Postoperative Nausea & Vomiting (PONV)
Plan prevention, prompt rescue and discharge treatment together. PONV can delay drinking, mobilization and discharge; persistent vomiting after abdominal reconstruction also warrants assessment for a surgical or metabolic cause. This workflow follows the Fifth Consensus Guidelines, first published online in 2025, with current product-label safety precautions.[1]
See also: Anesthesia, Analgesia, ERAS, Constipation & Ileus, and Corticosteroid pharmacology.
Assess Risk and Reduce Emetic Exposure
The adult Apfel score assigns one point each for female sex, nonsmoking, prior PONV/motion sickness and anticipated postoperative opioids. Historical approximate risks with 0–4 factors are 10%, 20%, 40%, 60% and 80%; these are population estimates rather than an individual's prediction after prophylaxis.[1]
| Adult risk | Prevention approach |
|---|---|
| No Apfel factors | Low risk; individualize prevention and account for consequences of vomiting. An ERAS pathway may still use general multimodal prophylaxis. |
| One or two factors | Use two preventive interventions, usually antiemetics from different classes plus appropriate baseline-risk reduction. |
| Three or four factors, or severe prior PONV | Multimodal prophylaxis with additional agents as appropriate and stronger baseline-risk mitigation. No single fixed triple regimen suits every patient. |
Use opioid-sparing analgesia, adequate hydration, propofol-based TIVA or regional/local techniques when suitable, and minimize volatile anesthetic/nitrous-oxide exposure. Avoid turning one retrospective model's blood-loss, positioning or laboratory associations into universal treatment thresholds. Adequate hydration does not mean indiscriminate fluid loading in cardiac or renal disease.[1]
Select a Practical Adult Prophylactic Regimen
Dexamethasone plus a 5-HT₃ antagonist is a well-studied combination. Add or substitute another class according to previous response, QT risk, retention/delirium risk and formulary availability. Combination therapy is generally more effective, but not every combination is superior to every single agent. The large Cochrane network review included 585 trials; evidence for vomiting prevention was stronger than evidence for uncommon serious harms. Its drug rankings do not establish a universally safest regimen.[1][2]
| Option | Adult workflow example | Important qualification |
|---|---|---|
| Dexamethasone | 4–8 mg IV at induction | Monitor glucose; coordinate with existing glucocorticoid coverage. |
| Ondansetron | 4 mg IV near the end of surgery | Timing differs from dexamethasone. Oral prophylaxis is not dose-equivalent to 4 mg IV. |
| Palonosetron | 0.075 mg IV | Longer acting; avoid routine repeat dosing in PACU. |
| Aprepitant | 40 mg orally before surgery | An NK₁ alternative/addition; review interactions and hormonal-contraception counseling. |
| IV aprepitant, APONVIE | 32 mg over 30 seconds before induction | FDA-labeled adult prophylaxis formulation; do not substitute chemotherapy formulations/doses automatically. |
| Amisulpride, BARHEMSYS | 5 mg IV over 1–2 minutes at induction | Prevention dose differs from the 10-mg treatment dose; QT precautions apply. |
| Droperidol | Consensus prophylactic dose 0.625 mg IV near the end of surgery | US boxed warning, patient selection and ECG monitoring requirements remain relevant. |
| Transdermal scopolamine | One patch the prior evening; US PONV label removes it 24 hours after surgery | Delayed onset; retention, cognitive and heat-related risks may favor another agent. |
These are selected adult examples, not interchangeable order sets. Some consensus-supported uses are off label; use the specific product's administration instructions and patient-specific limits.[1][3][4][5][6]
Safety Checks That Change Selection
- QT and interactions: assess QT-prolonging combinations, potassium/magnesium and cardiac history. BARHEMSYS labeling advises avoiding congenital long-QT syndrome and concurrent droperidol, with ECG monitoring in susceptible patients. Droperidol's US label reserves use for inadequate response/intolerance to other treatments, contraindicates known/suspected QT prolongation, and requires a pretreatment ECG plus monitoring for 2–3 hours afterward.[4][5]
- Ondansetron: avoid congenital long-QT syndrome; concomitant apomorphine is contraindicated. Severe hepatic impairment limits the total daily dose to 8 mg. The labeled oral adult PONV prophylaxis dose is 16 mg one hour before induction.[7]
- Dexamethasone: a studied single perioperative dose has reassuring SSI evidence, but can cause transient hyperglycemia. Required hydrocortisone coverage is not a proven equivalent antiemetic regimen. Coordinate total steroid exposure and consider a non-steroid antiemetic; see Steroids for PADDI and adrenal coverage.[1]
- Scopolamine: can worsen urinary retention and confusion; avoid angle-closure glaucoma. Its 2025 label adds hyperthermia/decreased-sweating precautions. Avoid excessive heat, and remove the patch and seek assessment if hyperthermia or concerning neuropsychiatric effects occur. Follow its removal instructions, including before MRI.[6]
- Aprepitant: review CYP interactions, warfarin monitoring and backup nonhormonal contraception for 28 days after exposure.[3]
Severe tissue injury, including gangrene, can occur. FDA prefers deep IM administration. If IV administration is necessary, follow the current diluted-infusion instructions using a large vein, preferably a central catheter; do not use a hand/wrist vein or administer an undiluted IV push. The FDA instructions specify normal-saline dilution, a concentration no greater than 1 mg/mL and infusion over 20–40 minutes. Stop and evaluate infusion-site pain. Promethazine is contraindicated below age two because of respiratory-depression risk.[8][9]
Treat Breakthrough PONV
Check which agents were given, at what time and at what dose. Assess pain/opioids, hydration, hypotension and other causes; after major abdominal surgery, consider ileus, obstruction, leak or infection when symptoms or examination warrant it. A nasogastric tube is a treatment for selected distension/obstruction, not routine PONV rescue.
