Comparison of 0.25 mg and 0.1 mg intrathecal morphine for analgesia after Cesarean section

Purpose: To test the hypothesis that 0.1 mg intrathecal morphine plus NSAID s provides satisfactory analgesia post-Cesarean section with fewer side eff ects than 0.25 mg intrathecal morphine. Methods: Sixty women, scheduled for elective Cesarean section under spinal anesthesia, were randomized to receive either 0.1 mg or 0.25 mg intrathecal morphine combined with hyperbaric bupivacaine 0.75% and 20 mu g fentanyl. All patients received a 100 mg indomethacin suppository at the end of surge ry and 500 mg naproxen po b.i.d, was started the evening of surgery and con tinued until discharge. A blinded researcher recorded the pain, pruritus, a nd nausea scores, the time to first request for additional analgesics, a vi sual analogue scale (VAS) satisfaction score, and the use of additional opi oids, antipruritics, and/or antiemetics. Results: Of the 60 patients enrolled, two were not included in the data ana lysis because of protocol violations leaving 30 patients in the 0.1 mg grou p and 28 in the 0.25 mg group. There were no differences in the VAS pain sc ores or the number of women requesting an opioid other than codeine between the two groups. The VAS pruritus scores in the 0.1 mg group were lower thr oughout the 24 hr (P < 0.001). Fewer women in the 0.1 mg group (4/30 vs 12/ 28) requested nalbuphine 'to treat itching (P = 0.018). Nausea scores were lower in the 0.1 mg group (P < 0.001). Conclusion: The use of 0.1 mg intrathecal morphine plus NSAIDs provides ana lgesia of similar quality to 0.25 mg but with fewer undesirable side effect s following Cesarean section.