Body Position and Ultrasound Examination of the Gastric Antrum (POSIGAST)

August 26, 2025 updated by: Hospices Civils de Lyon

Diagnostic Performance of the Ultrasound Examination of the Antrum to Detect a Full Stomach According to the Position of the Patient

Pulmonary aspiration of gastric contents is a complication causing significant morbidity and mortality related to anesthesia. Ultrasound examination of the gastric antrum allows the detection of preoperative gastric contents contributing to the preoperative assessment of pulmonary aspiration risk. In particular, this examination is based on the qualitative analysis of gastric contents performed in the supine and in the right lateral decubitus, using a qualitative score which makes it possible to discriminate a low liquid content of a large liquid volume. This score has been described in patients and volunteers installed on a bed without elevation of the upper section of the bed. However, in several studies, this qualitative score has been achieved in the 45° semirecumbent position, which may have affected the diagnostic performance of the examination thus performed, as suggested by the results of a study recently conducted by the investigating team. This study therefore aims to compare the diagnostic performance of the qualitative analysis of the gastric antrum performed in the supine and the right lateral decubitus for the diagnosis of gastric volumes higher than 50 ml and 100 ml, according to the bed angle: 45 ° elevation or no elevation of the upper section of the bed.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Completed

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

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Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Interventional

Enrollment (Actual)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
21

Phase

Phase

The stage of a clinical trial studying a drug or biological product, based on definitions developed by the U.S. Food and Drug Administration (FDA). The phase is based on the study's objective, the number of participants, and other characteristics. There are five phases: Early Phase 1 (formerly listed as Phase 0), Phase 1, Phase 2, Phase 3, and Phase 4. Not Applicable is used to describe trials without FDA-defined phases, including trials of devices or behavioral interventions.
  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • France
      • Bron, France, 69500
        • Hospices Civils de Lyon

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

18 years and older (Adult, Older Adult)

Accepts Healthy Volunteers

Yes

Description

Inclusion Criteria:

  • Adults 18 years old or older
  • Last consumption of solids at least 6 hours before the start of the study, last consumption of clear fluids at least 2 hours before the start of the study
  • Informed consent must have been signed.
  • No significant medical history (American Society of Anesthesiologists (ASA) class 1)

Exclusion Criteria:

  • Adult unable to give informed consent
  • Previous gastrointestinal surgery
  • Medication affecting gastric motility
  • Digestive diseases, gastroparesis, diabetes mellitus with insulin
  • Pregnancy or breastfeeding
  • Obesity (Body Mass Index (BMI) ≥ 30 kilograms/meter² (kg/m²))

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Basic Science
  • Allocation: Randomized
  • Interventional Model: Crossover Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm

Participant Group / Arm

A group or subgroup of participants in a clinical trial that receives a specific intervention/treatment, or no intervention, according to the trial's protocol.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
Active Comparator: 45° semirecumbent position
Other: Qualitative and quantitative assessment of gastric content volume with bed elevation
Ultrasound examination of the gastric antrum are performed 3 minutes after the ingestion of a volume of water (either 0, 50, 100, 150, or 200 milliliters (ml), determined by randomization). The procedure is repeated three times (three different volumes, the same volumes for each session with randomized order for each session).
Active Comparator: No elevation of the upper section of the bed
Other: Qualitative and quantitative assessment of gastric content volume without bed elevation
Ultrasound examination of the gastric antrum are performed 3 minutes after the ingestion of a volume of water (either 0, 50, 100, 150, or 200 milliliters (ml), determined by randomization). The procedure is repeated three times (three different volumes, the same volumes for each session with randomized order for each session).

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
Calculation of the sensitivity
Time Frame: 3 minutes
Diagnostic performance of the qualitative examination of the gastric antrum in the 45° semirecumbent position.
3 minutes

Secondary Outcome Measures

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
Calculation of the specificity
Time Frame: 3 minutes

Diagnostic performance of the qualitative examination of the gastric antrum in full supine/right lateral decubitus position.

