Aspiration RiskGUSGANCT07292935
Gastric Ultrasound Versus Gastroscopic Aspiration
A study testing Gastric Ultrasound in people with Aspiration Risk and Full Stomach Status, run by Hôpital Fribourgeois at 1 site in Switzerland.
Trial summary
This is a prospective, single-center observational study conducted at the Fribourg Cantonal Hospital to evaluate the diagnostic performance of preoperative gastric ultrasound in determining gastric content and volume. Read more about this study
- Who is it for?
- Ages 18 years and older
- Conditions the study is for
- Aspiration Risk, Full Stomach Status, Gastric Content
- What is being tested?
- Gastric Ultrasound
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 1,390 participants
- Where
- 1 siteSwitzerland
- Study dates
- Feb 2026to 31 Jan 2027
- Phase
- Interventional
- 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
Who may be able to join
- Adults aged ≥ 18 years
- Indication for gastroscopy (scheduled or urgent), allowing complete aspiration of gastric contents
- Feasibility of performing gastric ultrasound within one hour prior to the endoscopic procedure
- Provision of written informed consent
Who cannot join
- Pregnancy
- History of major gastric or esophageal surgery
- Known disorders of gastric emptying (e.g., gastroparesis, gastric outlet obstruction)
- Cognitive impairment or language barriers preventing understanding of the study protocol
- Active vomiting or technical impossibility to aspirate gastric contents
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
Switzerland1 site
HFR
Villars-sur-Glâne, Canton of Fribourg, 1752
hadhami Abdouli, Docteur, +41 26 306 33 91 ext. 63391, hadhami.abdouli@h-fr.ch
hadhamiabdouli@gmail.com
About this study
Official title: Diagnostic Performance of Preoperative Gastric Ultrasound Compared to Gastroscopic Aspiration: A Prospective Clinical Study
This is a prospective, single-center observational study conducted at the Fribourg Cantonal Hospital to evaluate the diagnostic performance of preoperative gastric ultrasound in determining gastric content and volume. Upper gastrointestinal endoscopy with complete suction of gastric contents serves as the reference standard.
Adult patients (≥ 18 years) scheduled for elective or urgent gastroscopy are consecutively recruited. A gastric ultrasound is performed within one hour before the endoscopic procedure. The antral cross-sectional area is measured in standardized positions (supine and right lateral decubitus), and gastric volume is estimated using validated formulas. Gastric content is categorized into three grades (empty, low-risk liquid content, or high-risk/solid content).
Read more
During gastroscopy, complete aspiration of gastric contents is performed at the start of the procedure. The aspirated volume and qualitative characteristics (liquid vs. solid) are recorded, and the stomach is classified as empty, partially full, or full by the endoscopist.
The primary objective is to determine the accuracy of gastric ultrasound in identifying a full stomach. Secondary objectives include evaluating the qualitative agreement between ultrasound and gastroscopy, correlating estimated gastric volume with aspirated volume, and identifying an optimal ultrasound-based volume threshold predictive of a full stomach.
Approximately 1,390 patients will be enrolled over one year to obtain at least 139 "full stomach" cases, based on prevalence estimates and sample size calculations. Statistical analyses will include diagnostic performance metrics, Cohen's kappa, correlation tests, Bland-Altman plots, and ROC curve analysis.
Read the detailed description
Study Procedure and Conduct Each participant enrolled in the study will undergo a standardized two-step assessment protocol, consisting of a preoperative gastric ultrasound followed by a gastroscopy with complete aspiration of gastric contents. These procedures will be performed within a maximum interval of one hour, and conducted at Fribourg Cantonal Hospital within the Departments of Anesthesiology and Gastroenterology. All examinations will be performed by trained and credentialed operators, adhering to validated clinical protocols.
Following the acquisition of written informed consent, baseline demographic and clinical data will be collected. Gastric ultrasound will then be performed using a portable ultrasound device equipped with a low-frequency curvilinear transducer. The patient will be positioned sequentially in the supine and right lateral decubitus positions, with the upper body inclined at 45°, to obtain sagittal views of the gastric antrum. Antral diameters (antero-posterior and cranio-caudal) will be measured in each position, and the cross-sectional antral area (CSA) will be calculated accordingly. The estimated gastric volume (EGV) will be derived using the validated formula proposed by Perlas et al. Gastric contents will be classified into three qualitative grades (Grade 0 to 2), enabling stratification of aspiration risk.
