右美托咪定预处理对心脏瓣膜置换术患者心肌肌钙蛋白Ⅰ和心肌酶学的影响

摘要

目的：观察右美托咪定预处理对脏瓣膜置换术患者心肌肌钙蛋白Ⅰ和心肌酶学的影响，探讨其对缺血再灌注损伤心肌的保护作用。方法拟择期行瓣膜置换术患者50例随机分为右美托咪定组（D 组，n＝25）和对照组（C 组，n＝25）。 D 组在麻醉诱导前经15 min 静脉泵注右美托咪定0．5μg／kg，随后以0．5μg·kg－1·h－1速率泵注至阻断主动脉。C组泵注等容量生理盐水。所有患者手术前（T0），主动脉阻断30 min（T1）、主动脉开放1 h（T2），术毕（T3）和术后24小时（T4）抽血测定磷酸肌酸激酶（CK）、磷酸肌酸激酶同工酶（CK－MB）的活性及心肌肌钙蛋白I（cTnI）的浓度。观察自动复跳率、心律失常发生率、左室射血分数（LVEF）以及血管活性药物使用情况。结果与 C 组相比，D 组的cTnI 浓度、CK 和 CK－MB 的活性、多巴胺和肾上腺素用量低于 C 组；两组自动复跳率和心律失常发生率无统计学差异；D 组术后LVEF 值高于C 组。结论右美托咪定预处理可减轻瓣膜置换患者的心肌损伤。%Objective To observe the effects of dexmedetomidine preconditioning on myocardial enzyme and cardiac troponin I in patients with heart value replacement and explore the protective effects on myocardium with ischemia/reperfusion injury. Methods Fifty patients undergoing heart valve replacement were randimized into dexemedetomine group (group D, n=25) and control group (group C, n=25). In group D, dexmedetomine was administered intravenously at 0.5 μg·kg-1·h-1 through a bolus infusion in 15 min before anesthesia and then continuous infusion- pumped carried on until aortic clamping, while the same volume of normal saline were given in group C. The central venous blood samples were collected in both groups at pre-opreration (T0), 30 min after aortic clamp (T1), 1 h after aortic-off clamping (T2), end of surgery (T3), 24 h after operation (T4) for detecting the plasma creatine kinase (CK), creating kinase-MB (CK-MB) activity and cardiac treponin I (cTnI) concentration. Meanwhile the rate of heart spontaneous rebeating, arrhythmia, left ventricular ejecfion fraction (LVEF) and usage of cardiac inotropic agents were recorded. Rusults The plasma CK, CK-Mb activity and the cTnI concentration , the doses of dopamine and adrenalin in group D were significantly lower than that in group C. There were no significantly statistical differences in the rate of heart spontaneous rebeating , arrhythmia between two groups. The postoperative LVEF was significantly higher in group D than in group C. Conclusion Dexmedetomidine pretreatment can attenuate the myocardial injury in patients undergoing cardiac valve replacement.