- Choose a different pharmacologic class after failed prophylaxis. If no prophylaxis was given, ondansetron 4 mg IV is one option.
- Amisulpride 10 mg IV over 1–2 minutes is labeled for adult treatment after no prophylaxis or prophylaxis with another class; apply its QT precautions.
- Immediate repeat dosing of the same class is usually ineffective. After more than six hours, a repeat short-acting 5-HT₃ antagonist or butyrophenone can be considered when alternatives are unavailable, within dose and safety limits.
- Do not routinely repeat long-acting palonosetron, aprepitant/fosaprepitant or dexamethasone in PACU. Scopolamine's delayed onset makes it unsuitable as the sole immediate rescue for active vomiting.[1][4]
Prevention efficacy does not automatically establish rescue efficacy; IV aprepitant's FDA indication is prophylaxis. Escalate persistent symptoms and reassess the diagnosis rather than repeatedly stacking sedating or QT-prolonging medicines.
Children and Discharge Planning
Use pediatric risk assessment and weight-based dosing, not adult Apfel probabilities. The Fifth Consensus recommends one preventive agent for children without clear risk factors, two for those with 1–2 factors, and at least two plus baseline-risk mitigation for higher risk. Evidence does not establish a routine third drug for every high-risk child. Its common-dose examples are ondansetron 0.1 mg/kg, maximum 4 mg, and dexamethasone 0.15 mg/kg, maximum 4 mg; pediatric anesthesia should determine age-appropriate indications and administration.[1]
Before ambulatory discharge, address continuing nausea, hydration and access to rescue treatment. Consider longer-acting prophylaxis for patients at high risk of postdischarge nausea/vomiting. Give return instructions for persistent inability to drink, severe/distending abdominal pain, fever or other concerning symptoms.
In GU practice, retention risk particularly matters after outlet and urogynecologic surgery. A freely draining ileal conduit does not develop bladder retention simply because an antihistamine is given; sedation, bowel effects and the patient's actual reconstructed anatomy remain relevant. Alvimopan treats selected postoperative ileus risk and does not replace antiemetic prophylaxis.
References
1. Gan TJ, Jin Z, Ayad S, et al. Fifth consensus guidelines for the management of postoperative nausea and vomiting: executive summary and full report. Anesth Analg. 2026;143:497–513; online 2025. doi:10.1213/ANE.0000000000007816. Full report; supplementary tables.
2. Weibel S, Rücker G, Eberhart LHJ, et al. Drugs for preventing postoperative nausea and vomiting in adults after general anaesthesia: a network meta-analysis. Cochrane Database Syst Rev. 2020;10:CD012859. doi:10.1002/14651858.CD012859.pub2
3. APONVIE (aprepitant) prescribing information. DailyMed.
4. BARHEMSYS (amisulpride) prescribing information. DailyMed.
5. Droperidol injection prescribing information. DailyMed.
6. TRANSDERM SCŌP (scopolamine) prescribing information, including 2025 hyperthermia warning. DailyMed.
7. Ondansetron oral prescribing information. DailyMed.
8. FDA. Updated labeling to reduce severe tissue injury from promethazine injection. December 27, 2023. Safety communication.
9. PHENERGAN injection prescribing information. DailyMed.