Baseline demographics of the study population
| Variable | Value |
| Age (years; mean (SD)), n = 88 | 70 (10) |
| Gender, n = 88 | 39 male (44%) |
| 49 female (56%) | |
| FEV1 (litres; mean (SD)), n = 82 | 0.68 (0.29) |
| FVC (litres; mean (SD)), n = 82 | 1.62 (0.56) |
| Known diagnosis of diabetes mellitus | Yes = 16 (18%; 4 prescribed insulin) |
| No = 72 (82%) | |
| Glucose level prior to NIPPV initiation, n = 88 | 0–6.9 mmol/l = 44 (50%) |
| >7 mmol/l = 44 (50%) | |
| Arterial pH prior to NIPPV initiation, n = 88 | 7.25 (0.64) |
| Arterial pCO2 prior to NIPPV initiation (kPa), n = 88 | 10.20 (2.17) |
| Arterial pO2 prior to NIPPV initiation (kPa), n = 88 | 8.19 (2.65) |
| Calculated bicarbonate (mmol/l), n = 88 | 25.65 (3.60) |
| Respiratory rate prior to NIPPV initiation (breaths/min), n = 88 | 27 (8) |
| APACHE II score prior to NIPPV initiation, n = 88 | 15 (4) |
| Charlson comorbidity index, n = 88 | 1.66 (0.76) |
Values are given as mean (SD).
APACHE II, Acute Physiology and Chronic Health Evaluation II; FEV1, forced expiratory volume in 1 s; FVC, forced vital capacity; NIPPV, non-invasive positive pressure ventilation.