Prevention

Postoperative nausea & vomiting

Patients often rate PONV as worse than pain. Estimate risk, then prevent it with drugs from different classes.

Simplified Apfel score

Female sex Non-smoker History of PONV or motion sickness Postoperative opioids expected

0 factors

≈ 10% baseline risk

Approximate risks for 0/1/2/3/4 factors: 10/20/40/60/80% (Apfel et al. 1999). Educational estimate — fictional or hypothetical patients only.

Drug	Typical dose / timing
Ondansetron	4 mg IV at end of surgery
Dexamethasone	4–5 mg IV after induction
Scopolamine patch	Evening before or ≥ 2 h pre-op
Others	Droperidol (boxed QT), amisulpride, aprepitant, metoclopramide, promethazine; propofol TIVA