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 ventricular septal defect under CPB were randomly divided into two groups of 10 patients. The patients in the ulinastatin group (U), 5 males and 5 females, aged 6.7 +/- 2.6, received ulinastatin 12,000 unit/kg, half of the dose being given intravenously 10 min before aorta cannulation and another half being added into the priming fluid. The patients in the control group (C), 6 males and 4 females, aged 5.9 +/- 2.7, received the same volume of normal saline instead of ulinastatin. Arterial blood samples were taken before CPB (T1), at release of the aortic cross-clamp (T2), 30 min after aortic release (T3), 4 h and 24 h after discontinuation of CPB (T4, T5) for determination of plasma levels of cardiac troponin I (cTnI), creatine phosphokinase (CK) and creatine phosphokinase isoenzyme (CK-MB).
Results: The CPB time, aortic cross-clamping time and duration of operation were comparable between these 2 groups. The plasma cTnI level and CK and CK-MB activities were all within normal range before CPB in both groups. In group C the plasma level of cTnI started to increase at T2, peaked at T4 and started to decrease at T5. In group U the plasma levels of cTnI at T3 and T4 were significantly higher than the baseline value (both P<0.01) and returned to the baseline value at T5. The plasma cTnI levels at T(3-5) were significantly lower in group U than in group C (all P<0.01). The plasma CK and CK-MB activities increased significantly at T(2-5) in both groups (all P<0.01). There was no significant difference in plasma CK and CK-MB activity at T(2-4) between the two groups, but at T5 their activities were significantly lower in group U than in group C (P<0.05). The rate of spontaneous recovery of heart beat without defibrillation was higher in group U (8/10) than in group C (4/10) (P<0.05). The drainage volume during the 24 hours after operation was greater in group C than in group U (P<0.05).
Conclusion: Ulinastatin effectively protects myocardium from ischemia-reperfusion injury during open heart surgery with CPB.