超声联合神经刺激器引导腋路臂丛神经阻滞最小容量的临床研究

目的:测定高频超声联合神经刺激器引导下行有效腋路臂丛神经阻滞局麻药(1%利多卡因加0.375%罗哌卡因的混合液)的最小容量.方法:择期行前臂及手部手术患者若干例,分为若干组(组数根据临床进展决定),每组10例.采用高频超声行腋路臂丛神经扫描,穿刺针在超声引导下进针到目标神经,经神经刺激器引出相应的肌肉运动,确认目标神经后,分别在桡神经、正中神经、尺神经及肌皮神经周围注入预定药量.第一组容量为每点10.0 mL(10.0 mL组)上述局麻药的混合液.分别观察10例患者四条神经阻滞的效果,如果10例患者各神经阻滞均完善,则第二组患者局麻药的容量在此基础上减半,为每点5.0 mL(5.0 mL组).如果5.0 mL组患者各神经阻滞均完善,则第三组患者局麻药的容量在此基础上再减半,为每点2.5ml(2.5 mL组).如果5.0 mL组患者各神经阻滞的完善率不能达到100%,则第三组患者的容量为第一组和第二组容量的中位数,即每点7.5 mL(7.5 mL组).如此反复进行,直到相邻容量组之差小于等于0.5 mL,得出最小容量为止.观察并记录麻醉操作时间,不同容量组四条神经的麻醉起效时间和麻醉持续时间以及可能引起的并发症.结果:10.0mL组、7.5 mL组、6.2 mL组及5.6 mL组各组10例患者阻滞均完善.5.3 mL组和5.0 mL组10例患者各有2例患者麻醉后30 min阻滞效果未达到手术要求,在超声引导下经锁骨下行第二个臂丛神经阻滞后完善.不同容量的各组麻醉操作时间相似,平均麻醉操作时间为8.4 min.每条神经起效时间和麻醉持续时间无统计学差异.所有患者均无麻醉并发症发生.结论:高频超声联合神经刺激器引导下行腋路臂丛神经阻滞各神经点有效神经阻滞局麻药的最小容量为5.6 mL.

Clinical study of the minimum volume of local anesthetic in performing axillary brachial plexus block guided by high-frequency ultrasound and neurostimulator

AIM:To study the minimum volume of local anesthetic(mixture with 1%lidocaine and 0.375%ropivocaine)in the effective axillary brachial plexus block guided by high-frequency ultrasound and neurostimulator.METHODS:Patients scheduled for elective surgery of the forearm and hand were allocated to several groups(the groups were determined by clinical progression,n=30 each).An axillary brachial plexus block was performed under real-time monitoring by ultrasound and neurostimulator.A setted dosage were respectively infused near the radial nerve(RN),median nerve,ulnar nerve(UN)and musculocutaneous nerve.The starting dose of local anesthetic was setted at 10 mL per point.The volume in the subsequent group was decreased by 50%,or the median volume of the previous two volumes according to the Success rate.A minimum volume was achieved until the volume difference between the two consecutive groups was less than 0.5 mL.The operation time.onset time of the four nerves,duration time and complications were observed.RESULTS:A 100%success rate was achieved in groups using 10 mL,7.5mL,6.2 mL and 5.6mL of local anesthetic.Each 2 of the 10 patients of the two groups(5.3 mL,5.0 mL)did not get the demanding effects,and were all retrieved by another ultrasound-guided infraclavicula brachial plexus block The operating times were similar in all groups.The mean operation time was 8.4 min.The onset time of each nerve and duration of anesthesia were comparable in all groups.There were no occurrence of wrongly vascular puncture,haematoma in the puncture site,local anesthetics poisoning and paresthesia of affected extremities.CONCLUSION:The minimum volume of local anesthetic in the effective axillary brachial plexus block guided by ultrasound and neurostimulator is 5.6 mL per point.