Prone positioning has been shown to improve survival in patients with acute respiratory distress syndrome (ARDS). However, a recent large observational study found that prone positioning was used in only 7% of all ARDS patients, and 16% in the severe category. However, this study did not focus on the prone position per se. In present study, the investigators would like to explore the rate of use of prone positioning in ARDS patients and the reasons why this treatment was not applied. The present study is one-day prevalence study repeated four times over one year.

The hypothesis is that the rate of use of prone position is greater than 50% in the severe ARDS category.

Inclusion Criteria:

• 1.ARDS criteria (Berlin definition) fulfilled the day of the study, whatever the ARDS stage. The onset of ARDS could have been established at any time between ICU admission and study day but ARDS criteria must be still present the day of the study. The ARDS criteria are listed below

  • Within 1 week of a known clinical insult or new or worsening respiratory symptoms
  • Bilateral opacities-not fully explained by effusions, lobar/lung collapse, or nodules
  • Respiratory failure not fully explained by cardiac failure or fluid overload. Need objective assessment (eg, echocardiography) to exclude hydrostatic edema if no risk factor present

• 2.PaO2/FIO2 ≤ 300 with PEEP ≥ 5 cmH2O

• 3.Age ≥ 18 years

• 4.Intubated or tracheotomized and mechanically ventilated

Exclusion Criteria:

• Patient non intubated the day of the study
• No criteria for ARDS the day of the study even if these criteria were present between ICU admission and day of the study

ARDS under mechanical ventilation