Epidural morphine for analgesia after caesarean section

A randomized double blind placebo controlled study of the efficacy, duration and safety of epidural morphine for the management of pain after Cesarean section is reported. Three similar groups of patients received either 0, 4 mg or 8 mg of morphine sulphate in 10 ml of normal saline through an epidural catheter at the completion of the operation. Compared to the saline controls, both the 4 mg and 8 mg epidural morphine groups had significant pain relief as judged by an analogue pain scale (p less than 0.001), the time to the first administration of narcotic analgesics (p less than 0.001) and the amount of supplemental analgesic required in the first 36 hours after operation (p less than 0.001). The side effects occurred in a dose-dependent fashion. Two patients who received epidural morphine 8 mg plus additional narcotic or antihistamine had reduced respiratory rates but were easily rousable. Our experience suggests that the epidural administration of morphine 4 mg may be a safe and reliable method of obtaining prolonged analgesia following Caesarean section.