Table 2.
Gas exchange and lung function during hospitalization and at the follow up visit.
| First PFT | Follow up PFT | Mean Difference (95% CI) | p-Value | |
|---|---|---|---|---|
| Gas exchange | ||||
| FiO2, % | 21 (21–32) | 21 (21–21) | - | 0.008 |
| pH | 7.45 (0.02) | 7.44 (0.03) | −0.01 (−0.02–0.01) | 0.436 |
| PaCO2, mmHg | 40 (32–43) | 38 (34–42) | - | 0.130 |
| PaO2, mmHg | 78 (71–88) | 90 (87–100) | - | 0.002 |
| HCO3-, mEq/L | 27.9 (3.1) | 26.5 (2.7) | −1.4 (−3.0–0.2) | 0.084 |
| PaO2/FiO2, mmHg | 316 (87) | 443 (69) | 126 (86–166) | <0.001 |
| A-a O2 gradient, mmHg | 34 (19–101) | 9 (4–19) | - | <0.001 |
| Spirometry | ||||
| FVC, liters | 2.61 (1.01) | 3.22 (1.07) | 0.61 (0.34–0.88) | <0.001 |
| FVC, % predicted | 69.6 (15.9) | 87.4 (16.0) | 17.8 (10.0–25.6) | <0.001 |
| VC, liters | 2.73 (1.09) | 3.35 (1.10) | 0.62 (0.39–0.86) | <0.001 |
| VC, % predicted | 71.7 (16.9) | 87.4 (16.2) | 15.7 (9.9–21.5) | <0.001 |
| FEV1, liters | 2.22 (0.91) | 2.69 (0.87) | 0.46 (0.28–0.65) | <0.001 |
| FEV1, % predicted | 75.1 (18.9) | 91.3 (15.2) | 16.3 (8.9–23.6) | <0.001 |
| FEV1/VC, % predicted | 104.5 (98.2–114.0) | 104.5 (98.2–111.0) | - | 0.751 |
| FEV1/VC < LLN, n (%) | 3 (15) | 0 (0) | - | 0.250 |
| Body-plethysmography* | ||||
| RV, liters | - | 1.74 (0.50) | - | - |
| RV, % predicted | - | 82.5 (28.8) | - | - |
| IC, liters | - | 2.32 (0.71) | - | - |
| IC, % predicted | - | 85.0 (23.5) | - | - |
| TLC, liters | - | 5.19 (1.27) | - | - |
| TLC, % predicted | - | 84.6 (15.6) | - | - |
| TLC < 80%predicted, n (%) | - | 7 (35) | - | - |
| sRawtot, kPa·s | - | 0.83 (0.32) | - | - |
| sRawtot, % predicted | - | 75.0 (28.0) | - | - |
| Lung diffusion capacity | ||||
| DLco, mmol·min−1·kPa−1 | 4.98 (2.05) | 5.95 (2.15) | 0.96 (0.58–1.35) | <0.001 |
| DLco, % predicted | 56.0 (16.3) | 67.2 (18.0) | 11.2 (6.9–15.4) | <0.001 |
| VA, liters | 3.88 (1.34) | 4.54 (1.38) | 0.66 (0.39–0.92) | <0.001 |
| VA, % predicted | 64.8 (14.0) | 75.3 (16.1) | 10.5 (6.1–14.9) | <0.001 |
| VC/VA | 0.70 (0.12) | 0.74 (0.07) | −0.04 (−0.1–0.03) | 0.234 |
| KCO, mmol·min−1·kPa−1·l−1 | 1.32 (0.36) | 1.32 (0.28) | −0.00 (−0.09–0.92) | 0.981 |
| KCO, % predicted | 89.1 (19.2) | 91.7 (14.8) | 2.65 (−3.2–8.5) | 0.358 |
Data are reported as means (standard deviation, SD), medians (inter-quartile range, IQR) and frequencies. When appropriate, the 95% confidence interval (CI) is provided for the difference between follow up and hospitalization measurement. FEV1 = forced expiratory volume in one second; FVC = forced vital capacity; VC = vital capacity; LLN = lower limits of normal; RV = residual volume; IC = inspiratory capacity; TLC = total lung capacity; sRAWtot = specific total airway resistances; DLco = lung diffusion capacity for carbon monoxide; VA = alveolar volume; KCO = transfer factor for carbon monoxide. *Plethysmographic parameters were measured only at the follow up visit. Two patients were unable to perform the test (one patient had hearing loss, one patient was claustrophobic). The data reported for plethysmography are referred to 18 patients.