Fasting options before procedures for people taking once-weekly GLP-1 medicines.
Effect of Fasting Recommendations on Residual Gastric Contents Among Patients Using Glucagon-like Peptide-1 Receptor Agonists: A Randomised Controlled Trial
This trial will test whether a 24-hour clear liquid diet versus standard fasting reduces leftover stomach contents in adults who take once-weekly GLP-1 receptor agonists.
Quick facts
| Phase | Not applicable |
|---|---|
| Study type | Interventional |
| Enrollment | 154 (estimated) |
| Ages | 18 Years and up |
| Sex | All |
| Sponsor | St Vincent's Hospital Melbourne Academic / other |
| Locations | 2 sites (Melbourne, Victoria and 1 other locations) |
| Trial ID | NCT06839248 on ClinicalTrials.gov |
What this trial studies
Adults using any once-weekly GLP-1 receptor agonist are randomized 1:1 to follow either a 24-hour clear liquid diet or standard ASA/ANZCA fasting guidelines prior to a study visit. Participants undergo a blinded gastric ultrasound at the visit to measure residual gastric contents and the presence of solids or thick fluids. The study also collects patient-reported outcomes (thirst, hunger, nausea, fatigue, anxiety) and measures of adherence and time since last oral intake. The primary outcome is the proportion of participants presenting with increased residual gastric contents under each fasting approach.
Who should consider this trial
Good fit: Adults aged 18 or older who have been taking any once-weekly GLP-1 receptor agonist for at least one month and are willing to follow the assigned fasting instructions and provide informed consent.
Not a fit: People not taking once-weekly GLP-1 receptor agonists or those with excluded abnormal gastrointestinal anatomy are unlikely to benefit from this specific comparison.
Why it matters
Potential benefit: If successful, this could identify a safer fasting approach that lowers the risk of residual stomach contents, reducing aspiration risk and procedure cancellations for patients on once-weekly GLP-1 RAs.
How similar studies have performed: There is observational evidence that GLP-1 RAs increase residual gastric contents, but randomized trials testing a 24-hour clear liquid diet for this purpose are limited or absent.
Eligibility criteria
Show full inclusion / exclusion criteria
Inclusion Criteria: * Age ≥18 years old at enrolment. * Have regularly administered any type of once-weekly GLP-1 RA medication for a period of at least one month prior to randomisation. * If allocated to follow standard fasting guidelines, willing to adhere to ASA and ANZCA preoperative fasting requirements. This requires participants to only consume clear liquids up to 2 hours, a light or low calorific meal up to 6 hours, and fasting from fried foods, fatty foods, or meat for at least 8 hours prior to the trial visit. * If allocated to follow a 24-hour clear liquid diet, willing to adhere to nothing-by-mouth (NPO) for solids and last intake of clear liquids no less than 2 hours prior to the trial visit. * Provide a signed and dated informed consent form for study participation in line with the requirements of the human research ethics committee (HREC) of the study site. Exclusion Criteria: Participants meeting any of the following criteria, indicative of abnormal anatomy and not validated by gastric ultrasound, will be excluded from this trial: * Has a recent history of gastrointestinal bleed within the previous 1 month from enrolment. * Has a history of previous lower oesophageal or gastric surgery. * Has a known abnormal upper gastrointestinal anatomy, including hiatus hernia or gastric tumours. In addition, participants meeting any the of following criteria will be excluded from this trial: * Participant reports having been previously diagnosed with a clinically significant gastric emptying abnormality such as gastroparesis. * Participant reports concomitant use of insulin. * Unable to assume the right lateral decubitus position required for gastric ultrasound assessment. * Participant has difficulty fully understanding PICF or study materials due to a primary language other than English.
Where this trial is running
Melbourne, Victoria and 1 other locations
- Melbourne Gastro Oesophageal Surgery (MGOS) — Melbourne, Victoria, Australia (Recruiting)
- St Vincent's Hospital Melbourne — Melbourne, Victoria, Australia (Recruiting)
Study contacts
- Principal investigator: Prof Michelle Dowsey, BHealthSci(Nursing), MEpi, PhD — St Vincent's Hospital Melbourne
- Study coordinator: Prof Michelle Dowsey, BHealthSci(Nursing), MEpi, PhD
- Email: mmdowsey@unimelb.edu.au
- Phone: 03 9231 3955
How to participate
- Review the eligibility criteria above with your treating physician.
- Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
- Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.