Effects of different target effect-site concentrations of remifentanil on propofol sedation in patients

Objective To study the effects of different target effectsite concentrations of remifentanil on propofol sedation.Methods A total of 75 patients who received elective surgery under general anesthesia were randomly divided into groups A,B,C,D and E.When bispectral index(BIS) reduced to 50,the propofol effect,target effect-site concentrations,total propofol dosage,time required,and BIS values and target concentrations when patients lost consciousness of propofol effect were recorded.Results The basic values at the onset of anesthetic induction showed no significant differences between the 5 groups.As the BIS values dropped to 50,the effect of propofol target concentration,propofol dosage and time required in groups C,D,E were significantly less than those in groups A and B.When patients lost consciousness,compared with the groups A and B,the effect of propofol target concentration was significantly lower,and the BIS value was significantly higher in groups C,D and E.Conclusion The optimal target concentration is 4 ng/mL when combined remifentanil-propofol is administered for general anesthesia.