脑电双频指数监测在临床特殊情况中的应用

随着临床监测控术的发展，脑电监测有望成为临床麻醉，急诊及重症监护病房的常规监测手段，其中研究较多的脑电双频指数（BIS）已在麻醉诱导，维持，恢复等方面显示出优势。近年也有研究报道在特殊情况下应用BIS监测，包括在颅脑损伤，低温体外循环，心跳骤停等，为临床更深一步应用BIS提供了帮助。     

脑电双频指数与丙泊酚麻醉

脑电双频指数（BIS）是公认的评价镇静程度的脑部监测指标。本文仅对BIS特点及其在丙泊酚镇静和麻醉中的应用进行简要综述。     

脑电双频指数反馈调控安氟醚麻醉用于子宫切除术病人的可行性

麻醉的反馈控制有利于维持麻醉深度稳定，满足个体药物需要量，同时还可根据术中刺激调节药物输注速度。而近年来数量化脑电监测技术的发展及其在静脉靶控麻醉中的成功应用。进一步促进了吸入麻醉药反馈控制麻醉的研究。由于吸入麻醉技术自身复杂性，吸入麻醉药反馈麻醉临床应用的可行性尚无定论。本试验应用自编吸入麻醉反馈软件“吸入麻醉执行者”，以脑电双频指数(BIS)为控制变量进行安氟醚反馈麻醉，观察其临床应用的可行性。     

脑电双频指数与听觉诱发电位指数用于麻醉深度监测的临床评价

随着经济的发展，脑电（EEG）监测有望成为临床麻醉、急诊及重症监护病房的常规监测手段，其中研究较多的脑电双频指数（BIS）和听觉诱发电位指数（AEPindex，AAI）已在麻醉诱导、维持、恢复等方面显示出优势。本文旨在就近年来BIS和AAI应用于麻醉实践中的优点及不足作一综述。     

肌松药对脑电双频指数监测麻醉深度的影响

脑电双频指数(bispectral index,BIS)是基于原始脑电图的一种麻醉深度监测指标,近年来已广泛用于临床.术中监测麻醉深度能提高麻醉质量和手术安全性,通过合理调控麻醉深度,减少麻醉用药量和避免麻醉并发症的发生.但是.关于BIS监测在临床麻醉中应用的实际意义或价值以及BIS值判读准确性及可能的影响因素仍是人们一直关心的热点问题,结合近期国内外有关文献,现就肌松药对BIS监测麻醉深度的影响及相关临床应用情况作一综述.     

脑电双频指数监测临床应用进展

脑电双频指数（BIS）是将脑电信号处理后得到的一个量化参数,主要用于监测麻醉深度。近年来的临床应用研究表明在BIS监测下调控麻醉深度能够为患者术后恢复提供更多的益处．而且BIS还可用于指导闭环靶控麻醉、监测脑缺血、预测心肺复苏的结局等。     

脑电双频指数监测临床应用的新进展

背景 麻醉深度判断一直是临床医师非常关注的问题.脑电双频指数（bispectral index,BIS）监测是目前应用最为广泛的量化麻醉深度的监测手段,随着BIS监测的普及,其应用价值也不断得到更深入的认识. 目的 就BIS临床应用的新进展作一综述. 内容 术中BIS监测可以使麻醉医师以适合的麻醉深度为目标个体化按需给药,既有助于避免麻醉过浅导致术中知晓,也可避免不必要的麻醉过深而造成的术后恢复延迟,这对于慢性肝病患者的麻醉尤其重要.术中BIS监测有助于通过避免麻醉过深加快患者术后认知功能恢复,并可能改善患者远期预后.对于围术期全脑缺血的高危患者,术中BIS突然下降可能提示脑灌注不足.BIS监测可能还有助于对心跳骤停、心肺复苏后患者的预后判断,但用于预后判断的最佳监测时间和界值仍有待进一步研究阐明. 趋向 术中BIS监测能够预防术中知晓和避免麻醉过深,降低术后谵妄的发生率,并在肝病患者神志判断和麻醉、高危手术围术期脑缺血监测及心肺复苏患者的预后判断等领域有很好的应用价值.     

