Postoperative Nausea and Vomiting (PONV): Risk Factors & Management
PONV is a common concern in anesthesia, especially in high-risk patients. Identifying risk factors and implementing preventative strategies can significantly reduce its incidence.
🚨 Risk Factors for PONV
🧑⚕️ Patient-Related Risk Factors:
1️⃣ Female gender
2️⃣ Non-smoker
3️⃣ History of motion sickness
4️⃣ History of PONV
5️⃣ Age <50 years
💉 Anesthesia-Related Risk Factors:
1️⃣ Use of nitrous oxide (N₂O)
2️⃣ Use of volatile anesthetics
3️⃣ Use of intraoperative & postoperative opioids
🏥 Prevention Strategies for High-Risk Patients
- Minimize N₂O use throughout surgery.
- Consider opioid-sparing techniques:
- Dexmedetomidine or ketamine for pain management instead of opioids like fentanyl.
- Reduce reliance on volatile anesthetics:
- Use a propofol-dominant anesthetic plan when possible.
- Multimodal PONV prophylaxis:
- Combination of dexamethasone, ondansetron, and scopolamine in high-risk patients.
💊 Common PONV Prophylactic Medications
🦸 Dexamethasone (Corticosteroid)
- One of the two main drugs used for PONV prophylaxis.
- ⚠️ Important: Only administer after induction of anesthesia to avoid a pruritic rash when given IV.
- 💉 Dose: 4 mg IV
🌊 Ondansetron (5-HT₃ Antagonist)
- Used in combination with dexamethasone for PONV prevention.
- 💉 Dose: 4 mg IV
🎢 Scopolamine (M1 Muscarinic Antagonist)
- Best for patients with a history of motion sickness.
- Application: Placed behind the ear several hours before surgery.
📚 References
1️⃣ Miller RD. Miller’s Anesthesia. 9th ed. Philadelphia, PA: Elsevier; 2020.
2️⃣ Morgan GE, Mikhail MS, Murray MJ. Morgan & Mikhail’s Clinical Anesthesiology. 6th ed. New York, NY: McGraw Hill; 2018.
3️⃣ Steiner J. Anesthesia Made Easy: The Survival Guide to Make Your First Anesthesia Rotation a Success. 2nd ed. Independently Published; 2019.