Table 1

 Baseline characteristics of the cohort of COPD survivors treated with non-invasive ventilation for acute respiratory failure (n = 110)

Characteristics
Data are expressed as mean (SD) unless otherwise specified.
IQR, interquartile range; FEV1, forced expiratory volume in 1 second; Pao2, Paco2, arterial oxygen and carbon dioxide tensions; Fio2, fraction of inspired oxygen; ADL, Activities of Daily Living.
Age (years)73.2 (7.6)
Sex (M:F)87:23
Smoking habit (current/ex/never smoker)8/97/5
Smoking history (pack-years)50 (31)
Pre-morbid MRC score (median, IQR)4 (3–4)
Pre-morbid Katz ADL score (median, IQR)5 (3.75–6)
Charlson’s co-morbidity score (median, IQR)1 (1–2)
No (%) on home oxygen before index admission57 (52%)
No (%) of patients with past history of intubation15 (14%)
No (%) of patients with past history of NIV36 (33%)
No of days in hospital in previous year(median, IRQ)22.5 (4–61.25)
FEV1 during previous 6 months (% predicted, n = 79)33.3 (16.6)
APACHE II19.4 (4.7)
Radiological evidence of pneumonia (yes/no)34/76
Cor pulmonale by ECG (yes/no)35/75
Initial respiratory rate (/min)26 (6)
Body mass index (kg/m2)20.2 (4.5)
Haemoglobin (g/dl)12.7 (1.9)
Albumin (g/dl)32.2 (5.4)
Initial Pao2/Fio2 ratio (kPa)37.9 (19.9)
Initial pH7.24 (0.005)
Initial Paco2 (kPa)11.2 (2.6)