Effect of ulinastatin on interleukins and pulmonary function in bypass patients: a meta-analysis of randomized controlled trials

Our aim was to evaluate the effect of urinary trypsin inhibitors (UTI) on interleukin, tumor necrosis factor-α (TNF-α), and polymorphonuclear neutrophil elastase (PMNE) levels as well as on pulmonary function in patients undergoing cardiopulmonary bypass. We searched the following databases for relevant studies: PubMed, Medline (Ovid SP), Cochrane Library, Wanfang Data, China Biology Medicine Database, Chinese Periodical Database, China Knowledge Resource Integrated Database, and Chinese Clinical Trial Registry. Two investigators independently collected the data and assessed the quality of each study. RevMan 5.3 was used for the meta-analysis. In total, 15 randomized controlled trials (646 patients) met the inclusion criteria. There was a significant decrease in TNF-α, interleukin-6 (IL-6), IL-8, and PMNE levels at 6 h and 24 h after UTI treatment and an increase in IL-10 levels; additionally, there was a decrease in respiratory index and an improvement in the oxygenation index. Nevertheless, UTI treatment did not affect the length of intensive care unit stay, alveolar–arterial oxygen partial pressure difference, adverse lung events, or hospital mortality. Because of the high heterogeneity of the included trials, the results should be assessed carefully. UTI treatment can suppress proinflammatory cytokine elevation and upregulate the release of anti-inflammatory mediators, thereby reducing pulmonary injury and improving pulmonary function after cardiopulmonary bypass.