<prompt> True about ARDS is all exceptAcute onsetPaO2 FiO2200mmHGPulmonary aery wedge Pressure 18mmHgTreatment of choice is mechanical ventilation  <response>: A less severe form is called acute lung injury ALI.A PaO2FiO2ra of less than 300 mm Hg with bilateral infiltrates indicates acute lung injury ALI. ARDS is characterized by:Acute onsetBilateral infiltrates on chest radiograph sparing costophrenic anglesPulmonary aery wedge pressure 18 mmHg obtained by pulmonary aery catheterization if PaO2:FiO2 200 mmHg 26.7 kPa To summarize and simplify, ARDS is an acute rapid onset syndrome that affects thelungs widely and results in a severe oxygenation defect, but is not due to hea failure. 