Epidural tramadol for postoperative pain relief.

The efficacy of epidurally administered tramadol hydrochloride, a weak centrally acting analgesic, was studied for the relief of postoperative pain. Sixty patients undergoing abdominal surgery were randomly allocated to three treatment groups to be given the following agents by the epidural route: group 1 tramadol 50 mg; group 2 tramadol 100 mg; group 3 10 ml of bupivacaine 0.25%. The drugs were administered at the patients' request with each patient being allowed four doses in the first 24 h following surgery. Blood pressure, pulse rate, respiratory rate, arterial blood gas analyses, pain scores, the interval between doses and the occurrence of any side effects were recorded. Pain scores (assessed using a visual analogue scale) were significantly less (p < 0.05) at 3, 12, and 24 h in patients receiving tramadol 100 mg than in those receiving tramadol 50 mg or bupivacaine. The mean interval between doses for groups 1, 2 and 3 was 7.40 h, 9.36 h and 5.98 h respectively. The mean interval in group 2 was significantly longer than in group 3 (p < 0.05). The incidence of nausea and vomiting in group 2 was significantly higher than in group 3 (p < 0.05).