[Usefulness of epidural infusion of ketamine for relief of localized superficial pain].

Three patients with localized superficial pain had their pain alleviated by single epidural infusion with low dose ketamine. The patients are as follows: a 62-year-old female with herpetic neuralgia on her right sixth thoracic nerve area; a 52-year-old male whose left shoulder, anterior chest and abdomen had been burned by acetylene gas; and a 49-year-old male whose bilateral hands suffering from frostbite by propane gas. Epidural tube insertion to administer a single dose of 10 mg ketamine with lidocaine or bupibacaine was performed in all the three patients. They were administered single epidural infusion of 10 mg ketamine with lidocaine or bupibacaine everyday and they continued to receive epidural block with lidocaine or bupivacaine including buprenorphine or morphine. Therefore, we suspect that single epidural infusion of ketamine, an antagonist for N-methyl-D-aspartic acid receptor, could be an effective and useful alternative treatment in patients with various refractory localized superficial pain of either acute or chronic nature.