脑电双频指数、听觉诱发电位指数用于老年人七氟醚麻醉深度监测的意义

目的探讨七氟醚的不同呼气末浓度对老年患者脑电双频指数(B IS)、听觉诱发电位指数(AAI)及血流动力参数的影响。方法行气管内全身麻醉术的老年患者30例,ASAⅠ～Ⅱ级,在8%七氟醚、罗库溴铵,瑞芬太尼麻醉诱导插管后机械通气,调节挥发罐浓度,使七氟醚呼气末浓度依次稳定在0.6最低肺泡气有效浓度(MAC)、1.0MAC、1.3MAC,每种浓度均维持15 m in,记录七氟醚呼气末浓度稳定在各点15 m in后的BIS、AAI、平均动脉压(MAP)和心率(HR)值。结果七氟醚呼气末浓度为0.6MAC、1.0 MAC、1.3 MAC时的BIS、AAI、MAP、HR值与麻醉前比较明显降低(P<0.01),1.0 MAC、1.3 MAC时的BIS、AAI值较0.6MAC时明显降低(P<0.01),而1.0 MAC和1.3 MAC时的B IS、AAI值比较差异无统计学意义(P>0.05)。七氟醚呼气末浓度在0.6～1.3MAC范围内,BIS、AAI、MAP随七氟醚浓度增高而降低,并呈显著的等级相关;HR与七氟醚浓度无相关性。结论 BIS和AAI可作为老年人七氟醚麻醉深度监测的有效指标。

Evaluation of bispectral index and auditory evoked potential index for monitoring the depth of sevoflurane anesthesia in the elderly

Objective To investigate the effect of different end-tidal concentrations of sevoflurane on electroencephalogram bispectral index（BIS）,auditory evoked potentials index（AAI）and hemodynamic parameters,and evaluate the accuracy of BIS,AAI for monitoring the depth of sevoflurane anesthesia in the elderly.Methods Thirty ASAⅠ-Ⅱ elderly patients who undergoing elective surgery under endotracheal anesthesia were recruited.Anesthesia was induced with 8% sevoflurane,rocuronium and remifentanil inhalation.After endotracheal intubation,the lung was ventilated with sevoflurane in oxygen.End-tidal concentrations of sevoflurane were maintained at 0.6 minimum alveolar concentration（MAC）,1.0MAC,1.3MAC for 15 minutes respectively.The BIS,AAI,MAP and HR values were recorded at each time point of different sevoflurane concentrations.Results With the end-tidal concentration of sevoflurane increasing,the BIS,AAI,MAP,HR values decreased significantly compared with those before anesthesia（P〈0.01）at the concentration of 0.6MAC,1.0 MAC,1.3 MAC of sevoflurane,the BIS,AAI were decreased significantly at the concentration of 1.0 MAC,1.3 MAC of sevoflurane compared with that of 0.6MAC（P〈0.01）,but there was no differents at the concentration of 1.0 MAC,1.3 MAC of sevoflurane（P〈0.05.BIS,AAI and MAP increased with the decrease of concentration of sevoflurane in the range of 0.6-1.3MAC,and there was a significant rank correlation,but there was no correlation between HR and the concentration of sevoflurane.Conclusion BIS,AAI can be used as valid indicators for monitoring the depth of anesthesia with sevoflurane in the elderly.