Effect of intrathecal bupivacaine on somatosensory evoked potentials following dermatomal stimulation.

摘要: The effect of spinal anesthesia with 3.6 +/- 0.1 ml (mean SEM) 0.5% bupivacaine on early (less than 150 msec) somatosensory evoked potentials (SEPs) electrical stimulation the L1 and S1 dermatomes was examined in 12 patients. mean level sensory analgesia (pinprick) T8,9 1.0 (+/- degree motor blockade 1.3 (Bromage scale). Intrathecal significantly (P less 0.05) decreased amplitude all SEP components after dermatome most during dermatome. also increased latency SEPs both dermatomes. disappeared 7 5 patients neural blockade. In three at locations. Sensory thresholds We found no correlation between decrease or analgesia. Thus, intrathecal plain has a strong depressant afferent transmission as assessed by SEPs. However, despite clinically effective pinprick nerve nociceptive within area block were often able to pass cerebral cortex.