Gastric RetentionNCT07251803
GLP1 Fasting Status and Gastric Retention Using Gastric Ultrasound
An observational study of Gastric Retention, run by Medical University of South Carolina at 1 site in United States.
Trial 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. Read more about this study
- Who is it for?
- Ages 18 years and older
- Conditions the study is for
- Gastric Retention
- What is being tested?
- Gastric Ultrasound
- How many people
- 150 participants
- Where
- 1 siteUnited States
- Study dates
- 3 Feb 2026to 31 Dec 2026
- Phase
- Observational
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 years and older
- All sexes
- No healthy volunteers
- Adult, Older adult
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.
Who may be able to join
- 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
Who cannot join
- Previous gastric or esophageal surgery
- Abnormal gastric anatomy
- Pregnancy
- Unable to provide written, informed consent
- Non-English speaking
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
United States1 site, 1 recruiting
- Recruiting
Medical University of South Carolina
Charleston, South Carolina, 29425
Haley Nitchie, MHA, 843-792-1869, nitchie@musc.edu
Christopher Wolla, M.D.
About this study
Official title: An Observational Study to Examine Non-inferiority of the Standard ASA Fasting Guidelines Versus 24-hour Clear Liquid Diet for Gastric Volume in Patients Taking GLP-1 Agonists
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.
Read the detailed description
Patients will be classified into one of two groups:
- Taking a GLP-1/GLP-GIP medication and undergoing an elective colonoscopy and have been on a clear liquid diet for the past 24-hours. or
- Taking a GLP-1/GLP-GIP medication and undergoing am elective surgery and have fasted appropriately according to ASA guidelines.
All participants will undergo a gastric ultrasound in the preoperative area prior to their scheduled procedure. This will be completed to determine the amount of retained gastric contents, if any, after fasting properly prior to the procedure. An anesthesiologist attending who is properly trained on performing gastric ultrasounds and listed as a study team member will be the one performing the scan.
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.
If based on the formula: GV (mL) = 27.0+(14.6*CSA)-(1.28*age) the patient is shown to have a gastric volume greater than 1.5mL/kg, or Antral Grade 2, the anesthesiologist assigned to the case will be alerted and will determine whether or not it is safe to continue with the scheduled surgery as the risk for aspiration may be higher based on the gastric ultrasound results.
Qualitative grading of the appearance of the gastric antrum in RLD will be graded as follows:
- Grade 0 antrum appears empty in both positions, and suggests no gastric content is present.
- Grade 1 antrum appears empty in the supine position, but clear fluid is visible in the RLD, consistent with a small volume of gastric fluid.
- Grade 2 antrum is that in which clear fluid is evident in both patient positions, or any solids in any position which is consistent with a higher volume state.
- Conditions
- Gastric Retention
- Being tested
- Gastric Ultrasound
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Gastric UltrasoundDiagnostic 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.
| Study group | Role | What they receive |
|---|---|---|
| ASA fasting guidelines | Scheduled elective surgery and meet ASA fasting guidelines (NPO for at least 8 hours prior) Receives: 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 Receives: Diagnostic Test: Gastric Ultrasound |
What is being measured
The primary outcome is the main question the study is designed to answer.
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).
Measured: From enrollment until completion of pre-operative gastric ultrasound (typically within 3 hours of scheduled procedure).
Secondary outcomes (5)
Perlas antral grade
Qualitative grading of the appearance of the gastric antrum in right lateral decubitus (RLD) will be graded as follows:1
- Grade 0 antrum appears empty in both positions, and suggests no gastric content is present.
- Grade 1 antrum appears empty in the supine position, but clear fluid is visible in the RLD, consistent with a small volume of gastric fluid.
- Grade 2 antrum is that in which clear fluid is evident in both patient positions, or any solids in any position which is consistent with a higher volume state.
Measured: From enrollment until completion of gastric ultrasound (within 3 hours of scheduled procedure).
Incidence of full stomach on gastric ultrasound assessment
Incidence of full stomach defined as solid or thick liquids on US or >1.5mL/kg of clear liquid upon gastric ultrasound.
Measured: From time of enrollment until the start of surgery, up to 24 hours.
Incidence of regurgitation under anesthesia
Measured: From induction of anesthesia until end of surgery (up to 8 hours).
Incidence of change in anesthetic management based on stomach contents
Measured: Assessed at enrollment and during gastric ultrasound (within 3 hours of scheduled procedure).
Differences in "high risk GLP-1" vs "low risk GLP-1"
High Risk includes:
- Escalation Phase: increase in dose within the past 30 days
- High Dose
- Weekly Dosing
- Presence of severe GI symptoms such as nausea, vomiting, or retching, abdominal bloating, or abdominal pain with GLP-1 administration
Low dose and high dose are classified as:
Oral Semaglutide (Rybelsus) Low dose: < 5 mg High dose: > 5 mg
Tirzepatide (Mounjaro and Zepbound) Low dose: 2.5, 5, and 7.5 mg High dose: 10, 12.5, 15 mg
SubQ Semaglutide (Ozempic and Wegovy) Low dose: 0.25 and 0.5 mg High dose: 1 and 2 mg
Dulaglutide (Trulicity) Low dose: 0.75 and 1.5 mg High dose: 3.0 and 4.5 mg
Liraglutide (Victoza) Low dose: 0.6 mg High dose: 1.2 and 1.8 mg
Exenatide (Byetta) Low dose: 5 mcg High dose: 10 mcg
Measured: assessed at time of enrollment from the past 30 days until completion of gastric ultrasound
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted26 Nov 2025
- Study start3 Feb 2026
- Primary completion31 Dec 2026 (estimated)
- Study completion31 Dec 2026 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Gastric RetentionStudies of the same condition, open and under way.
