Table 2.
Characteristics of the three groups of patients at inclusion.*
| Characteristic | Community-acquired pneumonia (n=38) | Ventilator-associated pneumonia (n=46) | No pneumonia (n=64) | P value† |
| Duration of mechanical ventilation before study entry [days] | 0.4 ± 0.2 | 6.4 ± 8.5 | 2.1 ± 4.8 | <0.001 |
| Previous antimicrobial therapy [n (%)] | 33 (87) | 19 (41) | 30 (47) | <0.001 |
| Shock [n (%)] | 18 (47) | 19 (41) | 30 (47) | 0.49 |
| Body temperature [°C] | 37.9 ± 2.0 | 38.1 ± 0.9 | 37.7 ± 1.1 | 0.82 |
| Leukocyte count [g/l] | 12.8 ± 7.9 | 13.4 ± 8.5 | 12.5 ± 5.8 | 0.99 |
| PaO2/FiO2 [mmHg] | 181 ± 80 | 203 ± 67 | 206 ± 91 | 0.51 |
| PCT [ng/ml] | 3.7 ± 1.9 | 2.6 ± 0.8 | 2.5 ± 1.2 | 0.58 |
| CRP [mg/l] | 197 ± 128 | 184 ± 108 | 141 ± 110 | 0.34 |
| BAL fluid TNF-α [pg/ml] | 298.2 ± 47.7 | 290.5 ± 39.7 | 147.2 ± 25.1 | <0.001 |
| BAL fluid TNF-1β [pg/ml] | 92.5 ± 22.5 | 95.1 ± 29.4 | 41.5 ± 12.5 | <0.001 |
| BAL fluid sTREM-1 [pg/ml] | 23.2 ± 2.8 | 33.6 ± 5.1 | 1.8 ± 0.9 | <0.001 |
* Values are expressed as the mean ± Standard Deviation unless otherwise indicated.
† P values are comparisons between community-acquired pneumonia, ventilator-associated pneumonia, and no pneumonia groups. Mann Whitney U test for numerical data and Pearson χ2 test for categorical data.
BAL, bronchoalveolar lavage; CRP, C-reactive protein; PaO2/FiO2, ratio of the partial pressure of arterial oxygen to the fraction of inspired oxygen; PCT, procalcitonin; sTREM-1, soluble triggering receptor expressed on myeloid cells-1; TNF, tumor necrosis factor.