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For clinicians

Nausea and vomiting after surgery: who is at risk and what prevents it

The four risk factors teams look for, how much each preventive step helps, and what large trials found.

2 minute read, written for clinicians4 sources, each checked word for wordLibrary checked October 18, 2026

A hospital room with an infusion pump and an empty bed

This is the clinician view. It keeps every sentence of the plain guide and adds, for each section, the study design and citations of its sources. Every added sentence is cited and checked like the rest. Back to plain language.

In short

  • Four factors predict nausea and vomiting after surgery: female sex, a history of motion sickness or past PONV, not smoking, and opioids after surgery.E2Good1
  • With none to four of these factors, rates in the original study were about 10%, 21%, 39%, 61% and 79%.E2Good1
  • Ondansetron, dexamethasone and droperidol each cut the risk by about 26%, and propofol by 19%.E1Strong2

How sure each claim is:E1StrongE2GoodOfficial textReviewWhat the grades meanUnderlined words open a definition

Who is most at risk?

A simplified score uses four predictors. They are female sex, a history of motion sickness or of nausea after earlier surgery, not smoking, and the use of opioids after surgery. With none, one, two, three or four, the rates of postoperative nausea and vomiting were 10%, 21%, 39%, 61% and 79%.E2Good1

The authors suggested considering preventive medicine for people with at least two of the four.E2Good1

The evidence in this section (1 source)
SourceDesignGradeCitations (NIH iCite)
1 Apfel CC, Anesthesiology, 1999Observational studyE2Good1,473 (RCR 57.76)

What prevents it?

In a large factorial trial, ondansetron, dexamethasone and droperidol each reduced the risk by about 26%. Propofol reduced it by 19%, so total intravenous anesthesia worked about as well as one anti-nausea drug.E1Strong2

The same trial concluded that prevention is rarely warranted in low-risk patients. It concluded that one measure may help moderate-risk patients and several measures are for high-risk patients.E1Strong2

A Cochrane network meta-analysis found high-certainty evidence that five single drugs (aprepitant, ramosetron, granisetron, dexamethasone and ondansetron) reduce vomiting.E1Strong3

Combinations generally worked better than single drugs, and NK1 receptor antagonists such as aprepitant were the most effective class.E1Strong3

The fourth consensus guidelines cover identifying high-risk patients, lowering baseline risk, choosing prevention and rescue treatment, in adults and children.E2Good4

The evidence in this section (3 sources)
SourceDesignGradeCitations (NIH iCite)
2 Apfel CC, N Engl J Med, 2004Randomized trialE1Strong1,026 (RCR 37.63)
3 Weibel S, Cochrane Database Syst Rev, 2020Meta-analysisE1Strong229 (RCR 20.14)
4 Gan TJ, Anesth Analg, 2020Consensus statementE2Good950 (RCR 85.96)

Questions you might bring to your anesthesia team

  1. I have had nausea after anesthesia before, or I get motion sickness: what is the prevention plan?
  2. Can the pain plan use fewer opioids?
  3. Would total intravenous anesthesia make sense for me?

Every claim in this guide was written from its sources and checked against them word for word. Its clinical review by Dr. Recio, a practicing nurse anesthesiologist (CRNA), is pending. This line changes when the review is done.

Sources

Each source opens on PubMed, DailyMed or the publisher's page. Under each one are the exact words from it that this page relies on, copied word for word and checked against the original.

  1. A simplified risk score for predicting postoperative nausea and vomiting: conclusions from cross-validations between two centers. Apfel CC, Anesthesiology, 1999. E2Good Observational studyPMID 10485781; DOI 10.1097/00000542-199909000-00022; cited 1,473 times, relative citation ratio 57.76 (NIH iCite, 2026-10-18)
    The words this page rests on
    The final score consisted of four predictors: female gender, history of motion sickness (MS) or PONV, nonsmoking, and the use of postoperative opioids. If none, one, two, three, or four of these risk factors were present, the incidences of PONV were 10%, 21%, 39%, 61% and 79%.
    For patients with at least two out of these four identified predictors a prophylactic antiemetic strategy should be considered.
  2. A factorial trial of six interventions for the prevention of postoperative nausea and vomiting. Apfel CC, N Engl J Med, 2004. E1Strong Randomized trialPMID 15190136; DOI 10.1056/NEJMoa032196; cited 1,026 times, relative citation ratio 37.63 (NIH iCite, 2026-10-18)
    The words this page rests on
    Ondansetron, dexamethasone, and droperidol each reduced the risk of postoperative nausea and vomiting by about 26 percent. Propofol reduced the risk by 19 percent, and nitrogen by 12 percent; the risk reduction with both of these agents (i.e., total intravenous anesthesia) was thus similar to that observed with each of the antiemetics.
    Prophylaxis is rarely warranted in low-risk patients, moderate-risk patients may benefit from a single intervention, and multiple interventions should be reserved for high-risk patients.
  3. Drugs for preventing postoperative nausea and vomiting in adults after general anaesthesia: a network meta-analysis. Weibel S, Cochrane Database Syst Rev, 2020. E1Strong Meta-analysisPMID 33075160; DOI 10.1002/14651858.CD012859.pub2; cited 229 times, relative citation ratio 20.14 (NIH iCite, 2026-10-18)
    The words this page rests on
    We found high-certainty evidence that five single drugs (aprepitant, ramosetron, granisetron, dexamethasone, and ondansetron) reduce vomiting, and moderate-certainty evidence that two other single drugs (fosaprepitant and droperidol) probably reduce vomiting, compared to placebo.
    Combinations of drugs were generally more effective than the corresponding single drugs in preventing vomiting. NK1 receptor antagonists were the most effective drug class and had comparable efficacy to most of the drug combinations.
  4. Fourth Consensus Guidelines for the Management of Postoperative Nausea and Vomiting. Gan TJ, Anesth Analg, 2020. E2Good Consensus statementPMID 32467512; DOI 10.1213/ANE.0000000000004833; cited 950 times, relative citation ratio 85.96 (NIH iCite, 2026-10-18)
    The words this page rests on
    This consensus statement presents a comprehensive and evidence-based set of guidelines for the care of postoperative nausea and vomiting (PONV) in both adult and pediatric populations.
    The guidelines provide recommendation on identifying high-risk patients, managing baseline PONV risks, choices for prophylaxis, and rescue treatment of PONV as well as recommendations for the institutional implementation of a PONV protocol.