INTRODUCTION: Intrathecal morphine, commonly administered at doses of 100 to 200 mcg, is a popular choice for post-cesarean analgesia; however, a trade-off between opioid analgesia and side effects exists. This study was conducted to determine the lowest dose of intrathecal morphine that will provide adequate analgesia with the least side effects among post-cesarean patients. METHODS: Sixty term parturients for cesarean delivery under spinal anesthesia were randomized into three treatment groups to receive 50, 100 or 150 mcg of intrathecal morphine with a standard multimodal pain regimen and intravenous tramadol as needed. Pain scores, demand for rescue analgesic, and incidence of adverse effects (nausea, vomiting, and pruritus) during the first 24 hours’ post-spinal anesthesia were recorded and compared between groups. RESULTS: Pain scores and demand for rescue doses of tramadol were higher for the 50-mcg group as compared to the other groups. There was no significant difference in pain scores between the 100 and 150-mcg groups. No rescue dose of tramadol was necessary in the 100 and 150-mcg groups. No significant difference was seen in the incidence and severity of nausea and vomiting across treatment groups. The incidence and severity of pruritus were significantly higher in the 150-mcg group. No significant difference was noted in the incidence and severity of pruritus between the 50 and 100-mcg groups. CONCLUSION A dose of 100 mcg of intrathecal morphine, in combination with a multimodal regimen, provides adequate analgesia with the least side effects.
pain management ; Pregnancy ; Female ; Cesarean Section ; Anesthesiology ; Analgesics, Opioid ; morphine