Characteristics of patients with acute exacerbations of chronic obstructive pulmonary disease assigned to standard treatment or non-invasive ventilation
| Characteristic | Standard treatment (n=118) | NIV (n=118) |
| Mean (SD) age (years) | 69 (8) | 69 (7) |
| M:F | 63:55 | 54:64 |
| Respiratory rate (breaths/min)1-150 | 28 (24–40) | 28 (24–36) |
| pH1-150 | 7.31 (7.26–7.35) | 7.32 (7.25–7.35) |
| Mean (SD) Paco 2 (kPa) | 8.65 (1.70) | 8.82 (1.51) |
| Pao 2 (kPa)1-150 | 7.00 (4.71–12.31) | 6.88 (4.50–13.8) |
| FEV1 at discharge (l)1-150 | 0.68 (0.37–2.00) | 0.71 (0.28–1.47) |
Paco2 , Pao 2 = arterial carbon dioxide and oxygen tensions; FEV1 = forced expiratory volume in one second.
↵1-150 Median data with 5th and 95th centiles.