Analgesia produced by epidural diamorphine is better following caesarean section under spinal anaesthesia than under epidural anaesthesia.

In a randomized double-blind study, the efficacy, duration of action and side-effects of epidural diamorphine 2.5 mg in 10 ml normal saline were compared following elective caesarean section under either spinal anaesthesia (using a combined spinal epidural technique, n = 32) or conventional epidural anaesthesia (n = 26). Median visual analogue pain scores were consistently lower in patients who had received spinal anaesthesia and this reached significance at 24 h (P = 0.02). If additional i.m. morphine was required, the mean (SD) time to its administration was significantly greater following spinal anaesthesia (12.6 h (5.9)) than epidural anaesthesia (6.6 h (3.1), P = 0.01). The incidence of side-effects was similar in the two groups. The improved analgesia following spinal anaesthesia is another advantage of the combined spinal epidural technique over conventional epidural anaesthesia for elective caesarean section.