Expiratory Flow Limitation Assessment (FLAIR)

November 28, 2025 updated by: Hospices Civils de Lyon

Expiratory Fow Assessment in ARDS Patients

This study intended to assess the expiratory flow limitation (EFL) during tidal breath in patients intubated in intensive care unit (ICU) for moderate or severe acute respiratory distress syndrome (ARDS). EFL is defined as the lack of increase in expiratory flow in response to an increase in alveolar-to-atmospheric pressure gradient. It reflects airway closure. Early studies have been done using the Negative expiratory pressure (NEP) technique, which is no longer available. We proposed in present study a new method, which consists of diverting manually the expiratory flow to the atmosphere by-passing the expiratory valve. We aimed at assessing EFL at positive expiratory pressure (PEP) 5 cmH2O in semi-recumbent then in supine position together with measurement of trans-pulmonary pressure and regional lung ventilation. Higher PEP levels will be tested, namely 10, 15 and a trans-pulmonary PEP of 3 cmH2O, in semi-recumbent position.

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

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.

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.
25

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
      • Grenoble, France
        • Chu Grenoble Alpes
      • Lyon, France, 69004
        • Hopital de la croix rousse

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

No

Description

Inclusion Criteria:

  • 18 years or more in age
  • moderate to severe ARDS according to the Berlin definition : Intubated (or tracheotomized) and mechanically ventilated in the ICU
  • no pregnancy
  • informed consent from the next of kin

Exclusion Criteria:

  • Contra-indication to PEP > 5 cmH2O
  • extracorporeal membrane oxygenation (ECMO)
  • chest tube
  • mean arterial pressure < 65 mmHg
  • Contra-indication to oesophageal device
  • underlying disease fatal in less than one year
  • active therapy limitation
  • under guardian
  • refusal to participate
  • not affiliated to insurance regimen
  • speaking barrier of the next of kin
  • investigator not available

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: Diagnostic
  • Allocation: Non-Randomized
  • Interventional Model: Parallel 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.
Other: Patients with EFL at PEP 5
Patients with EFL at PEP 5 at the time of inclusion either in supine or semi-recumbent position
Other: increase in positive end expiratory pressure
increase in positive end expiratory pressure from 5 to 10 then 15 cmH2O then at the value for trans pulmonary end expiratory pressure amounting to 3 cmH2O
Other: Patients with no EFL at PEP 5
Patients with no EFL at PEP 5 at the time of inclusion in both supine and semi-recumbent positions
Other: increase in positive end expiratory pressure
increase in positive end expiratory pressure from 5 to 10 then 15 cmH2O then at the value for trans pulmonary end expiratory pressure amounting to 3 cmH2O

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
EFL at PEP 5 cmH2O
Time Frame: at inclusion
A Fleish 2 pneumotachograph and a port to measure airway pressure are attached at the Y piece of the ventilator circuit and connected to a Biopac 150. At the end of inspiration the air is expelled to the atmosphere upstream the expiratory valve. The flow volume loop at baseline and that during the manoeuver are plotted and patients classified as EFL or not EFL (NFL). Measurements are taken in semi-recumbent then after 5 minutes in supine position.
at inclusion

