Table 2. Plasma profile comparison between ARDS and controls.
| ARDS Mean (95% CI) | Control Mean (95%CI) | P c | Healthy Reference Mean (95%CI) d | |
| All samples a | N = 67 | N = 63 | ||
| PI3 | 44.3 (35.0–56.0) | 69.3 (54.4–88.2) | 0.005 | 19.6 (13.9–27.5) |
| SLPI | 115.3 (101.2–131.5) | 132.5 (115.8–151.7) | 0.752 | 69.6 (62.3–77.9) |
| HNE | 643.6 (525.3–788.7) | 453.3 (367.6–558.9) | 0.017 | 77.1 (63.9–93.1) |
| HNE/PI3 ratio | 14.5 (10.9–19.4) | 6.5 (4.9–8.8) | <0.0001 | 3.9 (2.7–5.9) |
| Pulmonary injury b | N = 54 | N = 30 | ||
| PI3 | 44.6 (35.6–55.9) | 81.7 (60.2–110.8) | 0.001 | |
| SLPI | 126.2 (112.0–142.3) | 140.7 (119.6–165.4) | 0.221 | |
| HNE | 546.2 (447.5–666.7) | 396.3 (302.6–519.1) | 0.107 | |
| HNE/PI3 ratio | 12.2 (9.3–16.1) | 4.9 (3.3–7.0) | <0.0001 | |
| Extrapulmonary injury b | N = 13 | N = 33 | ||
| PI3 | 66.7 (36.2–122.9) | 77.9 (44.9–135.3) | 0.480 | |
| SLPI | 108.6 (74.0–159.3) | 136.9 (96.9–193.5) | 0.655 | |
| HNE | 639.9 (376.7–1087.1) | 491.0 (304.5–791.6) | 0.655 | |
| HNE/PI3 ratio | 13.7 (4.5–20.3) | 6.3 (3.2–12.4) | 0.254 |
ARDS, acute respiratory distress syndrome; Control, at-risk ICU control; PI3, neutrophil elastase inhibitor (elafin); SLPI, secretory leukocyte proteinase inhibitor; HNE, neutrophil elastase; the plasma levels of PI3, SLPI, and HNE were shown in unit of ng/ml; 95%CI, 95% confidence interval.
To account for repeated measurements, mean plasma levels were calculated using mixed models after adjusting for age, gender, type of lung injury, pre-admission steroid use, septic shock, and APACHE III score on ICU admission. Type of lung injury: pulmonary injury - pneumonia, aspiration, pulmonary contusions, or sepsis from lower pulmonary source; extrapulmonary injury - sepsis from an extrapulmonary source, trauma without pulmonary contusions, and multiple transfusions. Patients with both pulmonary and extrapulmonary injuries were considered to have pulmonary injury.
To account for repeated measurements, mean plasma levels were calculated using mixed models after adjusting for age, gender, pre-admission steroid use, septic shock and APACHE III score on ICU admission.
P values were calculated between the ARDS and the controls.
Mean plasma levels of anonymous healthy individuals (reference groups) were calculated directly without any adjustment.