术后镇痛布比卡因最小运动阻滞浓度的测定

目的测定硬膜外术后镇痛中布比卡因的最小运动阻滞浓度（minimal motor—blocking local analgesic concentration,MMLAC）。方法选择30例妇科手术患者,在术前硬膜外给予布比卡因lOml,第l例布比卡因的浓度为0．400％,下一例患者的药物浓度根据前一患者有无运动阻滞情况来上调或下调1个浓度级。注药30min后Bromage评分〈4分定为运动阻滞有效。结果用序贯法测得妇科手术硬膜外镇痛中布比卡因的最小运动阻滞浓度为0．443％,95％的可信区间为（0．4288％～0．4576％）。结论本研究测定的布比卡因最小运动阻滞浓度对术后硬膜外镇痛中布比卡因的合理应用有一定的理论指导意义。

Determination of Minimal Motor-blocking Local Analgesic Concentration of Epidural Bupivacaine in the Postoperative Analgesia

Objective The aim of this study was to determine the minimal motor-blocking concentration of epidural bupivacaine in the postoperative epidural analgesia. Methods 30 ASA I women who went gynaecologic operation and requested epidural analgesia were enrolled in the study. Epidural catheter was placed at L2-3 and advanced for 3 cm in the epidural space in a cephalad direction. Each received a 10 ml bolus of epidural bupivacaine. The first woman received 0.400%. Up-down sequential allocation was used to determine subsequent concentration：to increase the concentration one level if the previous woman did not respond and to reduce the concentration one level if the previous woman did respond. The up-down sequences were analyzed by using the Brownlee method to quantify the minimal motor-blocking local analgesic concentration. TWO-sided P 〈 0.05 defined significance. Results The minimal motor-blocking concentration of epidural bupivaeaine in the post-operative epidural analgesia was 0.443% , （95% confidence interval[ CI] ,0. 4288% -0.4576% ）. Conclusion The minimal motor-blocking local analgesic concentration of bupivacaine quantified in this study was a theoretic guideline for the clinical use of bupivacaine in the post-operative epidural analgesia.