神经阻滞对正中神经体感诱发电位的影响

Effect of nerve block on somatosensory evoked potential of median nerve

目的 :应用躯体感觉诱发电位技术(somatosensory evoked potentials,SSEPs)监测神经阻滞对正中神经的影响,为应用神经刺激仪阻滞臂丛神经提供依据。方法:选择行臂丛神经阻滞的患者40例,分为A、B 2组,各20例,A组神经刺激仪的最小电流值为0.5 m A,B组为0.3 m A。进入手术间后、术后24 h、72 h分别对正中神经体感诱发电位进行记录,并同步观察臂丛神经阻滞效果。结果:A组与B组一般资料无显著差别(P>0.05)。B组感觉、运动阻滞起效时间、阻滞评分及镇痛维持时间均优于A组(P<0.05)。正中神经体感诱发电位监测,术前A组与B组无差别(P>0.05);术后24 h,B组比A组平均延迟10%(P<0.05);术后72 h,A组与B组无显著差别(P>0.05)。结论:神经刺激仪引导下臂丛神经阻滞中,利用小于0.5 m A且大于0.3 m A的电流强度进行神经定位,能达到满意的麻醉效果,又不会对神经产生损伤。

Objective To provide references for blocking brachial plexus with the nerve stimulator by monitoring the effect of nerve block on median nerve with somatosensory evoked potentials（SSEPs）. Methods Totally 40 patients undergoing brachial plexus blocking were divided into A and B groups according to the minimum current value when muscle twitch occurred. The minimum value in A group was 0.5 m A, and that in B group was 0.3 m A. The SSEPs were recorded before and 24 h, 72 h after blocking brachial plexus, and the blocking results were observed simultaneously. Results There was no significant difference between the general information in the two groups, with P0.05. B group behaved better than A group in onset time for sensory block and motor block, block score and maintenance time, with P0.05. A group had no statistical difference in SSEPs with B group before blocking, with P 0.05. B group had SSEPs delayed by 10% than A group 24 h after blocking with P 0.05, while no significant difference with the latter 72 h after blocking with P 0.05.Conclusion The current strength between 0.5 m A and 0.3 m A can achieve satisfactory anesthetic effect and does not damage the nerves during the nerve stimulator-guided brachial plexus block.