Acute respiratory distress syndrome (ARDS) is an inflammatory injury of the lungs caused by various serious illnesses, such as a bacterial or viral lung infection. It is treated by artificial ventilation with the application of positive pressure. Pulmonary injury, coupled with artificial ventilation, can lead to right heart failure which hinders the ejection of blood to the pulmonary circulation. Modern mechanical ventilation modalities have reduced the frequency ("incidence") of this right heart failure in acute respiratory distress syndrome. A large-scale study has shown this a few years ago. However, the evolution of right heart failure during artificial ventilation, and the consequences it has on the patient's cardiovascular status are poorly determined. This study is conducted to improve knowledge in this area. In adult patients hospitalized in intensive care presenting acute respiratory distress syndrome, the investigators will collect the data recorded on cardiac ultrasound, doses of cardiovascular drugs as well as variables reflecting hemodynamic status and cell oxygenation. Data will be collected during the course of ARDS and mechanical ventilation, as well as after weaning from artificial ventilation.

During acute respiratory distress syndrome (ARDS), lung damage, coupled with positive pressure artificial ventilation, can lead to failure of the right ventricle by modifying its loading conditions. The "protective" modalities used today to ventilate these patients have reduced the incidence of this right heart failure in ARDS. However, the evolution of right heart failure during mechanical ventilation, and its consequence on the hemodynamic state of the patient are poorly determined. The aim of this study is to improve knowledge in this area.The main objective of the current project is to describe the incidence of right heart failure in patients with ARDS placed on artificial ventilation and its evolution over time. The secondary objectives are to describe the simultaneous evolution of the hemodynamic state, the use of cardiovascular drugs and the variables of tissue oxygenation, to describe the phenotypes of patients presenting with right heart failure during ARDS in function of ultrasound, hemodynamic and tissue oxygenation characteristics, to describe the association of these different phenotypes with the prognosis, to describe the risk factors for these different phenotypes and to describe the influence on right heart failure during ARDS on factors related to the patient's volume status.

In adult patients hospitalized in intensive care presenting with ARDS, the investigators will collect data recorded during the first 24 hours, after 48-96 hours, on day 5-7 and within 48 hours after extubation. The investigators will collect ventilatory and hemodynamic data, data provided by cardiac ultrasound, vasopressor and inotropic drug doses and tissue oxygenation variables.

This is an observational multicenter study, in which the investigators plan to include 500 patients over a total period of 24 months.

Inclusion Criteria:

• Age ≥18 years old
• Hospitalization in intensive care undergoing mechanical ventilation
• Presence of ARDS according to the current consensus definition (Berlin definition)
• Performance of at least one echocardiography during the first 24 hours of treatment, between the 2nd and 3rd day, between the 5th and 7th day, and within 48 hours of extubation

Exclusion Criteria:

Pregnancy Poor echogenicity preventing reliable measurement of the dimensions of the right and left ventricles.

• Hospitalization in intensive care
• Age ≥18 years
• Patients under mechanical ventilation
• Presence of acute respiratory distress syndrome according to the Berlin definition