A comparison of intrathecal fentanyl and diamorphine as adjuncts in spinal anaesthesia for Caesarean section

This randomised controlled trial examines the effects of fentanyl and diamorphine, alone and in combination, as adjuncts to spinal anaesthesia for Caesarean section. Ninety-nine women undergoing elective Caesarean section with spinal anaesthesia using 0.5% hyperbaric bupivacaine were randomly allocated to receive fentanyl 15 mu g (F), diamorphine 0.25 mg (D), or fentanyl 15 mu g plus diamorphine 0.25 mg (FD), intrathecally. All women received morphine via a patient controlled analgesia system after surgery. There was no significant difference between the groups in time to achieve a block, discomfort, ephedrine use, nausea and vomiting, pruritus and sedation during surgery. Significant differences were observed in morphine consumption 4, 8, 12 and 24 h after surgery between both F and D groups, and F and FD groups, and also at 2 h between F and FD groups. There was a significant difference in pruritus at 4 h between the F and FD group. Our results suggest that diamorphine alone provides optimum benefits during and after surgery, when used in combination with hyperbaric bupivacaine for Caesarean section.