Within one hour of the ultrasound, a diagnostic gastroscopy will be performed by an experienced gastroenterologist, following routine clinical practice. Immediately upon endoscope insertion and prior to any irrigation, complete aspiration of gastric contents will be performed to allow accurate measurement of the intragastric volume. The contents will be assessed macroscopically for appearance (e.g., clear, cloudy, bilious, alimentary) and consistency (liquid or solid). The aspirated volume will be quantified using a calibrated, graduated container. Based on visual assessment, the stomach will be classified as empty, partially full, or full.
All collected data will be documented using standardized case report forms and entered into a secure, anonymized database for subsequent statistical analysis.
- Conditions
- Aspiration Risk, Full Stomach Status, Gastric Content
- Being tested
- Gastric Ultrasound
- Keywords
- Gastric Ultrasound, Gastroscopy, Estimated Gastric Volume, Preoperative Evaluation
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Gastric UltrasoundDiagnostic test
All enrolled participants undergo a preoperative gastric ultrasound within one hour prior to the scheduled gastroscopy. The gastric antrum is measured in standardized positions, and estimated gastric volume is calculated.
| Study group | Role | What they receive |
|---|---|---|
| Gastric Ultrasound and Gastroscopy | Other | Single Group - Diagnostic Assessment Receives: Diagnostic Test: Gastric Ultrasound |
What is being measured
The primary outcome is the main question the study is designed to answer.
the diagnostic accuracy of gastric ultrasound in identifying a full stomach, using gastroscopy with aspiration as the reference standard.
Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and overall accuracy of preoperative gastric ultrasound in identifying a full stomach, compared to gastroscopy with complete aspiration of gastric contents. Gastric content is classified as empty, low-risk liquid content, or high-risk/solid content.
Measured: Within 1 hour prior to gastroscopy
Secondary outcomes (3)
Correlation coefficient between ultrasound-estimated gastric volume and aspirated gastric content volume during gastroscopy
Gastric volume is estimated by preoperative ultrasound and compared with the volume of gastric content aspirated during gastroscopy. The Pearson or Spearman correlation coefficient is calculated depending on data distribution.
Measured: Within 1 hour prior to gastroscopy
Cohen's kappa coefficient for agreement between ultrasound and gastroscopy regarding gastric content nature
Agreement between gastric ultrasound and gastroscopy for classification of gastric content nature (clear liquid, turbid liquid, solid) is assessed using Cohen's kappa coefficient.
Measured: Within 1 hour prior to gastroscopy
Optimal estimated gastric volume (EGV) threshold for predicting a full stomach
Determination of the optimal threshold of estimated gastric volume (EGV) measured by preoperative ultrasound for predicting a full stomach, using receiver operating characteristic (ROC) curve analysis. Sensitivity, specificity, and area under the ROC curve (AUC) will be calculated.
Measured: Within 1 hour prior to gastroscopy
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted18 Dec 2025
- Study startFeb 2026 (estimated)
- Primary completion31 Jan 2027 (estimated)
- Study completion31 Jan 2027 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Aspiration RiskStudies of the same condition, open and under way.
- 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
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Diagnosis
- Allocation
- Not applicable
- Intervention model
- Single group
- Model description
- This is a prospective, single-group observational study in which all participants undergo both the index test (preoperative gastric ultrasound) and the reference standard (gastroscopy with complete aspiration). Gastric ultrasound is performed within one hour prior to gastroscopy. No randomization or parallel groups are involved. The study is designed to evaluate the diagnostic accuracy of ultrasound in detecting a full stomach and to compare estimated gastric volume with aspirated gastric volume.
