Incidence of postoperative nausea and vomiting in patients undergoing oncosurgical anaesthesia: A single-center prospective observational study.

Postoperative nausea and vomiting(PONV) is a frequent and distressing complication after surgery, with an incidence ranging from 10–80% depending on patient factors, surgery type, and anaesthetic technique. Beyond discomfort, PONV can lead to complications like dehydration, electrolyte imbalance, aspiration, and wound dehiscence. These consequences delay recovery, increase healthcare costs, and reduce overall patient satisfaction.

Despite the availability of multiple antiemetic agents and preventive strategies, PONV continues to be challenging due to its multifactorial nature and different patient responses. Studies show that some patients avoid postoperative analgesics completely to prevent nausea, highlighting its significant physical burden to the patient .Such findings emphasize that nausea is more than just a symptom. Effective management is therefore essential for improved safety, comfort, and better surgical outcomes.

The mechanism of PONV involves complex interactions among serotonergic, dopaminergic, histaminergic, cholinergic, and neurokinin pathways. Established risk factors include female sex, younger age, non smoking status, opioid use, and prolonged anaesthesia. Common antiemetics include 5-HT3 antagonists, corticosteroids, and NK1 blockers, with ondansetron widely used for its safety and rapid onset. While multimodal prophylaxis is recommended for high-risk patients, single-agent therapy remains common in resource-limited settings.

PONV rates differ significantly across oncology surgeries, being especially high in gynecological, head-and-neck and neurosurgical cases . Orthognathic procedures also show elevated risk compared to minor oral surgeries. In India, limited observational research exists documenting the PONV incidence, particularly with ondansetron as a standalone prophylactic. Most studies focus on specific cancer types, creating a gap in comprehensive data across diverse oncology surgeries.

The aim of the present study is to determine the occurrence of PONV in patients undergoing oncological surgeries under anaesthesia. The primary objective is to assess the incidence of PONV within the first 24 hours postoperatively. The secondary objective is to evaluate associations between perioperative variables and the development of PONV. This will help identify high risk groups and guide more targeted preventive strategies.

All patients will undergo pre anaesthetic evaluation,  and have demographic and clinical risk variables recorded. Standard anaesthetic care with routine monitoring will be provided, and intraoperative variables such as type of surgery,type of anaesthesia ,type of iv fluids,amount of iv fluids,dosage of opioids ,input and output,duration of surgery will be documented. Postoperatively, patients will be assessed

immediately on arrival to PACU and later at 2, 6, and 24 hours after surgery. Injection ondansetron  and injection dexamethasone  iv given according to body weight and will be used as the rescue antiemetics.Postoperative variables recorded include nausea scores using the 11-point Numeric Nausea Score,opioid use, vomiting episodes, and the need for rescue antiemetics and the patients response closely monitored.