右美托咪定对非体外循环下冠状动脉旁路移植术患者的心肌保护作用

Myocardial protective effect of dexmedetornidine on patients undergoing off - pump coronary artery bypass grafting

目的观察右美托咪定对非体外循环下冠状动脉旁路移植术患者的心肌保护作用。方法择期行非体外循环下冠状动脉旁路移植术患者57例，年龄43～74岁，性别不限，美国纽约心脏病学会（NYHA）分级Ⅰ-Ⅱ级，美国麻醉师协会（ASA）分级Ⅱ～Ⅲ级，近期无急性心肌梗死、心力衰竭史，无心脏手术史，无明显肝、肾、肺功能异常。采用计算机随机软件将患者分为两组：对照组（Control组）和右美托咪定组（Dex组）。常规麻醉诱导前，Dex组静脉泵注1μg／kg负荷剂量的右美托咪定，10min泵注完毕。随后以0．5μg/（kg·h）泵注至手术结束；Control组以同样方式泵注等量生理盐水替代Dex，其余麻醉用药均相同。分别于人室后（TO）、负荷剂量注射完毕后（T1）、麻醉诱导前（T2）、气管插管后（T3）、血管吻合完毕（T4）、手术结束即刻（T5）记录患者动脉收缩压（SBP）、舒张压（DBP）、心率（HR）；于哟、手术结束后3h（T6）、手术结束后24h（T7）留取静脉血样本5ml，检测高敏肌钙蛋白T（hs-cTnT）浓度；记录患者手术时间、重症监护室（ICU）停留时间，并随访术后14d内心律失常发生率、心肌梗死发生率及患者死亡率。结果在仍、T4、T5时点SBP，Dex组[（127．70±10．g0）、（121．60±7．33）、（121．30±7．24）mmHg（1mmHg=0．133kPa）]较Control组[（139．00±13．09）、（137．20±10．50）、（142．00±9．00）mmHg]显著降低（P=0．000），T4、T5时点DBP，Dex组[（82．43±8．79）、（82．87±6．61）mmHg]较Control组[（96．93±10．17）、（101．3±9．89）mmHg]显著降低（P=0．000）；T2至T5时点HR，Dex组[（67．97±5．08）、（66．93±4．76）、（68．43±4．47）、（66．53±4．59）次／分]均显著低于Control组[（77．33±7．28）、（77．87±8．25）、（77．40±7．g0）、（75．43±7．27）础分]（P=0．000）。在T6、T7时点hs-cTnT浓度，Dex组[（124．3±55．8）、（101．3±41．8）ng／L]较Control组[（152．2±52．5）、（122．5±47．6）ng/L]均有一定程度降低，但差异无统计学意义（P=0．057、0．079）。结论右美托咪定可维持非体外循环下冠状动脉旁路移植术患者围术期血流动力学稳定、减轻心肌缺血再灌注损伤，具有心肌保护作用。

Objective To observe myocardial protective effect of dexmedetomidine （Dex） on patients undergoing off - pump coronary artery bypass grafting. Methods Fifty - seven patients scheduled for off - pump coronary artery bypass grafting surgery were selected, the gender was not restricted, aged 43 - 74 years and American Society of Anesthesiologists physical status Ⅱ or Ⅲ （ New York Heart Association Ⅱ or Ⅲ）. All patients had no history of acute myocardial infarction, heart failure, cardiac surgery, and obvious dysfunction of liver, kidney and lung. Enrolled patienrs were randomly divided into control group and Dex using computer random software. In Dex group, Dex was given as a bolus of 1 μg/kg over 10 min followed by an infusion of 0. 5 μg/（kg.h） throughout the surgery before induction of anesthesia, and the e- qual volume of normal saline was given in control group. Artery systolic blood pressure （ SBP）, diastolic blood pressure （DBP）, and heart rate （HR） were recorded after entering the operating room （TO）, after loading dose injection （T1）, before anesthesia induction （ T2）, immediately after endotracheal intubation （T3）, after the vascular anastomosis （T4）, and immediately at the end of surgery （T5）. Blood samples were collected from the central vein for detection of high- sensiti cardiac troponin T （hs- cTnT） concen-tration after entering the operating room （ T0）, 3 h （T6） and 24 h （ T7 ） after surgery. The operation time, intensive care unit （ICU） stay time, the incidence of arrhythmia and myocardial infarction, and mortality within 14 days postoperation were recorded. Results The levels of SBP in the Dex group [ （ 127.70 ± 10. 40）, （ 121.60 ± 7. 33 ） and （ 121.30 ± 7.24） mmHg （ 1 mmHg = 0. 133 kPa） ] were decreased significantly as compared with the control group [ （ 139.00 ± 13.09 ）, （ 137.20 ± 10. 50 ） and （142.00±9.00） mmHg] at T3, T4 and T5 （P=0.000）. The levels of DBP in the Dex group [ （82. 43 ± 8.79） and （82. 87 ±6. 61 ） mmHg] were decreased significantly as compared with the control group [ （96.95 ± 10. 17 ） and （101.5 ± 9.89） mmHg] at T4 and T5 （P = 0. 000）. The levels of HR in the Dex group [ （67.97 ± 5.08 ） , （ 66. 93 ± 4. 76）, （ 68. 43 ± 4.47 ） and （ 66. 53 ± 4. 59 ）/min ] were lower than in the control group [ （ 77. 33 ± 7. 28 ）, （ 77. 87 ± 8.25 ）, （ 77.40 ± 7.40 ） and （ 75.43 ± 7.27）/mini from T2 to T5 （P= 0.000）. The levels of hs -cTnT concentration in the Dex group [ （ 124. 3 ±55.8） and （ 101.3 ± 41.8 ） ng/L] were relatively decreased as compared with the control group [ （ 152. 2 ± 52. 5 ） and （ 122. 5 ± 47.6） ng/L] , but no significant difference was found at T6 and T7 （P = 0. 057, 0. 079）. Conclusion The continuous infusion of Dex can maintain hemodynamic stability, mitigate myocardial ischemia - reperfusion injury and protect the myocardial ceils in the patients undergoing off- pump coronary artery bypass grafting surgery.