熵指数监测脑电信号用于全身麻醉深度调控的临床研究

Entropy of EEG in regulating and controlling the depth of general anesthesia

目的研究熵指数（entropy）监测脑电信号指导全麻深度调控的有效性及特点。方法选全麻下行胆囊切除术患者100例，将患者随机分为两组，每组50例：G组（n=50）为对照组暨无熵指数监测组，根据传统的血压、心率等血流动力学指标调节靶控泵上异丙酚的模拟靶控浓度；E组（n=50）为熵指数[状态熵（stateentropy，SE）和反应熵（responseentropy，RE）]指导组，通过维持熵指数值在40～60调节异丙酚靶浓度维持适宜的麻醉深度。两组患者均采用异丙酚加瑞芬太尼联合靶控输注（TCI）全静脉全麻，采用TCI—I双通道麻醉靶控输注泵，诱导时设定异丙酚模拟血浆靶浓度3p^-／ml，瑞芬太尼模拟血浆靶浓度7ng／ml，意识消失后给予维库溴按0．1mg／kg辅助气管内插管接呼吸机行机械通气。G组根据术中患者血压或心率变化调节麻醉深度，E组患者根据熵指数变化调节麻醉深度。记录两组患者麻醉及手术期间血流动力学指标、麻醉药物用量、术毕清醒时间及拔管时间。E组记录麻醉诱导后、气管插管时、术中及手术结束麻醉苏醒期的熵指数（sE和RE），术毕询问患者是否发生术中知晓，记录麻醉苏醒期患者意识状态的镇静／警觉（OAA／S）评分，记录对应OAA／S评分的RE、SE数值，对熵指数（SE、RE）和麻醉苏醒期（OAA／S）评分进行相关性分析。结果E组患者SE基础值低于RE，诱导后RE、SE均下降，sE较RE下降明显，低于基础水平，术中血压、心率变化比较差异无统计学意义（胆囊切除时值较切皮时值，P〉0．05），恢复期明显回升但未能回到基础水平（P〈0．01）。诱导后血压较基础值显著降低（P〈0．01），与熵指数变化值相关性强。麻醉用药量比较：G组异丙酚的用量高于E组，差异有统计学意义（P〈0．05）。E组患者与G组相比，苏醒时间明显减少，差异有统计学意义（P〈0．05）；E组自主呼吸恢复快，拔管时间短，且患者定向力恢复迅速。熵指数与麻醉苏醒期OAA／S评分具有良好相关性（P〈0．05）。所有患者术后随访均未发生术中知晓。结论熵指数可准确监测脑电信号，及时指导全麻深度调控，值得临床推广运用。

Objective To investigate the characteristic and efficacy of Entropy of EEG in regulating and controlling the depth of general anesthesia. Methods One hundred cases who received cholecystectomy under general anesthesia, were included in this study. They were randomly divided into group G and group E（ state entropy and response entropy group）. In group G,adjustment of simulated concentration of propofol on target-controlled pump was based on the alteration of blood pressure, heart rate and other hemodynamic parameters. In group E, the control of appropriate depth of general an- esthesia was through maintaining theentropy indes value between 40 and 60. Intravenous infusion of prop- ofal combined with remifentanil was adopted for anesthesia induction. The simulated target plasma con- centration of propofol was setted at 3 μg/ml while remifentanil at 7 ng/ml. Hemodynamics parameter, so- ber time and extubation time during anesthesia and surgery, anesthetic drug consuption and the entropyindex（ SE and RE ） were recorded for analysis. Results Baseline values of SE were lower than RE in group E. Both RE and SE decreased after induction, however, SE decreased more significantly compared with RE and was lower than the basic level （P 〈 0. 01 ）. Blood pressure declined obviously after induc- tion and was lower than the baseline blood pressure （P 〈 0. 01 ） , and had a strong correlation with the alteration of entropyindex value. The consume of propofol in group G was more than that of group E, the difference was statistically significance （P 〈 0.05 ）. Recovery time in group E significantly reduced compared with group G （P 〈 0. 05 ）. Patients in group E can more rapidly recoverspontaneous breath- ing, had shorter extubation time and promptly recovered orientation. There was good correlation between the entropy index and OAA/S score （ P 〈 0.05）. All patients had no intraoperative awareness. Conclusions Entropy of EEG can accuratly regulate and control/the depth of general anesthesia and was worthy of clinical use.