Table 2.
Lung histology
| Present study | Previous study | P | |
|---|---|---|---|
| Emphysematous changes | 2 (2-3) |
2 (2-3) |
1.00 |
| Interstitial congestion | 2 (1-2) |
2 (1-2) |
0.23 |
| Alveolar haemorrhage | 1 (1-1) |
1 (0-1) |
0.60 |
| Alveolar neutrophil infiltration | 2 (2-2) |
2 (1-3) |
1.00 |
| Alveolar macrophage proliferation | 3 (2-3) |
2 (1-2) |
0.23 |
| Alveolar type II pneumocytes proliferation | 2 (2-2) |
2 (2-2) |
0.95 |
| Interstitial lymphocytes proliferation | 2 (1-2) |
2 (1-2) |
0.82 |
| Interstitial thickening | 2 (1-2) |
2 (2-3) |
0.05 |
| Hyaline membranes formation | 0 (0-0) |
0 (0-1) |
0.17 |
| Interstitial fibrosis | 1 (1-1) |
2 (1-3) |
0.02 |
| Organization of alveolar exudate | 1 (1-2) |
1 (0-1) |
0.19 |
| Total score | 18 (14-18) |
18 (16-19) |
0.43 |
Results of animals ventilated with high PEEP and low VT for 36 h and with no PEEP and low VT for 18 h (n = 5) (present study) were compared with those of animals ventilated with no PEEP and low VT for 54 h (n = 12) (previous study) [3]. Alterations were graded from 0 to 4, with higher scores indicating more severe and diffuse abnormalities. Total score was the sum of all individual scores. P values refer to Mann-Whitney rank sum test. PEEP, positive end-expiratory pressure; VT, tidal volume.