Pharmacokinetics of remifentanil under general anesthesia with propofol in operation patients

Objective To investigate the pharmacokinetics profile of remifentanil in operation patients under general anesthesia with target controlled infusion of propofol. Methods Twenty-four patients were anesthesized with target controlled infusion of propofol were received remifentanil by constant-rate infusion of 0.50,0.75 and 1.00 μg·kg·min~ -1 (group I,II, Ⅲ,n=8) for 20 min respectively . Remifentanil concentrations were determined by high performance liquid chromatography with ultraviolet detection (HPLC-UV). Pharmacokinetic analysis was performed using DAS program.Results Pharmacokintics of remifentanil in three groups were best described by a two compartment pharmacokinetic model. The pharmacokinetic parameters were similar in three groups.The RSD of AUC_ (0~∞) 、V、t_ 1/2β and CL were 33.42, 67.38 ,51.22 and 68.10 respectively.Conclusion The constant-rate infusion had not influence on the pharmacokinetics of remifentanil(P0.05).The dosage of remifentanil should be prescribed individually.