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

在全身麻醉下，将用于微透析的引导套管置于大鼠的延髓核中。并将脑电图电极置于对侧延髓背侧核。此后，在清醒状态下连续测量局部脑电图和定量局麻药。在人体研究中，研究了经硬膜外导管给予局麻药和静脉给予阿片类镇痛药对脑电双频指数（BIS）的影响。局麻药持续硬膜外输注后1h，脑电BIS变化趋于稳定。这一发现表明，局部麻醉药和阿片类镇痛药的效应部位浓度达到稳态。

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.