- ARDS is diagnosed clinically using the international consensus criteria (The Berlin Criteria)
- Essential components required for diagnosis are:
- PaO2/FiO2 ratio of ≤39.9 kPa / ≤300 mmHg
- Acute onset (within 1 week of known clinical insult)
- Bilateral opacities on CXR (not explained by effusions, collapse, or nodules)
- Respiratory failure not fully explained by heart failure or fluid overload (objective assessment such as echocardiogram recommended if no risk factor)
- The histological correlate for ARDS is known as ‘diffuse alveolar damage’:
- Considered the gold standard for diagnosis
- Rarely used as requires an open lung biopsy