Non-cardiogenic pulmonary edema characterized by acute respiratory failure.
Berlin criteria for diagnosis include acute onset within 7 days, bilateral pulmonary infiltrates on imaging, not fully explained by cardiac failure or fluid overload, and impaired oxygenation with PaO2/FiO2 ratio <300 mmHg, even with positive end-expiratory pressure (PEEP) >5 cm H2O.
Severity based on oxygenation (Berlin criteria):
Mild: PaO2/FiO2 200-300 mmHg
Moderate: PaO2/FiO2 100-200 mmHg
Severe: PaO2/FiO2 <100 mmHg
Epidemiology:
Occurs in up to 23% of mechanically ventilated patients.
Mortality rate of 30-40%, primarily due to multiorgan failure.
Differentiation from Cardiogenic Pulmonary Edema:
Chest CT shows diffuse edema and pleural effusion in cardiogenic edema; patchy edema, dense consolidation in ARDS.
Ultrasound may show diffuse B lines in cardiogenic edema; patchy B lines and normal A lines in ARDS.