Table 5

Predictive factors (adjusted for age and sex) of non-invasive ventilation (NIV) success and death

	Overall			Hypercapnic group
	OR	CI 95%	p	OR	CI 95%	p
Age, years	0.99	0.97–1.01	0.499	0.99	0.96–1.02	0.132
Sex (male = 1)	1.88	1.04–3.31	0.035	1.70	0.85–3.37	0.633
APACHE II	0.89	0.83–0.94	0.001	0.86	0.80–0.93	0.001
pH*	1.00	0.97–1.03	0.897	1.01	0.97–1.05	0.499
PaCO₂ (mm Hg)	0.99	0.98–1.01	0.237	0.97	0.96–0.99	0.017
Decreased level of consciousness	0.75	0.48–1.20	0.231	0.70	0.41–1.20	0.193

	Overall			Hypercapnic group
	OR	CI 95%	p	OR	CI 95%	p
*pH values were multiplied for 100. The OR obtained is for pH increments of 0.01.
†Improvement of PaCO₂ and pH within 6 h after NIV initiation.
Age, years	1.03	1.00–1.05	0.039	1.03	0.99–1.06	0.102
Sex (male = 1)	0.58	0.32–1.06	0.075	0.49	0.24–1.02	0.057
APACHE II	1.09	1.03–1.16	0.003	1.12	1.04–1.20	0.003
pH*	1.01	0.98–1.04	0.640	0.98	0.94–1.02	0.315
PaCO₂ (mm Hg)	1.00	0.98–1.01	0.612	1.01	0.99–1.03	0.410
Decreased level of consciousness	1.55	0.97–2.51	0.067	1.65	0.93–2.91	0.085
†PaCO₂ 6 h	0.44	0.17–1.14	0.091	0.33	0.97–1.13	0.078
†pH 6 h	0.16	0.05–0.50	0.002	0.14	0.03–0.62	0.009