1 Main characteristics of patients at the start of noninvasive positive pressure ventilation
| General ward | RIICU | ICU | All units | |
| Patients | 176 (17.0) | 779 (75.4) | 78 (7.6) | 1033 (100) |
| Males | 127 (72.2) | 515 (66.4) | 40 (72.7) | 682 (66.0) |
| Age yrs | 68.1±9.8 | 69.7±8.9 | 71.5±7.9 | 69.5±9.0 |
| APACHE II score | 18.2±4.5 | 20.3±6.1 | 25.7±6.2 | 20.3±5.9 |
| Glasgow Coma Scale | 14.3±1.5 | 13.0±2.4 | 12.3±3.0 | 13.2±2.3 |
| Previous LTOT | 99 (56.2) | 329 (42.2) | 18 (23.0) | 446 (43.1) |
| Previous home MV | 30 (17.0) | 90 (11.5) | 18 (23.0) | 138 (13.4) |
| Hospitalisations·yr−1 | 1.8±2.3 | 1.6±1.8 | 2.7±1.1 | 1.6±1.9 |
| Chronic comorbidity | 113 (64.2) | 344 (44.2) | 64 (82.1) | 521 (50.4) |
| Pa,O2 mmHg | 57.8±19.4 | 54.3±15.7 | 50.0±21.2 | 54.5±16.9 |
| Pa,CO2 mmHg | 75.9±16.3 | 80.7±16.9 | 88.0±18.3 | 80.4±16.9 |
| pH | 7.31±0.08 | 7.28±0.06 | 7.22±0.06 | 7.28±0.07 |
| Pa,O2/Fi,O2 | 201.9±43.6 | 186.9±46.8 | 127.1±58.1 | 180.3±48.2 |
| RR breaths·min−1 | 28.9±5.6 | 29.0±6.3 | 33.9±5.7 | 29.4±6.1 |
| Pneumonia | 32 (18.3) | 93 (12.0) | 5 (6.4) | 130 (12.6) |
Data are presented as mean±sd or n (%). RIICU: respiratory intermediate intensive care units; ICU: intensive care unit; APACHE: acute physiology and chronic health evaluation; LTOT: long-term oxygen therapy; MV: mechanical ventilation; Pa,O2: arterial oxygen tension; Pa,CO2: carbon dioxide arterial tension; Fi,O2: inspiratory oxygen fraction; RR: respiratory rate. 1 mmHg = 0.133 kPa.