Cardioprotective Effects Of Dexmedetomidine For Children With Congenital Heart Diseases During Perioperative Period

Objective:Dexmedetomidine,which is a selectiveα2-adrenoreceptor agonist,has been introduced to have a notable effect of cardioprotection.It can attenuate hemodynamic response,provide cardioprotective and antiarrhythmic effects because it can reduce catecholamine and adrenaline in blood,stimulate cardiac presynapticα2-adrenoreceptor,and also has a parasympathomimetic effect.More and more kids with congenital heart diseases can be cured through cardiosurgery nowadays while injuries is inevitable.These injuries are always associated with myocardial oxygen supply-demand imbalance,myocardial injury and ischemical reperfusion injury.these factors can lead to cardiovascular events during perioperative perild.Reducing and minimizing myocardial injury during perioperative period and rapid recovery are goals for patient undergo open-heart surgery.This research intended to determine whether dexmedetomidine can protect heart tissue and be safe in children with VSD.Methods:Thirty children who were scheduled to undergo on-pump(cardiac arrest)heart surgery with ventricular septal defect aged from 24 to 60 months were randomly allocated to dexmedetomidine group(group D)and the control group(group C)Patients in group D received intravenous dexmedetomidine(0.5μg·kg-1 10min before intubation,0.2-0.5μg·kg-1·h-1 after intubation depending on heart rate).Patients in group C received saline solution.Blood samples for measurement of CK-MB,cTnI and cTnT are collected at T0(immediately after into OR),T1(after intubation),T2(institution of CPB),T3(2 min after Ascending aorta occlusion),T4(at the end of surgery),T5(6 hours after Ascending aorta occlusion),T6(24 hours after Ascending aorta occlusion).Heart rate and mean arterial pressure were also recorded at these point.Other clinical observations were recorded as wellResults:Plasma levels of CK-MB,cTnI and cTnT in group D were lower than those in group C(P<0.05).Heart rate and mean blood preasure in group D had no statistic difference compared with those in group C.CPB time,time of intubation,the rate of heart spontaneous rebeating and hospital days were not statistically different between 2 groups eitherConclusion:Dexmedetomidine can reduce plasma levels of CK-MB,cTnI and cTnT and protect the myocardium from ischemic injury in children with ventricular septal defect during perioperative period.It has little influence on patients’ heart rate and mean blood preasure.Meanwhile,it is safe in children by monitoring and rational administration.