臂丛神经阻滞时神经刺激器诱发患者不同运动反应与桡神经阻滞效果的关系

目的 评价臂丛神经阻滞时神经刺激器诱发患者不同运动反应与桡神经阻滞效果的关系.方法 择期拟行手、腕或前臂手术患者120例,性别不限,ASA I或Ⅱ级,年龄18～60岁,随机分为2组(n=60),三点腋路臂丛神经阻滞在周围神经刺激器引导下,采用1%利多卡因与0.33%罗哌卡因混合液注射于肌皮神经、正中神经,分别为5、10 ml,I组和Ⅱ组分别诱发前臂外展或腕及手指外展时,采用上述混合液20 ml注射于桡神经周围,于注射完毕后5、10、15、20、25和30 min时采用针刺法评价肌皮神经、正中神经的感觉阻滞情况,桡神经近端和远端的感觉及运动阻滞情况.记录神经阻滞操作时间,记录桡神经定位次数,评价桡神经定位的难易程度.结果 与I组相比,Ⅱ组感觉完全阻滞成功率高,桡神经远端感觉及运动阻滞成功率高,神经阻滞操作时间长,桡神经定位困难程度高(P<0.05或0.01).结论 臂丛神经阻滞时,当神经刺激器诱发患者腕及手指外展较诱发前臂外展应用1%利多卡因与0.33%罗哌卡因混合液20 ml阻滞桡神经的效果更完善.

Relationship between different motor responses evoked by nerve stimulator and efficacy of radial nerve block during brachial plexus block

Objective To investigate the relationship between different motor responses evoked by nerve stimulator and efficacy of radial nerve block during brachial plexus block in patients. Methods One hundred and twenty ASA I or II patients aged 18-60 yr scheduled for hand, wrist or forearm surgery were randomly allocated into 2 groups ( n = 60 each) . The triple-injection axillary brachial plexus block was performed under the guidance of peripheral nerve stimulator. The mixture of 1% lidocaine and 0.33% ropivacaine was injected around the musculocutaneous nerve (S ml) and median nerve (10 ml) . When forearm extension in group I and the wrist and finger extension in group II were evoked, 20 ml of the mixture mentioned above was injected around the radial nerve. Sensory blocks of musculocutaneous and median nerves, sensory and motor blocks of the proximal or distal branches of the radial nerve were assessed at 5-min intervals in 30 min after the injection was completed. The time to perform the block and number of locating the radial nerve were recorded. Results The success rate of complete sensory block was significantly higher, the success rate of sensory and motor blocks of the distal branches of the radial nerve was significantly higher, the time to perform the block was significantly longer, and the localization of the radial nerve was more difficult in group II than in group I ( P < 0.05 or 0.01). Conclusion The wrist and finger extension evoked by peripheral nerve stimulator predicts better efficacy than forearm extension in triple-injection axillary brachial plexus block with 20 ml mixture of 1 % lidocaine and 0.33 % ropivacaine.