Table 1.
Demographics, comorbidities, and clinical parameters of the study subjects
| Mild (n = 42) | Moderate (n = 71) | Severe (n = 40) | P value | |
|---|---|---|---|---|
| Male gender, n (%) | 28 (66.7) | 49 (69.0) | 31 (77.5) | 0.49 |
| Age, mean ± SD (y) | 66.7 ± 16.8 | 68.1 ± 16.2 | 65.3 ± 16.9 | 0.7 |
| BMI, mean ± SD (kg/m2) | 20.4 ± 4.0 | 20.5 ± 4.5 | 20.6 ± 4.2 | 0.97 |
| Body temperature | 37.4 ± 0.9 | 37.7 ± 1.4 | 37.5 ± 2.6 | 0.64 |
| Underlying pneumonia (bacterial/aspiration/VAPa) | 8/17/4 | 28/19/1 | 20/7/0 | |
| Comorbidity | ||||
| chronic heart disease | 25% | 24% | 23% | 0.94 |
| chronic respiratory disease | 13% | 18% | 34% | 0.30 |
| chronic kidney disease | 19% | 18% | 25% | 0.71 |
| glucose intolerance | 24% | 21% | 25% | 0.88 |
| connective tissue disease | 2% | 10% | 15% | 0.14 |
| Direct lung injury | 71% | 87% | 78% | 0.095 |
| Sepsis | 81% | 62% | 58% | 0.045 |
| Use of catecholamine | 36% | 39% | 58% | 0.91 |
| Immunosuppressant usage | 22% | 16% | 18% | 0.71 |
| Clinical scores | ||||
| APACHE II score | 20.9 ± 6.5 | 23.6 ± 5.8 | 27.7 ± 8.4 | < 0.001 |
| SOFA score | 9.3 ± 3.1 | 10.7 ± 3.0 | 12.8 ± 3.9 | < 0.001 |
| SAPS II score | 55.4 ± 13.9 | 61.5 ± 13.5 | 65.9 ± 16.8 | 0.059 |
| Laboratory data | ||||
| White blood cell (× 103/mm3) | 16.1 ± 8.3 | 13.1 ± 8.1 | 13.4 ± 12.6 | 0.97 |
| Platelet (× 103/mm3) | 209 ± 135 | 196 ± 146 | 171 ± 152 | 0.25 |
| Total bililubin (mg/dL) | 2.1 ± 4.4 | 1.6 ± 3.6 | 2.8 ± 7.0 | 0.18 |
| Creatinine (mg/dL) | 1.4 ± 1.4 | 1.4 ± 1.3 | 1.9 ± 1.6 | 0.15 |
| C-reactive protein (mg/dL) | 10.6 ± 9.0 | 12.2 ± 10.4 | 14.3 ± 12.1 | 0.48 |
| LDH (IU/L) | 334 ± 181 | 339 ± 182 | 436 ± 259 | 0.078 |
| HCO3− (mEq/L) | 24.9 ± 10.4 | 25.9 ± 6.7 | 25.5 ± 9.1 | 0.83 |
| PaCO2 (Torr) | 41.0 ± 9.6 | 47.4 ± 18.8 | 46.7 ± 15.7 | 0.1 |
| Lactate (mmol/L) | 1.7 ± 1.2 | 2.5 ± 2.8 | 3.7 ± 4.2 | 0.004 |
| HRCT score | 151 ± 43 | 182 ± 71 | 204 ± 80 | 0.005 |
| Ventilatory variables | ||||
| Max. inspiratory pressure (cmH2O) | 17.0 ± 7.7 | 20.5 ± 6.8 | 21.4 ± 6.9 | 0.012 |
| Respiratory rate (breaths/min) | 23 ± 6 | 27 ± 8 | 28 ± 10 | 0.007 |
| PEEP (cmH2O) | 8 ± 3 | 10 ± 4 | 11 ± 4 | 0.002 |
| FiO2 | 0.43 ± 0.10 | 0.46 ± 0.10 | 0.5 ± 0.12 | 0.023 |
| Outcomes | ||||
| Ventilator-free days | 18.0 ± 8.1 | 11.5 ± 9.6 | 6.2 ± 8.8 | < 0.001 |
| ICU free days | 14.7 ± 8.2 | 11.9 ± 8.4 | 5.8 ± 7.5 | < 0.001 |
| 30-day mortality (%) | 4 (10%) | 16 (23%) | 22 (55%) | 0.012 |
aventilator-associated pneumonia