Moderate certainty evidence suggests the use of high-flow nasal cannula does not decrease hypoxia when compared with conventional oxygen therapy in the peri-intubation period: Results of a systematic review and meta-analysis

Objective: The role of high-flow nasal cannula during and before intubation is unclear despite a number of randomized clinical trials. Our objective was to conduct a systematic review and metaanalysis examining the benefits of high-flow nasal cannula in the peri-intubation period. Data Sources: We performed a comprehensive search of relevant databases (MEDLINE, EMBASE, and Web of Science). Study Selection: We included randomized clinical trials that compared high-flow nasal cannula to other noninvasive oxygen delivery systems in the peri-intubation period. Data Extraction: Our primary outcome was severe desaturation (defined as peripheral oxygen saturation reading < 80% during intubation). Secondary outcomes included peri-intubation complications, apneic time, Pao2 before and after intubation, Paco2 after intubation, ICU length of stay, and short-term mortality. Data Synthesis: We included 10 randomized clinical trials (n = 1,017 patients). High-flow nasal cannula had no effect on the occurrence rate of peri-intubation hypoxemia (relative risk, 0.98; 95% CI, 0.68-1.42; 0.3% absolute risk reduction, moderate certainty), serious complications (relative risk, 0.87; 95% CI, 0.71-1.06), apneic time (mean difference, 10.3 s higher with high-flow nasal cannula; 95% CI, 11.0 s lower to 31.7 s higher), Pao2 measured after preoxygenation (mean difference, 3.6 mm Hg higher; 95% CI, 3.5 mm Hg lower to 10.7 mm Hg higher), or Pao2 measured after intubation (mean difference, 27.0 mm Hg higher; 95% CI, 13.2 mm Hg lower to 67.2 mm Hg higher), when compared with conventional oxygen therapy. There was also no effect on postintubation Paco2, ICU length of stay, or 28-day mortality. Conclusions: We found moderate-to-low certainty evidence that the use of high-flow nasal cannula likely has no effect on severe desaturation, serious complications, apneic time, oxygenation, ICU length of stay, or overall survival when used in the peri-intu- bation period when compared with conventional oxygen therapy.