Background: Low-dose intrathecal (spinal) morphine (0.1-0.2 mg) for Caesarean section delivers excellent postoperative analgesia but is associated with significant nausea and vomiting. We compared the antiemetic efficacy of cyclizine, dexamethasone, and placebo in this clinical setting.
Methods: Ninety-nine women undergoing elective Caesarean section under spinal anaesthesia were allocated randomly, in a double-blind study design, to receive either cyclizine 50 mg, dexamethasone 8 mg, or placebo as a single-dose infusion in saline 0.9%, 100 ml on completion of surgery. Spinal anaesthesia consisted of: hyperbaric bupivacaine 0.5%, 2.0 ml; fentanyl 10 micro g; and spinal morphine 0.2 mg. The primary outcome measure was the incidence of nausea.
Results: The incidence of nausea was significantly less in patients receiving cyclizine compared with dexamethasone and placebo (33 vs 60 and 67%, respectively, P<0.05). Severity of nausea and number of vomiting episodes were also less at 3-6 h in cyclizine patients. Overall satisfaction with postoperative care at 24 h, expressed on a 100 mm visual analogue scale, was greater in cyclizine [78 (28)] than either dexamethasone [58 (31), P=0.03] or placebo [51 (28), P=0.008].
Conclusion: We conclude that following spinal morphine 0.2 mg and fentanyl 10 micro g analgesia for Caesarean section, cyclizine 50 mg i.v. reduces the incidence of nausea compared with dexamethasone 8 mg i.v. or placebo. It also lessens the severity of nausea and vomiting, and increases maternal satisfaction in the early postoperative period.