ABSTRACT
Objective To investigate the myocardial protection effect of dexmedetomidine hydrochloride during off-pump coronary artery bypass graft surgery. Methods Forty patients undergoing off-pump coronary artery bypass grafting were randomly divided into two groups:control group (group C) and dexmedetomidine group (group D).Dexmedetomidine hydrochlo-ride was given at a loading dose of 0. 5 μg?kg-1 to patients in group D, and then infused continuously at a rate of 0.5 μg?kg-1?h-1.The same amount of saline was given to patients in group C. After loading dosing,general anesthesia was per-formed with TCI technique.Trans-esophagus Doppler monitoring was conducted to monitor the blood volume and heart function, and close monitoring of fluid infusion to maintain stable circulation.Invasive blood pressure and heart rate were recorded every 5 min. Blood samples were taken for detection of cTnI,CK-MB,TNF-αand IL-6 contents at the following time points:after induction ( t0 ) ,before operation ( t1 ) ,after operation ( t2 ) ,12 h postoperation ( t3 ) and 24 h postoperation ( t4 ) . Results The blood pressure and heart rate decreased significantly at t0 and t1 in group D compared with group C,and there were no significant differ-ences in the two indexes at other time points between the two groups.Blood CK-MB,cTnI and inflammation factors TNF-α,IL-6 were much higher at t2,t3,t4 than at t0 and t1 in both groups(P<0.05).They were significantly decreased at t2,t3,t4 in group D relative to group C (P<0.05).Vessel active medicines were less given after the operation in group D (P<0.05). Conclusion Dexmedetomidine hydrochloride can mitigate the inflammation responses caused by off-pump coronary artery bypass grafting,re-duce the myocardial injury and improve the cardiac function of the patients.