Pharmacodynamic Interactions between Remifentanil and Sevoflurane during General Anesthesia for Laparoscopic Operations / 中国微创外科杂志

ABSTRACT

Objective To investigate the pharmacodynamic interactions between remifentanil and sevoflurane during general anesthesia for laparoscopic operation.Methods Sixty-five ASA I patients undergoing selective laparoscopic operations at the Department of Gynecology and the Department of General Surgery in People's Hospital were enrolled in this study.Sevoflurane was used for anesthesia induction with its expired concentration being kept stable,and different dosages of remifentanil(0,1,2,4,6,and 8 ng/ml)being added during the operation.When the expired concentration of sevoflurane reached an expected level(pseuto-state),the block somatic and cardiovascular responses to electrical tetanus stimuli(ETS;100 Hz,60 mA,5 s)were measured.The data were analyzed using NONMEM software to establish concentration-effect curves.Logistic regression was used to calculate the minimal alveolar concentration of sevoflurane under ETS(MACETS).Results In the cases received sevoflurane only,the somatic response was inhibited when MACETS reached 1.52%;while the cardiovascular response was inhibited when MACETS reached 2.24%.The MACETS was decreased significantly by adding low-dosage remifentanil.When the target-controlled concentration of remifentanil was 8 ng/ml,the MACETS for the inhibition of somatic and cardiovascular responses decreased by 70.0% and 76.3%,respectively.Conclusions There is a synergic effect between remifentanil and sevoflurane on the suppression of somatic and cardiovascular responses to ETS.Remifentanil produces a dose-dependent decrease of MACETS of sevoflurane.The effect is especially strong in low-dosage remifentanil group,but shows ceiling effect characteristics.