Regional anesthesia: sympathectomy-mediated vasodilation.

摘要

I read with interest the recent study concerning auto-nomic, sensory, and motor effects of lumbar epidural anesthesia in patients randomized to receive varying bupivacaine doses and concentrations.1 At lower concentrations, sensory block was observed in the mid-thoracic dermatomes with little change in the temperature or pulse oximeter perfusion index of the upper and lower extremities despite a concomitant decrease in systemic arterial pressure. These data were interpreted to suggest that sensory neural function may, in some cases, "be more susceptible than sympathetic neural function to local anesthetic blockade", in contrast to widely accepted dogma that the reverse is the case.