右美托咪定预处理联合后处理对心肌缺血再灌注损伤的影响

Effect of Dexmedetomidine preconditioning and postconditioning on myocardial ischemia-reperfusion injury during cardiopulmonary bypass

摘要:

目的 观察右美托咪定预处理联合后处理对心肌缺血再灌注损伤的保护作用。方法 选取天津医科大学总医院120例心脏瓣膜置换术患者。随机分为3组，右美托咪定预处理组（preD组）、右美托咪定后处理组（posD组）及右美托咪定预处理联合后处理组（pre-posD组），每组40例。preD组和pre-posD组于阻断主动脉前30?min静脉输注右美托咪定1?μg/kg，posD组输注等容量生理盐水；posD组和pre-posD组于开放主动脉前30?min灌注液中加入右美托咪定0.2～1.0?μg/kg进行心脏灌注，preD组灌注液中加入等容量生理盐水。观察麻醉诱导前5?min（T0）、开放主动脉后15?min（T1）、体外心肺转流（CPB）结束时（T2）、术后4?h（T3）、术后16?h（T4）、术后36?h（T5）、术后72?h（T6）的心率（HR）、平均动脉压（MAP）及术中脑电双频指数（BIS）的变化，记录心脏复跳时间和心脏复跳情况，记录3组前并行循环时间（Tpre）、主动脉阻断时间（Tab）及后并行循环时间（Tpos）。检测各时间点血浆肿瘤坏死因子α（TNF-α）、白细胞介素-6（IL-6）、血清心肌肌钙蛋白（cTn?I）浓度及肌酸激酶同工酶（CK-MB）活性。结果 不同时间点3组HR、MAP值差异无统计学意义（P?>0.05）。T1～T6 时pre-posD组血浆TNF-α浓度低于preD和posD组（P?<0.05）。T2～T6时pre-posD组血浆IL-6浓度低于preD组和posD组（P?<0.05）。T1～T6时pre-posD组血浆CK-MB活性弱于preD组和posD组（P?<0.05）。结论 右美托咪定预处理联合后处理较单纯的预处理或单纯的后处理能更有效地抑制炎症因子的产生和释放，具有更好的心肌保护功能。

Abstract:

Objective To observe the effects of Dexmedetomidine preconditioning and postconditioning on myocardial ischemia-reperfusion injury during cardiopulmonary bypass. Methods Totally 120 patients who underwent mitral valve or aortic valve replacement surgery were randomly divided into three groups (n?=?40): dexmedetomidine preconditioning group (pre-D group), the dexmedetomidine postconditioning group (post-D group), and dexmedetomidine preconditioning combined with postconditioning group (pre-post-D group). Dexmedetomidine preconditioning was achieved by intravenous injection of dexmedetomidine (1?μg/kg) 30 minutes before aortic cross-clamping. Dexmedetomidine postconditioning was achieved by intravenous injection of dexmedetomidine (0.2-1.0?μg/kg) 30 minutes before aorta declamping. Clinical characters were recorded including serum TNF-α, IL-6, CK-MB, and cTnI, MAP, HR, and BIS were recorded at various time point T0, 15 minutes after aorta de-clamping (T1), end of bypass (T2), 4 h (T3), 16 h (T4), 36 h (T5) and 72 h (T6) postoperatively. The incidence of spontaneous recovery of heart beat after aorta de-clamping and ventricular arrhythmia, the ante-parallel cycle time, aorta clamping time and post-parallel cycle time were also recorded. Results No obvious differences in the values of HR and MAP was identified. Compared with group preD and group posD, the serum levels of TNF-α, CK-MB and IL-6 were decreased in pre-post-D group at T1, T2, T3, T4, T5, T6. Conclusions Dexmedetomidine preconditioning combined with postconditioning may offer better myocardial protective effect against ischemia-reperfusion injury probably through downregulating inflammatory response.