EPIDURAL OPIOIDS DURING LAMINECTOMY SURGERY FOR POSTOPERATIVE PAIN

Study Objective: To determine whether morphine applied directly to the dura during laminectomy surgery provides superior postoperative analgesia during the first 24 hours. Design: Randomized, double-blind study. Setting: A university-affiliated hospital. Patients: Twenty ASA physical status I and II patients ages 18 to 60 years. Interventions: Simultaneous topical dural application and intramuscular (IM) injection of unknown solutions of saline and morphine 3 mg. Measurements and Main Results: Postoperative analgesia was assessed using the visual analog scale (VAS), a modified McGill-Melzack pain questionnaire, subjective nursing evaluations, and the amount of supplemental analgesic medication used. Patients were observed for complications and side effects. Compared with the patients who received epidural saline and IM morphine, the patients who received epidural morphine and IM saline had less postoperative pain as determined hy VAS scores, nursing evaluations, and amount of supplemental opioid analgesic doses (1.6 +/- 1.2 vs. 4.1 +/- 1.2 analgesic doses per patient; p < 0.05) required in the first 24 hours. Minor side effects were similar for the two groups. No patient developed respiratory depression. Conclusions: Morphine 3 mg applied topically to the dura at the end of laminectomy surgery is a simple, safe, and effective way of providing improved postoperative analgesia.