Lumbar epidural morphine as an effective analgesic following cholecystectomy.

Relief of pain with epidural morphine was evaluated in five patient subjects during two consecutive twenty-four periods after cholecystectomy. In one period, each subject received lumbar epidural morphine, first 4-6mg, and twelve hours later, 2-3 mg; in the other period, epidural placebo at the same times. Except for four hours before each injection and twenty minutes thereafter, intramuscular morphine was administered as required throughout. The experiments were double-blind. Epidural morphine, unlike epidural placebo, reduced both a visual pain analogue score (p less than 0.05) and a pain questionnaire score (p less than 0.01) twenty minutes after injection. Epidural morphine compared to placebo reduced by one-half the total amount of narcotic (epidural plus intramuscular) administered over the twenty-four hour period (p less than 0.05). Four of five subjects clearly preferred analgesia with epidural morphine over the effect of placebo plus therapeutic doses of intramuscular morphine. We conclude that epidural morphine, administered in this manner, is effective in relieving pain after cholecystectomy and that it may be preferred by patients over conventional intramuscular morphine.