The Impact Of The Droperidol Of The Propofol Patients Consciousness Disappears Effective Target Concentration

Objective:To investigate the effects of droperidol on the effective target concentration for propofol anesthesia at loss of consciousness.Methods:Eighty patients undergoing scheduled surgery were randomized into 4 groups(n=20 each):controll group (group A) and droperidol groups B,C,D(droperidol 0.625mg,1.25mg,2.5mg,respectively). Every patient in groups B, C, D received intravenous injection of droperidol (0.625mg,1.25mg,2.5mg,respectively). Patient in group A received physiologic saline (NS).10 minutes later, the TCI (target controlled infusion) of propofol was started. The Cp(target plasma) and Ce(effect-site concentration) for propofol at loss of consciousness were recorded. HR(heart rate), MAP(mean arterial pressure) and BIS (bispectral index) were recorded before induction of anesthesia(baseline) and at loss of consciousness. The number of cardiac adverse events were recorded.Results:1. The Cp and Ce were significantly lower in groups B, C, D than group A(P<0.01); The decrease was significantly larger in group D than in group B and C(P<0.01).2.There were no significant differences in the BIS at loss of consciousness(67±6) among four groups (P>0.05), so in the baseline BIS(>90). The HR, MAP and BIS in four groups at loss of consciousness obviously decreased comparing with baseline (P<0.05). The MAP in group A was significantly lower than in group D (P<0.05). 3. No cardiac adverse events happened in groups B, C, D.Conclusion:Safe dose droperidol(0.625～2.5mg) decrease the Cp and Ce for propofol anesthesia at loss of consciousness in a dose-dependment manner. Droperidol 2.5mg cooperating with TCI of propofol supports more stable condition in blood pressure for anesthesia induction.