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.


METHODS
Ovid Medline, Embase, and Cochrane Database of Systematic Reviews.


METHODS
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.


METHODS
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.


RESULTS
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, 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, 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.
1Department of Anaesthesia, Critical Care and Pain Medicine, Royal Infirmary of Edinburgh, Edinburgh, United Kingdom.2Department of Anaesthesia, Critical Care and Pain Medicine, Queen Elizabeth University Hospital, Glasgow, United Kingdom.3Department of Anaesthesia, Critical Care and Pain Medicine, Monklands General Hospital, Airdrie, United Kingdom.
Thalia
T
Monro-Somerville
Malcolm
M
Sim
James
J
Ruddy
Mark
M
Vilas
Michael A
MA
Gillies
D000208:Acute Disease; D000072601:Cannula; D003693:Delirium / Q000453:epidemiology; D017052:Hospital Mortality; D006801:Humans; D007442:Intubation, Intratracheal / Q000706:statistics & numerical data*; D010100:Oxygen / Q000008:administration & dosage*; D010102:Oxygen Inhalation Therapy / Q000009:adverse effects / Q000379:methods*; D017060:Patient Satisfaction; D012131:Respiratory Insufficiency / Q000401:mortality* / Q000628:therapy*
D010100:Oxygen