Effect of surfactant administration on outcomes of adult patients in acute respiratory distress syndrome: a meta-analysis of randomized controlled trials

PubMed, EMBASE, Medline, Cochrane database, Elsevier, Web of Science and http://​clinicaltrials.​gov were searched and investigated until December 2017. Randomized controlled trials(RCTs) comparing surfactant administration with general therapy in adult patients with ARDS were enrolled. The primary outcome was mortality (7–10-day, 28–30-day and 90–180-day). Secondary outcome included oxygenation (PaO₂/FiO₂ ratio). Demographic variables, surfactant administration, and outcomes were retrieved. Sensitivity analyses were used to evaluate the impact of study quality issues on the overall effect. Funnel plot inspection, Egger’s and Begger’s test were applied to investigate the publication bias. Internal validity was assessed with the risk of bias tool. Random errors were evaluated with trial sequential analysis(TSA). Quality levels were assessed by Grading of Recommendations Assessment, Development, and Evaluation methodology(GRADE).

Eleven RCTs with 3038 patients were identified. Surfactant administration could not improve mortality of adult patients [Risk ratio (RR) (95%CI)) = 1.02(0.93–1.12), p = 0.65]. Subgroup analysis revealed no difference of 7–10-day mortality [RR(95%CI)) = 0.89(0.54–1.49), p = 0.66], 28–30-day mortality[RR(95%CI) = 1.00(0.89–1.12), p = 0.98] and 90–180-day mortality [RR(95%CI) = 1.11(0.94–1.32), p = 0.22] between surfactant group and control group. The change of the PaO₂/FiO₂ ratio in adult ARDS patients had no difference [MD(95%CI) = 0.06(− 0.12–0.24), p = 0.5] after surfactant administration. Finally, TSA and GRADE indicated lack of firm evidence for a beneficial effect.

Surfactant administration has not been shown to improve mortality and improve oxygenation for adult ARDS patients. Large rigorous randomized trials are needed to explore the effect of surfactant to adult ARDS patients.