GLP1 Fasting Status and Gastric Retention Using Gastric Ultrasound

NCT07251803 | Recruiting DMC

• 1 other identifier: Pro00147318
• Study Type: observational
• Target: 150
• Locations: 1 country
• Sites: 1

Brief Summary

This study will enroll patients 18 years and older who are taking a GLP-1/GIP medication and 1) are scheduled for elective surgery and meet ASA fasting guidelines (nothing by mouth for at least 8 hours prior), or 2) scheduled elective colonoscopy and have been on a clear liquid diet for at least 24 hours prior. Participants will have a gastric ultrasound prior to surgery to measure any retained gastric contents. The purpose of this study is to determine if people taking GLP-1 receptor agonists and who fast normally are at an equal risk for having retained gastric contents after appropriately fasting for surgery, compared to patients who are on a liquid only diet for 24 hours prior to surgery.

Conditions

Gastric Retention

Outcome Measures

Primary Outcomes (1)

• Pre-operative gastric volume per unit of weight (ml/kg) as assessed by gastric ultrasound.

  While the patient is in supine position, the gastric volume will be measured via ultrasound and then calculated using a validated formula, GV (mL) = 27.0+(14.6\*CSA)-(1.28\*age).

  From enrollment until completion of pre-operative gastric ultrasound (typically within 3 hours of scheduled procedure).

Secondary Outcomes (5)

• Perlas antral grade

  From enrollment until completion of gastric ultrasound (within 3 hours of scheduled procedure).

• Incidence of full stomach on gastric ultrasound assessment

  From time of enrollment until the start of surgery, up to 24 hours.

• Incidence of regurgitation under anesthesia

  From induction of anesthesia until end of surgery (up to 8 hours).

• Incidence of change in anesthetic management based on stomach contents

  Assessed at enrollment and during gastric ultrasound (within 3 hours of scheduled procedure).

• Differences in "high risk GLP-1" vs "low risk GLP-1"

  assessed at time of enrollment from the past 30 days until completion of gastric ultrasound

Study Arms (2)

ASA fasting guidelines

Scheduled elective surgery and meet ASA fasting guidelines (NPO for at least 8 hours prior)

Diagnostic Test: Gastric Ultrasound

24-hour clear liquid diet

Scheduled elective colonoscopy and have been on a clear liquid diet for at least 24 hours prior

Diagnostic Test: Gastric Ultrasound

Interventions

Gastric Ultrasound DIAGNOSTIC_TEST

All participants will undergo a gastric ultrasound in the preoperative area prior to their scheduled procedure. The patient will be placed in supine position. A curvilinear ultrasound probe will be placed on the sagittal plane below the xiphoid process. The probe will then slide along the costal margin to the right until the gastric antrum is identified. At this point, the ultrasound image will be obtained, and appropriate measurements will be taken. The patient will be placed in the right lateral decubitus position (RLD), and the above procedure will be repeated. The measurement of gastric antral cross-sectional area while in the RLD position will be recorded and used to calculate the gastric volume.

24-hour clear liquid diet; ASA fasting guidelines

Eligibility Criteria

• Age: 18 Years+
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)
• Sampling Method: Non-Probability Sample

Study Population

This study will consist of patients who have taken a GLP-1 or GLP-GIP agonist medication within the past 30 days, and are scheduled for either an elective surgery and appropriately NPO for at least 8 hours prior, or scheduled for elective colonoscopy and have been on a clear liquid diet for at least 24 hours prior.

You may qualify if:

• Age 18+
• Have taken a GLP-1 or GLP-GIP agonist medication within the past 30 days
• ASA Physical Classification Status 1-3
• Fall into one of the following groups:
• Scheduled elective surgery and meet ASA fasting guidelines (NPO for at least 8 hours prior)
• Scheduled elective colonoscopy and have been on a clear liquid diet for at least 24 hours prior

You may not qualify if:

• Previous gastric or esophageal surgery
• Abnormal gastric anatomy
• Pregnancy
• Unable to provide written, informed consent
• Non-English speaking

Sponsors & Collaborators

• Medical University of South Carolina: lead

Study Sites (1)

Medical University of South Carolina

Charleston, South Carolina, 29425, United States

RECRUITING

Study Officials

• Christopher Wolla, M.D.

  Medical University of South Carolina

  PRINCIPAL INVESTIGATOR

Central Study Contacts

Haley Nitchie, MHA

CONTACT

843-792-1869; nitchie@musc.edu

Study Design

• Study Type: observational
• Observational Model: COHORT
• Time Perspective: PROSPECTIVE
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Assistant Professor-Faculty

Study Record Dates

• First Submitted: November 11, 2025
• First Posted: November 26, 2025
• Study Start: February 3, 2026
• Primary Completion (Estimated): December 31, 2026
• Study Completion (Estimated): December 31, 2026
• Last Updated: February 25, 2026

Record last verified: 2026-02

Data Sharing

• IPD Sharing: Will not share

Locations

US (1)