全凭静脉麻醉下后颅凹术中合理肌松深度的研究

The study of proper depth of muscle relaxant in posterior fossa surgery under total intravenous anesthesia

目的探讨在后颅凹占位手术中采用全凭静脉麻醉方式，寻找不影响神经传导功能监测的合理肌松深度。方法选择后颅凹桥小脑角区（CPA）占位手术患者40例，随机分为两组：A组不用肌松药，即采用常规麻醉方法，全麻诱导插管后到电生理监测结束前不用肌松药；B组使用肌松药，即在电生理监测过程中维持TOF值2％～25%。所有患者采用全凭静脉麻醉，维持BIS值在40～60。记录不同TOF值时肌电图波幅。记录手术时间及丙泊酚、舒芬太尼、罗库溴铵的用量。记录患者围术期的SBP、DBP、HR及术前、术后1周、术后6个月的面神经功能。结果两组患者均顺利完成神经监测，A组丙泊酚用量明显多于B组（P〈0．05），A组3例患者术中发生体动反应，B组在TOF为三个信号时有4例不能进行电生理监测。两组各时点DBP、SBP、HR及面神经功能差异无统计学意义。结论在非去极化肌松药辅助下维持TOF值在2％～25％不影响神经电生理监测，同时可避免术中出现体动反应并可减少镇静药物的用量。

Objective To investigate the proper depth of muscle relaxant without affecting electrophysiological monitoring in patients undergoing posterior fossa surgery under total intravenous an- esthesia （TIVA）. Methods Forty patients selected for posterior fossa surgery were randomly divided into two groups A and B. Group A： no muscle relaxants were administered after anesthesia induction until the EMG was completed. Group B： muscle relaxants maintained in range of TOF 2%-25 % during electrophysiological monitor. TIVA were used to all patients and BIS was maintained in range of 40-60. Two electrophysiological data were applied during the electrophysiological monitoring： sponta- neity EMG and evoked EMG. EMG amplitude was recorded at different TOF value. Operation time and the dosages of propofol, sufentanil, rocuronium bromide were recorded. Also, the SBP,DBP, HR at perioperational period and facial nerve function before surgery, one week and six months after surgery were recorded. Results The electrophysiological monitoring completed successfully in all patients. The total amount of propofol in group A significantly increased than those in group B（P〈 0.05）. Three patients in group A had body movement during the operation. Four cases in group B couldn＇t perform electrophysiological monitor when the TOF had three signals. There were no difference between the two groups in SBP, DBP, HR and facial nerve function. Conclusion Maintaining TOF value in range of 2%-25% under non-depolarizing muscle relaxant during CPA surgery doesn＇t affect intraoperative nerve electrophysiological monitor and prevent body movement, total dose of sed- ative anesthetics is also decresed.