Rationale Acute respiratory distress syndrome (ARDS) is a frequent cause of hypoxemic respiratory failure with a mortality rate of approximately 30%. The identification of ARDS phenotypes, based on focal or non-focal lung morphology, can be helpful to better target mechanical ventilation strategies of individual patients. Lung ultrasound (LUS) is a non-invasive tool that can accurately distinguish 'focal' from 'non-focal' lung morphology. The investigators hypothesize that LUS-guided personalized mechanical ventilation in ARDS patients will lead to a reduction in 90-day mortality compared to conventional mechanical ventilation.