部分神经肌肉阻滞及不同麻醉深度对经颅电刺激运动诱发电位的影响

Influences of partial muscle relax and depth of anesthesia on transcranial electrical motor evoked potential

目的将肌松监测和脑电监测相结合，探索在部分神经肌肉阻滞及不同麻醉深度对经颅电刺激运动诱发电位（TceMEP）的影响。方法12例行神经外科手术的患者术中行TceMEP监测，同时监测脑电图和5个成串刺激（TOF），计算爆发抑制比（BSR）和T4与T1比值，在BSR=0、肌松完全恢复后记录TceMEP基线；调节异丙酚和肌松药剂量，分别在肌松恢复、0．25〈BSR〈0．5和BSR〉0．75以及BSR=0、T4／T1为25％时记录TceMEP并评估刺激时患者出现体动的情况。结果基线时患者出现体动率较高（9／10），在肌松恢复、0．25〈BSR〈0．5和BSR〉0．75两种情况下体动发生率降低（1／10和0／10），TceMEP波幅较基线时下降明显（P〈0．05和P〈0．01）；部分肌松且BSR=0时TceMEP波幅较基线时相差不多（P〉0．05），10例中仅1例出现体动；各种情况下的潜伏期比较差异无统计学意义。结论术中进行TceMEP监测，需避免盲目增加麻醉药物剂量加深麻醉；在脑电图未出现爆发一抑制波形时，使T4／T1维持在25％，可以有效记录TceMEP，又能降低患者发生体动的风险。

Objective To explore the influences of partial muscle relax and depth of anesthesia on transcranial electrical motor evoked potential （TeeMEP）. Methods 12 patients undergoing neurosurgical operation were enrolled. Anesthesia was maintained with sevoflurane , propofol and remifentanil. The level of muscle relax and anesthesia depth were monitored by train of five stimulation （TOF） and burst - suppressed rate （BSR）. After the baseline recording when T4 equal to T1 and there was no burst suppression wave on EEG（ BSR = 0） , then BSR was increased to 0. 25 - 0. 5 and above 0.75 by regulating dosage of propofol and TceMEP was recorded respectively . At the state of disapperance of burst suppression wave and eisatracurium （40 - 80）μg/（kg/h） was administered simultaneously, when T4 / T1 was equal to 25% TeeMEP was elicited again. The movements of patients were also assessed during monitoring. Results The incidence of patient＇s movement at baseline was high （9/10）. At the state of recovery of muscle relax, movement incidence was decreased and the amplitude of TceMEP was attenuated greatly when 0. 25 〈 BSR 〈0. 5 and BSR 〉0. 75 comparing to baseline（ 〈0.05 and 〈0. 01 respectively）. When BSR =0 and T4 / T1 was equal to 25% , a similar intensity stimulation could almost maintain the amplitude of TceMEP as well as baseline（ P 〉 0.05） ,but there was only 1 patient showing movement. The latency of TceMEPs was not significantly different comparing to baseline. Conclusions Monitoring of TceMEP need to avoid the presence of burst suppression waves EEG by deepening anaesthesia. TceMEP could be recorded at the state of partial muscle relax by T4 / T1 equal to 25% and without burst suppression wave EEG, in which the risk of movement of patients responsed to transcranial stimulation is decreased and the effect on TceMEP is reduced.