TABLE 2

Demographic and clinical data of the chronically critically ill patients who achieved weaning success at respiratory care unit admission

	NIV	No NIV	p-value
Subjects	40	158
Male/female	21/19	108/50	0.158
Age years	64.74±13.78	60.99±15.52	0.780
Medical/surgical cause of critical illness	30/10	87/71	0.048
Charlson index	1.97±1.34	1.45±1.61	0.153
APACHE II	14.00±3.55	11.81±5.51	0.037
Intensive care stay days	43.25±20.32	40.40±29.75	0.850
Mechanical ventilation in intensive care days	34.81±18.45	35.96±20.69	0.606
Respiratory care unit stay days	58.97±38.09	51.73±31.20	0.275
Weaning time at respiratory care unit days	29.00±17.56	23.77±16.42	0.211
1-year mortality %	12.1	12.8	0.876
Pressure support on mechanical ventilation cmH₂O	20.34±1.03	21±0.92	0.876
PEEP cmH₂O	4.32±0.01	4.93±0.02	0.765
Back-up respiratory rate on mechanical ventilation breaths·min⁻¹	13.21±0.93	14.01±0.23	0.854
pH	7.38±0.06	7.35±0.09	0.055
P_aO₂ mmHg	94.87±27.76	99.31±61.46	0.628
P_aCO₂ mmHg	50.32±10.33	43.95±8.56	0.004
F_IO₂	0.38±0.7	0.37±0.16	0.437
Leukocytes per L	9968.18±2685.28	10 042.29±3832.71	0.975
Neutrophils %	72.05±12.53	75.92±11.12	0.233
Haemoglobin g·dL⁻¹	9.70±1.62	9.54±1.46	0.777
Haematocrit %	29.09±5.24	28.95±4.50	0.963
Platelets per L	284 454.54±0.01	307 065.57±0.01	0.461
Sodium mmol·L⁻¹	138.86±5.87	138.36±4.53	0.763
Potassium mmol·L⁻¹	4.10±0.54	4.03±0.56	0.476
Blood urea nitrogen mg·dL⁻¹	55.86±49.58	47.90±30.17	0.512
Creatinine mg·dL⁻¹	0.84±0.76	0.70±0.45	0.443
Serum albumin g·dL⁻¹	3.10±0.65	3.02±0.55	0.550
C-reactive protein mg·L⁻¹	38.06±39.70	57.12±54.38	0.132

Data are presented as n or mean±sd, unless otherwise stated. NIV: noninvasive ventilation; APACHE: Acute Physiology and Chronic Health Evaluation; PEEP: positive end expiratory pressure; P_aO₂: arterial oxygen tension; P_aCO₂: arterial carbon dioxide tension; F_IO₂: inspiratory oxygen fraction.