The Berlin Criteria defining ARDS9
| Timing | Within 1 week of either 1) clinical insult or 2) deterioration in respiratory symptoms | |
| Imaging | Chest imaging reveals bilateral opacities not fully explained by effusions, lung collapse, nodules | |
| Oedema | Respiratory failure not fully explained by pulmonary oedema secondary to cardiac failure | |
| Oxygenation | Mild | PaO2/FiO2 ≤39.9 kPa (≤300 mmHg) with PEEP or CPAP ≥5 cmH2O |
| Moderate | PaO2/FiO2 ≤26.6 kPa (≤200 mmHg) with PEEP ≥5 cmH2O | |
| Severe | PaO2/FiO2 ≤13.3 kPa (≤100 mmHg) with PEEP ≥5 cmH2O | |
CPAP = continuous positive airway pressure; FiO2 = action of inspired oxygen; PaO2 = partial pressure of arterial oxygen; PEEP = positive end expiratory pressure.