PREEMPTIVE EPIDURAL MORPHINE FOR POSTOPERATIVE PAIN RELIEF AFTER LUMBAR LAMINECTOMY

This study was designed to evaluate the efficacy of preemptive epidura l morphine for postoperative analgesia after lumbar laminectomy. Thirt y ASA physical status I adults undergoing elective lumbar laminectomy under general anesthesia were randomly allocated to one of two groups. Group 1 (study group) received 3 mg epidural morphine preemptively 60 min before surgery, followed by epidural placebo at the end of surger y. Group 2 (control group) received epidural placebo at the same time preoperatively as the study group, followed by 3 mg epidural morphine at the conclusion of surgery. Pain was assessed using visual analog sc ales (VAS), and sedation was graded on a 4-point rank drowsiness score . Time to first postoperative analgesic (TFA), the supplementary analg esia, and the amount of morphine used over the 24-h period were noted for the groups. VAS pain scores were significantly less in Group 1 (pr eemptive group) than in Group 2 8 h after surgery (P < 0.05). TFA in t he study group (19.9 +/- 2.3 h) was significantly prolonged compared w ith the control group (8.5 +/- 1.0 h, P < 0.05). The demand for supple mentary analgesia and postoperative morphine consumption in the preemp tive group was significantly lower than that in control group (P < 0.0 5). Patients in the control group were significantly sedated after 12 h and had a high incidence of nausea and vomiting (P < 0.05). The stud y shows that preemptive epidural morphine is superior to epidural morp hine given postoperatively for pain relief after lumbar laminectomy.