Mean (SD) clinical data of patients with acute respiratory distress syndrome (ARDS), severe pneumonia and controls receiving mechanical ventilation
| ARDS (n = 46) | Severe pneumonia (n = 20) | Controls (n = 10) | |
| Age (years) | 57.2 (15.2) | 67.1 (6.4) | 65.6 (6.4) |
| SAPS II | 43.8 (13.7) | 32.9 (9.9) | 34.6 (14.3) |
| Lung injury score | 2.9 (0.9) | 1.8 (0.6) | 0.9 (0.4) |
| Pao 2/Fio 2ratio | 114 (47) | 251 (102) | 428 (102) |
| Leucocyte count (/mm3) | 16184 (9270) | 14573 (7171) | 11260 (3589) |
| Duration of mechanical ventilation until the study (days) | 146 (192) | 103 (120) | 89 (84) |
| Total length of stay in ICU (days) | 23 (16) | 22 (11) | 12 (6) |
| Cause of ICU admission (n, %)1-150 | |||
| Community acquired pneumonia | 8 (17) | 7 (35) | — |
| Nosocomial pneumonia | 9 (20) | — | — |
| Exacerbation of COPD | 2 (4) | 3 (15) | 4 (40) |
| Other respiratory disease | 2 (4) | 1 (5) | 1 (10) |
| Severe sepsis or shock | 14 (30) | 15 (75) | — |
| Neurological | 2 (4) | 2 (10) | 5 (50) |
| Trauma | 2 (4) | 2 (10) | — |
| Postoperative | 15 (33) | 4 (20) | — |
| Others | — | 1 (5) | — |
SAPS = simplified acute physiology score; Pao 2 = arterial oxygen tension; Fio 2 = fractional inspired oxygen concentration.
↵1-150 Total greater than 100% due to multiple causes.