Effect of different doses of dexmedetomidine on myocardial injury on cardiopulmonary bypass in patients with rheumatic heart valve replacement surgery / 重庆医学

ABSTRACT

Objective To investigate the effect of different doses of dexmedetomidine on myocardial injury (in perioperative peri‐od) on cardiopulmonary bypass (CPB) in patients with rheumatic heart valve replacement surgery .Methods Patients undertook rheumatic heart valve replacement surgery with mitral stenosis were divided into three groups (n=20) in randomized and double‐blind method:control group (group C) ,dexmedetomidine 0 .3 μg/kg group (DEX1 group) ,dexmedetomidine 0 .6 μg/kg group (DEX2 group) .Central venous blood was drawn respectively before anesthesia induction (T0 ) ,2h after CPB (T1 ) ,24 h after CPB (T2 ) ,48 h after CPB (T3 ) ,72 h after CPB (T4 ) .Plasma muscle calcium protein I (cTnI) and creatine kinase (CreatineKinase MB , CK‐MB) were measured and mean arterial pressure and heart rate were recorded at each time point .Furthermore ,extubation time , ICU stay ,postoperative inotropic score 24 h after operation ,drainage 24 h after operation ,cardio auto‐resuscitation rates and ad‐verse cardiovascular events were recorded .Results Compared with T0 ,HR was significantly lower in the T1 time point in DEX2 group .Compared with group C ,HR ,plasma CK‐MB ,inotropic score 24 h after operation and cardiovascular adverse events was sig‐nificantly reduced in the T1 time points in DEX1 group (P<0 .05) ,but the heart auto‐resuscitation rate did not significantly im‐proved .HR at T1 ,plasma CK‐MB values at T1 and T2 ,and plasma cTnI values at T2 -T4 were significantly reduced ;the heart re‐suscitation significantly increased ,myocardial contraction power ratings 24 h after operation and the incidence of cardiovascular e‐vents was significantly lower in DEX2 group (P<0 .05) .The extubation time ,ICU stay time and drainage 24 h after operation did not change significantly in both groups .Conclusion Dexmedetomidine has a protective effect on perioperative myocardial injury in patients with rheumatic heart valve replacement surgery ,and the effect would be better when the dexmedetomidine was infused at 0 .6 μg · kg -1 · h-1 after a loading dose of 0 .6 μg/Kg continuously .