温血停搏液持续与间断灌注在冠状动脉搭桥术中的比较研究

Comparison of continuous versus intermittent warm blood cardioplegia during coronary artery bypass grafting

目的 比较温血持续与间断灌注心脏停搏液在冠状动脉搭桥术中心肌保护效应。方法将30例冠状动脉搭桥手术随机分为温血持续灌注组（n=15）;温血间断灌注组（n=15）,灌注心脏停搏液,在常温体外循环下分别于切皮前、转流60min、停机6、12h采集动脉血,以ELISA法测定血浆心肌肌钙蛋白T（cTnT）浓度。分别取主动脉阻断前、开放后心肌组织,观察三磷酸腺苷（ATP）含量及心肌超微结构。结果 温血间断组 cTnT在停机6h时点比温血持续组有显著性差异（P<0.05）。两组术中60min、停机6hcTnT升高,停机24h逐渐恢复术前水平。两组ATP含量比主动脉阻断前有显著性差异（P<0.05）。温血间断组线粒体计分主动脉阻断开放后比主动脉阻断开放前有显著性差异（P<0.05）,温血持续组略升高（P<0.05）。结论 常温体外循环中温血持续灌注停搏液优于温血间断灌注停搏液的心肌保护作用。

Objective To examine the difference in myocardial protection provided by continuous and intermittent warm blood cardioplegia during coronary artery bypass (CAB) .Methods Thirty ASA Ⅰ-Ⅱ patients undergoing CAB with warm CPB were randomly divided into two groups : (A) continuous warm blood cardioplegia ( n = 15) and (B) intermittent warm blood cardioplegia ( n = 15) . During CPB the body temperature was maintained at 33℃ -34℃ . Arterial blood samples were taken before skin incision (T0) , 1 h after going on CPB (T1 ) and 6h , 24h after coming off CPB (T2, T3 ), for determination of plasma concentration of cardiac troponin T (cTnT) using ELISA method. A small piece of myocardium was obtained from right ventricle (about 1g ) before aortic crass-clamping and after the aortic clamp was removed for determination of myocardial ATP content and ultrastractural examination. Results The demographic data were comparable between the two groups. Plasma cTnT level increased significantly at T1 and T2 as compared with the baseline values (T0) and then returned to normal level at T3 in both groups. The cTnT level was significantly higher in group B than that in group A at T2 (6h after weaning from CPB)The myocardial ATP content decreased significantly after aortic clamp was removed as compared with that before cross-clamping of aorta, but myocardial ATP content in group A was significantly higher than that in group B after release of arotic clamp. Mitochondria score was significantly higher after release of aortic cross-clamp than that before aortic cross-clamping.Conclusion Continuous warm blood cardiaplegia is superior to intermittent warm blood cardioplegia during CPB in terms of myocardial protection.