Table 1 Clinical characteristic of the study population
Variable | All patients n = 57 | Early ARDS n = 33 | Persistent ARDS n = 24 | P |
|---|---|---|---|---|
Patients’ characteristics | ||||
Age, yr | 71 ± 11 | 72 ± 11 | 70 ± 11 | 0.52 |
Male, n (%) | 37 (64.9) | 22 (66.7) | 15 (62.5) | 0.75 |
Body mass index, kg/m2 | 25.4 ± 2.9 | 24.9 ± 2.4 | 26.1 ± 3.4 | 0.10 |
Sequential organ failure assessment score | 8.4 ± 3.2 | 7.6 ± 2.7 | 9.5 ± 3.6 | 0.02 |
Timing of ARDS onset before first prone session, d | 5 [3, 8] | 3 [2, 4] | 9 [8, 11] | < 0.001 |
Use of noninvasive ventilation before intubation, n (%) | 36 (63.2) | 16 (48.5) | 20 (83.3) | 0.007 |
Duration of noninvasive MV before intubation, d | 2 (1, 4) | 1 (1, 2) | 4 (2.5, 6) | < 0.001 |
Duration of invasive MV before first prone position, d | 3 [2, 6] | 3 [1, 4] | 6 [3.5, 8.5] | < 0.001 |
Duration of first prone position, h | 17 [15, 18] | 17 [16, 18] | 16.5 [15, 18] | 0.68 |
Etiology, n (%) | 0.95 | |||
COVID-19 pneumonia | 26 (45.6) | 15 (45.5) | 11 (45.8) | |
Pneumonia | 28 (49.1) | 16 (48.5) | 12 (50.0) | |
Aspiration | 3 (5.3) | 2 (6.1) | 1 (4.2) | |
PaO2/FIO2, mmHg | 155 [130, 187] | 168 [137, 188] | 133 [118, 164] | 0.063 |
R/I ratio | 0.29 [0, 0.54] | 0.48 [0.22, 0.58] | 0 [0, 0.29] | 0.002 |
Computed tomography scan | ||||
Total gas volume, ml | 2580 [1755, 3115] | 2850 [2111, 3184] | 2355 [1616, 2895] | 0.21 |
Overinflated volume, ml | 175 [70, 306] | 108 [31, 226] | 188 [117, 316] | 0.10 |
Normally inflated volume, ml | 1257 [851, 1503] | 1433 [1209, 1753] | 1000 [772, 1503] | 0.18 |
Poorly inflated volume, ml | 597 [423, 714] | 625 [396, 779] | 455 [430, 624] | 0.48 |
Collapsed volume, ml | 478 [279, 703] | 633 [350, 731] | 327 [278, 568] | 0.07 |
ICU mortality | 9 (15.8) | 5 (15.2) | 4 (16.7) | 0.88 |