Objective To evaluate the effectiveness of intratracheal injection of pulmonary surfactant (LISA) combined with continuous positive airway pressure (CPAP) on the treatment of neonatal respiratory distress syndrome (RDS). Methods The databases of PubMed, EMBASE, Cochrane, China National Knowledge Infrastructure (CNKI), Wanfang Database, Weipu Database and China Biology Medicine disc (CBM) were searched, and all of the randomized controlled trial of LISA combined with CPAP for treatment of RDS were included. RevMan 5.2 was used to perform meta-analysis. The differences of mortality, bronchopulmonary dysplasia (BPD), retinopathy of prematurity (ROP), intraventricular hemorrhage (IVH), periventricular leukomalacia (PVL), and other complications between LISA group and control group were compared in <34 weeks gestational age preterm infants with RDS. Results Five randomized controlled trials were included with 759 infants in total. Compared with control group, the rate of mechanical ventilation (RR: 0.32,95% CI: 0.13-0.82) and the incidence of BPD (RR: 0.61,95%CI: 0.42-0.88) were significantly decreased in LISA group. There were no differences in mortality and the incidences of ROP, IVH, and PVL between two groups (P>0.05). Conclusion The mechanical ventilation and the incidence of BPD is significantly reduced in the treatment of neonatal respiratory distress syndrome by LISA, but it has no effect on the incidences of other complications and mortality.

Objective To investigate the efficacy of heated humidified high-flow nasal cannula (HHHFNC) as the primary means of respiratory support for preterm infants with mild or moderate respiratory distress syndrome (RDS).Methods Randomized controlled trials (RCTs) about HHHFNC and/or nasal continuous positive airway pressure (nCPAP) in preterm infants with RDS were searched in PubMed,EMBASE,Cochrane library,Chinese Journal Full-text Database (CJFD),Wanfang Data base,VIP Database and China Biology Medicine disc (CBM).Meta-analysis was conducted with Review Manager 5.2 software to compare HHHFNC and CPAP groups in the outcomes ofpreterm infants with RDS,which included initial support failure,nasal trauma,pre-discharge mortality and incidences of bronchopulmonary dysplasia (BPD) and patent ductus arteriosus (PDA) before discharge.Results Eight randomized trials,including 1 400 preterm infants with RDS were included.Results of the meta-analysis demonstrated that no significant difference in the percentage of initial support failure was observed between the two groups (RR=1.22,95％CI:0.94-1.59,P=0.13),and HHHFNC was associated with decreased risk for nasal trauma (RR=0.35,95％CI:0.24-0.52,P＜0.001).There was no significant difference in the incidence of death,BPD,PDA or gas leaking before discharge between the two groups.Conclusions HHHFNC is an efficient respiratory support for preterm infants (gestational age over 28 weeks) with mild or moderate RDS.