老年人异丙酚靶控输注时AAI与Ce的变化

目的探讨听觉诱发电位指数（AAI）和异丙酚效应室浓度（ce）反映老年患者异丙酚靶控输注（TCI）时镇静深度的准确性，并与脑电双频指数（BIS）比较。方法45例老年患者行异丙酚TCI，初始靶浓度为1μg／ml，按0．5μg／ml逐步递增，观察镇静警觉评分（OAA／S）和对口头指令、睫毛反射、尺神经刺激的反应及相应的AAI、BIS，比较AAI、Ce及BIS与镇静深度的相关性，并计算意识及疼痛反应消失时的异丙酚效应室EC50 EC95和AAI与BIS的ED50 ED95。结果AAI、BIS与OAA／S呈直线正相关，与Ce呈负相关。意识消失的AAIED孙ED95为40．1、30．3，BIS的ED50 ED95为59．5、51．7；痛反应消失的AAIED50、ED95为28．8、23．2，BIS的ED50、ED95为52．4、43．7；对应的异丙酚EC50、EC95分别为1．28、1．69μg／ml和1．76、2．34μs／ml。结论AAI和Ce可以反映老年患者异丙酚TCI的镇静深度。

Changes of auditory evoked potentials and effect compartment concentration during propofol target controlled infusion induction in the elderly

Objective To study changes of the auditory evoked potentials index （AAI） and effect compartment concentration（Ce） and compare their performance accuracy of detecting levels of sedation with bispetral index （BIS） during propofol target controlled induction in the elderly. Methods A total of 45 patients undergoing elective abdominal surgery were studied. Anesthesia was induced with propofol administered by a TCI system. The target concentration started at 1 μg/ml and increase by 0.5 μg/ml every three minutes step by step. At every step, the ability to respond to verbal com- mands using Observers Assessment of Alertness/Sedation Scale （ OAA/S）, eyelash reflex, and electrical titanic noxious stimulus were compared against BIS, AAI, and Ce. Regression and prediction probability were calculated. Results AAI was positive correlated with OAA/S and negative correlated with Ce, similar with BIS. But BIS is better. Ce was negative correlated with OAA/S. The predicted ED50 and ED95 of AAI on loss of consciousness were 40.1 and 30.3, and loss of electrical titanic noxious stimulus were 28.8 and 23.2 respectively. The propofol effect compartment EC50 and EC95 were 1.28,1.69 μg/ml and 1.76, 2.34 μg/ml. Conclusion Both AAl and Ce can detect levels of sedation in propofol TCI induction in the elderly. AAI was negative correlated with propofol Ce.