LONG-TERM EPIDURAL KETAMINE, MORPHINE AND BUPIVACAINE ATTENUATE REFLEX SYMPATHETIC DYSTROPHY NEURALGIA

Purpose: There is considerable evidence that NMDA receptor antagonists can abolish nociceptor hypersensitivity in animals. In the present ca se report, two patients with reflex sympathetic dystrophy were treated with ketamine, a NMDA antagonist, morphine and bupivacaine. Clinical features: Two patients were referred suffering from severe pain, allod ynia, hyperaesthesia, swelling and disability over their right lower l egs, diagnosed as reflex sympathetic dystrophy. They had received conv entional treatments with non-steroid anti-inflammatory drugs (NSAIDs), steroids, anticonvulsant, antidepressant, epidural lidocaine sympathe tectomy and rehabilitation which failed to provide satisfactory pain r elief We administered subanalgesic doses oi ketamine (7.5 mg), morphin e (0.75 mg) and 6 ml bupivacaine 0.1 % via a lumbar epidural catheter three times per day. After several courses of treatment over three and six months, satisfactory pain relief was achieved in each patient. Bo th are now able to walk with slight weight bearing with the assistance of crutch. The treatment is continuing with further improvement of sy mptoms and signs. Conclusion: Epidural coadministration of low doses o f morphine, ketamine and bupivacaine provided effective pain relief in two patients. This suggests synergy from this combination that provid es an alternative treatment for reflex sympathetic dystrophy.