Variables | Overall (n = 1057) | Non-proned (n = 409, 39%) | Proned (n = 648, 61%) | p value |
---|---|---|---|---|
Males, no. (%) | 831 (79) | 317 (78) | 514 (79) | 0.483 |
Age (years) | 63 (55–69) | 63 (55–69) | 63 (55–69) | 0.773 |
BMI (kg/m2) | 28 (25–31) | 27 (25–31) | 28 (25–31) | 0.023 |
SOFA score | 4 (3–5) | 4 (3–4) | 4 (3–5) |  < 0.001 |
APACHE II score | 10 (7–13) | 9 (7–13) | 10 (8–13) | 0.013 |
Intubated, no. (%)a | 892 (84) | 351 (86) | 541 (84) | 0.309 |
Respiratory Rate (breaths/min)b | 20 (18–25) | 20 (16–24) | 20 (18–25) |  < 0.001 |
FiO2 (%)b | 70 (60–90) | 60 (50–80) | 80 (60–90) |  < 0.001 |
PEEP (cmH2O)b | 12 (10–14) | 12 (10–14) | 12 (10–14) |  < 0.001 |
PaO2/FIO2 ratiob | 120 (88–173) | 145 (107–197) | 108 (81–148) |  < 0.001 |
ARDS severity, no. (%)b | ||||
 Mild | 128 (15) | 76 (23) | 52 (10) |  < 0.001 |
 Moderate | 426 (50) | 183 (56) | 243 (46) | |
 Severe | 298 (35) | 69 (21) | 229 (44) | |
Tidal volume/PBW (mL/kg)b | 7.0 (6.3–7.8) | 7.1 (6.3–7.9) | 7.0 (6.2–7.8) | 0.140 |
Plateau pressure (cmH2O)b | 24 (22–27) | 24 (21–26) | 25 (22–28) |  < 0.001 |
Driving pressure (cmH2O)b | 12 (9–14) | 12 (9–13) | 12 (9–14) | 0.120 |
Respiratory system compliance (mL/cmH2O)b | 40 (33–50) | 42 (35–50) | 38 (32–50) | 0.035 |
pH | 7.39 (7.32–7.46) | 7.40 (7.33–7.46) | 7.39 (7.31–7.45) | 0.220 |
PaO2 (mmHg) | 80 (67–101) | 86 (70–108) | 77 (65–97) |  < 0.001 |
PaCO2 (mmHg) | 43 (36–52) | 43 (37–51) | 43 (36–53) | 0.710 |
Ventilatory ratiob | 1.7 (1.4–2.2) | 1.7 (1.3–2.1) | 1.8 (1.4–2.2) | 0.061 |
LDH (units/L) | 479 (359–640) | 424 (324–593) | 507 (392–667) |  < 0.001 |
D-dimer (ng/mL) | 1492 (608–4602) | 1190 (520–3470) | 1730 (690–6576) | 0.001 |
Ferritine (ng/mL) | 1408 (811–2399) | 1214 (668–1903) | 1552 (1031–2491) | 0.003 |
ICU mortality, no. (%) | 374 (36) | 112 (28) | 262 (41) |  < 0.001 |
Hospital mortality, no. (%) | 405 (41) | 127 (33) | 278 (45) |  < 0.001 |
ICU LOS (days) | 15 (9–25) | 12 (7–21) | 16 (11–28) |  < 0.001 |
Hospital LOS (days) | 29 (17–46) | 26 (16–40) | 30 (17–49) | 0.008 |
Mechanical ventilation (days) | 14 (8–26) | 10 (6–19) | 16 (10–30) |  < 0.001 |