title: Efficacy of High-Flow Nasal Cannula Therapy in Intensive Care Units.
abstract: OBJECTIVE
  We conducted a meta-analysis to compare the physiological and clinical outcomes of high-flow nasal cannula (HFNC) with standard oxygen (O2) or conventional noninvasive ventilation (NIV) in intensive care units (ICUs).
  
  
  METHODS
  We selected the full-text prospective studies comparing HFNC with standard O2or NIV in ICU. The continuous variables were analyzed with sample size-adjusted pooled t test. The categorical variables were extracted and combined for recalculating odds ratio.
  
  
  RESULTS
  We included 18 articles with 2004 patients. No difference was observed in the below outcomes comparing HFNC with standard O2: oxygen saturation (95.0% vs 93.8%, P = .27), Pao2/Fio2(217.7 vs 161.9 mm Hg, P = .29), Paco2(38.3 vs 39.3 mm Hg, P = .33), pH (7.416 vs 7.419, P = .90), discomfort (1.19 vs 1.44, P = .44), intubation or reintubation rate (odds ratio = 0.79, 95% confidence interval [CI]: 0.39-1.21, P = .27), and ICU stay (4.0 vs 4.5 days, P = .90). Below outcomes were modestly improved with HFNC compared to standard O2: respiratory rate (21.6 vs 24.7, P = .06) and ICU mortality (odds ratio = 0.69, 95% CI: 0.43-1.11, P = .13). Below outcomes were significantly improved with HFNC compared to standard O2: heart rate (89.1 vs 98.4, P = .03), Pao2(104.5 vs 90.0 mm Hg, P = .04), and dyspnea (2.7 vs 4.3, P = .05). When comparing HFNC to NIV, below outcomes were significantly lower: Pao2(106.9 vs 134.2 mm Hg, P = .02), Pao2/Fio2(178.4 vs 220.0 mm Hg, P = .02), Paco2(37.7 vs 39.2 mm Hg, P = .04), and ICU mortality (odds ratio = 0.39, 95% CI: 0.19-0.82, P = .01).
  
  
  CONCLUSIONS
  When comparing to standard O2, the most effective outcomes from HFNC are reduced heart rate and dyspnea in both ICU and critical care unit patients. The HFNC modestly reduced intubation rate and ICU mortality. Patients with pneumonia may benefit from HFNC in reduced respiratory rate, heart rate, dyspnea, discomfort, intubation rate, ICU mortality, ICU stay, and improved Pao2. When comparing to NIV, HFNC group did not do as good in Pao2and Pao2/Fio2but had a slightly lower intubation rate and ICU mortality.
authors.affiliation: 1 Pulmonary and Critical Care Medicine, Lahey Hospital and Medical Center, Burlington, MA, USA.|2 Tufts University School of Medicine, Boston, MA, USA.
authors.forename: Timothy N
authors.initials: TN
authors.lastname: Liesching
authors.affiliation: 1 Pulmonary and Critical Care Medicine, Lahey Hospital and Medical Center, Burlington, MA, USA.
authors.forename: Yuxiu
authors.initials: Y
authors.lastname: Lei
keywords: high-flow nasal cannula; intensive care unit; respiratory failure