Relationship Between the Level of Positive End-expiratory Pressure and Venous Congestion During Acute Respiratory Distress Syndrome. (SURVEX)

February 27, 2026 updated by: University Hospital, Angers
The main objective is to assess the effect of increased PEEP on echo-Doppler venous congestion in ARDS patients at two PEEP levels, by grading congestion in each venous flow (suprahepatic, renal, portal) as "absent," "moderate," or "severe," and also calculating the VExUS score.

Study Overview

Status

Not yet recruiting

Conditions

Intervention / Treatment

Detailed Description

All analyzes will be carried out with collection intention. All information required by the protocol is obtained from the clinical file of the Intensive care and Hyperbaric Medicine department of Angers University Hospital. This research is not involving humans on prospective data from care. This research does not require any specific investigation and does not involve no changes to support.

Clinical and biological data to be collected at inclusion (D1) :

  • Demographic data: age, sex, weight (on the day of admission to intensive care and day of inclusion), medical history.
  • Cause of ARDS.
  • Ventilatory parameters: PEEP set by the clinician, total PEEP, Pplat, tidal volume, inspiratory and expiratory esophageal pressure if available as part of the treatment.
  • Hemodynamic parameters: systolic, diastolic, mean aretrial blood pressure ; central venous pressure (if available as part of routine care); heart rate; transpulmonary thermodilution monitor data (if available as part of the routine care) or Swan-ganz catheter (if available as part of the routine care), vasoactive treatments (type and dosage).

Assessments to be carried out as part of routine care on D1, between D3 and D5 and between D6 and D8 :

  1. Measures relating to the mechanics of the respiratory system:

    • Measurement of airway opening pressure (AOP).
    • Calculation of the R/I ratio (recruitability index)
    • The two PEEP levels, high and low, chosen by the clinician for performing the following measurements.

  2. At the two PEEP levels, the investigator will retrospectively collect the following clinical, biological, and echographic measurements, which were prospectively recorded by the clinician.

    • Cardiac ultrasound:

      • Right ventricular function parameters (TAPSE, S' wave, Vmax IT, diameter VD).
      • Cardiac output.
      • LVEF (once only)

    • Evaluation of venous congestion by Doppler of the veins :

      • Venous congestion is initially assessed by studying each flow individually. Doppler (suprahepatic veins, renal interlobar veins and portal vein) and graded in "absent", "moderate" or "severe" as follows :

        • Suprahepatic veins: S wave > D = absent (normal) ; S wave < D = moderate ; Positive S wave = severe
        • Renal interlobar veins: Continuous flow = absent (normal) ; Biphasic flow = moderate ; Monophasic flow = severe
        • Portal vein: Pulsatility index < 30% = absent (normal) ; Pulsatility index ≥ 30% and ≤ 50% = moderate ; Pulsatility index > 50% = severe NB : calculation of the portal trunk pulsatility index ([(Vmax - Vmin) / Vmax], average of 3 measurements)

    Then the VExUS score, integrating these three signals as well as the study of the diameter of the inferior vena cavan by ultrasound, is calculated as follows:

    • Grade 0 "absence of congestion": VCi < 20mm;
    • Grade 1 "mild congestion": VCi ≥ 20 mm and suprahepatic venous Doppler, portal and renal normal or with signs of moderate congestion;
    • Grade 2 "moderate congestion": VCi ≥ 20 mm and presence one venous flow (suprahepatic, portal, or renal) showing evidence of severe congestion;

    • Grade 3 "severe congestion": VCi ≥ 20 mm and presence of several flows vein showing signs of severe congestion.

      • Arterial and central venous gasometry (ScVO 2, PaCO2, PvCO2, lactate, PaO2, pH).
      • Collection of hemodynamic parameters: systolic blood pressure, mean, diastolic, heart rate, central venous pressure.
      • In patients with a pulmonary artery catheter: data collection following: systolic, diastolic and average PAP, cardiac index
      • Collection of ventilatory parameters: plateau pressure, total PEEP, and, if available, end-inspiratory and end-expiratory esophageal pressures.

  3. Collection of renal function with:

    • Serum creatinine and urea
    • Creatininuria on urine ionogram
    • 24-hour diuresis
  4. Collection of weight and input-output balance
  5. The echocardiographic data collected at inclusion and during follow-up will be processed a posteriori by two different observers.

End of monitoring data (D28):

During this visit, the following elements will be collected:

  • Occurrence of acute renal failure (according to KDIGO criteria) on day 8.
  • Use or not of extra-renal purification
  • Survival at D28 (to characterize the population)

Study Type

Observational

Enrollment (Estimated)

30

Contacts and Locations

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

Study Contact

Study Contact Backup

Study Locations

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

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Sampling Method

Non-Probability Sample

Study Population

All patients hospitalized in the Medical Intensive Care and Hyperbaric Medicine Unit of Angers University Hospital, receiving mechanical ventilation in assist-control mode (A/C ventilation), and presenting with ARDS

Description

Inclusion Criteria:

  • Patients hospitalized in the Medical Intensive Care and Hyperbaric Medicine Unit of Angers University Hospital, receiving mechanical ventilation in assist-control mode (A/C ventilation), and presenting with ARDS as defined by the following criteria (1):
  • Hypoxemia with a PaO₂ (mmHg)/FiO₂ (0.21 to 1.0) ratio <300 mmHg with a positive end-expiratory pressure (PEEP) ≥5 cmH₂O;
  • Pulmonary edema not fully explained by cardiac failure or fluid overload;
  • Presence of bilateral pulmonary opacities on chest imaging not fully explained by pleural effusions, atelectasis, or pulmonary nodules.