监测脑电双频谱指数预防全麻患者术中知晓的效果:meta分析

目的 采用meta分析评价脑电双频谱指数(BIS)监测用于预防全麻患者术中知晓的效果.方法 检索Cochrane Central Register of Controlled Trials (Central)、Pubmed、Medline、EMBASE等数据库有关BIS监测与未应用BIS监测全麻患者术中知晓效果的临床、随机、对照研究.应用Cochrane协作网系统评价法对纳入文献质量进行评价和资料提取,评价指标为术中知晓发生率.采用RevMan5.1软件进行meta分析.结果 共纳入5项研究,包括34181例患者,其中应用BIS监测患者17432例,术中知晓发生率0.132％;未应用BIS监测患者16749例,术中知晓发生率0.245％,BIS监测组与未应用BIS监测组术中知晓发生率比较差异无统计学意义(P＞0.05)；根据麻醉方式不同进一步分析:在吸入麻醉中,应用BIS监测患者13288例,术中知晓发生率0.128％,未应用BIS监测患者13202例,术中知晓发生率0.113％,BIS监测组与未应用BIS监测组术中知晓发生率比较差异无统计学意义(P＞0.05)；在全凭静脉麻醉中,应用BIS监测患者4144例,术中知晓发生率0.145％,未应用BIS监测患者3547例,术中知晓发生率0.733％,BIS监测组术中知晓发生率明显低于未应用BIS监测组(P＜0.01).结论 监测BIS可预防全凭静脉麻醉患者术中知晓的发生,但不能预防吸入麻醉患者术中知晓的发生.     

闭环靶控吸入麻醉用於肥胖病人的临床研究

目的：观察脑电双频谱指数（BIS）反馈调控异氟醚吸入麻醉用於肥胖病人的可行性．方法：选择40例肥胖择期手术病人，随机分为对照组（Ⅰ组）和BIS反镇组Ⅱ组），每组20例。工组根据MAP和HR以及病人对手术刺激的反应，作为调节麻醉深度的依据．Ⅱ组采用“吸入麻醉执行者”以比例-积分-微分（PID）控制运算法，对目标BIS值与实测值进行处理，调节异氟醚输注泵注入闭式呼吸环路的量，以控制麻醉深度。两组病人均在入室后、诱导期、插管前、插管后、切皮、术中及停吸异氟醚后的意识恢复时间，随访术中是否知晓。结果：麻醉诱导后两组病人的BIS值较基础值明显降低（P〈0．01），术中两组病人的BIS值无显着性差异（P〉0.05）。两组BIS高于60的发生率分别为14．03％和7．48％，具有显着性差异（P〈0．05）．两组BIS低于40的发生率分别为1．75％和1．21％，无显着性差异。术毕唤醒时间以Ⅱ组早于工组（P〈0.05）．术后随访病人均无术中知晓．结论：应用BIS值反镇调控吸入麻醉用於肥胖病人是可行的．     

脑电双频谱指数监测提高麻醉管理及全麻苏醒质量Meta分析研究

目的 评价脑电双频谱指数（BIS）监测是否改善麻醉管理和麻醉苏醒质量。方法按照制定的检索策略检索Pubmed和Medline—CDRom数据库（1990年1月至2004年1月），随后按照一定的入选原则找出符合要求的文献。按已制定的研究评价标准进行筛选，共10篇文献纳入最终的Meta分析。结果 BIS监测在镇痛药用量一致的情况下可减少催眠药物的用量。吸入麻醉中BIS监测可减少吸入麻醉药用量，但肌松药用量增加。BIS组病人睁眼时间、言语指令反应恢复时间、拔管时间、定向力恢复时间均缩短。BIS监测对术后恶心呕吐及术后疼痛的发生率没有影响。BIS监测减少术中知晓与术后记忆发生的证据尚不足。结论 BIS监测能减少全身麻醉中药物用量并提高麻醉苏醒质量。     

