Table 2. Lung injury classification from the AAST .
| Grade* | Injury type | Description |
|---|---|---|
| I | Contusion | Unilateral, <1 lobe |
| II | Contusion | Unilateral, single lobe |
| Laceration | Simple pneumothorax | |
| III | Contusion | Unilateral, >1 lobe |
| Laceration | Persistent (>72 h) air leak from distal airway | |
| Hematoma | Nonexpanding intraparenchymal | |
| IV | Laceration | Major (segmental or lobar) air leak |
| Hematoma | Expanding intraparenchymal | |
| Vascular | Primary branch intrapulmonary vessel disruption | |
| V | Vascular | Hilar vessel disruption |
| VI | Vascular | Total uncontained transection of pulmonary hilum |
*Advance one grade for bilateral injuries up to grade III. Hemothorax is scored under thoracic vascular injury scale