Common causes of direct lung injury are Acid aspiration Pneumonia Less common causes of direct lung injury are Amniotic fluid embolism Diffuse alveolar hemorrhage Drowning Fat embolism Lung transplantation Pulmonary contusion Irritant gas inhalation Common causes of indirect lung injury include Sepsis Trauma with prolonged hypovolemic shock Less common causes of indirect lung injury include Bone marrow transplantation Drug overdose (eg, aspirin, cocaine, opioids, phenothiazines, tricyclics) Burns Cardiopulmonary bypass Massive blood transfusion (> 15 units) Neurogenic pulmonary edema due to stroke, seizure, head trauma, anoxia Pancreatitis Preeclampsia Radiographic contrast (rare) Septic abortion Sepsis and pneumonia account for about 60% of cases of ARDS.