Effect of a human urinary protease inhibitor (Ulinastatin) on respiratory function in pediatric patients undergoing cardiopulmonary bypass

BACKGROUND: We performed this prospective randomized study to determine the effect of a human urinary protease inhibitor (Ulinastatin) on respiratory function in pediatric patients undergoing cardiopulmonary bypass. METHODS: Twenty-two children were included in this study. They were randomly allocated to 1 of the following groups; a control group (n=11) or a Ulinastatin group (n=11) in which patients received 5000 U/kg of Ulinastatin. Arterial blood samples were obtained before cardiopulmonary bypass (CPB), immediately after CPB, and 30 min after protamine administration, as well as 3 hours after and 18 hours after CPB, and Interleukin-8 and neutrophil elastase concentration were evaluated. RESULTS: CPB time and aortic clamp time did not differ between the groups. Interleukin 8 and neutrophil elastase concentrations before CPB increased significantly immediately after CPB, these concentrations did not differ between the groups. However, neutrophil elastase concentrations of a Ulinastatin group were significantly lower than that of a control group at 30 min after protamine administration (a Ulinastatin group: 1011.3+/-539.1 mg/ml, a control group: 1619.7+/-595.7 mg/ml, p<0.05) and A-aDO2 of a Ulinastatin group was significantly lower than that of a control group at 2 hours after CPB (a Ulinastatin group: 67.1+/-70.6 mmHg, a control group: 169.2+/-116.3 g, p<0.05). CONCLUSIONS: These results suggest that Ulinastatin suppresses the increase in neutrophil elastase and protects the respiratory function in pediatric patients undergoing cardiopulmonary bypass.