| Pathomorphological changes | Group 1 (n=14) | Group 2 (n=28) | Group 3 (n=40) |
| Irregular Emphysema | 11 (79%) | 26 (93%) | 33 (83%) |
| Bullous Emphysema | 6 (43%) | 13 (46%) | 19 (48%) |
| Microthrombosis of capillary | 5 (36%) | 7 (25%) | 13 (33%) |
| Angiomathosis | 5 (36%) | 12 (43%) | 37 (93%) |
| Old hemorrhages | 10 (71%) | 15 (54%) | 27 (68%) |
| Fibrosis | 14 (100%) | 21 (75%) | 32 (80%) |