Mean (SD) demographic, clinical, and functional characteristics recorded at baseline and during non-invasive mechanical ventilation (NIMV) at 1 and 24 hours in patients with COPD grouped according to the success of NIMV (group 1 = successful, group 2 = “late respiratory failure”)
| Group 1 (n=106) | Group 2 (n=31) | p value | |
| Age (years) | 70 (8.8) | 70 (10.1) | NS |
| pH | |||
| On admission | 7.25 (0.07) | 7.22 (0.08) | NS |
| 1 h | 7.30 (0.06) | 7.30 (0.06) | NS |
| 24 h | 7.36 (0.06) | 7.36 (0.06) | NS |
| Paco 2 (mm Hg) | |||
| On admission | 87.6 (17.1) | 82.9 (14.7) | NS |
| 1 h | 76.6 (13.6) | 72.7 (12.0) | NS |
| 24 h | 68.8 (13.2) | 62.8 (10.0) | 0.024 |
| Sao 2/Fio 2 at admission | 2.0 (0.6) | 1.8 (0.6) | NS |
| Heart rate (bpm) | 97 (17.8) | 104 (20.1) | 0.044 |
| Respiratory rate (bpm) | 26 (5.6) | 27 (6.5) | NS |
| Arterial pressure (mm Hg) | 105 (15) | 98 (15) | 0.034 |
| Compliance score | 3.7 (1.0) | 3.6 (1.0) | NS |
| APACHE II score | 22.0 (4.5) | 22.9 (6.0) | NS |
| ADL score | 2.1 (0.8) | 1.7 (0.7) | 0.024 |
| No of complications of admission | 0.45 (0.6) | 0.7 (0.7) | 0.039 |
| Community acquired pneumonia (no (%)) | 8 (7.5%) | 7 (22.6%) | NS |
| Albumin (mg/dl) | 34.2 (3.3) | 34.9 (4.6) | NS |
| Sodium (mEq/l) | 139 (3.6) | 138 (3.6) | NS |
| Potassium (mEq/l) | 4.2 (0.6) | 4.0 (0.4) | NS |
| Fasting glycaemia (mg/dl) | 83.5 (8.8) | 94.1 (53.2) | NS |
| FEV1 (% pred) | 17.6 (9.1) | 14,7 (13.5) | NS |
| FVC (% pred) | 45.6 (8.2) | 43.5 (14.3) | NS |
| FEV1/FVC | 38.5 (7.6) | 33.7 (11.4) | NS |
ADL = activity of daily living score; FEV1 = forced expiratory volume in one second; FVC = forced vital capacity. Dynamic lung volumes were recorded in 61 and 18 patients of groups 1 and 2, respectively.