评价七氟烷在不同呼气末浓度和不同刺激电压对脊髓手术中运动诱发电位监测的影响

Influence of Sevoflurane in different end tidal concentration and stimulating voltage on motor evoked potential monitor in spinal cord surgery

目的分析研究不同呼气末浓度和不同刺激电压下,七氟烷对脊髓手术中的运动诱发电位(MEPs)监测影响。方法随机选取2014-09—2015-11接受胸腰段脊髓肿瘤切除手术的患者57例,予以常规全麻诱导后,分别测定刺激电压300 V、500 V、600 V时,七氟烷呼气末浓度为0.0%、0.5%、1.0%时的MEPs变化情况。结果左右两侧的波幅变化规律基本一致,即当处于相同刺激电压下,随着七氟烷呼气末浓度的上升,MEPs波幅有明显下降;且当七氟烷呼气末浓度不变时,刺激电压越高,MEPs波幅越大(P<0.05);相同七氟烷呼气末浓度下,随着电压增大会提升MEPs的监测成功率;而在刺激电压相同时,MEPs监测成功率会随着七氟烷呼气末浓度的提升而下降(P<0.05)。结论七氟烷呼气末浓度会对MEPs的检测产生剂量依赖性抑制,临床手术中可考虑通过加大刺激电压,来帮助增大波幅、提高监测成功率。

Objective To analyze the influence of Sevoflurane in different end tidal concentration and stimulating voltage on motor evoked potential（MEPs） monitor in spinal cord surgery.Methods 57 sufferers undergoing resection operation for thoracolumbar spinal cord tumor from September 2014 to November 2015 were randomly selected and given conventional general anesthesia induction, then the MEPs changes were measured under the stimulating voltages of 300 V, 500 V and 600 V and the end tidal Sevoflurane concentration of 0.0%, 0.5% and 1.0%.Results The am- plitude variations on the left and right sides had consistent rules, that meant under the same stimulating voltage, with the increase of the end tidal Sevoflurane concentration,MEPs amplitude clearly decreased;When the end tidal Sevoflurane concentration was constant, with the rise of stimulating voltage, MEPs amplitude increased（P〈 0.05）.Un- der the same end tidal Sevoflurane concentration, with the rise of stimulating voltage, MEPs monitor success rate in- creased;While with the same stimulating voltage, MEPs monitor success rate decreased with the rise of the end tidal Sevoflurane concentration（P〈0.05）.Conclusion The end tidal Sevoflurane concentration can achieve dose-dependent restraint on MEPs detection, so in clinical surgery it should be considered to help magnify amplitude and increase monitor success rate by means of enlarging stimulating voltage.