The Effect Of Propofol On Cerebral Injury During Cardiopulmonary Bypass

Objective To investigate the effect of propofol on cerebral injury during CPB.Methods Forty patients undergoing elective cardiac operation of valvular replacement were randomized into four groups. Group A (unused propofol). In Group B, patients received propofol 2 mg?kg-1?h-1 during CPB. In group C, patients received propofol 4 mg?kg-1?h-1 during CPB. In group D, patients received propofol 6 mg?kg-1?h-1 during CPB. Jugular venous blood samples were taken for determination of S-100βprotein before CPB, 1 hour and 24 hour after CPB. Jugular venous blood samples were taken for determination of NSE before CPB, 24 hour and 72 hour after CPB. Jugular venous oxyhemoglobin saturation(SjO2) and cerebral oxygen extraction rate(CEO 2) were measured at various periods during CPB. DO2 and VO2 were measured at T2,T3,T4 during CPB.Results (1) The levels of S-100β protein increased on 1 hour after CPB and returned to baseline on 24 hour after CPB. The levels of NSE increased on 24 hour after CPB and returned to baseline on 72 hour after CPB. The levels of S-100β protein and NSE have no significant between Group A and Group B(P>0.05). The levels of S-100βprotein were lower in Group C and Group D than that in Group A on 1 hour after CPB(P<0.01). The levels of NSE were lower in Group C and Group D than that in Group A on 24 hour after CPB(P<0.01).(2)For all patiens, SjO2 increased in cooling and stable hypothermia stage , then decreased in rewarming stage. CEO 2 and VO2 decreased in cooling and stable hypothermia stage, then increased in rewarming stage. The differences of SjO2,DO2,VO2 and CEO 2 among four groups were not significant(P>0.05).Conclusions Propofol have the protective effect on cerebral injury during CPB with dosage-dependent. Propofol can not ameliorate cerebral oxygenation during CPB.