Dexamethasone enhances the anti-emetic effect of metoclopramide in women undergoing myomectomy under spinal anaesthesia
Background: The consequences of postoperative nausea and vomiting (PONV) range from associated increased resource utilization to the considerable effects on the patients like surgical wound disruption, oesophageal tear and delayed discharge from the post anaesthetic care unit. This study was designed to evaluate whether a combination of dexamethasone and metoclopramide had better antiemetic efficacy than either of the drugs alone for the prophylaxis of PONV in women undergoing myomectomy under spinal anaesthesia.
Patients and Methods: The study was a prospective randomized, double-blind controlled trial. Ninety patients, ASA I or II, aged 21-64years were randomly selected to either the dexamethasone-metoclopramide group, metoclopramide group or dexamethasone group using computer-generated random numbers . Spinal anaesthesia was induced in the sitting position under strict aseptic technique with hyperbaric solution of 0.5%
Bupivacaine 15mg (3ml). Immediately following the induction of spinal anaesthesia, the dexamethasone-metoclopramide group received intravenous (i.v.) dexamethasone 8mg and metoclopramide 10mg in separate syringes, the metoclopramide alone group received metoclopramide 10m i.v and the dexamethasone alone group received dexamethasone 8mg i.v.
Results: Combined dexamethasone-metoclopramide group had the least incidence of both early and late PONV, 10% and 6.67% respectively. Metoclopramide alone group had an incidence of 29.97% for early PONV and 26.6% for late PONV while dexamethasone alone group had 40% for early and 0% for late PONV.
Conclusion: A combined dexamethasone-metoclopramide anti-emetic therapy at a dose of 8mg and 10mg offers a better anti-emetic prophylaxis than10 mg metoclopramide alone and 8mg dexamethasone alone.
Key Words: Antiemetic, Myomectomy, Spinal Anaesthesia