Semaglutide and Preoperative Residual Gastric Volumes

Mitigating Harm: Assessing Preoperative Residual Gastric Volumes to Risk Stratify Patients Administering Semaglutide

Given the pharmacodynamic and pharmacokinetic properties of glucagon-like peptide-1 (GLP-1) agonists, the Canadian Anesthesiologists' Society has recognized that patients on GLP-1 agonists may have an increased aspiration risk due to a 'full stomach,' even after following preoperative fasting guidelines. In other words, safe fasting timelines are not known in individuals taking GLP-1 agonists, as demonstrated by recent case reports of patients who either retained or regurgitated stomach contents despite being adequately fasted.

To address this gap, we plan to measure preoperative residual gastric volumes with point-of-care ultrasound (POCUS) in patients taking this medication. The priority is to first gather data to identify which patient populations need risk stratification and to then use this data to support the development of specific guidelines that reduce anesthetic complications, such as aspiration pneumonia.

Our primary objective is to use POCUS preoperatively to assess gastric volumes of fasted patients to demonstrate if there is a clinically significant increase in residual gastric volumes in patients on semaglutide.

Study Overview

• Status: Completed
• Conditions: Pulmonary Aspiration
• Intervention / Treatment: Device: gastric antral sonography

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

Contacts and Locations

Study Locations

• Canada
  • Alberta
    • Calgary, Alberta, Canada, T3M 1M4
      • South Health Campus

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

• Sampling Method: Non-Probability Sample

Study Population

Elective surgical patients meeting inclusion/exclusion criteria at the South Health Campus (Calgary, AB, Canada)

Description

Inclusion Criteria:

• all elective surgical patients (> 18 years of age)
• followed institutional fasting protocol for surgery
• patients taking GLP-1 receptor agonist (subcutaneous for weight management and/or blood glucose control in type II diabetes mellitus, N = 45)
• patients not taking GLP-1 receptor agonist (N =45)

Exclusion Criteria:

• confounding delayed gastric emptying due to pregnancy
• previous esophageal or gastric operation
• etiologies at increased risk for delayed gastric emptying (hiatal hernia, Parkinson's disease, scleroderma, multiple sclerosis, and amyloidosis)
• on medication that could potentially cause gastroparesis or delayed gastric or intestinal emptying (opioids, proton pump inhibitors, tricyclic antidepressants, calcium channel blockers, antipsychotic medications, loperamide, diphenoxylate, oxybutynin, hyoscine butylbromide, scopolamine, promethazine, glycopyrrolate, atropine, chlordiazepoxide, and lithium)

Study Plan

How is the study designed?

Number of groups / cohorts

2

Cohorts and Interventions

Group / Cohort	Intervention / Treatment
GLP-1 Agonist Group; Intervention: elective surgical patients taking GLP-1 receptor agonists	Device: gastric antral sonography; Participant will undergo gastric antrum ultrasound and be scanned in the supine position followed by the right lateral decubitus position. Qualitative and quantitative assessments will be completed.
Non GLP-1 Agonist Group; Intervention: elective surgical patients not taking GLP-1 receptor agonists	Device: gastric antral sonography; Participant will undergo gastric antrum ultrasound and be scanned in the supine position followed by the right lateral decubitus position. Qualitative and quantitative assessments will be completed.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Number of participants presenting with a full stomach	Full stomach defined as either clear fluid > 1.5ml/kg or solid content found with point-of-care gastric antral sonography.	Measured in the preoperative holding area

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Number of occurrences requiring change in anesthetic management plan	Changes in plan include those from laryngeal mask airway to more advanced endotracheal tube with rapid sequence induction and intubation or spinal anesthetic without sedation to administration of a general anesthetic.	From time of preoperative ultrasound in holding area to anesthesia induction in operating room
Relationship between dose, duration and timing of GLP-1 receptor agonist and gastric volume	Explore if dose, duration, and timing of GLP-1 receptor agonist affects gastric volume	Measured in the preoperative holding area
Relationship between gastric emptying and purpose of GLP-1 receptor agonist administration	Explore if GLP-1 receptor agonist impacts gastric emptying different in patients administering for Type II diabetes mellitus or weight management	Measured in the preoperative holding area

Collaborators and Investigators

• Sponsor: University of Calgary
• Collaborators: Alberta Health services

Study record dates

Study Major Dates

• Study Start (Actual): May 31, 2024
• Primary Completion (Actual): May 16, 2025
• Study Completion (Actual): May 16, 2025

Study Registration Dates

• First Submitted: January 31, 2024
• First Submitted That Met QC Criteria: February 8, 2024
• First Posted (Actual): February 16, 2024

Study Record Updates

• Last Update Posted (Actual): April 28, 2026
• Last Update Submitted That Met QC Criteria: April 27, 2026
• Last Verified: April 1, 2026

More Information

Terms related to this study

• Other Study ID Numbers: REB23-1754

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

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