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

在全麻下，将微透析引导管置入大鼠伏隔核。在对侧伏隔核内放置脑电电极。此后，在清醒状态下连续测量局部脑电和局部麻醉药的定量。在人体研究中，观察了硬膜外插管局部麻醉药和联合静脉注射阿片类镇痛剂对脑电双频指数(BIS)的影响。硬膜外持续输注局麻药1h后，BIS的脑电变化稳定。这一发现表明，局麻药和阿片类镇痛剂的效应点浓度达到了稳定状态。

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.