Sodium bicarbonate reduces pain associated with ophthalmic nerve blocks

Administration of local nerve blocks for ophthalmic surgical procedures causes pain resulting in an unpleasant and stressful experience for the patient. A prospective, randomized, double-masked study compared injection pain of anesthetic solutions used for facial and retrobulbar nerve blocks. Anesthetic solutions to which sodium bicarbonate had been added were compared with anesthetic solutions without added sodium bicarbonate. Pain on injection of both facial and retrobulbar nerve blocks was significantly less (P = .0009 and P less than .0001 respectively), without diminution of effectiveness of either type of nerve block, in the group using anesthetic solutions to which sodium bicarbonate had been added.