The optimal plasma concentration of remifentanil for target-controlled infusion to suppress extubation response in obese patients

Abstract

Objective To investigate the optimal plasma concentration of remifentanil for target-controlled infusion (TCI) to inhibit extubation response in obese patients under general anesthesia. Methods A total of 70 obese patients, at ASA gradeⅠ, Ⅱ and with BMI of 30-35 kg/m2, were randomly divided into control group (n=20) and experimental group (n=50) undergoing elective anesthesia with laparoscopic cholecystectomy. The modified Dixon sequential method was used in the experimental group, and the median effective concentration (EC50) of remifentanil and its 95%CI were calculated with probit probability regression analysis. The extubation time in patients subjected to remifentanil at different concentrations for TCI was recorded and compared with that in the control group. Results The EC50 of plasma remifentanil for TCI to inhibit extubation reaction was 1.58 μg/L (95%CI was 1.40-1.81 μg/L) in obese patients under general anesthesia. The extubation time in patients received 1.40-1.81 μg/L remifentanil for TCI (8.5±0.4) min did not differ from that in control group (8.3±0.6) min (P>0.05). Conclusions Remifentanil at concentration of 1.58 μg/L for TCI inhibited extubation reaction but without affecting the extubation time in obese patients under general anesthesia. Key words: Remifentanil; Target controlled infusion; Extubation response; Median effective concentration