靶控异丙酚镇静时脑电双频指数和听觉诱发电位指数监测意识状态的比较

Comparison between the performance of bispectral index and auditory evoked potential index to predict the level of consciousness during propofol sedation with target-controlled infusion

目的 在靶控输注异丙酚镇静时比较脑电双频指数（BIS）和听觉诱发电位指数（AEPindex）监测意识状态的准确性。方法16例病人在全麻诱导前用异丙酚靶控输注镇静,同时监测BIS和AEPindex,用逻辑回归、ROC曲线（Receiver Operating Characteristic）过程、以及灵敏度和特异性比较两种方法监测意识状态的准确性。结果BIS和AEPindex均能很好的反映病人镇静时的意识状态（P=0.01）,AEPindex的ROC曲线下面积与BIS的ROC曲线下面积相比,差异无统计学意义（P>0.05）,镇静警醒评分（OAA/S）从2恢复到3时AEPindex从42急剧上升至67（P>0.01）,而BIS则从64逐渐上升至72（P>0.05）,提示AEPindex对患者意识状态的判别力更好。OAA/S与BIS、AEPindex和靶控浓度有显著相关性（r分别是0.781、0.684和-0.580,P均<0.01）。结论AEPindex和BIS均能正确反映靶控输注异丙酚镇静时的镇静深度,AEPindex对意识（有/无）的鉴别更佳,而BIS能很好的反映意识恢复的渐进性过程。

Objective Auditory evoked potential (AEP) index has recently been introduced to clinical application. The purpose of this study was to compare the performance of bispectral index(BIS) and AEP index to predict the level of consciousness during sedation produced by propofol with target-controlled infusion(TCI) . Methods Sixteen ASA I -Ⅱ patients with normal hearing undergoing elective surgery were enrolled in this study. Premedication consisted of intramuscular pethidine 50mg and phenobarbital 0.1g. BP, ECG and SpO2 were monitored. The patients were sedated with propofol given by TCI before induction anesthesia. BIS and AEP index were monitored and recorded simultaneously and correlated with OAA/S (5 = response quickly when the patient' s name is called, 0 = no response when the patient' s trapezius muscle is pinched). Logistic regression and receiver operating characteristic ( ROC) curve were used to compare the sensitivity and specificity of the two indices in predicting the level of sedation. Results Both BIS and AEP index predicted fairly well the level of sedation. The area under the ROC curve for AEP index was similar to that for BIS(P>0.05) . AEP index increased sharply from 42 to 67 when the patients regained consciousness (OAA/S increased from 2 to 3) but BIS increased gradually from 64 to 72 indicating that AEP index had better discriminatory performance. OAA/S correlated fairly well with BIS , AEP index and target-controlled concentration of propofol and r was 0.781, 0.684 and - 0.580 respectively. Conclusions Both AEP index and BIS can predict fairly well the level of sedation but AEP index prooes to be better in distinguishing conscious from unconscious.