Table 2.
Ventilation Characteristics, Adjunctive Therapies, Arterial Blood Gas Analysis and Outcomes
|
COVID–ARDS N = 6.702 |
CLASSIC–ARDS N = 1.415 |
p | |
|---|---|---|---|
| Ventilation characteristics | |||
| mode of ventilation, N (%) | < 0.001 | ||
| volume–controlled ventilation | 4.689 (70.3) | 521 (36.8) | |
| pressure–controlled ventilation | 1.403 (21.0) | 493 (34.8) | |
| pressure–support ventilation | 336 (5.0) | 143 (10.1) | |
| other | 242 (3.6) | 258 (18.2) | |
| VT, mL/kg PBW, median [IQR] | 6.6 [6.0 to 7.4] | 7.3 [6.4 to 8.5] | < 0.001 |
| < 6 ml/kg PBW | 1.464 (24.8) | 211 (16.3) | < 0.001 |
| 6–8 ml/kg PBW | 3.601 (61.2) | 645 (50.0) | < 0.001 |
| 8–10 ml/kg PBW | 698(11.9) | 324 (25.1) | < 0.001 |
| > 10 ml/kg PBW | 125 (2.1) | 102 (7.9) | < 0.001 |
| PEEP, cmH2O, median [IQR] | 12.0 [10.0 to 14.0] | 8.0 [6.0 to 10.0] | < 0.001 |
| < 8 cmH2O | 325 (4.8) | 530 (37.5) | < 0.001 |
| 8–12 cmH2O | 4.075 (60.8) | 713 (50.4) | < 0.001 |
| 12–16 cmH2O | 2.101 (31.3) | 140 (9.9) | < 0.001 |
| > 16 cmH2O | 201 (2.9) | 32 (2.3) | 0.37 |
| PMAX, cmH2O, median [IQR] | 25.5 [21.0 to 30.0] | 25.0 [22.0 to 28.0] | 0.001 |
| dynamic ΔP, cmH2O, median [IQR] | 13.0 [10.0 to 15.0] | 16.0 [12.0 to 20.0] | < 0.001 |
| CRS, mL/cmH2O, median [IQR] | 33.5 [26.6 to 42.1] | 28.1 [21.6 to 38.4] | < 0.001 |
| MP, J/min, median [IQR] | 16.6 [13.4 to 20.6] | 15.2 [11.3 to 19.2] | < 0.001 |
| FiO2, median [IQR] | 0.6 [0.5 to 0.9] | 0.6 [0.5 to 0.9] | 0.017 |
| total RR, breaths per min, median [IQR] | 22.0 [20.0 to 25.0] | 20.0 [16.0 to 25.0] | < 0.001 |
| ventilatory ratio, median [IQR] | 1.75 [1.43 to 2.20] | 1.76 [1.35 to 2.27] | 0.835 |
| Adjunctive therapies | |||
| prone positioning, N (%) | 4.615 (69.2) | 144 (10.2) | < 0.001 |
| recruitment manoeuvres, N (%) | 1.924 (39.4) | 313 (22.1) | < 0.001 |
| ECMO, N (%) | 142 (2.5) | 56 (4.0) | 0.005 |
| tracheostomy, N (%) | 2.033 (30.5) | 214 (15.1) | < 0.001 |
| neuromuscular blocking agents, N (%) | 3.838 (73.9) | 350 (24.7) | < 0.001 |
| continuous sedation, N (%) | 1.188 (84.0) | 1.785 (98.1) | < 0.001 |
| vasopressor use, N (%) | 4440 (85.5) | 1025 (72.5) | < 0.001 |
| Arterial blood gas analysis | |||
| pH, median [IQR] | 7.35 [7.28 to 7.41] | 7.34 [7.26 to 7.41] | < 0.001 |
| PaO2, mmHg, median [IQR] | 80.1 [67.5 to 98.5] | 83.6 [68.0 to 105.8] | < 0.001 |
| PaCO2, mmHg, median [IQR] | 44.25 [38.0 to 52.0] | 44.0 [37.0 to 54.0] | 0.320 |
| PaO2/FiO2, median [IQR] | 135.0 [94.0 to 184.9] | 146.0 [99.4 to 207.3] | < 0.001 |
| Outcomes | |||
| 60–day mortality, N (%) | 2963 (44.2) | 515 (36.4) | < 0.001 |
| VFD–60, median [IQR] | 11.0 [0.0 to 47.0] | 41.0 [0.0 to 54.0] | < 0.001 |
Abbreviations: ARDS Acute respiratory distress syndrome, VT Tidal volume; PBW Predicted bodyweight, IQR Interquartile range, N Number, PEEP Positive end–expiratory pressure, Pmax Maximum airway pressure, ΔP Driving pressure, MP Mechanical power, CRS Respiratory system compliance, FiO2 Fraction of inspired oxygen, RR Respiratory rate, PaO2 Partial pressure of arterial oxygen, PaCO2 Partial pressure of arterial carbon dioxide, VFD Ventilator–free days and alive