Table 1 Main patients characteristics
| Â | Total population (n = 391) | Successful liberation from MV 28 days (n = 165) | Unsuccessful liberation from MV 28 days (n = 226) | p |
|---|---|---|---|---|
Variables | ||||
 Age - year (IQR) | 66 (59–72) | 64 (56–70) | 68 (62–74) | < 0.001 |
 Sex - male – no (%) | 300 (76.7%) | 121 (73.3%) | 179 (79.2%) | 0.175 |
 BMI - median (IQR) | 28 (26–31) | 28 (26–31) | 28 (26–31) | 0.918 |
 SAPS II score | 38 (31–46) | 35 (28–42) | 39 (33–48) | < 0.001 |
 SOFA score at ICU admission | 5 (3–7) | 4 (3–6) | 6 (4–8) | < 0.001 |
Comorbidities | ||||
 Hypertension - no (%) | 222 (56.8%) | 79 (47.9%) | 143 (63.3%) | 0.003 |
 Chronic ischemic heart disease - no (%) | 35 (9.0%) | 12 (7.3%) | 23 (10.2%) | 0.416 |
 Chronic kidney disease (CKD) | 26 (6.6%) | 8 (4.8%) | 18 (8.0%) | 0.362 |
 CKD - patients in dialisys - no (%) | 4 (1.0%) | 1 (0.6%) | 3 (1.3%) |  |
 COPD - no (%) | 27 (6.9%) | 11 (6.7%) | 16 (7.1%) | 0.964a |
 COPD - home oxygen therapy/CPAP - no (%) | 2 (0.5%) | 1 (0.6%) | 1 (0.4%) |  |
 Diabetes - no (%) | 85 (21.7%) | 28 (17.0%) | 57 (25.2%) | 0.067 |
 Chronic liver disease (MELD > 10) - no (%) | 3 (0.8%) | 1 (0.6%) | 2 (0.9%) | 1.000 |
 Active cancer - no (%) | 7 (1.8%) | 0 (0%) | 7 (3.1%) | 0.058 |
 Immunosuppressive therapy - no (%) | 10 (2.6%) | 1 (0.6%) | 9 (4.0%) | 0.078 |
Smoker status (n = 213) b | ||||
 Current - no (%) | 13 (6.1%) | 8 (8.1%) | 5 (4.4%) | 0.507a |
 Previous - no (%) | 66 (31.0%) | 29 (29.3%) | 37 (32.5%) |  |
Characteristics before ICU admission | ||||
 Time from symptoms onset to hospital admission (n = 327)b - d (IQR) | 7 (4–9) | 7 (4–9) | 7 (4–10) | 0.480 |
 Time from hospital admission to ICU admission - d (IQR) | 2 (1–5) | 2 (1–5) | 2 (0–5) | 0.436 |
 Time from hospital admission to intubation - d (IQR) | 2 (1–5) | 2 (1–5) | 2 (1–6) | 0.389 |
Ward of admission | ||||
 Emergency department - no (%) | 70 (17.9%) | 20 (12.1%) | 50 (22.1%) | 0.04a |
 Medical ward - no (%) | 184 (47.1%) | 82 (49.7%) | 102 (45.1%) |  |
 Other ICU - no (%) | 137 (35.0%) | 63 (38.2%) | 74 (32.7%) |  |
 High flow nasal oxygen therapy before intubation (n = 362)b - no (%) | 31 (8.5%) | 14 (9.1%) | 17 (8.1%) | 0.880 |
 CPAP/Non-invasive ventilation trial before intubation (n = 363)b - no (%) | 254 (70%) | 117 (70.9%) | 137 (60.6%) | 0.029 |
Duration of CPAP/NIV trial (n = 363)b | ||||
 < 12 h - no (%) | 56 (22.1%) | 24 (20.5%) | 32 (23.5%) | 0.051a |
 12–24 h - no (%) | 63 (24.9%) | 35 (29.9%) | 28 (20.6%) |  |
 24–48 h - no (%) | 44 (17.4%) | 25 (21.4%) | 19 (14.0%) |  |
 > 48 h - no (%) | 90 (35.6%) | 33 (28.2%) | 57 (41.9%) |  |
 PaO2/FiO2 ratio before intubation (n = 297)b | 94 (75–119) | 96 (71–125) | 91 (77–116) | 0.544 |