This randomized controlled trial aims to evaluate the safety and efficacy of Ondansetron, Dexamethasone, and their combination in managing postoperative nausea and vomiting (PONV) in patients undergoing surgery under anesthesia. A total of 100 patients will be randomized into four groups: Placebo, Ondansetron, Dexamethasone, and Ondansetron-Dexamethasone combination. The primary outcome will be the incidence of PONV within 24 hours post-surgery, while secondary outcomes include severity of symptoms, need for rescue medication, adverse effects, and patient satisfaction.

Postoperative nausea and vomiting (PONV) is a common and distressing complication following surgery, affecting patient recovery and satisfaction. This study aims to compare the safety and effectiveness of Ondansetron, Dexamethasone, and their combination for PONV prevention.

The study will be conducted as a randomized, controlled trial at Federal Polyclinic Hospital Islamabad over four months. A total of 100 adult patients undergoing elective surgery under anesthesia will be enrolled and randomly allocated into one of four groups (n=25 each):

Placebo group - Receives no prophylactic antiemetic treatment. Ondansetron group - Receives 4 mg IV Ondansetron before surgery. Dexamethasone group - Receives 8 mg IV Dexamethasone before surgery. Ondansetron-Dexamethasone group - Receives 4 mg IV Ondansetron + 8 mg IV Dexamethasone before surgery.

Methodology:

Patients will be assessed at multiple time points (2, 4, 6, 12, and 24 hours postoperatively) for PONV incidence and severity, along with the need for rescue medication. Side effects such as headache, dizziness, hypertension, and hyperglycemia will also be monitored.

Statistical Analysis:

Data will be analyzed using chi-square tests and ANOVA to compare outcomes across treatment groups. A p-value < 0.05 will be considered statistically significant.

This study will help determine the most effective and safest antiemetic regimen, guiding clinical decision-making for better PONV management.

Inclusion Criteria:

• Adult patients (≥18 years) scheduled for elective surgery under anesthesia.
• Patients at moderate to high risk for postoperative nausea and vomiting (PONV), as determined by an Apfel risk score ≥2.
• Patients able to provide informed consent or have a legally authorized representative provide consent.

Exclusion Criteria:

• Known allergy or hypersensitivity to Ondansetron, Dexamethasone, or any of their components.
• History of significant adverse reactions to previous PONV prophylaxis with Ondansetron or Dexamethasone.
• Pre-existing conditions or medications contraindicating the use of Ondansetron or Dexamethasone, e.g. QT prolongation or severe cardiac arrhythmias (e.g., torsades de pointes, congenital long QT syndrome), Uncontrolled hypertension (for Dexamethasone use), Severe hepatic impairment (Child-Pugh C) or end-stage renal disease, Uncontrolled diabetes mellitus (due to Dexamethasone-induced hyperglycemia).
• Patients with active malignancy undergoing chemotherapy or radiotherapy.
• Pregnant or lactating women (unless safety in this population is specifically being studied).
• Chronic opioid users (≥3 months of continuous opioid use), as this may alter PONV risk and response to prophylaxis.

At this stage, no final decision has been made regarding the sharing of individual participant data (IPD). Data sharing will be considered based on future research needs, ethical guidelines, and institutional policies. Any decision to share IPD will be made in compliance with data protection regulations and patient confidentiality standards.

This study will be single-blinded, meaning that the patients will not be aware of their assigned treatment group, but the healthcare provider administering the medication will know.