Table 1 Patient characteristics
Variables | All (n = 110) | Weaning success (n = 73) | Weaning failure (n = 37) | P value |
|---|---|---|---|---|
Age, years | 71.3 ± 17.3 | 70 ± 19 | 73.8 ± 13.4 | 0.291 |
Male, n (%) | 78 (70.9) | 52 (71.2) | 26 (70.3) | 0.916 |
APACHE II score | 17 [15–20] | 17 [15–20] | 16 [15–18.5] | 0.268 |
Length of MV until SBT, day | 5.5 [3–9] | 5 [3–8] | 7 [4–9.5] | 0.163 |
HR, beats/min | 85.8 ± 13.7 | 85.1 ± 13.1 | 87.3 ± 15.1 | 0.429 |
RR prior to SBT, breaths/min | 17.4 ± 3.4 | 16.9 ± 2.9 | 18.5 ± 3.9 | 0.015 |
MAP, mmHg | 87 [77–95.5] | 89 [77.5–95] | 84 [74–99] | 0.253 |
Reason for MV, n (%) | ||||
 Pneumonia | 30 (27.3) | 20 (27.4) | 10 (27) | 0.967 |
 AECOPD | 22 (20) | 13 (17.8) | 9 (24.3) | 0.42 |
 Heart failure | 12 (10.9) | 9 (12.3) | 3 (8.1) | 0.728 |
 Septic shock | 8 (7.3) | 5 (6.8) | 3 (8.1) | 0.882 |
 Traumatic brain injury | 8 (7.3) | 6 (8.2) | 2 (5.4) | 0.882 |
 Poisoning | 3 (2.7) | 2 (2.7) | 1 (2.7) | 0.543 |
 Postsurgery | 5 (4.5) | 4 (5.5) | 1 (2.7) | 0.86 |
 Acute stroke | 13 (11.8) | 8 (11) | 5 (13.5) | 0.937 |
 CPR | 2 (1.8) | 1 (1.4) | 1 (2.7) | – |
 Hemorrhagic shock | 5 (4.5) | 4 (5.5) | 1 (2.7) | 0.86 |
 Others | 2 (1.8) | 1 (1.4) | 1 (2.7) | – |
Blood gas analysis prior to SBT | ||||
 PaO2 (mmHg) | 107.5 [98–130.3] | 108 [99–124.5] | 106 [95.5–147.5] | 0.862 |
 PaCO2 (mmHg) | 37.5 [30, 31, 33–41] | 37 [31–41.5] | 39 [33–46] | 0.204 |
 PaO2/FiO2 (mmHg) | 300 [254.4–350.4] | 300 [253.8–340] | 312.5 [250–383.3] | 0.423 |
MV parameters prior to SBT | ||||
 PS, cmH2O | 14 [12–15] | 13 [12–15] | 14 [11–15.5] | 0.847 |
 PEEP, cmH2O | 3 [3, 4] | 3 [3, 4] | 4 [3, 4] | 0.525 |
 VT, ml | 427.5 [408–508.3] | 427 [408.5–514.5] | 434 [398.5–503] | 0.912 |
Clinical outcomes | ||||
 ICU length of stay, day | 10 [6–15] | 9 [5–13.5] | 14 [10–17] |  < 0.001 |
 Hospital length of stay, day | 17 [12–21, 32] | 15 [10–20.5] | 19 [16.5–23] | 0.001 |