Ulinastatin treatment for acute respiratory distress syndrome in China: a meta-analysis of randomized controlled trials

Background: Epidemiologic studies have shown inconsistent conclusions about the effect of ulinastain treatment for acute respiratory distress syndrome (ARDS). It is necessary to perform a meta-analysis of ulinastatin's randomized controlled trials (RCTS) to evaluate its efficacy for treating ARDS. Methods: We searched the published RCTs of ulinastatin treatment for ARDS from nine databases (the latest search on April 30th, 2017). Two authors independently screened citations and extracted data. The meta-analysis was performed using Rev. Man 5.3 software. Results: A total of 33 RCTs involving 2344 patients satisfied the selection criteria and were included in meta-analysis. The meta-analysis showed that, compared to conventional therapy, ulinastatin has a significant benefit for ARDS patients by reducing mortality (RR = 0.51, 95% CI:0.43 similar to 0.61) and ventilator associated pneumonia rate (RR = 0.50, 95% CI: 0.36 similar to 0.69), and shortening duration of mechanical ventilation (SMD = -1.29, 95% CI: -1.76 similar to-0.83), length of intensive care unit stay (SMD = -1.38, 95% CI: -1.95 similar to-0.80), and hospital stay (SMD = -1.70, 95% CI:-2.63 similar to-0.77). Meanwhile, ulinastatin significantly increased the patients' oxygenation index (SMD = 2.04, 95% CI: 1.62 similar to 2.46) and decreased respiratory rate (SMD = -1.08, 95% CI: -1.29 similar to-0.88) and serum inflammatory factors (tumor necrosis factor-alpha: SMD = -3.06, 95% CI:-4.34 similar to-1.78; interleukin-1 beta: SMD = -3.49, 95% CI: -4.64 similar to-2.34; interleukin-6: SMD = -2.39, 95% CI: -3.34 similar to-1.45; interleukin-8: SMD = -2.43, 95% CI: -3.86 similar to-1.00). Conclusions: Ulinastatin seemly showed a beneficial effect for ARDS patients treatment and larger sample sized RCTs are needed to confirm our findings.