Relationship between seizure duration and bispectral index during modified electroconvulsive therapy

BACKGROUND: The relationship between seizure duration and bispectral index (BIS) has not been studied well in modified electroconvulsive therapy (mECT). METHODS: We studied the changes in BIS and recorded the seizure duration during mECT under propofol and suxamethonium anesthesia. We examined the relationship between seizure duration and BIS. RESULTS: The BIS value immediately before turning on the electricity correlated with seizure duration. The range of BIS values that caused effective seizure duration were 53.6-58.8. CONCLUSIONS: Our study shows the possibility of determining the moment of application of electricity in mECT by using BIS values.     

脑电双频指数的临床矛盾性评价

背景 1996年10月,美国食品药品管理局批准BIS监护仪用于临床监测镇静效应.BIS的临床使用减少了术中知晓,改善了患者术后恢复,提高了围手术期安全性,但临床应用发现,BIS数值和变化与临床表现有时并非一致(即矛盾性). 目的 对引起BIS矛盾性变化的原因进行阐述,以指导临床应用. 内容 原因可能与全身麻醉药的药理特点、作用部位、频谱干扰、特殊病理生理状态(包括低血糖、脑缺血、低血容量、神经功能障碍等)及年龄、手术方式、血管活性药物等诸多因素有关. 趋向 鉴于BIS的矛盾性,如何利用BIS监测或联合其他监测手段加强特殊人群麻醉管理,是需要积极思考的问题.     

Bispectral index and anaesthesia in the elderly

BACKGROUND: Due to pharmacokinetic and pharmacodynamic reasons, the elderly are at particular risk of incurring unwanted side effects of drugs commonly used in anaesthesia. The bispectral index (BIS) is an EEG-derived value that measures the sedative component of the anaesthetic state. The BIS could be useful in guiding titration of anaesthetic drugs in the elderly. METHODS: A review of the published data was performed by the authors in order to assess the suitability of BIS technology application to the geriatric population. RESULTS: Age-related EEG differences exist in the normal population but they do not affect the BIS. The BIS correlates with depth of sedation independently of age. Senile dementia may be associated with significantly lower BIS values. CONCLUSIONS: The BIS is a useful guidance for titration of anaesthetic drugs in the elderly. The presence of senile dementia may be a confounding factor in the interpretation of the BIS values during anaesthesia.     

脑电双频指数指导快通道麻醉在夹层动脉瘤腔内隔绝术中的应用

目的 观察BIS指导快通道麻醉在夹层动脉瘤腔内隔绝术中的应用及对麻醉恢复的影响.方法 行主动脉腔内隔绝术治疗B型主动脉夹层30例,随机分为两组,B组根据脑电双频指数(BIS)调整丙泊酚的输注速率,C组丙泊酚输注速率为0.06～0.1 mg·kg-1·min-1.记录两组丙泊酚总用量、意识恢复时间、拔管时间及不良反应发生率.结果 B组的丙泊酚总用量明显少于C组(P＜0.05),意识恢复时间、拔管时间均明显短于C组(P＜0.01).B组术后嗜睡1例(6.7%)明显少于C组8例(53%)(P＜0.05).结论 BIS指导快通道麻醉可让夹层动脉瘤腔内隔绝术的患者术后尽早苏醒,有利于术后恢复.     

Pressure applied on the extra 1 acupuncture point reduces bispectral index values and stress in volunteers

