Background and Aims Scorpion stings can cause failure of spinal anaesthesia(1). We report a case of successful spinal anaesthesia with bupivacaine laced with adjuvant drugs in a patient with history of scorpion sting and failed spinal anaesthesia.

Methods A 26 years old gentleman with a history of scorpion sting at 2, 20 and 21 years of age was operated twice for fracture of right femur and left tibia . First time he was administered general anaesthesia after the failure of spinal anaesthesia with bupivacaine and fentanyl. 3 days later, he was operated again for tibial plating. This time, he was administered spinal anaesthesia with a combination of 1.5 ml of 0.5% bupivacaine heavy, 1.5 ml of 5% lignocaine heavy, 15mcg of clonidine (0.1 ml) and 7.5% sodium bicarbonate(0.2 ml) to make a total volume of 3.3 ml. Spinal anaesthesia was successfully established.

Results The scorpion toxins cause repetitive action potentials and persistent depolarization of sodium channels in nerve axons(2,3). An antigen-antibody response also may cause competitive antagonism of sodium channels.(1) We are not clear whether there is remodelling of the receptor resulting in resistance to local anaesthetics. Our presumption was that adjuvants can enhance the action of local anaesthetics and reverse this mechanism.

Conclusions In our patient with a history of scorpion sting and failed spinal anaesthesia, either one or a combination of the ingredients added to bupivacaine resulted in successful spinal anaesthesia.