[Protective effect of breviscapine on cardiac function in children after cardiopulmonary bypass undergoing open heart surgery].

Objective: To assess the condition of myocardial injury after cardiopulmonary bypass (CPB) and the effects of breviscapine (BVC) on cardiac function in children undergoing open heart surgery.

Methods: Thirty-six children (ASA II or III, aged 2-65 months) scheduled to receive ventricular septal defect repairing were randomly assigned to three groups, the control group treated with saline, and the BVC treated groups treated respectively with low dose (0.5 mg/kg) and high dose (1.0 mg/kg) BVC, 12 patients in each group. Saline or BVC (in volume of 15 mL) was administered intravenously after induction of anesthesia with micro-pump within 30 min. Blood levels of troponin I (cTn-I ) and malondialdehyde (MDA) were measured at different time points: pre-operation (T0), during aortic unclamping (T1), and 30 min, 1 h, 6 h, 24 h after aortic unclamping (T2, T3, T4, T5). And the time of operation, CPB, aortic unclamping, and the condition of drainage in 24 h after operation as well as the dosages of narcotics (midazolam, propofol and fentanyl) used were recorded.

Results: No significant difference among groups was found in terms of sex ratio, age, body weight, time of aortic unclamping, CPB and operation, as well as the dosages of narcotics used and the volume of post-operation drainage. Compared with baseline (T0), levels of cTn-I at T1, T4 and T5 increased significantly in all three groups (P<0.01), with the peak revealed at T4; cTn-I in the control group were higher than those in the low dose BVC treated group at T1 and T4 (P<0.01), and those in the high dose BVC group at T1, T4, and T5, while it was insignificantly different between the two BVC treated groups. Level of plasmal MDA began to rise in all groups at T1 with the peak revealed at T2, it lowered after then, and reached the baseline at T5; comparison between groups showed that it was lower in the BVC treated groups than in the control group at T1-T4.

Conclusions: Different degree of cardiac injury always happens after open heart surgery and CPB, showing high level of cTn- I within 24 h with the peak revealed at 6 h after aortic unclamping. Intravenous perfusion BVC before CPB at the dose of 0.5 or 1 mg/kg could protect the cardiac function to some extent.