Post-Operative Nausea and Vomiting
Common and distressing anaesthetic complication that:
- Affects up to 30% of patients
- May prolong PACU stay or require hospital admission
Significant ↑ in healthcare costs. - PONV prevention therefore aims to improve patient comfort, throughput, and reduce cost
Risk Factors
Key patient risk factors:
- Female
- PHx PONV
- PHx motion sickness
- Younger age
- Non-smoker
Anaesthetic risk factors:
- General anaesthesia
- Use of volatile anaesthetics
Dose dependent. - Use of nitrous oxide
Has minimal impact when baseline risk is low. - Duration of anaesthesia
- Post-operative opioids
Key risk factors in children:
- Surgery ⩾30 minutes
- Age ⩾4 years
- Family history of PONV
- Strabismus surgery
Risk Scores
Apfel Score:
- Four predictors
- Female
- Previous PONV/motion sickness
- Nonsmoker
- Use of post-operative opioids
- Scored as:
- 0-1: Low risk
- 2: Moderate risk
- ⩾3: High risk
Management
Preventative therapy is titrated to risk:
- Low risk
Nil intervention required. - Moderate risk
1 or 2 interventions. - High risk
⩾2 interventions.
Preventative Interventions
Include:
- TIVA
- Regional anaesthesia
- Acupuncture
- Antiemetic prophylaxis
- 5-HT3 antagonists
Give at end of surgery.- Ondansetron 4-8mg
- Granisetron 0.3-3mg
- Corticosteroids
Give at induction.- Dexamethasone 4mg
- Butyrophenones Give at end of surgery.
- Droperidol 0.625-1.25mg
- NK-1 antagonists
Give at induction.- Aprepitant 40mg PO
- Transdermal scopolamine
Give evening prior to surgery or 2/24 prior.
- 5-HT3 antagonists
Rescue Interventions
- Treatment should use a different agent to the initial prophylaxis
- If no prophylaxis given, then initial treatment should be with a 5-HT3 antagonist
- Propofol 20mg
Effective but brief. - Antiemetic
Antiemetics
| Drug | Class |
|---|---|
| Ondansetron | 5-HT3 antagonist |
| Granisetron | 5-HT3 antagonist |
| Dexamethasone | Corticosteroid |
| Droperidol | Butyrophenones |
| Aprepitant | NK-1 antagonist |
| Scopolamien | Anticholinergic |
References
- Gan, Tong J., Pierre Diemunsch, Ashraf S. Habib, Anthony Kovac, Peter Kranke, Tricia A. Meyer, Mehernoor Watcha, et al. ‘Consensus Guidelines for the Management of Postoperative Nausea and Vomiting’: Anesthesia & Analgesia 118, no. 1 (January 2014): 85–113. https://doi.org/10.1213/ANE.0000000000000002.