Gastric Ultrasound Assessment for Patients Taking GLP1 Agonists

Assessment of Preoperative Gastric Content With Ultrasound in Patients Taking GLP1 Agonists

The aim of this study is to perform bedside gastric point of care ultrasound (POCUS) exams to assess the gastric volume and content (clear liquids vs solid food) perioperatively in patients who take glucagon-like peptide 1 (GLP-1) agonist medications compared to patients who do not take GLP-1 agonists.

Study Overview

• Status: Completed
• Conditions: Glucagon-like Peptide 1; Gastric Ultrasound; Point of Care Ultrasound
• Intervention / Treatment: Other: Gastric Ultrasound Exam

Detailed Description

Glucagon-like peptide 1 (GLP-1) agonists have existed since 2005, however the newer once-weekly injectable medications particularly semaglutide, and tirzepatide have exploded in popularity due to their weight loss potential.

Anesthesiologists nationally have seen an increase in perioperative complications amongst patients taking these medications due to delayed gastric emptying increasing the risk of aspiration in the perioperative period. At HSS the majority of our anesthetics are done under sedation and therefore would not protect the patient from aspiration in the event of vomiting.

Protecting patients from aspiration secondary to vomiting during induction or maintenance of anesthesia has always been an important goal to make anesthesia safer leading to the development of NPO guidelines which are intended to protect against the presence of gastric content during anesthetic care. However there is growing concern that patients taking GLP-1 agonists may not be adequately protected using the current nothing by mouth or "NPO" guidelines. Up to this day there is no literature on how much gastric emptying is delayed during the use of GLP1 following the standard NPO guidelines.

Recently Gastric Ultrasound (GUS) has been introduced as a bedside tool for assessing a patients stomach contents and for the risk of aspiration. Gastric ultrasound can identify an empty stomach, a stomach filled with clear liquids, thick liquids or solid food content. If a stomach has clear liquid the volume can be calculated accurately. Generally a stomach with solid or thick liquid content or with clear liquid measuring more than 1.5 ml/kg body weight is considered a full stomach. As GUS is noninvasive and well tolerated, it offers the perfect solution to assessing patient risk in the preoperative period.

• Study Type: Observational
• Enrollment (Actual): 354

Contacts and Locations

Study Locations

• Canada
  • Ontario
    • Toronto, Ontario, Canada, M5G 2C4
      • University Health Network
• United States
  • District of Columbia
    • Washington D.C., District of Columbia, United States, 20037
      • George Washington University Hospital
  • Florida
    • Jacksonville, Florida, United States, 32224
      • Mayo Clinic
  • New York
    • Albany, New York, United States, 12208
      • Albany Medical Center
    • New York, New York, United States, 10065
      • Weill Cornell Medicine
    • New York, New York, United States, 10065
      • Memorial Sloan Kettering Cancer Center
    • New York, New York, United States, 10021
      • Hospital for Special Surgery
  • Virginia
    • Charlottesville, Virginia, United States, 22903
      • University of Virginia

Participation Criteria

Eligibility Criteria

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

• Sampling Method: Non-Probability Sample

Study Population

The study population will be comprised of patients scheduled for surgery at HSS who meet the following inclusion criteria and none of the exclusion criteria.

Description

Inclusion Criteria:

• GLP 1 patient group: any patient on GLP1 agonists that are dosed once per week (semaglutide, dulaglutide, tirzepatide), for all indications.
• Control group (No GLP 1 patients): any patient not on GLP1 agonists that are dosed once per week, for all indications.

Exclusion Criteria:

• patient refusal to participate
• patients with gastric bypass or any other gastric surgery
• large hiatal hernia
• patients with large ascites
• patients on peritoneal dialysis
• emergency surgery
• pre-existing diagnosis of gastroparesis

Study Plan

How is the study designed?

Number of groups / cohorts

2

Cohorts and Interventions

Group / Cohort	Intervention / Treatment
Control; The control group will be comprised of patients who are not currently taking any GLP-1 agonist medications. Controls will receive the ultrasound exam to assess stomach contents.	Other: Gastric Ultrasound Exam; A gastric ultrasound is a simple, fast, non-invasive bedside diagnostic test that provides a qualitative and quantitative assessment of gastric contents. There are no known risks of a gastric ultrasound exam.
GLP-1 agonist intake; The GLP-1 agonist intake group will be comprised of patients who are currently taking any GLP-1 agonist medications. This group will receive the ultrasound exam to assess stomach contents.	Other: Gastric Ultrasound Exam; A gastric ultrasound is a simple, fast, non-invasive bedside diagnostic test that provides a qualitative and quantitative assessment of gastric contents. There are no known risks of a gastric ultrasound exam.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
incidence of delayed gastric emptying	delayed gastric emptying is defined by the presence of either solid food, thick liquids or a specific volume (>1.5 ml/kg) of clear liquids on gastric ultrasound.	This will be measured pre-operatively in the holding room area.

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Nothing by mouth (NPO) intervals	Measure the NPO interval after last solid, liquids, and clears precisely for a subgroup analysis.	This will be measured pre-operatively in the holding room area.
Presence of gastric peristalsis	Gastric peristalsis will be graded as present/ absent on gastric ultrasound	This will be measured pre-operatively in the holding room area.

Collaborators and Investigators

• Sponsor: Hospital for Special Surgery, New York
• Investigators: Principal Investigator: Oliver Panzer, MD, Hospital for Special Surgery, Department of Anesthesiology

Publications and helpful links

General Publications

• Nakatani Y, Maeda M, Matsumura M, Shimizu R, Banba N, Aso Y, Yasu T, Harasawa H. Effect of GLP-1 receptor agonist on gastrointestinal tract motility and residue rates as evaluated by capsule endoscopy. Diabetes Metab. 2017 Oct;43(5):430-437. doi: 10.1016/j.diabet.2017.05.009. Epub 2017 Jun 23.
• Silveira SQ, da Silva LM, de Campos Vieira Abib A, de Moura DTH, de Moura EGH, Santos LB, Ho AM, Nersessian RSF, Lima FLM, Silva MV, Mizubuti GB. Relationship between perioperative semaglutide use and residual gastric content: A retrospective analysis of patients undergoing elective upper endoscopy. J Clin Anesth. 2023 Aug;87:111091. doi: 10.1016/j.jclinane.2023.111091. Epub 2023 Mar 2.
• Maselli DB, Camilleri M. Effects of GLP-1 and Its Analogs on Gastric Physiology in Diabetes Mellitus and Obesity. Adv Exp Med Biol. 2021;1307:171-192. doi: 10.1007/5584_2020_496.

Study record dates

Study Major Dates

• Study Start (Actual): August 29, 2023
• Primary Completion (Actual): January 31, 2025
• Study Completion (Actual): February 1, 2025

Study Registration Dates

• First Submitted: August 15, 2023
• First Submitted That Met QC Criteria: August 15, 2023
• First Posted (Actual): August 22, 2023

Study Record Updates

• Last Update Posted (Actual): November 26, 2025
• Last Update Submitted That Met QC Criteria: November 19, 2025
• Last Verified: November 1, 2024

More Information

Terms related to this study

• Keywords: gastric ultrasound; GLP1
• Other Study ID Numbers: 2023-0867

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
• product manufactured in and exported from the U.S.: No