Effect of high-flow nasal cannula oxygen therapy in adults with acute hypoxemic respiratory failure: a meta-analysis of randomized controlled trials

BACKGROUND: Conflicting recommendations exist on whether high-flow nasal cannula (HFNC) oxygen therapy should be administered to adult patients in critical care with acute hypoxemic respiratory failure. We performed a meta-analysis of randomized controlled trials (RCTs) to evaluate its effect on intubation rates. METHODS: We searched electronic databases from inception to April 2016. We included RCTs that compared HFNC oxygen therapy with usual care (conventional oxygen therapy or noninvasive ventilation) in adults with acute hypoxemic respiratory failure. Because of the different methodologies and variation in clinical outcomes, we conducted 2 subgroup analyses according to oxygen therapy used and disease severity. We pooled data using random-effects models. The primary outcome was the proportion of patients who required endotracheal intubation. RESULTS: We included 6 RCTs (n = 1892). Compared with conventional oxygen therapy, HFNC oxygen therapy was associated with a lower intubation rate (risk ratio [RR] 0.60, 95% confidence interval [CI] 0.38 to 0.94; I-2 = 49%). We found no significant difference in the rate between HFNC oxygen therapy and noninvasive ventilation (RR 0.86, 95% CI 0.68 to 1.09; I-2 = 2%). In the subgroup analysis by disease severity, no significant differences were found in the intubation rate between HFNC oxygen therapy and either conventional oxygen therapy or noninvasive ventilation (interaction p = 0.3 and 0.4, respectively). INTERPRETATION: The intubation rate with HFNC oxygen therapy was lower than the rate with conventional oxygen therapy and similar to the rate with noninvasive ventilation among patients with acute hypoxemic respiratory failure. Larger, high-quality RCTs are needed to confirm these findings.