Intrathecal Opioids

Case Synopsis

An otherwise healthy 26-year-old woman undergoes cesarean section for delivery of a breech infant. Spinal anesthesia is used, consisting of 1.6 mL of 0.75% hyperbaric bupivacaine (12 mg) with preservative-free morphine (0.3 mg). The surgery is uneventful, and the infant has Apgar scores of 9 and 9 at 5 and 10 minutes, respectively. The patient remains in the recovery room for 2 hours and is then transferred to the floor. She is treated with diphenhydramine 50 mg intravenously (IV) for generalized pruritus 6 hours after surgery and promethazine 25 mg IV for vomiting 7 hours after surgery. Ten hours after surgery, she complains of persistent pruritus, noting that the diphenhydramine had no effect.