- Masking
- None (open label)
- Enrolment
- 1,390 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Hôpital Fribourgeois
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Abdouli Hadhami, Hôpital Fribourgeois
- Investigators
- Hadhami Abdouli, Docteur, Principal investigator, Hôpital Cantonal Fribourgeois
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07292935
- Sponsor's protocol ID
- GUSGA-2025
- Acronym
- GUSGA
- Status last verified
- Dec 2025
- First submitted
- 6 Dec 2025
- Last updated
- 24 Dec 2025
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- Yes: The shared individual participant data (IPD) will include only the data used in the publication of the study results, specifically: * Gastric ultrasound measurements (antral cross-sectional area, estimated gastric volume, gastric content grade) * Gastroscopy findings (aspirated gastric volume, qualitative gastric content classification) * Basic participant characteristics (age, sex, weight)
Study at a glance
From the registry record, last updated by the sponsor on 24 Dec 2025. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Diagnostic Performance of Preoperative Gastric Ultrasound Compared to Gastroscopic Aspiration: A Prospective Clinical Study
- ClinicalTrials.gov ID
- NCT07292935
- Acronym / sponsor ID
- GUSGA / GUSGA-2025
- Conditions
- Aspiration Risk, Full Stomach Status, Gastric Content
- Keywords
- Gastric Ultrasound, Gastroscopy, Estimated Gastric Volume, Preoperative Evaluation
- Study type
- Interventional
- Recruitment status
- Not yet recruiting
- Enrolment
- 1,390 participants (estimated)
- Lead sponsor
- Hôpital FribourgeoisUniversity, hospital or other
- Study start
- Feb 2026 (estimated)
- Primary completion
- 31 Jan 2027 (estimated)
- Study completion
- 31 Jan 2027 (estimated)
- First posted
- 18 Dec 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 is a prospective, single-center observational study conducted at the Fribourg Cantonal Hospital to evaluate the diagnostic performance of preoperative gastric ultrasound in determining gastric content and volume. Upper gastrointestinal endoscopy with complete suction of gastric contents serves as the reference standard.
Adult patients (≥ 18 years) scheduled for elective or urgent gastroscopy are consecutively recruited. A gastric ultrasound is performed within one hour before the endoscopic procedure. The antral cross-sectional area is measured in standardized positions (supine and right lateral decubitus), and gastric volume is estimated using validated formulas. Gastric content is categorized into three grades (empty, low-risk liquid content, or high-risk/solid content).
During gastroscopy, complete aspiration of gastric contents is performed at the start of the procedure. The aspirated volume and qualitative characteristics (liquid vs. solid) are recorded, and the stomach is classified as empty, partially full, or full by the endoscopist.
The primary objective is to determine the accuracy of gastric ultrasound in identifying a full stomach. Secondary objectives include evaluating the qualitative agreement between ultrasound and gastroscopy, correlating estimated gastric volume with aspirated volume, and identifying an optimal ultrasound-based volume threshold predictive of a full stomach.
Approximately 1,390 patients will be enrolled over one year to obtain at least 139 "full stomach" cases, based on prevalence estimates and sample size calculations. Statistical analyses will include diagnostic performance metrics, Cohen's kappa, correlation tests, Bland-Altman plots, and ROC curve analysis.
Detailed description
Study Procedure and Conduct Each participant enrolled in the study will undergo a standardized two-step assessment protocol, consisting of a preoperative gastric ultrasound followed by a gastroscopy with complete aspiration of gastric contents. These procedures will be performed within a maximum interval of one hour, and conducted at Fribourg Cantonal Hospital within the Departments of Anesthesiology and Gastroenterology. All examinations will be performed by trained and credentialed operators, adhering to validated clinical protocols.
Following the acquisition of written informed consent, baseline demographic and clinical data will be collected. Gastric ultrasound will then be performed using a portable ultrasound device equipped with a low-frequency curvilinear transducer. The patient will be positioned sequentially in the supine and right lateral decubitus positions, with the upper body inclined at 45°, to obtain sagittal views of the gastric antrum. Antral diameters (antero-posterior and cranio-caudal) will be measured in each position, and the cross-sectional antral area (CSA) will be calculated accordingly. The estimated gastric volume (EGV) will be derived using the validated formula proposed by Perlas et al. Gastric contents will be classified into three qualitative grades (Grade 0 to 2), enabling stratification of aspiration risk.
