A patient has been hospitalized in the ICU for a near drowning event. The patient's respiratory function has been deteriorating over the last 24 hours. The physician suspects acute respiratory distress syndrome. A STAT chest x-ray is ordered. What finding on the chest x-ray is indicative of ARDS?

A. Localized infiltrates indicate a focal process, such as bacterial pneumonia or aspiration in a single lobe. ARDS affects the lungs diffusely, so a localized pattern would not support the diagnosis. B. Cardiomegaly is associated with cardiogenic pulmonary edema, where heart failure causes fluid accumulation in the lungs. In ARDS, the pulmonary edema is non-cardiogenic, and the heart size is typically normal. C. In ARDS, the alveoli fill with fluid, protein, and inflammatory cells, causing widespread opacification on chest x-ray. This appears as bilateral, patchy, or confluent “white-out” infiltrates, indicating severe alveolar involvement and impaired oxygenation. These findings correlate with the patient’s rapidly worsening hypoxemia and respiratory distress. D. Hyperinflation is characteristic of obstructive airway diseases like COPD or asthma, where air is trapped in the lungs. In ARDS, the lungs are stiff and noncompliant, so hyperinflation does not occur.