[High-flow nasal cannulae oxygen in patients with respiratory failure: a Meta-analysis]

To systematically evaluate the efficacy of high-flow nasal cannulae oxygen (HFNC) in patients with respiratory failure.

Computerized PubMed, Embase, Web of Science, the Cochrane Library, CNKI, CBM, VIP, Wanfang Database up to March 31st, 2017, all published available randomized controlled trials (RCTs) or cohort studies about HFNC therapy for patients with respiratory failure were searched. The control group was treated with face mask oxygen therapy (FM) or non-invasive positive pressure ventilation (NIPPV), while the experimental group was treated with HFNC. The main outcome measurements included endotracheal intubation rate, patient comfort, and the secondary outcome was in-hospital mortality. The quality of the literature was completed by two professionally trained evidence-based medical students, and meta-analysis was performed on quality-compliant literature. Funnel plot was used to analyze the publication bias.

A total of 17 articles were enrolled including 15 RCTs and 2 cohort studies. There were 3 909 patients enrolled, 1 907 patients in HFNC group, and 2 002 in control group (1 068 patients with FM, and 934 with NIPPV). Meta-analysis showed that HFNC had a significant advantage over FM in reducing the tracheal intubation rate of patients with respiratory failure [odds ratio (OR) = 0.51, 95% confidence interval (95%CI) = 0.29-0.89, P = 0.02], but there was no significant difference as compared with that of NIPPV (OR = 0.80, 95%CI = 0.54-1.17, P = 0.25). It was shown by pooled analysis of two subgroups that compared with FM/NIPPV, HFNC had a significant advantage in reducing tracheal intubation rate in patients with respiratory failure (pooled OR = 0.66, 95%CI = 0.47-0.94, P = 0.02). Compared with FM, patients with respiratory failure were more likely to receive HFNC for comfort [standardized mean difference (SMD) = -0.41, 95%CI = -0.56 to -0.26, P < 0.000 01]. There was no significant difference in hospital mortality between HFNC and FM (OR = 0.82, 95%CI = 0.55-1.24, P = 0.35) or NIPPV (OR = 0.66, 95%CI = 0.37-1.17, P = 0.16). The results of pooled analysis of two subgroups were still unchanged (pooled OR = 0.75, 95%CI = 0.54-1.05, P = 0.09). It was shown by the funnel analysis that there was a bias in the study of tracheal intubation rate in the literature, while the bias of patient comfort and hospital mortality was low.

Compared with FM, HFNC could reduce the rate of tracheal intubation in patients with respiratory failure, but no difference was found as compared with NIPPV. Compared with FM, HFNC made patients more comfortable, and it was easier to be accepted and tolerated. However, there was no difference in hospital mortality among FM, NIPPV, and HFNC.