Central nervous system effect of local anesthetics : Influences on electroencephalogram and electroencephalographic changes induced by co-administered opioids

在全身麻醉下，在大鼠伏隔核内置入微透析引导管。在对侧伏隔核放置一个脑电图电极。然后，在清醒状态下进行连续的局部脑电图测量和局麻药定量。在人体研究中，研究了通过硬膜外导管给药的局部麻醉剂和静脉注射阿片类镇痛药对双谱指数（BIS）的影响。持续硬膜外注射局麻药1小时后，BIS脑电图变化稳定。提示局麻药和阿片类镇痛药的作用部位浓度达到稳定状态。

Under general anesthesia, a guide cannula for microdialysis was placed into nucleus accumbens of a rat. And an electroencephalogram electrode was placed into opposite nucleus accumbens. Thereafter, serial measurement of topical electroencephalogram and quantification of local anesthetics were enabled in awake state. In human study, influences on bispectral index(BIS) induced by local anesthetics administered via epidural catheters and by co-administered opioid analgesics intravenously were investigated. Following one hour after continuous epidural infusion of local anesthetics, electroencephalographic changes of BIS were stabilized. This finding suggests that effect site concentration of local anesthetics and of opioid analgesics reached steady state.