Table 1 Characteristics of patients receiving respiratory support in the ICU and outside the ICU under intensivist supervision

Age (median, IQR)

65 (56–73)

77 (65–82)

< 0.0001

Male (n, %)

352 (80.0)

188 (72.3)

0.048

Comorbidities (n, %)

N = 433

N = 260

 No comorbidities

73 (16.9)

0 (0.00)

< 0.0001

 COPD

62 (14.3)

39 (15.0)

NS

 Diabetes

103 (23.8)

50 (19.2)

NS

 Obesity

136 (31.4)

40 (15.4)

< 0.0001

 HIV infection

3 (0.7)

1 (0.4)

NS

 Immunocompromised state

10 (2.3)

9 (3.5)

NS

 Cardiovascular disease

275 (63.5)

158 (60.8)

NS

 Cerebrovascular disease

25 (5.8)

34 (13.1)

< 0.001

 Chronic kidney disease

23 (5.3)

26 (10.0)

0.0200

 Chronic liver failure

6 (1.4)

3 (1.2)

NS

 Active neoplasm

16 (3.7)

9 (3.5)

NS

 No answer

100 (23.1)

43 (16.5)

0.0390

Respiratory support (n, %)

N = 439

N = 241

 Conventional O₂ therapy

4 (0.9)

114 (47.3)

< 0.0001

 HFNC

3 (0.7)

68 (28.2)

< 0.0001

 Non-invasive respiratory support

69 (15.7)

59 (24.5)

0.0052

  CPAP

28 (6.4)

18 (7.5)

NS

  NIV

41 (9.3)

41 (17.0)

0.0033

 Invasive mechanical ventilation

359 (81.8)

0 (0.0)

< 0.0001

Physiological variables^a

N = 425

N = 243

 PaO₂ pressure (mmHg)

92 (76–123)

62 (55–73)

< 0.0001

 PaO₂/FiO₂ ratio

165 (117–230)

244 (147–296)

< 0.0001

 PaCO₂ (mmHg)

42 (37–50)

34 (31–38)

< 0.0001

 pH

7.40 (7.34–7.45)

7.46 (7.43–7.49)

< 0.0001

 Respiratory rate (breath/min)

20 (16–24)

24 (18–27)

< 0.0001

 Base excess (mEq/L)

1.30 (− 1.10–3.90)

0.60 (− 2.5–2.0)

0.0018