Residual Gastric Content After Holding of Glucagon-like Peptide-1 Receptor Agonists Before Elective Surgery (RESIDUAL)

The RESIDUAL Study : Residual Gastric Content After Holding of Glucagon-like Peptide-1 Receptor Agonists Before Elective Surgery: a Cross-sectional Study

Glucagon-like peptide-1 agonists (GLP-1RA) are a family of medications used for diabetes and weight loss. One of their effect is to slow down stomach emptying. The goal of this study is to evaluate the effect of GLP-1RA on the effectiveness of fasting before a scheduled surgery.

The question it aims to answer is: does this kind of medication increase the risk of having food or too much liquid in the stomach before a scheduled surgery, even if the minimum 6 hour fast is done?

For this project, researchers will use gastric ultrasound to compare participants already taking one of these medications as part of their home treatment to participants who are not taking them. Gastric ultrasound is a simple bedside exam using an echography machine that takes less than 5 minutes to do.

Participants will:

-Have a gastric ultrasound performed on them before their surgery

Study Overview

• Status: Completed
• Conditions: Gastric Retention
• Intervention / Treatment: Diagnostic test: Gastric ultrasound

Detailed Description

Background: Glucagon-like peptide-1 receptor agonists (GLP-1RA) are glucose-lowering drugs that act through three mechanisms: stimulation of insulin secretion, inhibition of glucagon secretion and decrease of gastric emptying. The GLP-1RA are now an important part of glycemic control in type 2 diabetes mellitus (T2DM). Recently, GLP-1 RA have received approval for weight loss, expanding their use in overweight or obese non-diabetic patients.The effect of GLP-1RA on decreased gastric emptying has long been established but he clinical implication of this in the periprocedural setting is uncertain. Recent guidelines recommend holding the weekly-dosed for at least a week before elective surgery. Considering the extended half-lives of once-weekly GLP-1RA (approximately 6 days for semaglutide and 5 days for dulaglutide), it is unclear if following those guidelines is sufficient to make sure patients are not at high risk of aspiration

Hypothesis: This study will compare ultrasound-assessed residual gastric content (RGC) between once-weekly GLP-1RA users that stopped their medication for 7 days or more before elective surgery and patients not taking GLP-1RA. The investigators hypothesized that even with appropriate holding of GLP-1RA, those patients may have increased RGC and be at higher risk of aspiration.

Objectives:

Primary objective:

• To investigate the relation between GLP-1RA use and increased RGC

Secondary objectives:

• To assess the relation between the number of days since the last dose of GLP-1RA and increased RGC
• To assess the relation between the dose of GLP-1RA and RGC

Exploratory objectives:

• To explore the relation between other known risk factors of gastroparesis and increased RGC
• To explore the relation between the time since the last oral intake and increased RGC

Methods : A gastric ultrasound (GUS)will be performed on all patients to assess RGC using a published validated and reproductible method used in recent trials. The acquisition of images will be performed by a blinded anesthesiologist or anesthesiology resident using a dedicated ultrasound machine. The images will be saved and reviewed by another blinded trained anesthesiologist.

Significance/importance: The results of this study could challenge the actual recommendations for GLP-1RA stoppage before surgery and help improve perioperative care for patients taking GLP-1RA.

• Study Type: Observational
• Enrollment (Actual): 94

Contacts and Locations

Study Locations

• Canada
  • Quebec
    • Montreal, Quebec, Canada, H1T2M4
      • Ciusss de L'Est de l'Île de Montréal

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: Yes

• Sampling Method: Non-Probability Sample

Study Population

Adult population undergoing elective surgery

Description

Inclusion Criteria:

• American Society of Anesthesiologists (ASA) class 1-4 patients
• Age ≥ 18 years old
• Fasted state (2 hours for clear liquids, 6 hours for solids)
• Elective surgery
• Last dose of once-weekly semaglutide or dulaglutide 7 days or more before surgery (for GLP-1RA group)

Exclusion Criteria:

• Last dose of GLP-1RA less than 7 days before surgery
• Inability to lay on the right-side for ultrasound
• Pregnancy
• History of gastric surgery or large hiatal hernia

Study Plan

How is the study designed?

