Table 1 Baseline characteristics between two groups before PSM
Items | Overall (n = 234) | SPP group (n = 133) | PPP group (n = 101) | P |
|---|---|---|---|---|
Age | 63.00 [52.00, 73.00] | 61.00 [51.00, 72.00] | 65.00 [55.00, 76.00] | 0.033 |
Gender [n(%)] | ||||
 Male | 186 (79.5) | 103 (77.4) | 83 (82.2) | 0.029 |
 Female | 48 (20.5) | 30 (22.6) | 18 (17.8) |  |
Height (m) | 160.0 [155.0, 170.0] | 158 [154.0, 171.0] | 160.0 [155.0, 170.0] | 0.391 |
Weight (kg) | 60.0 [52.5, 66.6] | 59.9 [50.1, 66.2] | 60.5 [51.5, 65.6] | 0.091 |
Body mass index (kg/m2) | 22.8 [21.9, 24.8] | 22.5 [21.1, 24.5] | 23.0 [21.3, 25.0] | 0.439 |
Etiologies [n(%)] | ||||
 Pneumonia | 226 (96.6) | 130 (97.7) | 96 (95.0) | 0.447 |
 Sepsis | 82 (35.0) | 41 (30.8) | 41 (40.6) | 0.058 |
 Trauma | 14 ( 6.0) | 4 (3.0) | 10 (9.9) | 0.054 |
 Other etiologies | 25 (10.7) | 9 (6.8) | 16 (15.8) | 0.044 |
ARDS severity [n(%)] | ||||
 Mild | 34 (14.5) | 19 (14.3) | 15 (14.9) | 0.911 |
 Moderate | 138 (59.0) | 80 (60.2) | 58 (57.4) |  |
 Severe | 62 (26.5) | 34 (25.6) | 28 (27.7) |  |
Microbiology | ||||
 Virus [n(%)] | 193 (82.5) | 116 (87.2) | 77 (76.2) | 0.044 |
 Bacteria [n(%)] | 177 (75.6) | 99 (74.4) | 78 (77.2) | 0.735 |
 Fungus [n(%)] | 109 (46.6) | 62 (46.6) | 47 (46.5) | 1 |
APACHE II | 23 [18, 29] | 23 [20, 28] | 23 [16, 31] | 0.779 |
SOFA score | 8 [5, 9] | 8 [5, 10] | 9 [5, 10] | 0.273 |
Murrary score | 3.00 [2.50, 3.50] | 3.00 [2.00, 3.50] | 3.00 [2.50, 3.50] | 0.824 |
Charlson index | 5 [4, 7] | 5 [4, 7] | 6 [4, 7] | 0.369 |
Number of the prone position sessions | 2 [1, 5] | 3 [1, 5] | 2 [2, 5] | 0.078 |
Days from ICU to pronation (days) | 1.67 [0.74, 4.70] | 1.75 [0.82, 4.95] | 1.44 [0.69, 4.01] | 0.052 |
Treatment [n(%)] | ||||
 Mechanical Ventilation | 215 (91.9) | 118 (88.7) | 97 (96.0) | 0.045 |
 Muscle relaxants | 92 (39.3) | 51 (38.4) | 41 (40.6) | 0.124 |
 ECMO | 28 (12.0) | 16 (12.0) | 12 (11.9) | 0.087 |
Mechanical ventilation parameters | ||||
 PEEP (cmH2O) | 10 [8, 10] | 10 [8, 11] | 10 [8, 10] | 0.703 |
 Compliance (mL/cm H2O) | 32 [23, 40] | 32 [22, 40] | 32 [24, 39] | 0.773 |
 etCO2 (mmHg) | 35 [33, 47] | 37 [33, 46] | 36 [34, 46] | 0.182 |
 FiO2 (%) | 70 [50, 100] | 70 [50, 100] | 70 [55, 100] | 0.711 |
 Tidal volume (mL/kg) | 7.3 [6.0, 9.0] | 7.1 [5.9,9.1] | 7.4 [6.1,9.0] | 0.314 |
Arterial blood gas measurements | ||||
 PaO2 (mmHg) | 93.05 [77.00, 125.50] | 94.50 [78.70, 127.00] | 91.80 [75.20, 121.00] | 0.271 |
 PaCO2 (mmHg) | 42.30 [37.60, 52.10] | 42.20 [37.60, 48.70] | 43.20 [37.53, 55.22] | 0.474 |
 PaO2/FiO2 ratio | 145.00 [100.25, 203.75] | 149.00 [101.00, 213.00] | 145.00 [97.00, 200.00] | 0.360 |