Gastric Ultrasound Versus Gastroscopic Aspiration

NCT07292935 | Not Yet Recruiting

• 1 other identifier: GUSGA-2025
• Study Type: interventional
• Target: 1,390
• Locations: 1 country
• Sites: 1

Brief 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. 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.

Conditions

Aspiration Risk; Full Stomach Status; Gastric Content

Keywords

Gastric Ultrasound; Gastroscopy; Estimated Gastric Volume; Preoperative Evaluation

Outcome Measures

Primary Outcomes (1)

• 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.

  Within 1 hour prior to gastroscopy

Secondary Outcomes (3)

• Correlation coefficient between ultrasound-estimated gastric volume and aspirated gastric content volume during gastroscopy

  Within 1 hour prior to gastroscopy

• Cohen's kappa coefficient for agreement between ultrasound and gastroscopy regarding gastric content nature

  Within 1 hour prior to gastroscopy

• Optimal estimated gastric volume (EGV) threshold for predicting a full stomach

  Within 1 hour prior to gastroscopy

Study Arms (1)

Gastric Ultrasound and Gastroscopy

OTHER

Single Group - Diagnostic Assessment

Diagnostic Test: Gastric Ultrasound

Interventions

Gastric Ultrasound DIAGNOSTIC_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.

Gastric Ultrasound and Gastroscopy

Eligibility Criteria

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

You may qualify if:

• 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

You may not qualify if:

• 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

Sponsors & Collaborators

• Hôpital Fribourgeois: lead

Study Sites (1)

HFR

Villars-sur-Glâne, Canton of Fribourg, 1752, Switzerland

Location

Study Officials

• Hadhami Abdouli, Docteur

  Hôpital Cantonal Fribourgeois

  PRINCIPAL INVESTIGATOR

Central Study Contacts

Hadhami Abdouli, Docteur

CONTACT

+41 26 306 33 91; hadhami.abdouli@h-fr.ch

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: NA
• Masking: NONE
• Purpose: DIAGNOSTIC
• Intervention Model: SINGLE GROUP
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Docteur, Cheffe de clinique Adjointe en anesthésiologie

Model Details: 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.

Study Record Dates

• First Submitted: December 6, 2025
• First Posted: December 18, 2025
• Study Start: February 1, 2026
• Primary Completion (Estimated): January 31, 2027
• Study Completion (Estimated): January 31, 2027
• Last Updated: December 24, 2025

Record last verified: 2025-12

Data Sharing

• IPD Sharing: Will share
• Shared Documents: STUDY PROTOCOL, SAP
• Time Frame: Starte Date: After publication of the study results End Date: 5 years after publication
• Access Criteria: Researchers who submit a reasonable request for research purposes. Requests should be sent via email to the corresponding author. Access will be granted only after the request has been reviewed and approved by the study team. All shared data will be anonymized to protect participant confidentiality. The data and documents can be used solely for scientific research, and recipients are expected not to attempt to identify individual participants.

Locations

CH (1)