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
Trans-pulmonary pressure at end expiratory at PEP 5
Time Frame: at inclusion
After insertion of esophageal balloon together with pneumotachograph and port for airway pressure trans-pulmonary pressure (airway-esophageal pressure) is measured after a 3-sec end-expiratory pause in semi-recumbent and then after 5 minutes in supine position
at inclusion
Trans-pulmonary pressure at end expiratory at PEP 10 in EFL and NFL patients
Time Frame: 15 minutes after PEP set to 10 cm H2O
PEP is increased to 10 cmH2O and 15 minutes later trans-pulmonary pressure is measured after a 3-sec end-expiratory pause in semi-recumbent position
15 minutes after PEP set to 10 cm H2O
Lung compliance at PEP 10 in EFL and NFL patients
Time Frame: 15 minutes after PEP set to 10 cm H2O
PEP is increased to 10 cmH2O and 15 minutes later lung compliance is measured after a 3-sec end-expiratory pause in semi-recumbent position
15 minutes after PEP set to 10 cm H2O
lung ventilation distribution at PEP 10 in EFL and NFL patients
Time Frame: 15 minutes after PEP set to 10 cm H2O
PEP is increased to 10 cmH2O and 15 minutes later lung ventilation is measured by using electrical impedance tomography (EIT) in semi-recumbent position (an EIT belt having been inserted together with the previous measurement devices).
15 minutes after PEP set to 10 cm H2O
Transcutaneous oxygen saturation (SpO2) at PEP 10 in EFL and NFL patients
Time Frame: 15 minutes after PEP set to 10 cm H2O
PEP is increased to 15cmH2O and 15 minutes later SpO2 is read from the vital functions monitoring device and SpO2/FIO2 computed
15 minutes after PEP set to 10 cm H2O
Trans-pulmonary pressure at end expiratory at PEP 15 in EFL and NFL patients
Time Frame: 15 minutes after PEP set to 15 cm H2O
PEP is increased to 15 cmH2O and 15 minutes later trans-pulmonary pressure is measured after a 3-sec end-expiratory pause in semi-recumbent position
15 minutes after PEP set to 15 cm H2O
Lung compliance at PEP 15 in EFL and NFL patients
Time Frame: 15 minutes after PEP set to 15 cm H2O
PEP is increased to 15 cmH2O and 15 minutes later lung compliance is measured after a 3-sec end-expiratory pause in semi-recumbent position
15 minutes after PEP set to 15 cm H2O
lung ventilation distribution at PEP 15 in EFL and NFL patients
Time Frame: 15 minutes after PEP set to 15 cm H2O
PEP is increased to 15 cmH2O and 15 minutes later lung ventilation is measured by using electrical impedance tomography (EIT) in semi-recumbent position (an EIT belt having been inserted together with the previous measurement devices).
15 minutes after PEP set to 15 cm H2O
transcutaneous oxygen saturation (SpO2) at PEP 15 in EFL and NFL patients
Time Frame: 15 minutes after PEP set to 15 cm H2O
PEP is increased to 15 cmH2O and 15 minutes later SpO2 is read from the vital functions monitoring device and SpO2/FIO2 computed.
15 minutes after PEP set to 15 cm H2O
Trans-pulmonary pressure at end expiratory at PEP to reach Trans-pulmonary pressure at end expiratory =+3 cmH2O in EFL and NFL patients
Time Frame: 15 minutes after PEP set to reach Trans-pulmonary pressure at end expiratory =+3 cmH2O
PEP is set to reach Trans-pulmonary pressure at end expiratory =+3 cmH2O and 15 minutes later trans-pulmonary pressure is measured after a 3-sec end-expiratory pause in semi-recumbent position
15 minutes after PEP set to reach Trans-pulmonary pressure at end expiratory =+3 cmH2O
Lung compliance at PEP to reach Trans-pulmonary pressure at end expiratory =+3 cmH2O in EFL and NFL patients
Time Frame: 15 minutes after PEP set to reach Trans-pulmonary pressure at end expiratory =+3 cmH2O
PEP is set to reach Trans-pulmonary pressure at end expiratory =+3 cmH2O and 15 minutes later lung compliance is measured after a 3-sec end-expiratory pause in semi-recumbent position
15 minutes after PEP set to reach Trans-pulmonary pressure at end expiratory =+3 cmH2O
lung ventilation distribution at PEP set to reach Trans-pulmonary pressure at end expiratory =+3 cmH2O in EFL and NFL patients
Time Frame: 15 minutes after PEP set to reach Trans-pulmonary pressure at end expiratory =+3 cmH2O
PEP is set to reach Trans-pulmonary pressure at end expiratory =+3 cmH2O and 15 minutes later lung ventilation is measured by using electrical impedance tomography (EIT) in semi-recumbent position (an EIT belt having been inserted together with the previous measurement devices).
15 minutes after PEP set to reach Trans-pulmonary pressure at end expiratory =+3 cmH2O
Transcutaneous oxygen saturation (SpO2) at PEEP set to reach Trans-pulmonary pressure at end expiratory =+3 cmH2O in EFL and NFL patients
Time Frame: 15 minutes after PEEP set to reach Trans-pulmonary pressure at end expiratory =+3 cmH2O
PEEP is increased to 15 cmH2O and 15 minutes later SpO2 is read from the vital functions monitoring device and SpO2/FIO2 computed.
15 minutes after PEEP set to reach Trans-pulmonary pressure at end expiratory =+3 cmH2O
lung recruitment at PEEP 10 in EFL and NFL patients
Time Frame: 15 minutes after PEEP set to 10 cm H2O
PEEP is increased to 10 cmH2O and 15 minutes later lung recruitment is measured between PEEP 10 and PEEP 5 (in each body position) from volume-pressure curves recorded at PEEP 10 and PEEP 5. The lung recruitment is the change in lung volume for a given pressure (higher PEEP and 20 cmH2O)
15 minutes after PEEP set to 10 cm H2O
lung recruitment at PEEP 15 in EFL and NFL patients
Time Frame: 15 minutes after PEEP set to 15 cm H2O
PEEP is increased to 15 cmH2O and 15 minutes later lung recruitment is measured between PEEP 15 and PEEP 5 (in each body position) from volume-pressure curves recorded at PEEP 15 and PEEP 5. The lung recruitment is the change in lung volume for a given pressure (higher PEEP and 20 cmH2O)
15 minutes after PEEP set to 15 cm H2O
lung recruitment at PEEP set to reach Trans-pulmonary pressure at end expiratory =+3 cmH2O in EFL and NFL patients in EFL and NFL patients
Time Frame: 15 minutes after PEEP set to 15 cm H2O
PEEP is increased to PEEP set to reach Trans-pulmonary pressure at end expiratory =+3 cmH2O and 15 minutes later lung recruitment is measured between PEEP set to reach Trans-pulmonary pressure at end expiratory =+3 cmH2O and PEEP 5 (in each body position) from volume-pressure curves recorded at PEEP set to reach Trans-pulmonary pressure at end expiratory =+3 cmH2O and PEEP 5. The lung recruitment is the change in lung volume for a given pressure (higher PEEP and 20 cmH2O)
15 minutes after PEEP set to 15 cm H2O

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: Claude Guerin, Pr, 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

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

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.
February 5, 2018

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.
May 2, 2019

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.
May 2, 2019

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).
March 6, 2018

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.
March 6, 2018

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.
March 13, 2018

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.
December 5, 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.
November 28, 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.
November 1, 2025

More Information

Terms related to this study

Keywords

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.
  • 69HCL17_0595
  • 2017-A02557-46 (Other Identifier: ANSM)

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

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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