Objective: To investigate the brain protective effects of Ginkgo biloba leaf extract (Ginaton) in patients who underwent hypothermic cardiopulmonary bypass (CPB).
Methods: Sixty patients with rheumatic heart disease of ASA grade II-III, who were scheduled for mitral valve replacement with intravenous anaesthesia, were randomly assigned to two groups, the Ginaton group (30 patients) treated with Ginaton 1 mg/kg by intravenous dripping before open heart for CPB, and the control group (30 patients) with normal saline instead. Blood was synchronously collected from arteriae radialis and vena jugularis interna at 5 time points, namely, before CPB (T1), nasopharyngeal temperature (lowered to 30-31 degrees C) stabilized stage (T2), nasopharyngeal temperature restoration (36 degrees C) stage (T3), 30 min after CPB (T4) and 3 after CPB (Ts) for determining blood gas, lactate acid concentration, activity of superoxide dismutase (SOD) and malonaldehyde (MDA) content. And the oxygen content in artery (CaO2) and jugular vein (CjvO2), the difference of oxygen contents in arterial and jugular vein (Ca-jvO2), the cerebral oxygen extraction ratio (ERO2) as well as the arteriojugular lactate difference (ADVL) were calculated.
Results: After the beginning of CPB, as compared with those in the control group, in the Ginaton group, the reduction of Ca-jvO2 and ERO2 was significantly higher (P < 0.05 or P < 0.01) and the increase of lactate acid, ADVL and MDA were significantly lower, and with a remarkably higher SOD activity (P < 0.01).
Conclusion: Ginaton could improve cerebral oxygen supply, promote SOD activity to inhibit production of free radicals in patients undergoing CPB, and thus shows an evident protective effect in the brain.