摘要目的 研究神经刺激器引导下垂直锁骨下臂丛神经阻滞(vertical infraclavicular brachial plexus blockade,VIB)中使用0.5%罗哌卡因半数有效麻醉容量.方法 30例拟行前臂或手部手术患者,神经刺激器引导下行VIB麻醉,使用序贯法计算出50%患者局麻药有效容量(50% effective vanesthetic volume,EAV50).首位患者0.5%罗哌卡因给药容量定为0.55 ml/ks,如麻醉成功,则下一个患者容量在原基础上减少1.1倍,如麻醉失败,下一个患者容量增加1.1倍.评估实验中臂丛神经感觉和运动阻滞效果.结果 (1)VIB中,0.5%罗哌卡因的EAV50为0.417 ml/kg,95%的可信区间 为(0.392～0.443)ml/kg;(2)序贯法实验中,VIB给药对臂丛内侧束、外侧束和后束的麻醉成功率差异有统计学意义(P<0.01).结论 神经刺激器引导下垂直锁骨下臂丛神经阻滞中局麻药给药容量必须足量才能充分阻滞臂丛神经内侧束、外侧柬和后束,0.5%罗哌卡因的EAV50为0.417 ml/kg,95%的可信区间为(0.392~0.443)ml/kg.

abstractsObjective To research the 50% effective anesthetic volume ( EAV50) of 0.5% ropivacaine in nerve stimulator-guided vertical infraclavicular brachial plexus block. Methods Thirty patients scheduled for forearm or hand surgery were blocked using 0. 5% ropivacaine in nerve stimulator-guided vertical infraclavicular brachial plexus block. The EAV50, which is the anesthetic volume corresponding to 50% success and 50% failure was determined by up-and-down sequential test. The starting dose of 0. 5% ropivacaine was 0. 55ml/kg. Block failure resulted in a dose increase 110% , and block success in a reduction 110%. The sensory and motor blockade were accessed at 5- min intervals (up to 60 min). Results In nerve stimulator-guided vertical infraclavicular brachial plexus block, EAV50 for 0.5% ropivacaine was 0.417ml/kg. In up-and-down sequential test, there were significantly different in the block success rates of lateral, medial and posterior cord ( P <0.01). Conclusion In nerve stimulator-guided vertical infraclavicular brachial plexus block, enough anesthetic volume must be given to increase block success rates of all the cords of brachial plexus, and EAV50 for 0. 5% ropivacaine was 0.417ml/kg.