Table 1 Baseline values between groups

Age, years

73 ± 12

74 ± 13

0.68

67 ± 14

58 ± 19

<0.01^c

<0.01^c

Females/males, n

32/76

33/39

0.04^c

12/59

27/78

0.20

<0.01^c

 AECOPD

74

31

<0.01^c

46

26

<0.01^c

<0.01^c

 Pneumonia

26

32

0.01^c

13

36

0.03^c

0.42

 ARDS

2

5

0.12

9

22

0.23

<0.01^c

 Asthma

2

0

0.52

1

5

0.40

0.17

 Other

4

4

0.72

2

16

0.01^c

0.04^c

 Upon admission

24 ± 6

23 ± 6

0.46

21 ± 6

19 ± 7

0.02^c

<0.01^c

 At extubation

13 ± 3

13 ± 3

0.65

12 ± 3

11 ± 3

0.02^c

<0.01^c

Intubation period before extubation, days

8 ± 12

7 ± 5

0.44

7 ± 5

5 ± 4

<0.01^c

0.01^c

Cough peak flow, L/minute

48 ± 14

44 ± 15

0.07

98 ± 34

108 ± 29

0.04^c

<0.01^c

Hemoglobin, g/dl

10.8 ± 2.3

10.4 ± 2.2

0.26

11.3 ± 2.5

11.3 ± 2.4

0.97

0.01^c

Secretions, ml/24 h

75 ± 45

85 ± 54

0.18

72 ± 49

77 ± 73

0.61

0.56

Suction frequency/24 h

11 ± 4

13 ± 4

<0.01^c

12 ± 4

12 ± 4

0.71

0.96

GCS score

14.7 ± 1.2

14.2 ± 1.8

0.06

14.9 ± 0.1

14.9 ± 0.1

0.80

<0.01^c

 pH

7.42 ± 0.05

7.43 ± 0.05

0.30

7.45 ± 0.05

7.46 ± 0.05

0.25

<0.01^c

 PaCO₂, mmHg

51 ± 13

45 ± 13

<0.01^c

48 ± 11

39 ± 10

<0.01^c

<0.01^c

 PaO₂/FiO₂

222 ± 63

269 ± 86

<0.01^c

225 ± 55

265 ± 94

<0.01^c

0.33

 Respiratory rate, breaths/minute

23 ± 5

23 ± 5

0.65

23 ± 6

22 ± 5

0.09

0.44

 Rapid shallow breathing index

60 ± 27

66 ± 24

0.12

55 ± 21

48 ± 23

0.06

<0.01^c

 Heart rate, beats/minute

99 ± 16

93 ± 16

0.02^c

100 ± 17

94 ± 15

0.01^c

0.96

 Mean arterial pressure, mmHg

93 ± 13

90 ± 12

0.18

94 ± 12

93 ± 12

0.53

0.40