Effect of different target effect-site concentrations of remifentanil on median effective concentration of etomidate required for loss of consciousness and disappearance of nociceptive stimuli-induced body movement / 中华麻醉学杂志

ABSTRACT

Objective To investigate the effect of different target effect-site concentrations (Ces) ofremifentanil on the median effective concentration (EC50 ) of etomidate required for loss of consciousness and disappearance of nociceptive stimuli-induced body movement. Methods Eighty ASA Ⅰ orⅡ patients aged 18-64 yr scheduled for elective gynecological surgery under general anesthesia were randomly divided into 4 groups ( n = 20 each) group R0 received no remifentanil and R1-3 groups received remifentanil at 3 predetermined target Ces of 1,2 and 3 ng/ml respectively. At the beginning of anesthesia induction, remifentanil was given by target-controlled infusion (TCI) until the predetermined Ces were achieved, TCI of etomidate was then started at a target plasma concentration of 0.6 μg/ml and then the target plasma concentration of etomidate increased by 0.1 μg/ml every 1 min until the patients lost consciousness and the body movement induced by the nociceptive stimuli disappeared. The Ce of etomidate required for loss of consciousness and disappearance of nociceptive stimuli-induced body move-ment was recorded and the EC50 was calculated by Probit method. Results With the increase in the target Ces of remifentanil, the EC50 of etomidate required for loss of consciousness and disappearance of nociceptive stimuli-induced body movement decreased gradually (P < 0.05) .Conclusion Remifentanil given by TCI can enhance the sedative and analgesic effect of etomidate concentration-dependently.