Fig. 1

Study design: Group A started CPAP/NIV when P/F fell below 200, Group B underwent CPAP/NIV when P/F fell below 150. Group C derives from patients initially excluded from the study for refusal of non-invasive treatment and who subsequently initiated treatment with CPAP/NIV in a severe stage of ARDS (P/F ≤ 100). CPAP Continuous Positive Airway Pressure, NIV Non-Invasive Ventilation, P/F PaO₂/FiO₂ rate