Cauda equina syndrome after spinal anaesthesia with hyperbaric 5% lignocaine: a review of six cases of cauda equina syndrome reported to the Swedish Pharmaceutical Insurance 1993-1997.

Six cases of cauda equina syndrome with varying severity were reported to the Swedish Pharmaceutical Insurance during the period 1993-1997. All were associated with spinal anaesthesia using hyperbaric 5% lignocaine. Five cases had single-shot spinal anaesthesia and one had a repeat spinal anaesthetic due to inadequate block. The dose of hyperbaric 5% lignocaine administered ranged from 60 to 120 mg. Three of the cases were most likely caused by direct neurotoxicity of hyperbaric 5% lignocaine. In the other 3 cases, direct neurotoxicity was also probable, but unfortunately radiological investigations were not done to definitely exclude a compressive aetiology. All cases sustained permanent neurological deficits. We recommend that hyperbaric lignocaine should be administered in concentrations not greater than 2% and at a total dose preferably not exceeding 60 mg.