Table 2.
| Characteristic | White (n=1715) |
Black (n=449) |
Hispanic (n=198) |
P value |
|---|---|---|---|---|
| Age | 52 ± 17 | 48 ± 16 | 44 ± 16 | <0.0005 |
| Male | 936 (55) | 251 (56) | 128 (65) | 0.16 |
| BMI, kg/m2 | 28.0 ± 7.3 | 27.0 ± 7.5 | 28.0 ± 6.6 | 0.049 |
| Acute Physiology Score (calculated from APACHE III) |
78 ± 30 | 86 ± 30 | 83 ± 30 | <0.0005 |
| Vasopressor use | 506 (33) | 131 (32) | 70 (38) | 0.36 |
| Cause of lung injury | 0.001 | |||
| pneumonia | 667 (39) | 210 (47) | 77 (39) | |
| sepsis | 397 (23) | 107 (24) | 61 (31) | |
| aspiration | 260 (15) | 71 (16) | 17 (9) | |
| trauma | 161 (9) | 25 (6) | 20 (10) | |
| transfusion | 46 (3) | 5 (1) | 7 (4) | |
| other or unknown | 184 (11) | 31 (7) | 16 (8) | |
| Comorbid conditions‡ | ||||
| Diabetes | 241 (14) | 89(20) | 41(22) | 0.001 |
| Chronic Dialysis | 21 (1) | 23 (3) | 1(0.5) | 0.03 |
| HIV or AIDS | 56 (3) | 76 (17) | 20 (11) | <0.001 |
| Cirrhosis | 45 (3) | 21 (5) | 9 (5) | 0.04 |
| Solid tumors | 31 (2) | 4 (1) | 3 (2) | 0.40 |
| Leukemia | 40(2) | 5 (1) | 3(2) | 0.26 |
| Lymphoma | 26 (2) | 0 (0) | 2(1) | 0.009 |
| Immunosuppression | 188 (11) | 54 (12) | 13(7) | 0.14 |
| Baseline respiratory variables | ||||
| Tidal volume (ml)/kg PBW§ | 8.6 ± 2.2 | 7.9 ± 2.0 | 8.6 ± 2.4 | <0.001 |
| Plateau pressure, cm H20 | 28 ± 8 | 28 ± 8 | 28 ± 7 | 0.31 |
| Peak airway pressure, cm H20 | 34 ± 10 | 34 ± 9 | 34 ± 9 | 0.90 |
| Mean airway pressure, cm H20 | 16 ± 9 | 16 ± 8 | 16 ± 5 | 0.97 |
| PEEP, cm H20 | 9.1± 4.1 | 8.8 ± 4.0 | 9.3 ± 3.7 | 0.16 |
| Arterial pH | 7.38 ± 0.09 | 7.37 ± 0.09 | 7.37 ± 0.09 | 0.003 |
| PaO2, mm Hg | 86 ± 34 | 93 ± 46 | 87 ± 38 | 0.08 |
| PaCO2, mm Hg | 39 ±9 | 38 ± 10 | 37 ± 9 | 0.008 |
| PaO2:FiO2 ratio | 149 ± 66 | 158 ± 81 | 144 ± 61 | 0.03 |
*
Values are mean ± SD or n (%).
†
All clinical variables were measured at the time of trial enrollment, prior to randomization.
‡
Comorbid conditions available for n=1686 whites, n=443 blacks and n=187 Hispanics.
§
Predicted body weight