RESUMO
Objective To investigate the protective effect of ulinastatin on myocardium against ischemia-reperfusion injury in open heart surgery with cardiopulmonary bypass (CPB) .Methods Twenty ASA Ⅰ - Ⅱ patients undergoing atrioseptopexy or surgical repair of VSD under CPB were randomly divided into two groups: in ulinastatin group (U n = 10) patients received ulinastatin 12000 unit?kg-1, half of the dose was given iv, 10 min before aorta cannulation and another half was added into the priming fluid; in control group (C n = 10) the patients received same volume of saline instead of ulinastatin. Premedication consisted of intramuscular pethidine 1 mg?kg-1 and scopolamine 0.01 mg?kg-1 .Anesthesia was induced with midazolam 0.1 mg?kg-1, fentanyl 10 ?g?kg-1 and pancuronium 0.1 mg**kg-1 and maintained with fentanyl, enflurane or isoflurane, diazepam and pancuronium. Arterial blood samples were taken before CPB (T1), at release of the aortic cross-clamp (T2), 30 min after aortic release (T3), 4h and 24h after discontinuation of CPB (T4, T5 ) for determination of plasma levels of cardiac troponin I (cTnI), creatine phosphokinase (CK) and creative phosphokinase isoenzyme (CK-MB) .Results The demographic data were comparable between the two groups. The CPB time, aortic cross-clamping time and duration of operation were also comparable. The plasma cTnI level and CK, CK-MB activity were all within normal range before CPB in both groups. In group C the plasma level of cTnI started increasing at T2, peaked at T4 and started decreasing at T5. In group U the plasma level of cTnI at T3 and T4 was significantly higher than the baseline (P