BACKGROUND: Critically ill patients with respiratory failure undergoing intubation have an
increased risk of hypoxemia-related complications. Delivering oxygen via a high-flow nasal cannula
(HFNC) has theoretical advantages and is increasingly used. This study was conducted to compare
HFNC with bag-valve-mask (BVM) for preoxygenation and to assess oxygenation during intubation
in subjects with hypoxemic respiratory failure. METHODS: This study was a randomized controlled
trial including 40 critically ill subjects with hypoxemic respiratory failure who received
either HFNC or BVM for preoxygenation before intubation in the ICU. The primary outcome was
the mean lowest SpO2
during intubation. RESULTS: The mean lowest SpO2
during intubation was
89 18% in the HFNC group and 86 11% in the BVM group (P .56). In subjects receiving
HFNC, a significant increase in SpO2
after preoxygenation was only seen in those previously receiving
low-flow oxygen (P .007), whereas there was no significant difference in SpO2
in subjects
previously receiving noninvasive ventilation or HFNC (P .73). During the 1 min of apnea after
the induction of anesthesia, SpO2
dropped significantly in the BVM group (P .001), whereas there
was no significant decrease in the HFNC group (P .17). There were no significant differences
between the 2 groups at any of the predefined time points before or after intubation concerning
SpO2
, PaO2
/FIO2
, and PaCO2
. CONCLUSIONS: Preoxygenation using HFNC before intubation was
feasible and safe compared with BVM in critically ill subjects with acute, mild to moderate hypoxemic
respiratory failure. There was no significant difference in the mean lowest SpO2
during
intubation between the HFNC and the BVM group. There was also no significant difference in SpO2
between the 2 groups at any of the predefined time points. However, on continuous monitoring,
there was a significant decrease in SpO2
during the apnea phase before intubation in the BVM group,
which was not seen in the HFNC group. (ClinicalTrials.gov registration NCT01994928.)