定量脑电图监测全麻状态下意识的变化

A Study of qEEG during Monitoring of Consciousness under General Anesthesia

目的 :判断定量脑电图在全麻下监测意识的价值。方法 :无神经系统损伤的健康志愿者 ,按 0、0 2、0 3、0 4MAC递增呼末异氟醚浓度 ,观察 qEEG及指令反应变化 ,通过事后调查麻醉中的外显及内隐记忆。结果 :按全麻下意识水平的 1～ 4个阶段 ,第 2与第 1阶段相比 ,qEEGF7、F8、A1 导联θ波相对功率明显降低 (P <0 0 5) ;第 3与第 2阶段相比 ,O1 、及O2 导联的α波相对功率明显降低 (P <0 0 5) ,O2 导联δ波功率明显升高 (P <0 0 5)。余 qEEG参数包括SEF、MPF及δ比率均无明显变化 (P >0 0 5)。所有qEEG参数变异较大 ,不能定出界值。结论 :qEEG在判断按意识分级的麻醉深度上只能作为一种趋势的预示 。

Objective:To evaluate the value of qEEG during monitoring of consciousness under general anesthesia.Methods:The end expiratory concentration of isoflurane was increased gradually from 0 2MAC by step of 0 1MAC in each of ten healthy volunteers until no response to command.The changes of qEEG and the response to command were observed.The explicit and implicit memories about introexperiment events were investigated at one hour of stopping inhalation of isoflurane.Results:Compared with the first stage of the cognitive function,the θ power of qEEG about the second stage decreased significantly in F7,F8,A1 recording electrodes( P< 0 05);compared with the second stage,the α power of qEEG about the third stage decreased remarkably in O1 and O 2 recording electrodes,the δ power increased significantly in O 2 recording electrodes ( P< 0 05).The critical value of all descriptors of qEEG could not be defined because of the considerable variations.Conclusion:qEEG is not the credible index in determining the depth of anesthesia and can only be used for predictiong the tendency.