High-flow nasal cannula for hypoxia in the post-anesthetic recovery unit: A systematic review and meta-analysis

Earlier meta-analyses demonstrated conflicting results on whether high-flow nasal cannula (HFNC) reduces rate of intubation in the postoperative period when compared to conventional oxygen therapy (COT). Since then, newer studies have come out, so an updated comparison of these two modalities is warranted.

To determine whether HFNC reduces the rate of reintubation compared to COT.

We conducted a random-effects meta-analysis, searching databases (MEDLINE, EMBASE, Web of Science) to identify randomized controlled trials comparing HFNC with COT on postoperative patient outcomes of interest including reintubation, escalation to noninvasive ventilation, mortality, length of stay, pneumonia, postoperative pulmonary complications, vital signs and blood gas measurements. We assessed the quality of data using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) framework.

Twenty-five trials, including 4260 patients met the inclusion criteria. Thirteen investigated reintubation and the pooled result was not significant [odds ratio (OR); 0.93; 95% confidence interval (CI): 0.36-2.38; I ² = 47.1%; P = 0.86]. However, HFNC reduced the incidence of atelectasis (OR 0.33; 95%CI: 0.18-0.59; I ² = 10.8%; P = 0.0046) and hypoxemia (OR 0.42; 95%CI: 0.21-0.83; I ² = 78.3%; P = 0.017). There were no clinical differences detected in other outcomes. GRADE for certainty of evidence was low to moderate.

HFNC does not reduce reintubation risk in our analysis with moderate certainty. Use of HFNC should not delay escalation of therapy to noninvasive ventilation or a definitive airway.