关键词: 右美托咪定, 心肌保护, 再灌注损伤, 心肌肌钙蛋白I, 肌酸激酶

Abstract: 【Abstract】〓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.

Key words: Dexmedetomidine, Myocardial protection, Reperfusion injury, Cardiac troponin I, Creatine kinase