The median effective plasma concentration of propofol blunting cardiovascular responses to tracheal intubation on anesthesia induction with sufentanil in elderly patients

Objective To investigate the median effective plasma concentration (Cp50) of propofol blunting cardiovascular responses to tracheal intubation with sufentanil at different targeted concentrations on anesthesia induction in elderly patients.Methods Ninty-four patients (60 years-79 years) with an American Society of ASA physical status of Ⅰ -Ⅲ,undergoing scheduled surgery under general anesthesia were randomly allocated into one of the four groups:group A,B,C and D.The patients in group A and group B (60 years-69 years) and the ones in group C and group D(70 years-79 years) received sufentanil with a target effect concentration of 0.2 μg/L,0.3 μg/L respectively.Induction of anesthesia was initiated by targeted-controlled infusion (TCI) of sufentanil at target effect-site concentration and was maintained stable before administration of propofol,determined by up and down sequential test.At the moment of loss of consciousness,cisatracurium 0.2 mg/kg was administered and intubated after 3 min.Results The Cp50 of propofol were 3.60,2.03,2.70,1.97 mg/L with 95％ confidence interval of 3.44 mg/L-3.76 mg /L,1.88 mg/L-2.20 mg/L,2.56 mg/L-2.84 mg/L and 1.81 mg/L-2.12 mg/L in group A,B,C and D respectively. Conclusions With the concentrations of sufentanil or increased age,the Cp50 of propofol decreases in elderly patients. Key words: Propofol; Sufentanil; Targeted-controlled infusion; The median effective plasma concentration; Tracheal intubation ; The elderly