Objective To systematically evaluate the effect of high-1low nasal cannula oxy gen therapy after extubation in patients undergoing mechanical ventilation. Methods We searched Cochrane Library , Joanna Briggs Institute Library (JBI), Pubmed ,MEDLIN E, Embase ,CINAHL,CNKI, VIP Database , China Biomedical Literature Database (CBM) and W anfang Database for randomized controlled trials on the effects of high-flow nasal catheter oxygen therapy after extubation in patients undergoing mechanical ventilation. After screening the literature , extracting data and evaluating literature quality , RevMan 5.3 software was used for meta-analysis. Results A total of 14 randomized controlled trials and 3, 375 patients were included. Meta-analysis showed that high-flow nasal catheter oxygen therapy had no advantage in reducing patient reintubation rate[ 95%Cl(0.52, 1.22) ,Z= 1.03, P=0.30], reducing patient mortality[95%CI(0.79, 1.56), Z=0.61 ,P=0.45],shortening the ICU length of stay[95%CI(-1.53, 1.27) ,Z=0.18, P=0.86] and .the incidence of spittoon [95%CI (0.01,1 .88),Z=1.47 ,P=0.14],and had some effects in reducing the incidence of pulmonary infection. Conclusion Compared with conventional oxygen therapy , nasal high-flow oxygen therapy can reduce the incidence of pulmonary infection,but it cannot reduce the patient's re intubation rate, ICU mortality incidence of spittoon and the ICU length of stay.
