Postoperative Nausea and Vomiting

1. Epidemiology
   1. Incidence of PONV: 30% (70% in high risk patients)
2. Risk factors
   1. Patient characteristics with higher PONV risk
      1. Female sex
      2. History of Motion Sickness
      3. Prior episode Postoperative Nausea and Vomiting
      4. Non-smokers
      5. Postoperative use of opiod Analgesics
   2. Surgeries with higher PONV risk
      1. Craniotomy
      2. Ear, nose and throat surgery
      3. Major Breast surgery
      4. Laparoscopy or Laparotomy
      5. Strabismus surgery
   3. Anesthetics with higher PONV risk
      1. Opiod Analgesics
      2. Nitrous oxide
      3. Volatile inhalational anesthetics
3. Prophylaxis: Mild Risk of PONV (1-2 risk factors)
   1. Dexamethasone (<8 mg single dose)
   2. Scopolamine
   3. Serotonin Antagonist (e.g. Ondansetron, Granisetron)
      1. Ondansetron 4 mg IV given in last 20 min of surgery
   4. Droperidol (Inapsine)
      1. Not recommended as first line due to QT Prolongation
      2. Combination given within 20 min of anesthesia
         1. Droperidol 1.25 mg IV and
         2. Dexamethasone 4 mg IV
4. Prophylaxis: Moderate Risk of PONV (3-4 risk factors)
   1. Serotonin Antagonist with Dexamethasone
   2. Serotonin Antagonist (e.g. Ondansetron) with Droperidol
5. Prophylaxis: High Risk of PONV (>4 risk factors)
   1. Combination agents in Moderate risk list above and
   2. Total intravenous anesthesia with Propofol and
   3. High concentration oxygen (80%) intraoperatively
6. References
   1. Gan (2002) JAMA 287:1233-6