冠状动脉搭桥体外循环手术中心肌缺血缺氧性损伤的临床观察

Clinical observation of the myocardial ischemic and hypoxia injury during coronary artery surgery under cardiopulmonary bypass

目的以心肌肌钙蛋白(IcTnI)和冠状静脉窦血液氧合参数作为评判指标,观察体外循环(CPB)下接受冠状动脉旁路移植手术患者心肌缺血缺氧性损伤的状况。方法选取择期进行冠状动脉旁路移植手术(CABG)的患者12例,分别于CPB前,主动脉开放后0min、0.5min、1min,1.5min、3min和5min经冠状静脉窦取血,测定血清cTnI浓度,冠状静脉窦血流量和血气值,计算心肌氧输送量、氧耗量及其比值以反映心肌氧代谢状况。结果主动脉开放后,冠状静脉窦内cTnI浓度明显升高(P<0.05),而冠状静脉窦血氧分压和氧饱和度均较高,氧耗量较低(P<0.05),心肌氧输送量/氧耗量比值较高;随着心跳恢复,心肌氧耗增加明显,表现心肌氧输送量/氧耗量比值降低(P<0.01)。结论主动脉阻断期间心肌有一定程度的缺血缺氧性损伤和酸中毒;主动脉开放心跳恢复后,心肌供氧和耗氧状况一般能较快趋于正常,但需注意心肌氧供/氧耗的变化。

Objective To evaluate the myocardial isehemic and hypoxia injury during CABG under CPB by using cTnⅠ, DO2, VO2 and DO2/VO2. Methods 12 patients undergoing coronary bypass grafts with pump were studied. Blood samples were obtained from the coronary sinus before the beginning of CPB, during CPB and after cardiac reperfusion. Serum cTnⅠ concentration and blood gas was measured,DO2,VOz and DO2/VO2 were calculated. Results After the beginning of reperfusion, the cTnⅠ concentration in coronary circulation increased significantly （P〈0.05）, the PO2 and SatO2 were very high, but VO2 was low at first then rose to a high level （P〈 0.05）, DO2/VO2 changed from high to low （P〈0.01）. Conclusion The ischemic and hypoxia injury of myocardial exists during the clamping of ascending aorta. After declamping, the change of DO2/VO2 should be attentioned to.