右美托咪定对全麻低温心肺转流下冠状动脉旁路移植术围术期的心肌保护作用

Cardioprotection of dexmedetomidine in on pump coronary artery bypass grafting surgery by general anesthesia with low temperature

目的观察右美托咪定对全麻低温心肺转流（CPB）下冠状动脉旁路移植术患者围术期的心肌保护作用。方法择期行全麻低温CPB下冠状动脉旁路移植术患者80例,男67例,女13例。随机均分为右美托咪定组（A组）和对照组（C组）。在中心静脉置管后,A组静脉泵注右美托咪定4μg·kg^-1·h^-1持续15min后调节维持剂量0.7μg·kg^-1·h^-1直到手术结束,C组用同样方案静注等容量生理盐水。记录入室后（T0）、麻醉诱导后（T1）、切皮时（T2）、CPB终止时（T3）和手术结束时（T4）的HR、SBP、DBP和血管活性药物用量。测定T1～T4、术后6h（T5）和术后24h（T6）血浆肌酸激酶同工酶（CK-MB）、心肌肌钙蛋白T（cTnT）、肾上腺素（E）和去甲肾上腺素（NE）浓度。结果与T0时比较,T1时两组HR明显减慢,SBP和DBP明显降低（P〈0.05）。与T1、T2时比较,T3～T6时两组CK-MB、cTnT、E浓度明显升高（P〈0.05）,T3～T5时A组NE浓度明显下降（P〈0.05）,T6时明显升高（P〈0.05）。T3～T6时A组CK-MB和cTnT浓度明显低于C组（P〈0.05）。T3～T5时A组E和NE浓度明显低于C组（P〈0.05）。两组在围术期均未出现严重不良反应。结论右美托咪定能降低全麻低温CPB下冠状动脉旁路移植术围术期心肌缺血的发生,达到围术期心肌保护的作用。

Objective The aim of this study is to observe the impact of dexmedetomidine on postoperative myocardial injury in patients undergoing on pump coronary artery bypass grafting（CABG）in a randomized,double-blind,placebo-controlled,prospective study.Methods Eighty patients,sixty-seven for male and thirteen for female,undergoing on-pump CABG surgery were randomly divided into dexmedetomidine group（group A）and control group（groups C）.After central venous catheter（CVC）inserted,in group A,dexmedetomidine infusion was started by a loading dose of 4μg·kg^-1·h^-1 for 15 minutes,followed by a continuous infusion of 0.7μg·kg^-1·h^-1 during the operation.Group C received the same volume saline.The HR,SBP,DBP and vasoactive drugs were recorded at the time points of room enter（T0）,induction of anesthesia（T1）,skin incision（T2）,the termination of CPB（T3）and the end of surgery（T4）.Blood was sampled for CK-MB,cTnT,E and NE at T1,T2,T3,T4,6 h post-surgery（T5）and 24 h post-surgery（T6）.Results Compared with T0,HR was decreased,SBP and DBP were increased in both groups at T1（P〈0.05）.At T3-T6,the CK-MB,CTnT and NE level were much higher than those at T1 and T2in the two groups（P〈0.05）.In group A,E level decreased at T3-T5（P〈0.05）,and rose promptly at T5（P〈0.05）.At T3-T6,the CK-MB and cTnT level in group A were significantly lower than those in group C（P〈0.05）.At T3-T5,the E and NE level were much lower than those in group C（P〈0.05）.There were no severe adverse events in both groups.Conclusion Dexmedetomidine reduced postoperative myocardial injury in patients undergoing on-pump coronary artery bypass grafting.