Table 1 Clinical characteristics on admission to the weaning center
|  | All patients (n = 378) | Transfused (n = 168) | Non-transfused (n = 210) | P valued |
|---|---|---|---|---|
Clinical characteristics | ||||
 Age (years) | 69.3 (± 12.0) | 70.6 (± 10.2) | 68.3 (± 13.2) | 0.058a |
 Gender (male) | 229 (60.6) | 100 (59.5) | 129 (61.4) | n.s.b |
 Body mass index (kg/m2) | 27.1 (± 7.7) | 25.7 (± 6.7) | 28.2 (± 8.3) | 0.001a |
 Smoking history | 165 (43.7) | 68 (40.5) | 97 (46.2) | n.s.b |
 APACHE-II | 16.2 (± 5.0) | 17.1 (± 5.0) | 15.5 (± 5.0) | 0.002a |
 Albumin (g/dl) | 2.0 (± 0.5) | 1.9 (± 0.5) | 2.1 (± 0.5) | 0.002a |
 No. of patients with anemia | 372 (98.4) | 167 (99.4) | 205 (97.6) | n.s.b |
 Hemoglobin on the day of admission (g/dl) | 9.0 (± 1.3) | 8.5 (± 1.0) | 9.4 (± 1.3) | <  0.001a |
 Ventilator days on admission | 28.4 (± 19.9) | 31.4 (± 22.0) | 26.0 (± 17.7) | 0.010a |
 Time from ETI to tracheostomy (days) | 10.2 (± 7.0) | 11.0 (± 7.7) | 9.5 (± 6.4) | 0.035a |
 ECLA | 20 (5.3) | 10 (6.0) | 10 (4.8) | n.s.b |
Comorbidities | ||||
 No. of comorbidities per patient | 2.1 (± 1.6) | 2.1 (± 1.5) | 2.0 (± 1.6) | n.s.a |
 Charlson comorbidity index | 6.2 (± 2.6) | 6.7 (± 2.2) | 5.9 (± 2.8) | 0.001a |
 COPD | 103 (27.2) | 37 (22.0) | 66 (31.4) | 0.041b |
 Coronary artery disease | 113 (29.9) | 59 (35.1) | 54 (25.7) | 0.047b |
 Left ventricular dysfunction (systolic) | 83 (22.0) | 46 (27.4) | 37 (17.6) | 0.023b |
 Renal insufficiency (GFR < 60 ml/min) | 88 (23.3) | 52 (31.0) | 36 (17.1) | 0.001b |
 Hepatopathy | 22 (5.8) | 12 (7.1) | 10 (4.8) | n.s.b |
 Diabetes mellitus | 114 (30.2) | 45 (26.8) | 69 (32.9) | n.s.b |
 Neuromuscular disease | 21 (5.6) | 6 (3.6) | 15 (7.1) | n.s.b |
 Interstitial lung disease | 21 (5.6) | 8 (4.8) | 13 (6.2) | n.s.b |
 Malignancy (active) | 39 (10.3) | 20 (11.9) | 19 (9.1) | n.s.b |
 Immunosuppression | 49 (13.0) | 20 (11.9) | 29 (13.8) | n.s.b |
Cause of acute respiratory failure | ||||
 Pneumonia | 124 (32.8) | 49 (29.2) | 75 (35.7) | n.s.b |
 Sepsis (incl. Septic shock) | 33 (8.7) | 16 (9.5) | 17 (8.1) | n.s.b |
 Acute exacerbation of COPD | 36 (9.5) | 6 (3.6) | 30 (14.3) | <  0.001b |
 Cardiac failure | 12 (3.2) | 2 (1.2) | 10 (4.8) | 0.049b |
 Cardiopulmonary resuscitation | 31 (8.2) | 20 (11.9) | 11 (5.2) | 0.019b |
 Surgery | 94 (24.9) | 57 (33.9) | 37 (17.6) | <  0.001b |
  Cardiac surgery | 39 (10.3) | 27 (16.1) | 12 (5.7) | 0.001b |
  Thoracic surgery | 32 (8.5) | 19 (11.3) | 13 (6.2) | n.s.b |
  Abdominal surgery | 14 (3.7) | 7 (4.2) | 7 (3.3) | n.s.b |
  Other | 9 (2.4) | 4 (2.4) | 5 (2.4) | n.s.b |
 Trauma | 9 (2.4) | 4 (2.4) | 5 (2.4) | n.s.b |
 Other | 39 (10.3) | 14 (8.3) | 25 (11.9) | n.s.b |