Median effective concentration of lidocaine for obturator nerve block guided by nerve stimulator in patients undergoing transurethral resection of bladder tumor / 中华麻醉学杂志

ABSTRACT

Objective To determine the median effective concentration (EC50) of lidocaine for obturator nerve block (ONB) guided by a nerve stimulator in patients undergoing transurethral resection of bladder tumor (TURBT).Methods American Society of Anesthesiologists physical status Ⅰ or Ⅱ patients with bladder tumor,scheduled for elective TURBT,required ONB according to the results of cystoscopy or CT examination performed before operation,with body mass index of 19-30 kg/m2,aged 18-64 yr,were enrolled in the study.ONB was performed with lidocaine using the suprainguinal approach under the guidance of a nerve stimulator.The concentration of lidocaine was determined by up-and-down sequential trial.The initial concentration of lidocaine was 1.5％,and the ratio between the two successive concentrations was 1.2.Successful ONB was considered to be positive response.The EC50 and 95％ confidence interval of lidocaine for ONB guided by a nerve stimulator was calculated.Results The EC50 of lidocaine was 0.57％,and the 95％ confidence interval was 0.55％-0.59％ when used for ONB guided by a nerve stimulator.Conclusion The EC50 of lidocaine is 0.57％ when used for ONB guided by a nerve stimulator in the patients undergoing TURBT.