We investigated the effect of pressure application on the acupuncture point "extra 1" and on a control point on the bispectral index (BIS) values and on stress in 25 volunteers. In each volunteer, pressure was applied on the extra 1 point for 10 min and on a control point for 5 min on different days and in a randomized manner. The BIS value was recorded before applying pressure on the extra 1 point, during pressure application every 30 s for 10 min, and after pressure release. Regarding the control point, BIS values were recorded for 5 instead of 10 min during pressure application because acupressure on that point was associated with an unpleasant feeling. Each volunteer was asked to score stress before and after pressure application from 0 to 10. The BIS values were significantly reduced 2.5, 5, 7.5, and 10 min during pressure application on the extra 1 point (P < 0.001 for each comparison, respectively) and returned to the baseline values after pressure release. Pressure application on the control point decreased BIS values (P < 0.01 and P < 0.05 at 2.5 and 5 min, respectively). However, these values were maintained close to 90% and were significantly higher than those obtained during pressure on the extra 1 point (P < 0.001 and P < 0.001 for the 2.5- and 5-min comparisons). The verbal sedation score values obtained after pressure application on the extra 1 point were also lower when compared with the values obtained after pressure application on the control point (P < 0.001). IMPLICATIONS: This crossover study investigated the effect of pressure application on the acupuncture "extra 1" point in healthy volunteers. Acupressure applied for 10 min on the extra 1 point significantly reduced the BIS values and the verbal stress score when compared with acupressure applied on a control point.     

The effect of bispectral index monitoring on end-tidal gas concentration and recovery duration after outpatient anesthesia

We performed this study to determine whether instituting monitoring of bispectral index (BIS) throughout an entire operating room would affect end-tidal gas concentration (as a surrogate for anesthetic use) or speed of recovery after outpatient surgery. Primary caregivers (n = 69) were randomly assigned to a BIS or non-BIS Control group with cross-over at 1-mo intervals for 7 mo. Data were obtained in all outpatients except for those having head-and-neck surgery. Mean end-tidal gas concentration and total recovery duration were compared by unpaired t-test. Overall, 469 patients (80%) received propofol for induction and sevoflurane for maintenance. This homogeneous group was selected for statistical analysis. Mean end-tidal sevoflurane concentration was 13% less in the BIS group (BIS, 1.23%; Control, 1.41%; P < 0.0001); differences were most evident when anesthesia was administered by first-year trainees. Mean BIS values were 47 in the BIS-Monitored group. Total recovery was 19 min less with BIS monitoring in men (BIS group, 147 min; Controls, 166 min; P = 0.035), but not different in women. We conclude that routine application of BIS monitoring is associated with a modest reduction in end-tidal sevoflurane concentration. In men, this may correlate with a similar reduction (11%) in recovery duration.     

Electrocardiographic electrodes provide the same results as expensive special sensors in the routine monitoring of anesthetic depth.

The Bispectral Index (BIS) is a mathematically derived electroencephalographic (EEG) derivative that has been introduced to monitor depth of anesthesia (1,2). The A-2000 BIS monitoring system (Aspect Medical Systems, Inc., Newton, MA) is currently the only commercially available system to monitor depth of anesthesia. In several studies, its propensity to optimize the use of hypnotics to maintain and achieve a certain depth of anesthesia has been described (3,4). Some studies have even proposed that the routine use of the monitoring system can decrease awareness (1,5), an increasing factor in malpractice claims. The cost-benefit calculations for BIS monitoring suffer from the fact that like its predecessor, the 1000-A BIS monitor, the A-2000 BIS monitoring system demands the use of expensive, special electrodes (6). Although the application of the single-use BIS sensor is very comfortable and easy to use, its high price of approximately $10-20 US prevents many anesthesiologists from using it. Furthermore, whereas the former model of the monitor (1000-A BIS monitor; Aspect Medical Systems, Inc.) used standardized connectors, which allowed the use of other electrodes such as electrocardiogram (ECG), the new monitoring system makes this very difficult because of special connectors that match the equivalent connector at the proximal BIS sensor site. The purpose of this prospective study was to compare BIS values derived from the original BIS sensor with BIS values derived from commercially available ECG electrodes. This comparison was made possible by designing and manufacturing a connector allowing the use of ECG electrodes. IMPLICATIONS: The Bispectral Index (BIS) monitor adequately monitors depth of anesthesia. The routine use of this monitor has been hampered by the benefit-cost equation because only special expensive electrodes can be used. We examined the agreement of BIS values obtained by original sensor electrodes and commercial electrocardiogram (ECG) electrodes. These ECG electrodes can replace more expensive BIS sensors.