Table 1 Baseline characteristics of patients according to LnPaO₂/FiO₂ (N = 19, 233)

N

19,233

4803

4808

4791

4821

Age at admission(years)

65.57 ± 15.65

65.87 ± 15.44

66.24 ± 14.46

66.47 ± 15.08

63.69 ± 17.32

 < 0.001

Sex, n(%)

0.004

 female

11,613(60.41%)

2855 (59.44%)

2992 (62.23%)

2922 (60.99%)

2844 (58.99%)

 male

7610(39.59%)

1948 (40.56%)

1816 (37.77%)

1869 (39.01%)

1977 (41.01%)

White, n (%)

12,735(66.21%)

3171 (66.02%)

3286 (68.34%)

3212 (67.04%)

3066 (63.60%)

 < 0.001

Charlson Comorbidity Index

5.75 ± 2.87

6.14 ± 2.91

5.86 ± 2.80

5.68 ± 2.72

5.34 ± 2.98

 < 0.001

SOFA

7.71 ± 3.98

9.14 ± 4.14

8.28 ± 3.82

7.13 ± 3.71

6.29 ± 3.63

 < 0.001

Vital signs

 Heart rate (bpm)

104.77 ± 24.27

108.74 ± 25.68

104.44 ± 23.49

102.96 ± 23.47

102.94 ± 23.90

 < 0.001

 Respiratory rate (bpm)

26.31 ± 9.96

29.45 ± 9.47

26.86 ± 9.52

25.08 ± 9.88

23.84 ± 10.07

 < 0.001

 Temperature (℃)

36.71 ± 1.42

36.93 ± 1.39

36.75 ± 1.43

36.62 ± 1.40

36.53 ± 1.44

 < 0.001

 MAP (mmHg)

76.45 ± 9.43

75.33 ± 9.86

75.74 ± 9.01

77.37 ± 9.13

77.37 ± 9.52

 < 0.001

 FiO₂

0.56 ± 0.22

0.72 ± 0.22

0.58 ± 0.20

0.50 ± 0.18

0.44 ± 0.18

 < 0.001

 PaO₂ (mmHg)

97.85 ± 54.49

62.73 ± 19.71

82.42 ± 27.10

104.21 ± 40.62

141.92 ± 75.04

 < 0.001

MV, n (%)

 < 0.001

 No

4940(25.70%)

1733 (36.08%)

1115 (23.19%)

1070 (22.33%)

1022 (21.20%)

 Yes

14,283(74.30%)

3070 (63.92%)

3693 (76.81%)

3721 (77.67%)

3799 (78.80%)

RRT

 < 0.001

 No

17,885(92.88%)

4321 (89.96%)

4443 (92.41%)

4521 (94.36%)

4570 (94.79%)

 Yes

1368(7.12%)

482 (10.04%)

365 (7.59%)

270 (5.64%)

251 (5.21%)

Noradrenaline

 < 0.001

 No

11,973(62.28%)

2501 (52.07%)

2929 (60.92%)

3180 (66.37%)

3363 (69.76%)

 Yes

7250(37.72%)

2302 (47.93%)

1879 (39.08%)

1611 (33.63%)

1458 (30.24%)

Dopamine, n (%)

 < 0.001

 No

17,813(92.67%)

4355 (90.67%)

4439 (92.33%)

4466 (93.22%)

4553 (94.44%)

 Yes

1410(7.33%)

448 (9.33%)

369 (7.67%)

325 (6.78%)

268 (5.56%)

Dobutamine, n (%)

0.02

 No

18,384(95.63%)

4589 (95.54%)

4568 (95.01%)

4584 (95.68%)

4643 (96.31%)

 Yes

839(4.37%)

214 (4.46%)

240 (4.99%)

207 (4.32%)

178 (3.69%)

IVIG, n (%)

 < 0.001

 No

18,810(97.85%)

4660 (97.02%)

4710 (97.96%)

4702 (98.14%)

4738 (98.28%)

 Yes

413(2.15%)

143 (2.98%)

98 (2.04%)

89 (1.86%)

83 (1.72%)

Dexamethasone, n(%)

 < 0.001

 No

17,425(90.65%)

4336 (90.28%)

4410 (91.72%)

4403 (91.90%)

4276 (88.70%)

 Yes

1798(9.35%)

467 (9.72%)

398 (8.28%)

388 (8.10%)

545 (11.30%)

Methylprednisolone, n (%)

 < 0.001

 No

15,887(82.65%)

3710 (77.24%)

3963 (82.43%)

4077 (85.10%)

4137 (85.81%)

 Yes

3336(17.35%)

1093 (22.76%)

845 (17.57%)

714 (14.90%)

684 (14.19%)

Cortisone, n(%)

 < 0.001

 No

18,905(98.35%)

4690 (97.65%)

4728 (98.34%)

4725 (98.62%)

4762 (98.78%)

 Yes

318(1.65%)

113 (2.35%)

80 (1.66%)

66 (1.38%)

59 (1.22%)

Carbapenem, n(%)

 < 0.001

 No

15,511(80.69%)

3589 (74.72%)

3885 (80.80%)

3943 (82.30%)

4094 (84.92%)

 Yes

3712(19.31%)

1214 (25.28%)

923 (19.20%)

848 (17.70%)

727 (15.08%)

Cephalosporins, n(%)

0.088

 No

17,775(92.47%)

4472 (93.11%)

4427 (92.08%)

4404 (91.92%)

4472 (92.76%)

 Yes

1448(7.53%)

331 (6.89%)

381 (7.92%)

387 (8.08%)

349 (7.24%)

Penicillins, n(%)

 < 0.001

 No

10,026(52.16%)

2206 (45.93%)

2531 (52.64%)

2654 (55.40%)

2635 (54.66%)

 Yes

9197(47.84%)

2597 (54.07%)

2277 (47.36%)

2137 (44.60%)

2186 (45.34%)

Vancomycin, n (%)

 < 0.001

 No

3648(18.98%)

491 (10.22%)

876 (18.22%)

1018 (21.25%)

1263 (26.20%)

 Yes

15,575(81.02%)

4312 (89.78%)

3932 (81.78%)

3773 (78.75%)

3558 (73.80%)

28-day mortality

 < 0.001

 No

15,545(80.87%)

3403 (70.85%)

3976 (82.70%)

4077 (85.10%)

4089 (84.82%)

 Yes

3678(19.13%)

1400 (29.15%)

832 (17.30%)

714 (14.90%)

732 (15.18%)