Table 2 Clinical, echographic, and spirometric characteristics of the overall population and of successfully and unsuccessfully weaned patients

 RR (breaths/min)

20 ± 6

18 ± 5

24 ± 7

<0.0001

 VT (ml/kg IBW)

5.9 ± 2.3

6.3 ± 2.2

5.1 ± 2.2

0.084

 DD (mm)

14.0 (9.0–17.7)

15.5 (11.7–23.0)

7.0 (6.0–14.7)

<0.0001

 D-RSBI (breaths/min/mm)

1.7 (0.8–2.7)

1.2 (0.8–1.9)

2.7 (1.7–4.1)

<0.0001

 RSBI (breaths/min/L)

47 (33–61)

43 (32–52)

63 (37–90)

0.012

 MIP (cmH₂O)

26 (20–31)

28 (22–36)

22 (19–25)

0.020

 PS (cmH₂O)

7.2 ± 2.8

7.3 ± 3.1

7.1 ± 2.0

0.878

 PEEP (cmH₂O)

6.2 ± 1.3

6.1 ± 1.4

6.5 ± 1.2

0.281

 Duration of PEEP >8 cmH₂O (h)

43 ± 23

34 ± 13

69 ± 37

0.003

Intra-abdominal pressure (cmH₂O)

13 ± 2

12.7 ± 1.7

13.1 ± 0.8

0.781

Length of MV until SBT (h)

69 (53–173)

57 (49–66)

169 (73–296)

0.001

ICU length of stay (days)

5.0 (3.0–9.2)

3.0 (2.3–4.5)

9.2 (6.1–15.3)

0.001

Hospital length of stay (days)

15 (9–23)

10 (8–13)

26 (19–29)

0.001

Hospital mortality

9 (18)

3 (9)

6 (35)

0.045