Patients will be randomized to one of four arms: Ondansetron (4O-PE: 4 mg Ondansetron pre-emergence, 8O-PE: 8 mg Ondansetron pre-emergence, 4O-PI: 4 mg Ondansetron pre-incision, 8O-PI: 8 mg Ondansetron pre-incision), Dexamethasone (4D-PE: 4 mg Dexamethasone pre-emergence, 8D-PE: 8 mg Dexamethasone pre-emergence, or 4D-PI: 4 mg Dexamethasone pre-incision, or 8D-PI: 8 mg Dexamethasone pre-incision), Combination Therapy group (4O-PI+8D-PI: 4 mg Ondansetron pre-incision + 8 mg Dexamethasone pre-incision, 4O-PI+8D-PE: 4 mg Ondansetron pre-incision + 8 mg Dexamethasone pre-emergence, 4 O-PE+8D-PI: 4 mg Ondansetron pre-emergence + 8 mg Dexamethasone pre-induction, 4 O-PE+8D-PE: 4 mg Ondansetron pre-emergence + 8 mg Dexamethasone pre-emergence), and Placebo group 2 ml Saline 0.9%. Primary outcome will be the incidence of PONV in the PACU prior to discharge.
The aim is to evaluate the effectiveness of different regimens of prophylactic Ondansetron, Dexamethasone, or both, on the incidence and severity of post-operative nausea and vomiting.