Table 1 Patient characteristics

Age (years)

60 (53–70)

62 (53–62)

0.43

Male gender

35 (59)

34 (62)

0.78

 Smoker

18 (35)

21 (47)

0.23

 Heavy drinker

11 (19)

16 (30)

0.17

 Obesity

12 (20)

10 (18)

0.78

 Congestive heart failure

16 (27)

12 (22)

0.51

 Peripheral vascular disease

10 (17)

9 (17)

0.93

 Cerebrovascular disease

3 (5)

6 (11)

0.31

 Diabetes

13 (22)

12 (22)

0.68

 Chronic kidney disease

6 (10)

6 (11)

0.89

 Chronic liver disease

2 (3)

6 (11)

0.02

 Malignancy^a

7 (12)

12 (22)

0.15

 COPD

20 (34)

23 (42)

0.71

 Restrictive lung disease

5 (8)

7 (13)

0.92

 Obstructive sleep apnea syndrome

8 (14)

5 (9)

0.45

 Neuromuscular disease

11 (19)

2 (4)

0.02

 Charlson Index of Comorbidity

5 (4–7)

6 (4–8)

0.16

 Postoperative

6 (10)

6 (11)

0.92

 Acute tetraplegia

7 (12)

8 (15)

0.79

 Trauma (excluding tetraplegia)

3 (5)

4 (7)

0.71

 Acute neurologic failure (excluding tetraplegia)

10 (17)

1 (2)

0.06

 Acute cardiac failure

6 (10)

4 (7)

0.74

 Septic shock

1 (2)

12 (22)

<0.001

 Pneumonia (without septic shock)

19 (32)

37 (67)

<0.001

 Exacerbation of COPD or other structural lung disease

16 (27)

10 (18)

0.26

Acute on chronic hypercapnic failure at admission^c

22 (37)

12 (22)

0.07

Vasopressor therapy during ICU stay

27 (46)

35 (63)

0.48

Hemodialysis during ICU stay

9 (15)

10 (18)

0.67

Time to tracheostomy (days)

14 (8–20)

16 (10–25)

0.23

Time to ICU discharge (days)

20 (10–39)

29 (15–51)

0.17

Time to weaning (days)

-

18 (7–31)

-