Table 3 Performance of invasive mechanical ventilation and mortality at 28-day

Invasive Mechanical Ventilation

PaO2 mmHg < = 60

55.3 (52.7–57.9)

36.8 (34.2–39.3)

44.7 (17.9–15.8)

76.8 (74.6–79)

1.21 (1.082–1.364)

0.88 (0.779–0.983)

0.536 (0.496–0.576)

0.085

SaO2% <= 90

61.4 (58.8–64)

31 (28.5–33.4)

17.5 (15.5–19.6)

77 (74.8-0)

1.25 (1.123–1.384)

0.89 (0.801–0.987)

0.545 (0.505–0.585)

0.032

PaO2/FiO2 ≤ 300

13.9 (12.1–15.8)

71.5 (69.1–73.9)

10.8 (9.2–12.5)

77 (74.7–79.2)

1.2 (0.884–1.641)

0.49 (0.358–0.665)

0.669 (0.628–0.711)

< 0.001

SpO2/FiO2 ≤ 350

54.7 (52-57.3)

25.5 (23.2–27.9)

15.1 (13.2–17)

69.9 (67.5–72.3)

1.77 (1.582–1.989)

0.73 (0.655–0.824)

0.629 (0.588–0.67)

< 0.001

ROX index ≥ 4.8

89.4 (87.8–91.1)

2.5 (1.7–3.4)

18.1 (16.1–20.1)

50 (47.3–52.7)

4.15 (3.978–4.331)

0.92 (0.88–0.958)

0.608 (0.565–0.65)

< 0.001

ΔPaO2/FiO2 ratio

83 (81–85)

5.4 (4.2–6.6)

17.7 (15.7–19.7)

56.3 (53.7–59)

3.16 (2.992–3.348)

0.88 (0.877–0.928)

0.612 (0.573–0.651)

< 0.001

ΔSaO2/FiO2 ratio

90.5 (88.9–92.2)

4.8 (3.6-6)

20.8 (18.6–23.1)

64.8 (62.1–67.5)

1.96 (1.884–2.047)

0.95 (0.912–0.992)

0.589 (0.546–0.632)

< 0.001

SOFA score ≥ 4

55.1 (51.6–58.7)

76.6 (73.6–79.6)

42 (38.5–45.5)

84.7 (82.2–87.3)

2.36 (2.039–2.724)

0.59 (0.507–0.677)

0.633 (0.595–0.671)

< 0.001

4C score ≥ 8

72.1 (69.1–75.1)

48.7 (45.4–52)

29.8 (26.7–32.8)

85.2 (82.9–87.6)

1.4 (1.301–1.515)

0.57 (0.532–0.62)

0.64 (0.602–0.677)

< 0.001

Charlson index ≥ 3

48.5 (45.9–51.1)

61.5 (59-64.1)

23.5 (21.2–25.7)

83.1 (81.2–85.1)

1.26 (1.158–1.374)

0.84 (0.768–0.911)

0.563 (0.524–0.602)

0.003

Mortality

PaO2 mmHg < = 60

59.2 (56.6–61.8)

37.6 (35.1–40.2)

22.1 (19.9–24.3)

75.5 (73.2–77.8)

1.08 (0.979–1.157)

0.95 (0.856–1.052)

0.515 (0.474–0.557)

0.449

SaO2% <= 90

66 (63.5–68.5)

32 (29.5–34.5)

22.3 (20.1–24.5)

76.1 (73.8–78.4)

1.06 (0.986–1.25)

0.97 (0.886–1.063)

0.513 (0.472–0.553)

0.536

PaO2/FiO2 ≤ 300

70.6 (68.2–73)

9.3 (7.8–10.8)

18.9 (18.9–21)

51.3 (48.7–54)

3.17 (2.943–3.411)

0.78 (0.723–0.838)

0.624 (0.582–0.667)

< 0.001

SaO2/FiO2 ≤ 350

58.8 (56.2–61.4)

25.9 (23.6–28.2)

19.1 (17-21.1)

67.9 (65.4–70.4)

1.59 (1.441–1.757)

0.79 (0.718–0.876)

0.581 (0.539–0.623)

< 0.001

ROX index ≥ 4.8

91.6 (90.2–93.1)

2.8 (2-3.7)

21.8 (19.6–24)

53.6 (50.9–56.2)

2.94 (2.836–3.05)

0.94 (0.911–0.977)

0.588 (0.545–0.63)

< 0.001

ΔPaO2/FiO2 ratio

81.1 (79-83.2)

6.5 (5.2–7.8)

20.7 (18.6–22.9)

53.2 (50.5–55.8)

2.92 (2.76–3.086)

0.87 (0.82–0.917)

0.547 (0.507–0.587)

0.021

ΔSaO2/FiO2 ratio

87.9 (86-89.7)

7.3 (5.9–8.8)

20.8 (18.5–23.1)

68.6 (66-71.2)

1.65 (1.574–1.734)

0.95 (0.904–0.995)

0.567 (0.526–0.608)

0.001

SOFA score ≥ 4

58.1 (54.6–61.7)

75.9 (72.8–78.9)

37.2 (33.8–40.7)

88 (85.7–90.4)

2.41 (1.978–2.933)

0.55 (0.453–0.672)

0.633 (0.595–0.67)

< 0.001

4C score ≥ 8

74.9 (72-77.8)

48.2 (44.9–51.5)

25.3 (22.4–28.2)

89.1 (87.1–91.2)

1.45 (1.292–1.619)

0.52 (0.466–0.584)

0.706 (0.669–0.742)

< 0.001

Charlson index ≥ 3

49.8 (47.2–52.4)

61.3 (58.7–63.8)

19.2 (17.2–21.3)

86.8 (85.1–88.6)

1.29 (1.105–1.495)

0.82 (0.705–0.953)

0.672 (0.636–0.709)

< 0.001