Patient-controlled analgesia: a controlled trial.

Thirty-six patients undergoing lower abdominal surgery were included in a prospective randomized controlled study to compare the effects of patient-controlled analgesia (PCA) and a standard intramuscular/intravenous treatment (conventional analgesia, CA) of postoperative pain. Morphine was used in both groups. There were no significant differences between the two analgesic regimens in respect of linear analogue pain scores, verbal pain-relief scores, amount of morphine used or side-effects. No treatment-induced alterations in vital values were experienced.