Exclusion Criteria:

  • Minor patient (<18 years old)
  • ECMO (Extracorporeal Membrane Oxygenation)
  • Hemodynamic instability (mean arterial pressure <60 mmHg)
  • Respiratory instability (SpO₂ <90% under FiO₂ >90%)
  • Severe organic tricuspid regurgitation
  • Congenital heart disease
  • Pneumothorax
  • Renal or hepatic transplant recipient
  • Liver cirrhosis Child-Pugh C
  • Portal vein thrombosis or Budd-Chiari syndrom
  • Abdominal compartment syndrome documented by intra-abdominal pressure ≥20 mmHg
  • Pregnant, breastfeeding, or peripartum women
  • Persons deprived of liberty by judicial or administrative decision
  • Persons subject to compulsory psychiatric care
  • Persons under legal protective measures

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

Cohorts and Interventions

Group / Cohort
Intervention / Treatment
ARDS (Acute respiratory distress syndrome)
Patient with ARDS who are placed on mechanical ventilation
Other: Non-interventionnal study
Non-interventionnal study

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Evolution of the level of venous congestion evaluated on the different abdominal Doppler venous flows (portal, suprahepatic and renal venous Doppler) and on the VExUS score between the different levels of PEEP (high and low)
Time Frame: Baseline
The evolution of venous congestion between two PEEP levels (high and low), assessed by analyzing each Doppler flow individually (hepatic veins, renal interlobar veins, and portal vein) and grading them as 'absent,' 'moderate,' or 'severe,' as well as by the VExUS score, graded from 0 to 3.
Baseline

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
In patients with a pulmonary artery catheter: evolution between venous congestion in abdominal venous flow and the VExUS score with right heart pressures (systolic, diastolic and mean pulmonary arterial pressure at D1, D3-D5 and D6-D8)
Time Frame: From Baseline to day 8
Measurement of pulmonary pressures (PAPs, PAPm, PAPd, PAPO) via Swan-Ganz catheters at each PEEP level (high and low)
From Baseline to day 8
Evaluate the evolution of venous congestion (VExUS score) according to the PEEP level over time (D1, D3-D5 and D6-D8) for each patient individually
Time Frame: From baseline to Day 8
From baseline to Day 8
Evaluate the evolution of venous congestion in abdominal venous flows and the VExUS score according to PEEP level
Time Frame: From baseline to Day 8
From baseline to Day 8
Incidence of acute renal failure at day 28 in patients with markers of significant venous congestion
Time Frame: From baseline to day 28
Vexus score greater than or equal to 2 and/or change in portal flow, renal venous flow, or suprahepatic venous flow
From baseline to day 28
Incidence of renal replacement therapy on day 28 in patients with markers of significant venous congestion
Time Frame: From baseline to Day 28
Description: score greater than or equal to 2 and/or change in portal flow, renal venous flow, or suprahepatic venous flow
From baseline to Day 28
Evolution of the level of venous congestion evaluated on the different abdominal Doppler venous flows (portal, suprahepatic and renal venous Doppler) and on the VExUS score between the different levels of PEEP (high and low)
Time Frame: from day 3 to day 5
The evolution of venous congestion between two PEEP levels (high and low), assessed by analyzing each Doppler flow individually (hepatic veins, renal interlobar veins, and portal vein) and grading them as 'absent,' 'moderate,' or 'severe,' as well as by the VExUS score, graded from 0 to 3.
from day 3 to day 5
Evolution of the level of venous congestion evaluated on the different abdominal Doppler venous flows (portal, suprahepatic and renal venous Doppler) and on the VExUS score between the different levels of PEEP (high and low)
Time Frame: From Day 6 to Day 8
The evolution of venous congestion between two PEEP levels (high and low), assessed by analyzing each Doppler flow individually (hepatic veins, renal interlobar veins, and portal vein) and grading them as 'absent,' 'moderate,' or 'severe,' as well as by the VExUS score, graded from 0 to 3.
From Day 6 to Day 8
Evolution between venous congestion in abdominal venous flow and the VExUS score and echocardiographic markers of right heart function (D1, D3-D5 and D6-D8)
Time Frame: From baseline to day 8
Measurement of TAPSE (Tricuspid annular plane systolic excursion), tricuspid S' wave, peak tricuspid regurgitation velocity at each PEEP level (high and low)
From baseline to day 8

Collaborators and Investigators

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

Sponsor

University Hospital, Angers

Investigators

  • Study Chair: Pierre ASFAR, University Hospital of Angers

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 (Estimated)

March 1, 2026

Primary Completion (Estimated)

November 1, 2027

Study Completion (Estimated)

November 1, 2027

Study Registration Dates

First Submitted

January 23, 2026

First Submitted That Met QC Criteria

February 27, 2026

First Posted (Actual)

March 5, 2026

Study Record Updates

Last Update Posted (Actual)

March 5, 2026

Last Update Submitted That Met QC Criteria

February 27, 2026

Last Verified

January 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • 49RC26_0031

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

UNDECIDED

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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