title: Effect of high-flow nasal cannula oxygen therapy in adults with acute hypoxemic respiratory failure: a meta-analysis of randomized controlled trials.
abstract: 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;I2= 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;I2= 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 (interactionp= 0.3 and 0.4, respectively).
  
  
  CONCLUSIONS
  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.
authors.affiliation: Department of Anesthesiology and Translational Neuroscience Center (Ou, Liu, Gong, Zhao), Laboratory of Anesthesia and Critical Care Medicine, West China Hospital of Sichuan University, Chengdu, Sichuan; Department of Anesthesiology (Hua), Subei People's Hospital of Jiangsu Province, Clinical Medical College, Yangzhou University, Yangzhou, Jiangsu, China.
authors.forename: Xiaofeng
authors.initials: X
authors.lastname: Ou
authors.affiliation: Department of Anesthesiology and Translational Neuroscience Center (Ou, Liu, Gong, Zhao), Laboratory of Anesthesia and Critical Care Medicine, West China Hospital of Sichuan University, Chengdu, Sichuan; Department of Anesthesiology (Hua), Subei People's Hospital of Jiangsu Province, Clinical Medical College, Yangzhou University, Yangzhou, Jiangsu, China.
authors.forename: Yusi
authors.initials: Y
authors.lastname: Hua
authors.affiliation: Department of Anesthesiology and Translational Neuroscience Center (Ou, Liu, Gong, Zhao), Laboratory of Anesthesia and Critical Care Medicine, West China Hospital of Sichuan University, Chengdu, Sichuan; Department of Anesthesiology (Hua), Subei People's Hospital of Jiangsu Province, Clinical Medical College, Yangzhou University, Yangzhou, Jiangsu, China 2014324020096@stu.scu.edu.cn.
authors.forename: Jin
authors.initials: J
authors.lastname: Liu
authors.affiliation: Department of Anesthesiology and Translational Neuroscience Center (Ou, Liu, Gong, Zhao), Laboratory of Anesthesia and Critical Care Medicine, West China Hospital of Sichuan University, Chengdu, Sichuan; Department of Anesthesiology (Hua), Subei People's Hospital of Jiangsu Province, Clinical Medical College, Yangzhou University, Yangzhou, Jiangsu, China.
authors.forename: Cansheng
authors.initials: C
authors.lastname: Gong
authors.affiliation: Department of Anesthesiology and Translational Neuroscience Center (Ou, Liu, Gong, Zhao), Laboratory of Anesthesia and Critical Care Medicine, West China Hospital of Sichuan University, Chengdu, Sichuan; Department of Anesthesiology (Hua), Subei People's Hospital of Jiangsu Province, Clinical Medical College, Yangzhou University, Yangzhou, Jiangsu, China.
authors.forename: Wenling
authors.initials: W
authors.lastname: Zhao
mesh_terms: D000328:Adult; D000072601:Cannula; D006801:Humans; D000860:Hypoxia / Q000628:therapy*; D007442:Intubation, Intratracheal / Q000706:statistics & numerical data*; D063087:Noninvasive Ventilation; D010102:Oxygen Inhalation Therapy / Q000379:methods*; D016032:Randomized Controlled Trials as Topic; D012131:Respiratory Insufficiency / Q000628:therapy*; D016896:Treatment Outcome