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Table 1 Patient characteristics, ventilator settings, arterial blood gas results, and outcomes

From: P/FP ratio: incorporation of PEEP into the PaO2/FiO2 ratio for prognostication and classification of acute respiratory distress syndrome

 

All patients (N = 3442)

Demographics

 Age, median (IQR), years

51 (39 – 63)

 Gender, male (%)

1888 (54.9)

Cause of ARDS, N (%)

 Pneumonia

1699 (49.4)

 Sepsis

748 (21.7)

 Aspiration

429 (12.5)

 Trauma

239 (6.9)

 Transfusion

71 (2.1)

 Others

256 (7.4)

Severity

Severe (≤ 100)

Moderate (101–200)

Mild (201–300)

Categorization

P/F

P/FP

P Value

P/F

P/FP

P Value

P/F

P/FP

P Value

N (%)

640 (19)

794 (30)

 < 0.001

1928 (57)

1252 (47)

 < 0.001

839 (25)

640 (24)

0.368

Ventilator settings, mean ± SD

 FiO2

0.82 ± 0.14

0.79 ± 0.16

 < 0.001

0.55 ± 0.14

0.56 ± 0.14

0.049

0.43 ± 0.12

0.49 ± 0.13

 < 0.001

 PEEP, cmH2O

12.6 ± 4.4

14.2 ± 3.6

 < 0.001

9.32 ± 3.5

10.2 ± 2.6

 < 0.001

8.0 ± 3.6

8.1 ± 2.4

0.544

 PaO2, mmHg

         

Arterial blood gases

65.0 ± 11.4

71.7 ± 19.7

 < 0.001

80.0 ± 19.8

81.9 ± 24.9

0.017

104.5 ± 31.2

96.1 ± 38.2

 < 0.001

 SaO2, %

91.2 ± 5.7

92.2 ± 5.4

 < 0.001

94.6 ± 3.2

94.5 ± 3.7

0.419

96.9 ± 2.3

95.8 ± 3.0

 < 0.001

 PaCO2, mmHg

43.7 ± 12.9

44.4 ± 13.0

0.309

40.1 ± 9.9

40.3 ± 9.3

0.569

37.8 ± 8.5

38.5 ± 9.0

0.126

 pH

7.33 ± 0.10

7.33 ± 0.10

1.000

7.38 ± 0.08

7.38 ± 0.07

1.000

7.39 ± 0.07

7.38 ± 0.07

0.006

  1. P values refer to comparisons between patients classified according to the P/F ratio versus patients classified according to the P/FP ratio in each severity category. Definition of abbreviations: ARDS  acute respiratory distress syndrome, FiO2  fraction of inspired oxygen, IQR  interquartile range PaCO2  partial pressure of arterial carbon dioxide, PaO2  partial pressure of arterial oxygen, PEEP positive end-expiratory pressure, P/F =ratio of the PaO2 to FiO2; P/FP = (PaO2 * 10)/(FiO2 * PEEP); SaO2  arterial oxygen saturation; SD standard deviation