咪唑安定对体感诱发电位的影响

Influence of midazolam on somatosensory evoked potentials

目的：了解咪唑安定对体感诱发电位的影响。方法：选择３０例ＡＳＡＩ～Ⅱ级的脑外科手术病人，根据国际１０～２０系统，在Ｃ３或Ｃ４、ＦＰｚ（参考）和ＳＣ（第二颈椎棘突处）安放盘状记录电极，记录体感诱发电位。均分为三组按剂量（０．２ｍｇ／ｋｇ、０．３ｍｇ／ｋｇ和０．４ｍｇ／ｋｇ）静脉注射咪唑安定，连续观察皮层Ｎ２０、Ｐ２３和颈髓Ｎ１４电位的变化。结果：（１）用药后，皮层Ｎ２０和颈髓Ｎ１４电位的波幅降低，分别抑制到术前的６３．７５％和４８．７５％（Ｐ＜０．０５），苏醒后恢复到基础水平；（２）颈髓Ｎ１４、皮层Ｎ２０和Ｐ２３的潜伏期及中枢传导时间均无显著延长，（３）各剂量组间的ＳＥＰ变化无明显差别。结论：咪唑安定对ＳＥＰ一定程度的抑制作用临床意义不足，可用作ＳＥＰ监测时的静脉麻醉药。

Objective:To study effects of midazolam on somatosensory evoked potentials.Methods:We selected 30 ASA grade I to Ⅱ neurosurgical patients undergoing craniotomy All patients were allocated randomly and equally into three groups.Different dosages(0.2mg/kg,0.3mg/kg and 0.4mg/kg)of midazolam were injected intravenously within 2 minutes in three groups respectively Disc recording electrodes were affixed at C3 or C4,SC(the second cervical spinous process)and FPz(as reference)according to international 10 20 system.Cortical(N 20 ,P 23 )and cervical(N 14 )potentials were monitored during whole procedures.Results:Amplitudes of cortical potential N 20 and cervical potential N 14 declined to 63.75% and 48.75% of baselines (P<0.05),but no statistical significances were found among three groups.When consciousness of patients recovered,these amplitudes came to the preoperative values.Latencies of cervical potential N 14 ,cortical potentials N 20 and P 23 ,central conductive time unchanged statistically after the administration.There were no significant changes in SEP among three groups.Conclusion:SEP can be reliable as an intraoperative monitoring method when midazolam is given.