异氟醚预处理对心脏瓣膜置换术病人血清心肌肌钙蛋白与心肌酶学的影响

Myocardial protective effect of isoflurane pretreatment during value replacement with cardiopulmonary bypass

目的 观察吸入异氟醚对心肌缺血再灌注损伤的保护效应。方法 准备行心脏瓣膜置换术的风湿性心脏瓣膜病病人25例,随机分为异氟醚组(n=13)和对照组(n=12),异氟醚组以芬太尼复合异氟醚维持麻醉,于主动脉阻断前吸入1.1％异氟醚30 min以上;对照组以芬太尼维持麻醉。分别于体外循环前、主动脉开放后30 min、术后8 h和24 h收集中心静脉血,检测血清心肌肌钙蛋白I(cTnI)浓度、CK-MB与CK的活性,记录相应时点的MAP、CVP、HR值,并在主动脉阻断前和开放后30min取右心房标本,对照观察心肌超微结构(线粒体记分)的变化。结果 两组病人术前cTnI、CK-MB、CK均在正常范围,在主动脉开放后各观察时点明显升高(P<0.01),对照组术后8 h、24 h血清中cTnI含量和CK-MB的活性显著高于异氟醚组(P<0.05);两组病人术后心肌细胞都出现不同程度的肿胀,线粒体记分升高(P<0.01),但异氟醚组明显低于对照组(P<0.05)。结论 在主动脉阻断前吸入异氟醚能产生心肌保护效应,在一定程度上减轻了心肌再灌注损伤。

Objective To investigate the protective effect of isoflurane pretreatment on myocardium against ischemia-reperfusion injury induced by cardiopulmonary bypass (CPB) .Methods Twenty-five patients (11 male, 14 female) aged (SD) (48± 9) yr and weighing (53 ± 11) kg, undergoing value replacement with CPB were randomized to one of 2 groups: (A) control group ( n = 12) and (B) isoflurane group ( n = 13). The patients were premedicated with intramuscular morphine and scopolamine. Anesthesia was induced with midazolam 0.05-0.08 mg·kg-1 , fentanyl 10-15 μg·kg-1 and vecuronium 0.12 mg·kg-1 iv. In isoflurane group anesthesia was maintained with isoflurane combined with intermittent iv boluses of fentanyl and vecuronium and 1.1% isoflurane was inhaled for 30 min before CPB . In control group anesthesia was maintained with intermittent iv boluses of fentanyl and vecuronium. Blood samples were taken from CVP line for determination of serum cardiac troponin Ⅰ(cTnI) concentration and creatine kinase isoenzyme CK-MB and CK activity before CPB (T0), at 30 min after release of aortic cross-clamping (T1), 8 h and 24 h after operation(T2 ,T3). Myocardium specimen was taken from right atrium before aortic cross-clamping and at 30 min after release of aortic cross-clamp for electron microscopic examination.Results Serum cTnl concentration and CK-MB, CK activities were within normal range before CPB (T0) but were significantly increased after release of aortic cross clamp (T1-3 ) in both groups. In control group serum cTnI concentration and CK-MB activity were significantly higher than those in isoflurane group at T2 and T3 (P < 0.05) . Different degrees of mitochondrial swelling could be seen after operation in both groups but the changes were significantly milder in isoflurane group as compared with the control. Conclusion Isoflurane pretreatment can protect myocardium from ischemia-reperfusion injury induced by CBP to some extent.