Skip to main content
OpenTrials
Not yet recruiting

NCT Number: NCT07823296

Assessment of Blood Viscosity in ARDS (Acute Respiratory Distress Syndrome)

Acute respiratory distress syndrome (ARDS) is characterized by damage to the alveolar-capillary membrane, resulting in hypoxemia, decreased pulmonary compliance, and hemodynamic changes.

Critical conditions (hypoxia; septic shock associated with ARDS) can alter blood viscosity. These changes in viscosity can affect blood flow and hemodynamics.

There is only one clinical study that has measured one of the determinants of blood viscosity in ARDS (deformability), even though other parameters are involved in viscosity (elongation, deformability, hematocrit, etc.), and it is possible to measure blood viscosity comprehensively. To date, therefore, no study has evaluated the various parameters of blood viscosity in ARDS.

The aim of this study is to investigate hyperviscosity in patients with ARDS and to assess whether this hyperviscosity correlates with respiratory or hemodynamic changes.

The investigators will therefore compare blood viscosity and its determinants in patients admitted to the intensive care unit for ARDS and in patients admitted for other reasons (excluding ARDS or sepsis/septic shock).

The investigators will also conduct a longitudinal assessment of changes in hemodynamic, respiratory, and viscosity parameters during ARDS

Not yet recruiting

Trial opening soon.

Get Notified

Key information

Conditions

ARDS Acute Lung Injury Lung Diseases Lung Injury Respiratory Tract Diseases

Age range

18 year and older

Sex eligibility

All sexes

Study type

Observational

Primary location

Who can participate

Healthy volunteers accepted: No

Only the study team can determine whether someone qualifies for participation.

Case Group

Inclusion criteria

  • Age ≥ 18 ans
  • Moderate-to-severe ARDS according to the global definition:
  • with PaO₂/FiO₂ ≤ 200 mmHg (based on arterial blood gas analysis in patients receiving invasive or non-invasive mechanical ventilation or high-flow nasal oxygen therapy).
  • Participation agreement obtained (either from the patient themselves or from a relative)

Exclusion criteria

  • ARDS that has been present for more than 72 hours
  • Terminally ill patient with death expected within 24 hours
  • Patient who has received a blood transfusion within the past month
  • Patient with a known hematologic malignancy (lymphoma; myeloma; acute or chronic leukemia)
  • Patient with a known hemoglobinopathy.
  • Hemorrhagic shock
  • Hemoglobin < 70 g/dL

Control group

Inclusion criteria

  • Age ≥ 18 ans
  • Participation agreement obtained (either from the patient themselves or from a relative)

Exclusion criteria

  • Presence of ARDS according to the global definition
  • P/F < 300 mmHg
  • Presence of sepsis defined by an infection and a SOFA score delta ≥ 2.
  • Terminally ill patient with death expected within 24 hours
  • Patient who has received a blood transfusion within the past month
  • Patient with a known hematologic malignancy (lymphoma; myeloma; acute or chronic leukemia)
  • Patient with a known hemoglobinopathy.
  • Hemorrhagic shock
  • Hemoglobin < 70 g/dL

Treatment and study plan

Blood draws (peripheral venous puncture)

Biological

Procedure performed by intensive care nurses. Case group : Daily blood draws (4 mL) for 7 days. Control group : blood draws (4 mL) on Day 1.

Blood draws (arterial catheter, central venous line, or Swan-Ganz catheter)

Other

Case group : For patients with an arterial catheter, central venous line, or Swan-Ganz catheter, an additional blood sample will be collected on Day 1.

Primary outcomes

  1. Comparison of Blood Viscosity in Patients with ARDS and Control Group on Day 1

    Time frame: At day 1

    Blood viscosity will be determined after complete oxygenation of the blood, at native hematocrit, at a temperature of 25 °C. Measurements will be performed at different shear rates (11.5, 22.5, 45, 90, and 225 s-¹) using a cone-plate viscometer (Brookfield DVII+ equipped with a CPE40 cone, Brookfield Engineering Labs, Natick, MA, USA). This technique is based on applying a well-defined shear rate gradient between a moving conical surface and a fixed flat surface, with the blood sample placed between them. The fluid subjected to this shear resists flow in proportion to its viscosity. The higher the viscosity, the greater the torque required to maintain motion. This approach allows for the precise measurement of the apparent viscosity of blood across a wide range of mechanical stresses, replicating the flow conditions encountered in the bloodstream. The value at 225 s-¹ will be used as the primary endpoint (with an accuracy of 5-10 centipoise at this shear rate).

Study contacts

Contact information is provided by the study sponsor or research team.

Hippolyte LEQUAIN, Dr

CONTACT

[email protected]

0472071281 ext. +33

Jean-Christophe RICHARD, Pr

CONTACT

[email protected]

0472009272 ext. +33

Sponsors and collaborators

Lead sponsor

Hospices Civils de Lyon

Other

Registry information

Official study title

Assessment of Blood Viscosity in ARDS

Acronym: VISC-ARDS

Important dates

Study start
2026
Primary completion
2028
Study completion
2028
First posted
Sep 16, 2026
Registry last updated
Sep 16, 2026

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

Related clinical trials

Published trials that share one or more normalized conditions with this study.