Within one hour of the ultrasound, a diagnostic gastroscopy will be performed by an experienced gastroenterologist, following routine clinical practice. Immediately upon endoscope insertion and prior to any irrigation, complete aspiration of gastric contents will be performed to allow accurate measurement of the intragastric volume. The contents will be assessed macroscopically for appearance (e.g., clear, cloudy, bilious, alimentary) and consistency (liquid or solid). The aspirated volume will be quantified using a calibrated, graduated container. Based on visual assessment, the stomach will be classified as empty, partially full, or full.
All collected data will be documented using standardized case report forms and entered into a secure, anonymized database for subsequent statistical analysis.
Study design
- Primary purpose
- Diagnosis
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Number of arms
- 1
- Model description
- This is a prospective, single-group observational study in which all participants undergo both the index test (preoperative gastric ultrasound) and the reference standard (gastroscopy with complete aspiration). Gastric ultrasound is performed within one hour prior to gastroscopy. No randomization or parallel groups are involved. The study is designed to evaluate the diagnostic accuracy of ultrasound in detecting a full stomach and to compare estimated gastric volume with aspirated gastric volume.
| Arm | Type | Receives |
|---|---|---|
| Gastric Ultrasound and Gastroscopy | Other | Diagnostic Test: Gastric UltrasoundSingle Group - Diagnostic Assessment |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (4 listed)
- Adults aged ≥ 18 years
- Indication for gastroscopy (scheduled or urgent), allowing complete aspiration of gastric contents
- Feasibility of performing gastric ultrasound within one hour prior to the endoscopic procedure
- Provision of written informed consent
Key exclusion criteria (5 listed)
- Pregnancy
- History of major gastric or esophageal surgery
- Known disorders of gastric emptying (e.g., gastroparesis, gastric outlet obstruction)
- Cognitive impairment or language barriers preventing understanding of the study protocol
- Active vomiting or technical impossibility to aspirate gastric contents
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 enrolled participants undergo a preoperative gastric ultrasound within one hour prior to the scheduled gastroscopy. The gastric antrum is measured in standardized positions, and estimated gastric volume is calculated. | Diagnostic test | Gastric Ultrasound and Gastroscopy |
Primary outcome
the diagnostic accuracy of gastric ultrasound in identifying a full stomach, using gastroscopy with aspiration as the reference standard.
Time frame: Within 1 hour prior to gastroscopy
Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and overall accuracy of preoperative gastric ultrasound in identifying a full stomach, compared to gastroscopy with complete aspiration of gastric contents. Gastric content is classified as empty, low-risk liquid content, or high-risk/solid content.
3 secondary outcomes
Correlation coefficient between ultrasound-estimated gastric volume and aspirated gastric content volume during gastroscopy
Time frame: Within 1 hour prior to gastroscopy
Cohen's kappa coefficient for agreement between ultrasound and gastroscopy regarding gastric content nature
Time frame: Within 1 hour prior to gastroscopy
Optimal estimated gastric volume (EGV) threshold for predicting a full stomach
Time frame: Within 1 hour prior to gastroscopy
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 24 Dec 2025.
- Individual participant dataSharing planned: Yes. The shared individual participant data (IPD) will include only the data used in the publication of the study results, specifically: * Gastric ultrasound measurements (antral cross-sectional area, estimated gastric volume, gastric content grade) * Gastroscopy findings (aspirated gastric volume, qualitative gastric content classification) * Basic participant characteristics (age, sex, weight)
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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.
Hadhami Abdouli, Docteur principal investigator
Hôpital Cantonal Fribourgeois
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Gastric Ultrasound in people with Aspiration Risk and Full Stomach Status, run by Hôpital Fribourgeois at 1 site in Switzerland.
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 4 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: opening soon, as of the sponsor's last update on 24 Dec 2025. 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 Switzerland. 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 Hadhami Abdouli, Docteur (+41 26 306 33 91 ext. 63391, hadhami.abdouli@h-fr.ch), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
the diagnostic accuracy of gastric ultrasound in identifying a full stomach, using gastroscopy with aspiration as the reference standard. (time frame: Within 1 hour prior to gastroscopy). 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 24 Dec 2025.