Ulinastatin for acute lung injury and acute respiratory distress syndrome: A systematic review and meta-analysis

AIM: To investigate the efficacy and safety of ulinastatin for patients with acute lung injury (ALI) and those with acute respiratory distress syndrome (ARDS). METHODS: A systematic review of randomized controlled trials (RCTs) of ulinastatin for ALI/ARDS was conducted. Oxygenation index, mortality rate [intensive care unit (ICU) mortality rate, 28-d mortality rate] and length of ICU stay were compared between ulinastatin group and conventional therapy group. Meta-analysis was performed by using Rev Man 5.1. RESULTS: Twenty-nine RCTs with 1726 participants were totally included, the basic conditions of which were similar. No studies discussed adverse effect. Oxygenation index was reported in twenty-six studies (1552 patients). Ulinastatin had a significant effect in improving oxygenation [standard mean difference (SMD) = 1.85, 95%CI: 1.42-2.29, P < 0.00001, I(2) = 92%]. ICU mortality and 28-d mortality were respectively reported in eighteen studies (987 patients) and three studies (196 patients). We found that ulinastatin significantly decreased the ICU mortality [I(2) = 0%, RR = 0.48, 95%CI: 0.38-0.59, number needed to treat (NNT) = 5.06, P < 0.00001], while the 28-d mortality was not significantly affected (I(2) = 0%, RR = 0.78, 95%CI: 0.51-1.19, NNT = 12.66, P = 0.24). The length of ICU stay (six studies, 364 patients) in the ulinastatin group was significantly lower than that in the control group (SMD = -0.97, 95%CI: -1.20--0.75, P < 0.00001, I(2) = 86%). CONCLUSION: Ulinastatin seems to be effective for ALI and ARDS though most trials included were of poor quality and no information on safety was provided.