The Effect of High-Flow Nasal Cannula Oxygen Therapy on Mortality and Intubation Rate in Acute Respiratory Failure: A Systematic Review and Meta-Analysis

Objective: High-flow nasal cannulae are used in adults with or at risk of acute respiratory failure. We conducted a systematic review and meta-analysis to evaluate the evidence for their use in this setting. Data Sources: Ovid Medline, Embase, and Cochrane Database of Systematic Reviews. Study Selection: Databases were searched for randomized controlled trials comparing administration of high-flow nasal cannulae with usual care (i.e., conventional oxygen therapy or noninvasive ventilation) in adults with respiratory failure. The primary outcome was hospital mortality; the rate of intubation and assessment of delirium and comfort were secondary outcomes. Data Extraction: One hundred forty-seven nonduplicate citations were screened, 32 underwent full screening and data extraction, and 14 trials were eligible for inclusion in the review. Nine trials were used in the meta-analysis, including a total of 2,507 subjects. Data Synthesis: When high-flow nasal cannulae were compared with usual care, there was no difference in mortality (high-flow nasal cannulae, 60/1,006 [6%] vs usual care, 90/1,106 [8.1%]) (n = 2,112; p = 0.29; I-2, 25%; fixed effect model: odds ratio, 0.83; 95% CI, 0.58-1.17) or rate of intubation (high-flow nasal cannulae, 119/1,207 [9.9%] vs usual care, 204/1,300 [15.7%]) (n = 2,507; p = 0.08; I-2, 53%; random effect model: odds ratio, 0.63; 95% CI, 0.37-1.06). A qualitative analysis of 13 studies on tolerability and comfort suggested that high-flow nasal cannulae are associated with improved patient comfort and dyspnea scores. Trial sequential analyses on primary and secondary outcomes suggested that required information size was not reached. Conclusions: No difference in mortality or intubation was detected in patients with acute respiratory failure treated with high-flow nasal cannulae compared with usual care. High-flow nasal cannulae seem well tolerated by patients. Further large randomized controlled trials are required to evaluate their utility in this setting.