Table 1.
Patient characteristics
| VD/VT Cohort | ARDSNet Cohort (n = 3,135) |
||||
|---|---|---|---|---|---|
| ALTA (n = 92) |
EPVent (n = 57) |
APC (n = 61) |
Total (n = 210) |
||
| Demographics | |||||
| Age | 50 ± 17 | 54 ± 19 | 52 ± 18 | 52 ± 18 | 51 ± 16 |
| Female | 46 (50%) | 22 (39%) | 26 (43%) | 94 (45%) | 1,439 (46%) |
| Non-white race | 28 (30%) | 7 (12%) | 18 (30%) | 53 (25%) | 871 (28%) |
| Body mass index (kg/m2) | 29.0 ± 9.0 | 30.7 ± 9.3 | 28.3 ± 7.4 | 29.3 ± 8.7 | 28.7 ± 7.6 |
| Clinical Characteristics | |||||
| APACHE II | 26 ± 7 | 26 ± 6 | 20 ± 7 | 25 ± 7 | 27 ± 7 |
| Shock | 59 (64%) | 33 (58%) | 16 (26%) | 108 (51%) | 1,733 (55%) |
| Primary cause of lung injury | |||||
| Aspiration or pneumonia | 50 (54%) | 8 (14%) | 44 (72%) | 102 (49%) | 1,952 (62%) |
| Sepsis | 24 (26%) | 14 (25%) | 9 (15%) | 47 (22%) | 659 (21%) |
| Multiple transfusions | 2 (2%) | 0 | 0 | 2 (1%) | 65 (2%) |
| Trauma | 8 (9%) | 15 (26%) | 0 | 23 (11%) | 223 (7%) |
| Other | 8 (9%) | 20 (35%) | 8 (13%) | 36 (17%) | 235 (8%) |
| Respiratory Characteristics | |||||
| Tidal volume (mL) | 390 ± 70 | 493 ± 96 | 415 ± 92 | 425 ± 94 | 408 ± 94 |
| Tidal volume (mL/kg PBW) | 6.3 ± 0.9 | 7.7 ± 1.4 | 6.7 ± 1.4 | 6.8 ± 1.3 | 6.5 ± 1.4 |
| Respiratory rate (breaths/min) | 28 ± 7 | 25 ± 6 | 27 ± 7 | 27 ± 7 | 27 ± 7 |
| PEEP (cmH2O) | 9 ± 3 | 13 ± 4 | 9 ± 3 | 10 ± 4 | 10 ± 4 |
| PaO2/FiO2 | 184 ± 63 | 148 ± 57 | 160 ± 63 | 167 ± 63 | 172 ± 76 |
| PaCO2 (mmHg) | 40 ± 8 | 41 ± 8 | 41 ± 11 | 41 ± 9 | 41 ± 10 |
| Respiratory system compliance (mL/cmH2O) | 32 ± 17 | 36 ± 11 | 31 ± 22 | 33 ± 17 | 32 ± 17 |
| Murray lung injury score | 2.4 ± 0.6 | 2.8 ± 0.6 | 2.6 ± 0.6 | 2.6 ± 0.6 | 2.6 ± 0.7 |
| VD/VT measured | 0.57 ± 0.12 | 0.67 ± 0.10 | 0.59 ± 0.12 | 0.60 ± 0.12 | N/A |
| Clinical Outcomes | |||||
| Mortality | 12 (13%) | 15 (26%) | 7 (11%) | 34 (16%) | 693 (22%) |
| Vent-free days through day 28 | 16 ± 10 | 10 ± 9 | 15 ± 10 | 14 ± 10 | 14 ± 11 |
Data are reported as mean ± standard deviation or number (%).
Abbreviations: PEEP = positive end-expiratory pressure; VD/VT = dead-space fraction.