[Effects of ulinastatin on plasma polymorphonuclear leukocyte elastase activity and respiratory function in patients undergoing cardiopulmonary bypass].

Plasma polymorphonuclear leukocyte elastase (PMNE) activity is known to increase during cardiopulmonary bypass (CPB), and is considered to mediate pulmonary tissue damage causing postoperative respiratory failure. We made a clinical study in order to clarify the effects of ulinastatin (Miraclid), a proteolytic enzyme inhibitor, on plasma PMNE activity and respiratory function. Twenty adult patients undergoing coronary artery bypass grafting were divided into 2 groups; 10 to group U and 10 to group C. The patients in group U received 500 U/kg body weight of ulinastatin intravenously before and after CPB, and the patients in group C not receiving the dose served as controls. Arterial blood samples were obtained before the operation, 1 hour after CPB, 3 hours, 1 day and 4 days after the operation. The leukocyte count was significantly lower in group U 1 hour after CPB and 3 hours after the operation compared to group C (p less than 0.01). The plasma PMNE activity rose rapidly after starting CPB and the peak level appeared 1 hour after CPB; 1165 +/- 560 micrograms/l in group U and 1981 +/- 562 micrograms/l in group C (p less than 0.02). There was a significant correlation between the leukocyte reduction and the rate of increase of beta-glucuronidase activity were diminished in group U compared to preoperative values (p less than 0.05). The recovery of the oxygenation index (PaO2/F1O2), which was used for evaluation of the respiratory function, was worse in group C (p less than 0.01). These results suggest that the administration of ulinastatin in patients undergoing CPB is useful for the prevention of the deleterious effects of PMNE on the lung.