Table 1 Baseline data

Age, years

76 ± 8

72 ± 9

68 ± 11

 < 0.01

81 ± 7

74 ± 8

69 ± 10

 < 0.01

Male

64 (70%)

73 (86%)

35 (95%)

 < 0.01

19 (73%)

78 (77%)

70 (88%)

0.11

Charlson comorbidity index

2 (1–3)

1 (1–2)

1 (0–2)

0.02

2 (1–3)

2 (1–2)

1 (1–2)

 < 0.01

Weaning category

 Simple weaning

47 (51%)

62 (73%)

28 (76%)

0.02

11 (42%)

61 (60%)

59 (74%)

 < 0.01

 Difficult weaning

37 (40%)

20 (24%)

8 (22%)

10 (39%)

37 (36%)

18 (23%)

 Prolonged weaning

8 (9%)

3 (4%)

1 (3%)

5 (19%)

4 (4%)

3 (4%)

Variables collected before extubation

 Duration of MV before extubation, d

6 (4–9)

5 (3–6)

5 (3–7)

0.04

8 (6–10)

5 (3–8)

4 (3–6)

 < 0.01

 PEEP, cmH₂O

5 (4–6)

5 (4–6)

5 (4–5)

0.44

5 (5–6)

5 (4–6)

5 (4–5)

0.10

 APACHE II score

13 ± 3

12 ± 3

11 ± 3

 < 0.01

14 ± 3

13 ± 3

11 ± 3

 < 0.01

 Hemoglobin, g/dl

11.1 ± 2.2

12.0 ± 2.1

12.8 ± 2.0

 < 0.01

10.2 ± 2.1

11.6 ± 2.2

12.5 ± 2.1

 < 0.01

 Albumin, g/L

30 ± 4

31 ± 5

32 ± 5

0.04

30 ± 4

30 ± 4

31 ± 5

0.44

 Respiratory rate, breaths/min

22 ± 5

21 ± 5

22 ± 6

0.67

23 ± 5

21 ± 5

21 ± 5

0.35

 Rapid shallow breathing index

59 ± 25

51 ± 24

50 ± 24

0.06

61 ± 23

58 ± 26

49 ± 23

0.02

 Heart rate, beats/min

96 ± 16

99 ± 16

95 ± 13

0.23

96 ± 17

99 ± 15

96 ± 16

0.37

 Systolic blood pressure, mmHg

134 ± 22

135 ± 22

132 ± 22

0.74

133 ± 17

136 ± 24

132 ± 21

0.47

 Diastolic blood pressure, mmHg

70 ± 12

74 ± 12

73 ± 12

0.03

67 ± 10

73 ± 12

74 ± 12

0.03

 PH

7.42 ± 0.05

7.41 ± 0.05

7.42 ± 0.05

0.47

7.43 ± 0.06

7.41 ± 0.05

7.42 ± 0.05

0.41

 PaCO_2, mmHg

54 ± 11

56 ± 11

51 ± 12

0.12

50 ± 12

56 ± 11

53 ± 12

0.02

 PaO₂/FiO_2, mmHg

232 ± 71

212 ± 55

212 ± 48

0.06

249 ± 67

223 ± 67

210 ± 50

0.02

Prophylactic use of NIV or HFNC

68 (74%)

70 (82%)

20 (54%)

 < 0.01

17 (65%)

82 (80%)

55 (69%)

0.12

Reintubation at 72 h

14 (15%)

2 (2%)

2 (5%)

 < 0.01

7 (27%)

6 (6%)

4 (5%)

 < 0.01

Duration of hospital stay, days

21 (14–31)

17 (12–26)

17 (11 -22)

0.04

21 (15–25)

19 (13–28)

17 (10–23)

0.03

Duration of ICU stay, days

14 (10–23)

12 (7–16)

9 (6–12)

 < 0.01

14 (12–23)

13 (8–22)

9 (6–15)

 < 0.01

Duration of hospital stay after extubation, days

12 (7–18)

11 (6–17)

10 (6–13)

0.21

9 (5–14)

11 (8–19)

10 (5–16)

0.08

Duration of ICU stay after extubation, days

7 (4–14)

6 (3–9)

4 (2–8)

 < 0.01

7 (4–11)

7 (5–11)

5 (2–8)

 < 0.01