Number of groups / cohorts

2

Cohorts and Interventions

Group / Cohort	Intervention / Treatment
GLP-1RA agonists users; Participants presenting for elective surgery and taking once-weekly semaglutide or dulaglutide as part of their usual treatment with the last dose at least 7 days before surgery	Diagnostic test: Gastric ultrasound; Using a curved array low-frequency abdominal probe (2-5 MHz) with abdominal presets and with the patient in right lateral decubitus position, the gastric antrum will be identified in a standardized plane at the level of the aorta. The stomach will be considered empty if the antrum appears flat or round with anterior and posterior walls collapsed. Normal gastric secretions and clear fluids have an anechoic or hypoechoic aspect on ultrasonography. Solid or thick fluids have a hyperechoic aspect and can create "ring-down" artifacts blurring gastric content, its posterior wall, the pancreas and the aorta. Following qualitative examination, quantitative assessment will be performed if there is presence of clear fluids. The cross-sectional area (CSA) of the antrum will be measured with three measurements to calculate a mean value.
Control group; Participants presenting for elective surgery and not taking semaglutide or dulaglutide	Diagnostic test: Gastric ultrasound; Using a curved array low-frequency abdominal probe (2-5 MHz) with abdominal presets and with the patient in right lateral decubitus position, the gastric antrum will be identified in a standardized plane at the level of the aorta. The stomach will be considered empty if the antrum appears flat or round with anterior and posterior walls collapsed. Normal gastric secretions and clear fluids have an anechoic or hypoechoic aspect on ultrasonography. Solid or thick fluids have a hyperechoic aspect and can create "ring-down" artifacts blurring gastric content, its posterior wall, the pancreas and the aorta. Following qualitative examination, quantitative assessment will be performed if there is presence of clear fluids. The cross-sectional area (CSA) of the antrum will be measured with three measurements to calculate a mean value.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Increased residual gastric content	The primary endpoint will be the prevalence of increased residual gastric content defined by the presence of any of the following: Solid or thick fluid content on gastric ultrasound; Content of more than 1.5 mL/kg of clear fluids on gastric ultrasound using the following formula : Gastric volume (mL) = 27 + [14.6 × right lateral cross-sectional area (in cm2)] - [1.28 × age (in years)]	Preoperative (day of surgery)

Collaborators and Investigators

• Sponsor: Ciusss de L'Est de l'Île de Montréal
• Collaborators: Institut de Cardiologie de Montréal
• Investigators: Principal Investigator: Louis Morisson, MD, MSc, CIUSS de l'Est de l'Île de Montréal

Study record dates

Study Major Dates

• Study Start (Actual): October 9, 2024
• Primary Completion (Actual): February 28, 2025
• Study Completion (Actual): February 28, 2025

Study Registration Dates

• First Submitted: July 8, 2024
• First Submitted That Met QC Criteria: July 8, 2024
• First Posted (Actual): July 15, 2024

Study Record Updates

• Last Update Posted (Estimated): January 16, 2026
• Last Update Submitted That Met QC Criteria: January 15, 2026
• Last Verified: December 1, 2025

More Information

Terms related to this study

• Keywords: diabetes; semaglutide; surgery; weight loss; gastric ultrasound; glucagon-like peptide 1; dulaglutide; increased residual gastric content
• Additional Relevant MeSH Terms: Endocrine System Diseases; Metabolic Diseases; Body Weight; Body Weight Changes; Glucose Metabolism Disorders; Pathological Conditions, Signs and Symptoms; Nutritional and Metabolic Diseases; Signs and Symptoms; Weight Loss; Diabetes Mellitus
• Other Study ID Numbers: MP-12-2025-3794

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No