神经刺激器对超声引导锁骨上臂丛神经阻滞的辅助作用

The adjunct role of nerve stimulator in enhancing the effectiveness of ultrasound-guided supraclavicular nerve blocks

目的评价神经刺激器对超声引导锁骨上臂丛神经阻滞的辅助作用。方法对62例锁骨上臂丛神经阻滞下行上肢手术成年患者(ASAⅠ～Ⅱ),在超声引导锁骨上臂丛神经阻滞中正确辨认神经及穿刺针的位置。神经刺激器引出臂丛神经支配肌群运动的刺激电流﹤0.5mA即认为穿刺针位置接近臂丛神经。根据神经刺激器能否引出肌群收缩分为NT组(不能引出肌群收缩)和T组(能引出肌群收缩)。超声定位时在显示器上必须至少能清楚看到臂丛3干中的2干及穿刺针。记录肌皮神经、桡神经、正中神经、尺神经阻滞的起效时间,并评价阻滞完善率;评定手术全程的麻醉效果(优、良、差),记录麻醉并发症。结果62例患者超声图像清晰。52例患者神经刺激器引出明确的肌群运动,其中45例(88%)患者臂丛阻滞完全。10例未引出上肢肌群收缩,其中9例(90%)患者臂丛阻滞完全。结论对于超声图像清晰的超声引导锁骨上臂丛神经阻滞,应用神经刺激器引出肌群收缩不能增加锁骨上臂丛神经阻滞的成功率(P﹥0.05)。另外,即使没有引出肌群运动(假阴性率较高),最终也证明这些阻滞是成功的。神经刺激器对超声引导锁骨上臂丛神经阻滞的辅助作用有限。

Objective To evaluate the effectiveness of nerve stimulation to support ultrasound-guided supraclavicular nerve blocks, Methods 62 adult patients, ASA Ⅰ - Ⅱ, who underwent upper limb surgery and agreed to receive supraclavicular nerve block were included, The point of study was to identify nerves and localized needles in supraclavicular nerve block under the guidance of ultrasound, A nerve stimulator with under 0,5 mA motor response was used to confirm the findings, If two trunks of brachial plexus were visualized and the needle was completely seen along the long axis, the ultrasound image was considered to be valid, The intensity of sensory block of musculoeutaneous, median, radial and ulnar nerves were measured and the grades for analgesia were excellent, effective and failure, Results 62 patients had valid ultrasound images. Among the 52 patients with a positive motor response, 88% had a successful block. Among the 10 patients without a motor response, the block of 90% of them was successful （P 〉 0.05）. Conclusions A positive motor response to nerve stimulation does not increase the success rate of the block. Even in the absence of a motor response, the high false negative rate suggests that these blocks are usually effective. Therefore, the role of nerve stimulation as an adjunct to ultrasound guidance is very limited.