The effects of dexamethasone and metoclopramide on early and late postoperative nausea and vomiting in women undergoing myomectomy under spinal anaesthesia.

Abstract

Post-operative nausea and vomiting (PONV); early or late, has detrimental effects on surgical patients such as surgical wound disruption, esophageal tear and delayed discharge from the post anesthetic care unit. This study evaluated the effects of dexamethasone-metoclopramide (DM) in the prevention of early and late PONV in women undergoing myomectomy under subarachnoid block. Following approval from the Research and Ethics Committee of the Hospital, informed consent was obtained from each prospective patient. Patients were randomly allocated to either the DM group, metoclopramide only (MO) group or dexamethasones only (DO) group using the computer-generated random numbers in sealed envelopes. Immediately after the induction of spinal anesthesia, the DM group received intravenous (i.v.) dexamethasone 8 mg and metoclopramide 10 mg, the MO group received metoclopramide 10 mg i.v and the DO group received dexamethasone 8 mg i.v. The incidence of early and late PONV formed the primary outcome. A total of 90 patients, with aged range between 21-64 years were studied. Dexamethasone alone group had the highest incidence of 40% for early but no for late PONV ( P = 0.003) Metoclopramide alone group had an incidence of 29.97% for early PONV and 26.6% for late PONV. There was reduced incidence of both early and late PONV in the DM group, but of lesser magnitude than DO or MO respectively. Dexamethasone protects against the incidence of late PONV with a minimal effect on early PONV. The combination of dexamethasone and metoclopramide had comparable effect on both and of better magnitude than metoclopramide alone.