Table 1.

Patient characteristics

	Mean (SD)	Range
Age (years)	67.6 (10.1)	46–97
BMI	28.9 (7.0)	17–43
FEV1% predicted	32.7 (10.8)	13–64
FEV1/FVC	48.0 (11.3)	19–66
pH-t0	7.26 (0.06)	7.03–7.41
pCO2-t0 (mmHg)	80.1 (19.7)	46.2–151

Legend:

BMI body mass index, FEV1 forced expiratory volume over 1 s, FVC forced vital capacity, pCO2 arterial partial pressure of carbon dioxide

t0 = before the start of NIV