After approval from the Institutional Ethics Committee, written informed consent will be obtained from female participants in reproductive age group with ASA physical status â…  and â…¡ who will be posted for oocyte retrieval procedure under intravenous sedation (propofol based).Participants will be in randomised into two groups by simple randomisation, Participants allotted in each group by lottery method, A and B, with 42 participants in each group.

Group A will receive intravenous ondansetron (4 mg).Group B will receive (ODF) of ondansetron (8 mg).Thorough detailed medical history and physical examination will be obtained and co morbidities, if any will be noted. Nil per oral (NPO) status will be confirmed. Participants will be randomised into group A and group B. Ondansetron ODF formulation which is administered in the preoperative room 30 min before procedure. ODF is formulation which disintegrates within 5 sec in mouth when placed on tongue. Given preoperatively to prevent PONV .

In the operating room, i.v. access will be secured and standard ASA monitors [Electrocardiogram (ECG), pulse oximeter (SpO2) and noninvasive blood pressure (NIBP)] will be attached. Group A will receive i.v. ondansetron (4 mg diluted to 10 ml with 0.9% normal saline) given over 5 minutes and placebo ODF. Group B will receive ODF ondansetron and 10 ml 0.9% normal saline given over 5 minutes. Anaesthesia will be standardised. Premedication with Inj. midazolam 1 mg will be administered. Analgesia will be provided by Inj. fentanyl 1mcg/kg. Anaesthesia will be induced with Inj. propofol 1 mg/kg and maintained on propofol infusion in the dose of 3 mg/kg/hr. Patients will be ventilated with oxygen through face mask @6-8 L/min to maintain a SpO2 of more than 95%. Patients will maintained on spontaneous ventilation. At the end of procedure all patients will receive paracetamol 250 mg suppository.

Postoperatively, all patients will be monitored for a minimum of 2 hours in the PACU and kept nil per oral for 4 hours. PONV will be assessed every hour for 6 hours or till discharge whichever is earlier. The parameters will be recorded on the proforma and tabulated in the master chart preoperatively. Main benefit is cost effectiveness and more convienient to use. Free hospitalisation and medication will be provided in case of any adverse effects. Rescue anti emetic drug given -Dexamethasone 4-8mg intravenous if participant experience PONV.