The diagnostic performance will be calculated according to the results of the qualitative assessments performed 3 minutes after the ingestion of water (either 0, 50, 100, 150 or 200 milliliters (ml)) by the volunteers.
3 minutes
Calculation of the positive predictive value,
Time Frame: 3 minutes
Diagnostic performance of the qualitative examination of the gastric antrum in full supine/right lateral decubitus position. The diagnostic performance will be calculated according to the results of the qualitative assessments performed 3 minutes after the ingestion of water (either 0, 50, 100, 150 or 200 milliliters (ml)) by the volunteers.
3 minutes
Calculation of the negative predictive value
Time Frame: 3 minutes
Diagnostic performance of the qualitative examination of the gastric antrum in full supine/right lateral decubitus position. The diagnostic performance will be calculated according to the results of the qualitative assessments performed 3 minutes after the ingestion of water (either 0, 50, 100, 150 or 200 milliliters (ml)) by the volunteers.
3 minutes
Calculation of the positive and negative likelihood ratio.
Time Frame: 3 minutes
Diagnostic performance of the qualitative examination of the gastric antrum in full supine/right lateral decubitus position. The diagnostic performance will be calculated according to the results of the qualitative assessments performed 3 minutes after the ingestion of water (either 0, 50, 100, 150 or 200 milliliters (ml)) by the volunteers.
3 minutes
Diagnostic performance of the qualitative examination of the gastric antrum for the detection of gastric fluid volume ≥ 0.8 milliliters/kilogram (ml/kg) in the full supine and right lateral decubitus position and in the 45° semirecumbent position
Time Frame: 3 minutes
Calculation of the sensitivity. The diagnostic performance will be calculated according to the results of the qualitative assessments performed 3 minutes after the ingestion of water (either 0, 50, 100, 150 or 200 milliliters (ml)) by the volunteers
3 minutes
Diagnostic performance of the qualitative examination of the gastric antrum for the detection of gastric fluid volume ≥ 0.8 milliliters/kilogram (ml/kg) in the full supine and right lateral decubitus position and in the 45° semirecumbent position
Time Frame: 3 minutes
Calculation of the specificity The diagnostic performance will be calculated according to the results of the qualitative assessments performed 3 minutes after the ingestion of water (either 0, 50, 100, 150 or 200 milliliters (ml)) by the volunteers
3 minutes
Diagnostic performance of the qualitative examination of the gastric antrum for the detection of gastric fluid volume ≥ 0.8 milliliters/kilogram (ml/kg) in the full supine and right lateral decubitus position and in the 45° semirecumbent position
Time Frame: 3 minutes
Calculation of the positive predictive value negative The diagnostic performance will be calculated according to the results of the qualitative assessments performed 3 minutes after the ingestion of water (either 0, 50, 100, 150 or 200 milliliters (ml)) by the volunteers
3 minutes
Diagnostic performance of the qualitative examination of the gastric antrum for the detection of gastric fluid volume ≥ 0.8 milliliters/kilogram (ml/kg) in the full supine and right lateral decubitus position and in the 45° semirecumbent position
Time Frame: 3 minutes
Calculation of the negative predictive value. The diagnostic performance will be calculated according to the results of the qualitative assessments performed 3 minutes after the ingestion of water (either 0, 50, 100, 150 or 200 milliliters (ml)) by the volunteers
3 minutes
Diagnostic performance of the qualitative examination of the gastric antrum for the detection of gastric fluid volume ≥ 0.8 milliliters/kilogram (ml/kg) in the full supine and right lateral decubitus position and in the 45° semirecumbent position
Time Frame: 3 minutes
Calculation of the positive and negative likelihood ratio. The diagnostic performance will be calculated according to the results of the qualitative assessments performed 3 minutes after the ingestion of water (either 0, 50, 100, 150 or 200 milliliters (ml)) by the volunteers
3 minutes
Cut-off value for antral area measured in the supine position (semirecumbent or full supine position) associated with the best diagnostic performance for the detection of a gastric volume ≥1.5 milliliters/kilogram (ml/kg).
Time Frame: 3 minutes
The cut-off value will be calculated according to the results of the measurements performed 3 minutes after the ingestion of water (either 0, 50, 100, 150 or 200 milliliters (ml)) by the volunteers
3 minutes
Diagnostic performance of the qualitative examination of the gastric antrum in the semirecumbent position without bed elevation
Time Frame: 3 minutes
Calculation of the sensitivity. The diagnostic performance will be calculated according to the results of the qualitative and quantitative assessments performed 3 minutes after the ingestion of water (either 0, 50, 100, 150 or 200 milliliters (ml)) by the volunteers
3 minutes
Diagnostic performance of the qualitative examination of the gastric antrum in the semirecumbent position without bed elevation
Time Frame: 3 minutes
Calculation of the specificity. The diagnostic performance will be calculated according to the results of the qualitative and quantitative assessments performed 3 minutes after the ingestion of water (either 0, 50, 100, 150 or 200 milliliters (ml)) by the volunteers
3 minutes
Diagnostic performance of the qualitative examination of the gastric antrum in the semirecumbent position without bed elevation
Time Frame: 3 minutes
Calculation of the positive predictive value. The diagnostic performance will be calculated according to the results of the qualitative and quantitative assessments performed 3 minutes after the ingestion of water (either 0, 50, 100, 150 or 200 milliliters (ml)) by the volunteers
3 minutes
Diagnostic performance of the qualitative examination of the gastric antrum in the semirecumbent position without bed elevation
Time Frame: 3 minutes
Calculation of the negative predictive value. The diagnostic performance will be calculated according to the results of the qualitative and quantitative assessments performed 3 minutes after the ingestion of water (either 0, 50, 100, 150 or 200 milliliters (ml)) by the volunteers
3 minutes
Diagnostic performance of the qualitative examination of the gastric antrum in the semirecumbent position without bed elevation
Time Frame: 3 minutes
Calculation of the positive and negative likelihood ratio. The diagnostic performance will be calculated according to the results of the qualitative and quantitative assessments performed 3 minutes after the ingestion of water (either 0, 50, 100, 150 or 200 milliliters (ml)) by the volunteers
3 minutes
Mathematical model for the calculation of the gastric fluid volume
Time Frame: 3 minutes
Multiple linear regression including the antral surface measured in right lateral decubitus and the age, height, weight of the volunteer. The mathematical model will be built according to the results of the measurements performed 3 minutes after the ingestion of water (either 0, 50, 100, 150 or 200 milliliters (ml)) by the volunteers
3 minutes

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
Hospices Civils de Lyon

Investigators

Investigators

A researcher involved in a clinical study. Related terms include site principal investigator, site sub-investigator, study chair, study director, and study principal investigator.
  • Principal Investigator: Sophie Barnoud, Dr, Hospices Civils de Lyon

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

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Study Major Dates

Study Start (Actual)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
November 27, 2019

Primary Completion (Actual)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
September 6, 2021

Study Completion (Actual)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
September 6, 2021

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
May 15, 2019

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
September 19, 2019

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
September 20, 2019

Study Record Updates

Last Update Posted (Estimated)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
September 3, 2025

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
August 26, 2025

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
August 1, 2025

More Information

Terms related to this study

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • 69HCL19_0244
  • 2019-A01333-54 (Other Identifier: ID-RCB)

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

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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