A/Prof Jai Darvall (Univeristy of Melbourne and the Royal Melbourne Hospital)
The Chewy Trial completed recruitment in February 2023 and is now in the process of data cleaning. We hope to have results available soon. A big thanks to all 17 sites for your hard work in running this trial.
The primary hypothesis
Chewing gum (one stick of Wrigley's peppermint-flavoured gum, chewed for 15 minutes) is non inferior to 4mg IV ondansetron in achieving complete cessation of nausea, retching and vomiting postoperatively, within two hours of administration, with no recurrence of nausea and no need for rescue medication. This has the potential to dramatically change the management of one of the most common complications of anaesthesia worldwide.
More than 300 million people have surgery worldwide annually; it is thus likely tens-of-millions of patients suffer from postoperative nausea, retching and vomiting (PONV) each year. PONV is a leading cause of unplanned admission of day surgery patients, and contributes significantly to patient discomfort and distress. The financial implications are particularly burdensome in low-income nations, where surgery is expanding rapidly. Surprisingly, despite many trials examining PONV prophylaxis, there has been little research assessing treatment. The aim of the Chewy trial is to explore chewing gum as an alternative treatment that is readily-available, cheap, easy to administer and free of side effects. This multicentre, randomised, controlled noninferiority trial, will randomise 272 women who experience PONV following surgery to either 4mg IV ondansetron, or chewing gum (one stick of Wrigley's peppermint-flavoured gum, chewed for 15 minutes). Primary outcome is the complete cessation of PONV, with no recurrence and no need for rescue medication for two hours. If shown to be effective, the Chewy trial has the potential to positively influence post-operative outcomes for millions of patients worldwide each year.
Australian and New Zealand College of Anaesthetists Foundation.
Darvall J, von Ungern-Sternberg BS, Braat S, Story D, Davidson A, Allen M, Tran-Duy A, Middleton D, Leslie K. Chewing gum to treat postoperative nausea and emesis in female patients (CHEWY): rationale and design for a multicentre randomised trial. BMJ Open. 2019 Jun 12;9(6):e027505.
Australian New Zealand Clinical Trial Registry registration number: ACTRN12618000429257
$50 per patient payment for each recruited participant plus a $350 payment for randomising and following up patient at discharge or day one - whichever is earlier (estimated 30 per cent randomisation rate to recruitment).
For further information about this study, please contact the Chewy Project Manager, Vi Ha by email.