Direct epidural morphine injection during lumbar discectomy for postoperative analgesia.

A double-blind controlled study was done on 42 patients to test the analgesic activity of epidural morphine after lumber laminectomy for single level disc herniation. Sixteen patients received 3 mg preservative-free morphine. Twenty-six patients received normal saline. The patients given epidural morphine had a longer postoperative pain-free period (6.28 vs 2.37 hours) and needed less postoperative analgesia (0.2 vs 0.9 times for paracetamol, and 0.16 vs 0.51 times for morphine). Epidural morphine injection under direct vision during discectomy operation is an effective and safe method for postoperative pain relief.