Prevention and Treatment of Post-operative Nausea and Vomiting (PONV)

This guideline is aimed at providing quick guidance on PONV. Refer to ADTC 115 - Prevention & Treatment of Post-operative Nausea & Vomiting in Adults (link only active if accessing via NHS network) for more information.

Introduction

Post-operative nausea and vomiting (PONV) remains a common cause of morbidity within the post-operative period. Untreated, it has an incidence from 20-30% in the general surgical population, to 80% in patients pre-identified to be higher risk. PONV is associated with patient distress and many would rather suffer pain than nausea or vomiting.

Throughout the NHS increasing numbers of patients are undergoing surgery as day cases, and PONV can result in medical complications, patient dissatisfaction, delayed discharge, readmission, and increased hospital costs.

Aetiology

PONV is nausea or vomiting occurring following surgery, and is due to stimulation of the vomiting centre within the medulla. The vomiting centre receives input from a number of different sources including the gut, vestibular system, chemoreceptor trigger zone and the cortex. A number of different mediators are involved, including serotonin, histamine, acetylcholine and dopamine. Drugs which antagonise these mediators are commonly used in clinical practice to prevent and treat PONV.

PONV can occur early (within 4 hours of surgery), or late (from 4 to 24 hours following surgery).

Risk Stratification

Patient, surgical and anaesthetic factors can all increase risk of developing PONV. Several risk models have been suggested in the literature. Whilst no single model can accurately predict the likelihood of an individual developing PONV, they do allow us to estimate risk amongst different patient groups. The model proposed by Apfel is now generally accepted throughout the literature. This model has identified four individual patient risk factors:

  • Female gender
  • Previous PONV or motion sickness
  • Non-smokers
  • Post-operative opiate use

Using these factors risk can be stratified from 0 (low risk) to 4 (high risk):

Number of risk factors Incidence of PONV
0 10%
1 20%
2 40%
3 60%
4 80%

Prevention of PONV

Reduce Baseline Risk Factors for PONV

Anaesthetic technique has significant influence on incidence of PONV, therefore the initial step should be to reduce baseline risk by considering:

  • Using total intravenous anaesthesia (TIVA) [i.e. avoiding volatile anaesthetics and nitrous oxide]
  • Minimisation of intraoperative and post-operative opioids e.g. regional anaesthesia
  • Using sugammadex for neuromuscular block reversal (i.e. avoid use of neostigmine)
  • Ensuring adequate hydration

Pharmacological PONV prophylaxis

  • Low risk (0 risk factors): patients should not be given pharmacological PONV prophylaxis.
  • Medium risk (1-2 risk factors): patients should be given two prophylactic drugs. Dexamethasone plus ondansetron are suggested as the first-line preventative agents of choice.
  • High risk (3-4 risk factors): patients should be given a combination of three to four antiemetics (e.g. dexamethasone, ondansetron, cyclizine and droperidol) and TIVA should be strongly considered.

N.B. More liberal prophylaxis is appropriate for patients in whom vomiting poses a particular medical risk, including those with wired jaws, increased intracranial pressure, gastric or oesophageal surgery.

Treatment of patients with PONV who did not receive prophylaxis or in whom prophylaxis failed

Ondansetron, cyclizine, droperidol and prochlorperazine can all be used for the treatment of established PONV. The choice of drug depends primarily on whether prophylaxis or treatment has already been given and whether it was effective or not.

  • If prophylaxis was given, and PONV occurs:
    • during the therapeutic time of the drug, then do not re-administer the prophylactic drug. Choose a rescue drug from a different class.
    • after the therapeutic time of the drug, consider re-administering the prophylactic drug.
  • If no prophylaxis was given, then administer ondansetron (1st choice), cyclizine, droperidol or prochlorperazine.
  • If there has been no response after 30 minutes, administer a further drug from another class.
  • When there has been good response to an antiemetic, consider prescribing this agent regularly for the following 24 hours.
  • Dexamethasone can be used once daily to treat persistent PONV, but takes 90 minutes to work.

N.B. The attempt at rescue should be initiated when the patient complains of PONV and, at the same time, an evaluation should be performed to exclude an inciting medication or mechanical factor for nausea and/or vomiting. Contributing factors might include opioids or intestinal obstruction.

Guideline reviewed April 2025
Page updated November 2025



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