Table 1 Patients with and without delirium

Age, years

69 (61–77)

78 (71–84)

 < 0.01

Female/male

261/626

49/147

0.22

APACHE II score

14 (12–17)

17 (14–20)

 < 0.01

Reasons for NIV

 COPD exacerbation

477 (53.8%)

107 (54.6%)

0.67

 Pneumonia

184 (20.7%)

48 (24.5%)

 ARDS

63 (7.1%)

11 (5.6%)

 Pulmonary cancer

49 (5.5%)

11 (5.6%)

 Interstitial lung disease

22 (2.5%)

6 (3.1%)

 Asthma

14 (1.6%)

1 (0.5%)

 Heart failure

10 (1.1%)

2 (1.0%)

 OHS

11 (1.2%)

2 (1.0%)

 Pulmonary embolism

15 (1.7%)

0 (0%)

 Others

42 (4.7%)

8 (4.1%)

Underlying disease

 Hypertension

335 (37.8%)

86 (43.9%)

0.12

 Diabetes mellitus

180 (20.3%)

51 (26.0%)

0.08

 Chronic heart disease

163 (18.4%)

47 (24.0%)

0.09

 Chronic liver disease

36 (4.1%)

4 (2.0%)

0.21

 Chronic kidney disease

30 (3.4%)

11 (5.6%)

0.15

Variables collected before NIV

 GCS

15 (15–15)

15 (14–15)

 < 0.01

 HR, beats/min

111 ± 23

112 ± 22

0.92

 RR, breaths/min

30 (26–35)

30 (26–35)

0.75

 MAP, mmHg

98 (87–111)

92 (83–106)

 < 0.01

 pH

7.37 (7.29–7.45)

7.34 (7.26–7.44)

 < 0.01

 PaCO₂, mmHg

57 (35–77)

58 (37–81)

0.20

 PaO₂/FiO₂, mmHg

167 (127–224)

168 (126–243)

0.71

Outcomes

 NIV failure

186 (21.0%)

74 (37.8%)

 < 0.01

 NIV duration, days

3.7 (1.7–5.9)

6.3 (2.7–11.0)

 < 0.01

 ICU LOS, days

6.0 (3.8–9.2)

9.0 (4.8–15.2)

 < 0.01

 Hospital LOS, days

11.0 (6.8–17.0)

14.5 (7.1–21.1)

 < 0.01

 ICU mortality

127 (14.3%)

65 (33.2%)

 < 0.01

 Hospital mortality

151 (17.0%)

73 (37.2%)

 < 0.01