Efficacy of High-Flow Nasal Cannula Therapy in Intensive Care Units.

PURPOSE: 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).

PROCEDURES: We selected the full-text prospective studies comparing HFNC with standard O2 or 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.

FINDINGS: 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).

CONCLUSION: 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 Pao2 and Pao2 /Fio2 but had a slightly lower intubation rate and ICU mortality.