- More trials run by Medical University of South CarolinaThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Observational
- Observational model
- Cohort
- Time perspective
- Prospective
- Enrolment
- 150 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Medical University of South Carolina
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Christopher Wolla, Medical University of South Carolina
- Investigators
- Christopher Wolla, M.D., Principal investigator, Medical University of South Carolina
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07251803
- Sponsor's protocol ID
- Pro00147318
- Status last verified
- Feb 2026
- First submitted
- 11 Nov 2025
- Last updated
- 25 Feb 2026
- Results posted
- No
- Data monitoring committee
- Yes
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
Study at a glance
From the registry record, last updated by the sponsor on 25 Feb 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- An Observational Study to Examine Non-inferiority of the Standard ASA Fasting Guidelines Versus 24-hour Clear Liquid Diet for Gastric Volume in Patients Taking GLP-1 Agonists
- ClinicalTrials.gov ID
- NCT07251803
- Acronym / sponsor ID
- Pro00147318
- Conditions
- Gastric Retention
- Study type
- Observational
- Recruitment status
- Recruiting
- Enrolment
- 150 participants (estimated)
- Lead sponsor
- Medical University of South CarolinaUniversity, hospital or other
- Study start
- 3 Feb 2026 (actual)
- Primary completion
- 31 Dec 2026 (estimated)
- Study completion
- 31 Dec 2026 (estimated)
- First posted
- 26 Nov 2025 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
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.
Detailed description
Patients will be classified into one of two groups:
- Taking a GLP-1/GLP-GIP medication and undergoing an elective colonoscopy and have been on a clear liquid diet for the past 24-hours. or
- Taking a GLP-1/GLP-GIP medication and undergoing am elective surgery and have fasted appropriately according to ASA guidelines.
All participants will undergo a gastric ultrasound in the preoperative area prior to their scheduled procedure. This will be completed to determine the amount of retained gastric contents, if any, after fasting properly prior to the procedure. An anesthesiologist attending who is properly trained on performing gastric ultrasounds and listed as a study team member will be the one performing the scan.
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.
If based on the formula: GV (mL) = 27.0+(14.6*CSA)-(1.28*age) the patient is shown to have a gastric volume greater than 1.5mL/kg, or Antral Grade 2, the anesthesiologist assigned to the case will be alerted and will determine whether or not it is safe to continue with the scheduled surgery as the risk for aspiration may be higher based on the gastric ultrasound results.
Qualitative grading of the appearance of the gastric antrum in RLD will be graded as follows:
- Grade 0 antrum appears empty in both positions, and suggests no gastric content is present.
- Grade 1 antrum appears empty in the supine position, but clear fluid is visible in the RLD, consistent with a small volume of gastric fluid.
- Grade 2 antrum is that in which clear fluid is evident in both patient positions, or any solids in any position which is consistent with a higher volume state.
Study design
- Observational model
- Cohort
- Time perspective
- Prospective
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| ASA fasting guidelines | – | Diagnostic Test: Gastric UltrasoundScheduled elective surgery and meet ASA fasting guidelines (NPO for at least 8 hours prior) |
| 24-hour clear liquid diet | – | Diagnostic Test: Gastric UltrasoundScheduled elective colonoscopy and have been on a clear liquid diet for at least 24 hours prior |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
- 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.
Key inclusion criteria (6 listed)
- 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:
Key exclusion criteria (5 listed)
- Previous gastric or esophageal surgery
- Abnormal gastric anatomy
- Pregnancy
- Unable to provide written, informed consent
- Non-English speaking
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Gastric UltrasoundAll 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. | Diagnostic test | 24-hour clear liquid diet, ASA fasting guidelines |
Primary outcome
Pre-operative gastric volume per unit of weight (ml/kg) as assessed by gastric ultrasound.
Time frame: From enrollment until completion of pre-operative gastric ultrasound (typically within 3 hours of scheduled procedure).
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).
5 secondary outcomes
Perlas antral grade
Time frame: From enrollment until completion of gastric ultrasound (within 3 hours of scheduled procedure).
Incidence of full stomach on gastric ultrasound assessment
Time frame: From time of enrollment until the start of surgery, up to 24 hours.
Incidence of regurgitation under anesthesia
Time frame: From induction of anesthesia until end of surgery (up to 8 hours).
Incidence of change in anesthetic management based on stomach contents
Time frame: Assessed at enrollment and during gastric ultrasound (within 3 hours of scheduled procedure).
Differences in "high risk GLP-1" vs "low risk GLP-1"
Time frame: assessed at time of enrollment from the past 30 days until completion of gastric ultrasound
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 25 Feb 2026.
- Individual participant dataSharing planned: No
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
Christopher Wolla, M.D. principal investigator
Medical University of South Carolina
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
An observational study of Gastric Retention, run by Medical University of South Carolina at 1 site in United States.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 6 inclusion and 5 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: looking for participants now, as of the sponsor's last update on 25 Feb 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in United States. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Haley Nitchie, MHA (843-792-1869, nitchie@musc.edu), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Pre-operative gastric volume per unit of weight (ml/kg) as assessed by gastric ultrasound. (time frame: From enrollment until completion of pre-operative gastric ultrasound (typically within 3 hours of scheduled procedure).). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 25 Feb 2026.