Desflurane reduces intraoperative remifentanil requirements more than sevoflurane: comparison using surgical pleth index-guided analgesia.

Ryu, K-H; Kim, J-A; Ko, D-C; Lee, S-H; Choi, W-J

BACKGROUND Sevoflurane and desflurane are widely used in balanced anaesthesia in combination with opioid analgesics. The opioid remifentanil is frequently chosen because of its extremely rapid pharmacokinetics. However, intraoperative high-dose remifentanil is associated with increased postoperative pain and rescue analgesic use owing to acute tolerance and opioid-induced hyperalgesia. This study aimed to compare intraoperative remifentanil requirements during equi-minimum alveolar concentration (MAC) sevoflurane and desflurane anaesthesia via surgical pleth index-guided remifentanil administration. METHODS Eighty-two subjects undergoing laparoscopic cholecystectomy were randomly allocated to two groups receiving either sevoflurane (n=40) or desflurane (n=42). Anaesthesia was maintained with the assigned inhaled anaesthetics and remifentanil. End-tidal anaesthetic concentration was maintained at age-corrected 1.0 MAC, and remifentanil infusion was continuously adjusted to achieve a surgical pleth index of 20-50. Mean remifentanil infusion rate, which was the primary outcome of the study, was calculated as the total infused remifentanil dose per kg body weight per minute of total operative time. RESULTS Mean remifentanil infusion rate [mean (standard deviation)] was significantly higher in the sevoflurane group than in the desflurane group [0.192 (0.064) vs. 0.099 (0.033) μg kg-1 min-1; difference, 0.093 (95% confidence interval, 0.071-0.115); P<0.001]. CONCLUSIONS During equi-MAC anaesthesia of 1.0 MAC, sevoflurane and desflurane did not show similar intraoperative remifentanil consumption under surgical pleth index-guided opioid administration. Further studies using other monitors with different measuring mechanisms are warranted to determine the cause of this difference. CLINICAL TRIAL REGISTRATION NCT02830243 (ClinicalTrials.gov).