ABSTRACT
Objective To evaluate the myocardial protective effect of dexmedetomidine during non-cardiac surgery in patients with coronary heart disease.Methods Eighty ASAⅡor Ⅲ patients with coronary heat disease (NYHA Ⅱ or Ⅲ)aged 43-76 yr weighing 52-80 kg scheduled for elective upper abdominal surgery were randomly divided into 2 groups(n=40 each)：control group(group C)and dexmedetomidine group(group D).Anesthesia was induced with etomidate 0.25 mg／kg，sufentanil 0.5 μg／kg and vecuronium 0.1 mg／kg.The patients were tracheal intubated and mechanically ventilated.A loading dose of dexmedetomidine 1μg/kg was injected intravenously 10 min before induction followed by infusion at 0.4 μg·kg-1·h-1 until the end of operation in group D.While equal volume of normal saline was given in group C.BIS was maintained at 40-49.Blood samples were taken before induction and at the end of operation for determination of serum concenlrations of IL-6，TNF-α，cardiac troponin Ⅰ(cTnI)and glycogen phosphorylase BB(GP-BB).The adverse cardiovascular events were recorded during operation.Results The serum concentrations of IL-6，TNF-α，cTnI and GP-BB and incidences of tachycardia and myocardial ischemia were significantly lower，while the incidences of bradycardia highcr in group D than in group C (P<0.05).Conclusion Dexmedetomidine Can exert the myocardial protective effect during non-cardiac surgery in patients with coronary heart disease and the mechanism may be related to the inhibition of the release of pro-inflammatory cytokines.