Table 2. Ventilatory and clinical parameters at baseline and follow-up.
| Parameter | Baseline | Follow up | p-value |
|---|---|---|---|
| Ventilation | |||
| IPAP [mbar], median (IQR) | 19.5 (16.0–26.0) | 13.8 (12.5–14.9) | <0.001* |
| EPAP [mbar], median (IQR) | 6.0 (4.8–9.0) | 6.0 (5.0–7.0) | 0.175 |
| Oxygen supplementation | |||
| oxygen rate on NIV [L/min], median (IQR) | 2.0 (0.8–2.0) | 1.0 (0.9–2.0) | 0.722 |
| oxygen rate off NIV [L/min), median (IQR) | 2.0 (1.8–2) | 2.0 (0.8–2) | 0,371 |
| Capillary blood gas analysis¶ | |||
| pH, median (IQR) | 7.41 (7.40–7.43) | 7.41 (7.39–7.42) | 0.477 |
| pCO2 [mmHg], median (IRQ) | 46.9 (43.8–55.7) | 50.0 (45.9–59.5) | 0,303 |
| pO2 [mmHg], median (IRQ) | 76.5 (73.0–81.4) | 75.2 (70.7–81.0) | 0.713 |
| Base excess [mmol], median (IQR) | 5.2 (3.8–10.7) | 5.4 (3.5–10.2) | 0.900 |
| Exercise tolerance | |||
| 6MWT distance [m], median (IQR) | 200 (153.8–266.3) | 270 (211.3–323.8) | <0.001* |
| BORG scale before 6MWT, median (IQR) | 3 (1.5–3.75) | 3 (2.25–3) | 0.947 |
| BORG scale after 6MWT, median (IQR) | 7.5 (5.625–8.625) | 6 (5–7) | 0.191 |
| Lung function tests | |||
| FEV1 [% predicted], median (IQR) | 24.5 (20.8–32.1) | 27.3 (20.8–31.3) | 0.203 |
| FVC [% predicted], median (IQR) | 49.5 (39.0–57.0) | 53.0 (41.8–60.8) | 0.040* |
| FVC [l], median (IQR) | 1.6 (1.3–2.1) | 1.8 (1.3–2.4) | 0.050* |
| FEV1/FVC [%], median (IQR) | 41.5 (35.1–47.4) | 38.6 (34.0–42.9) | 0.163 |
| VCin[l], median (IQR) | 1.6 (1.3–2.3) | 2.0 (1.3–2.7) | 0.148 |
| TLC [% predicted), median (IQR) | 120.1 (116.8–149.3) | 140.0 (110.3–156) | 0.717 |
| ITGV [l], median (IQR) | 6.7 (5.5–7.3) | 6.6 (5.5–7.4) | 0.774 |
| VCin/TLC, mean (IQR) | 0.3 (0.17–0.27) | 0.3 (0.21–0.32) | 0.177 |
| Reff [kPa×s×l−1], median (IQR) | 1.1 (0.4–1.2) | 0.8 (0.7–1.1) | 0.027* |
| Quality of life | |||
| CAT [score], median (IQR) | 26.5 (24.8–31.0) | 17 (11.3–22.5)§ | n.a. |
§At follow-up, only n = 4 patients competed the CAT questionnaire. Thus, no p-value is given.
¶Blood gas analysis was performed under oxygen supplementation in patients who had an established long-term oxygen therapy.
Abbreviations: IPAP, Inspiratory Positive Airway Pressure; EPAP, Expiratory Positive Airway Pressure; IQR, interquartile range; pCO2, partial pressure of carbon dioxide; pO2, partial pressure of oxygen; BE, Base Excess; 6MWT, 6 minute walk test: FEV1, Forced Expiratory Volume in One Second; FVC, Forced Vital Capacity; VCin, inspiratory vital capacity; TLC, total lung capacity; ITGV, intrathoracic gas volume; Reff, effective respiratory resistance.; CAT, COPD Assessment Test; n.a., not applicable.