ventilation group had severe hypoxemia, as compared with 45 patients(22.8%) in the no-ventilation group (relative risk, 0.48; 95% confidence interval[CI], 0.30 to 0.77). Operator-reported aspiration occurred during 2.5% of intubationsin the bag-mask ventilation group and during 4.0% in the no-ventilation group(P = 0.41). The incidence of new opacity on chest radiography in the 48 hours aftertracheal intubation was 16.4% and 14.8%, respectively (P = 0.73).

CONCLUSIONS: Among critically ill adults undergoing tracheal intubation, patients receiving bag-mask ventilation had higher oxygen saturations and a lower incidence of severe hypoxemiathan those receiving no ventilation.