Table 1 Comparison of patients with acute respiratory distress syndrome with or without diffuse alveolar damage patterns at histological examination

 Age, years

66.4 ± 14.0

64.3 ± 14.7

0.17

 Female sex, n (%)

58 (29.4%)

68 (42.8%)

0.01

 SAPS II, points

55.5 ± 19.6

50.9 ± 16.1

0.02

 Duration of MV before death, days

12.7 ± 21.7

13.1 ± 11.0

0.82

 Duration of ARDS evolution ≥ 72 h, n (%)

101 (51%)

128 (81%)

<0.01

 Pneumonia, n (%)

62 (31.5%)

66 (41.5%)

0.04

 Other pulmonary risk factors of ARDS, n (%)

12 (6.1%)

7 (4.4%)

0.48

 Shock, n (%)

118 (59.9%)

83 (52.2%)

0.14

 Extrapulmonary sepsis, n (%)

73 (37.1%)

56 (35.2%)

0.72

 Pancreatitis, n (%)

12 (6.1%)

7 (4.4%)

0.48

 PaO₂, mmHg

93 ± 37

79 ± 27

<0.01

 PaO₂/FiO₂, mmHg

140 ± 67

104 ± 53

<0.01

 PaCO₂, mmHg

44.5 ± 12.8

49.1 ± 15.0

<0.01

Severity of hypoxemia

<0.01

 200 < PaO₂/FiO₂ ≤ 300 mmHg, n (%)

43 (22%)

6 (4%)

 100 < PaO₂/FiO₂ ≤ 200 mmHg, n (%)

85 (43%)

56 (35%)

 PaO₂/FiO₂ ≤ 100 mmHg, n (%)

69 (35%)

97 (61%)

 Tidal volume, ml

620 ± 133

623 ± 157

0.87

 Respiratory rate, cycles/minute

20 ± 6

22 ± 7

<0.01

 Minute ventilation, L/minute

11.9 ± 3.2

13.1 ± 3.4

<0.01

 FiO₂

0.75 ± 0.25

0.85 ± 0.22

<0.01

 PEEP, cmH₂O

7.9 ± 4.5

9.6 ± 4.1

<0.01

 PEEP ≥ 10 cmH₂O, n (%)

91 (46%)

106 (67%)

<0.01

 Peak pressure, cmH₂O

37 ± 10

44 ± 10

<0.01

 Dynamic driving pressure (peak − PEEP), cmH₂O

28 ± 11

34 ± 9

<0.01

 Dynamic compliance, ml/cmH₂O

24 ± 11

20 ± 7

<0.01

 Dynamic compliance < 40 ml/cmH₂O, n (%)

174 (88%)

155 (97%)

<0.01

 VE corrected PaCO₂, L/minute

13 ± 5

16 ± 7

<0.01

 VE corrected PaCO₂ ≥ 10 L/minute, n (%)

135 (69%)

133 (84%)

<0.01

Extent of infiltrates on chest radiograph

<0.01

 Two quadrants, n (%)

64 (32%)

17 (11%)

 Three quadrants, n (%)

63 (32%)

41 (26%)

 Four quadrants, n (%)

70 (36%)

101 (63%)

Lung weight at autopsy examination, g

1567 ± 709

1848 ± 748

<0.01