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School of Anesthesia


Anesthesiology | Medical Education | Nursing


Background Postoperative nausea and vomiting remains a common and unpleasant side effect for patients following surgery. Uncontrolled PONV can result in prolonged hospital stays, unanticipated hospital readmissions, and decreased patient satisfaction. The Apfel score identifies and counts independent risk factors for PONV; females, non-smokers, postoperative opioid use, and history of PONV or motion sickness. Rates of PONV increases as the number of risk factors increase. The primary intervention to decrease PONV is administration of prophylactic antiemetics. Research supports the use of combination antiemetic therapy for patients with a high number of risk factors. The purpose of this evidence based practice (EBP) project was to report the rate of PONV among surgical patients who received general anesthesia, comparing combination prophylactic antiemetics of ondansetron and dexamethasone to single antiemetic administration.

Methods A retrospective, EBP project was conducted at Providence Sacred Heart Medical Center (PSHMC) in Spokane, WA. • Permission was obtained by the facility and exemption determination was granted by the IRB. • Patient data was securely extracted and stored in a HIPPA compliant REDCap database. Patient data was fully de-identified. Data extraction included all surgeries in the 2018 calendar year. • Inclusion criteria: Adult patients > 18 years old, non-emergent surgery, general anesthesia (ETT, LMA) using volatile inhalational agents or total intravenous anesthesia. • Exclusion criteria: Pediatric, obstetric, emergency surgery, direct admission to ICU. • PONV outcome determined by nursing documentation of PONV scale, intervention, reassessment or signs/symptoms or administration of antiemetic medication. • Descriptive data analysis completed and stratified by the number of Apfel risk factors. Independent risk factors determined using binary logistic regression. Level of significance set at 0.05.

Discussion CONCLUSION When controlling for all literature reported PONV risk factors, this EBP project demonstrated that the odds of PONV reduction were similar for combination and individual antiemetic therapy. Similar to current research evidence, the identified independent risk factors for PONV were female gender, history of PONV or motion sickness, postoperative opioid administration, younger age, high risk procedures, and increased case duration. Non-smoking status and nitrous oxide use were not observed to be independent risk factors. As Apfel reported, this project similarly reported an increase rate in PONV as the number of PONV risk factors increased. The observed risk of PONV decreased among patients with at least one Apfel risk factor following prophylactic antiemetic administration. IMPLICATIONS Practice at PSHMC is demonstrating that combination prophylactic treatment is being used for patients with higher PONV risk factors. Practice is following current research evidence. Anesthetists should continue to tailor prophylactic antiemetic administration to patients based on presenting risk factors.





Conference / Event Name

AANA 2019 Congress


Chicago, IL

Comparison of Ondansetron, Dexamethasone, and its Combination in the Prevention of Postoperative Nausea and Vomiting