CNS Toxicity after Combined Sciatic and Femoral Nerve Block with Lidocaine

Abstract

Combined sciatic-femoral nerve block was performed in a 48-year-old woman for the removal of a right lateral malleolar lesion. The patient became unconscious at the 12th minute of the block. As vital signs were stable and no additional complication was seen, the operation was carried out and completed. The patient began to respond to painful stimulus, and was conscious and fully oriented. 95 and 135 minutes after the block respectively. Although the patient's symptoms were not consistent with classical central nervous system toxicity, relatively high dose of lidocaine used, and coexistence of anemia, occurrence of muscular twitching which could be related to seizure activity, and the treatment of this twitching with a small dose of midazolam were thought to indicate toxicity.