ObjectiveTo systematically evaluate the efficacy of high-flow nasal cannula oxygen therapy (HFNC) in post-extubation intensive care unit (ICU) patients.MethodsThe PubMed, Embase, Cochrane Library, CNKI, WanFang, VIP Databases were searched for all published available randomized controlled trials (RCTs) or cohort studies about HFNC therapy in post-extubation ICU patients. The control group was treated with conventional oxygen therapy (COT) or non-invasive positive pressure ventilation (NIPPV), while the experimental group was treated with HFNC. Two reviewers separately searched the articles, evaluated the quality of the literatures, extracted data according to the inclusion and exclusion criteria. RevMan5.3 was used for meta-analysis. The main outcome measurements included reintubation rate and length of ICU stay. The secondary outcomes included ICU mortality and hospital acquired pneumonia (HAP) rate.ResultsA total of 20 articles were enrolled. There were 3 583 patients enrolled, with 1 727 patients in HFNC group, and 1 856 patients in control group (841 patients with COT, and 1 015 with NIPPV). Meta-analysis showed that HFNC had a significant advantage over COT in reducing the reintubation rate of patients with postextubation (P<0.000 01), but there was no significant difference as compared with that of NIPPV (P=0.21). It was shown by pooled analysis of two subgroups that compared with COT/NIPPV, HFNC had a significant advantage in reducing reintubation rate in patients of postextubation (P<0.000 01). There was no significant difference in ICU mortality between HFNC and COT (P=0.38) or NIPPV (P=0.36). There was no significant difference in length of ICU stay between HFNC and COT (P=0.30), but there had a significant advantage in length of ICU stay between HFNC and NIPPV (P<0.000 01). It was shown by pooled analysis of two subgroups that compared with COT/NIPPV, HFNC had a significant advantage in length of ICU stay (P=0.04). There was no significant difference in HAP rate between HFNC and COT (P=0.61) or NIPPV (P=0.23).ConclusionsThere is a significant advantage to decrease reintubation rate between HFNC and COT, but there is no significant difference in ICU mortality, length of ICU stay or HAP rate. There is a significant advantage to decrease length of ICU stay between HFNC and NIPPV, but there is no significant difference in ICU mortality, reintubation rate or HAP rate.