Effect of midazolam on anesthesia induction with propofol TCI

Objective To observe the effects of midazolam on anesthesia induction with propofol TCI.Methods Forty ASA physical status 1 or 2 patients scheduled for laparoscopic gynecologic surgery were randomly divided into two groups with 20 cases each.The patients in group P were induced with propofol TCI and fentanyl and vecuronium.Additional midazolam 0.05 mg/kg was used during anesthesia induction in group M.The plasma and effect-site propofol target concentrations at the time of BIS value 50 were recoved.MAP and HR were recoved before and after induction and at the time of intubation.Results when BIS value decreased to 50,the plasma and effect-site propofol target concentrations of propofol in group M were significantly lower than those in group P(P0.01).MAP after induction in two groups was significantly lower than that before(P0.01).HR in group P was lower after induction than that before(P0.01) and lower than that in group M(P0.05);HR of postintubation of P group was significantly slower than preinduction(P0.05).Conclusion Keeping the BIS at 50,propofol TCI combined with midazolam can significantly lower the plasma and effect-site propofol target concentrations and avoid propofol-induced slowdown of HR,but can not decrease propofol-induced hypotention.