Post-operative Nausea and Vomiting

A 32-year-old woman undergoes elective laparoscopic cholecystectomy under general anesthesia with sevoflurane and nitrous oxide. Anesthesia is maintained with propofol infusion and fentanyl. She has a history of motion sickness and previous postoperative nausea and vomiting (PONV) after cesarean delivery 2 years ago. On postoperative day 0, she develops severe nausea and vomiting 2 hours after emergence from anesthesia, unresponsive to a single dose of ondansetron 4 mg IV. What is the most appropriate next step in her management?

A 58-year-old man with type 2 diabetes and hypertension undergoes open abdominal aortic aneurysm repair under general anesthesia. Intraoperatively, he receives nitrous oxide, isoflurane, and fentanyl. He is extubated in the operating room. Within 30 minutes of arrival in the recovery room, he develops nausea and vomiting. His blood glucose is 280 mg/dL, blood pressure is 165/95 mmHg, and heart rate is 110 bpm. Which of the following is the MOST important modifiable intraoperative factor that should be avoided in future cases to reduce PONV risk in this patient?

Which 5-HT3 receptor antagonist has the longest duration of action and is preferred for prophylaxis of postoperative nausea and vomiting?