Effect of Midazolam on Effective Target Conncentration on Propofol

Objective:To observe and compare the influence of target-controlled infusion of different doses of midazolam on the effective target concentration of propofol.Metheds:Sixty ASAⅠ—Ⅱpatients undergoing elective surgery,randomize divided into three groups(n=20 each):propofol group(group P),midazolam I group(group M1) and midazolamⅡgroup(group M2).Berore propofol induction,midazolam(0.05 mg·kg~(-1))was intravenously injected followed by two doses of midazolam(0.04 mg·kg~(-1)·h~(-1) in group Ml,0.08 mg·kg~(-1)·h~(-1) in group M2).At the end of mostly operates stoped midazolam infusion,at the time of sewing skin stopped Propofol infusion and gave atropine and neostigmine to reversing muscle Paralysis.The effective Propofol concentration was noted every 5 min,the time of emergence from anesthesia and OAA/S scores were recorded in each group.Results:Along with the increase of the midazolam doses,the required effective propofol concentration was significant decreased(P0.05).Although the times of emergence from anesthesia were inereased,there were no significant differences among the three groups(P 0.05).OAA/S scores were higher in the group than in groups Ml and M2(P0.05),and the Post operative sleepiness was more common in the midazolam groups(P0.05).There was no significant difference in the occurrence of the adverse reactions among the three groups(P0.05).Conclusion:/There was a dose-dependent decrease in the effective propofol concentration when midazolam doses were increased.For Propofol based anesthesia used for surgery, continuous intravenous infusion of Midazolam at the dose of 0.08 mg·kg~(-1)·h~(-1) is the optimal combination of these tw anesthetics.