Table 2.
Patient Characteristics of the Validation Cohort
| Certain No ARDS (n = 46) | Uncertain Classification |
Certain ARDS (n = 44) | ||
|---|---|---|---|---|
| Likely No ARDS (n = 25) | Likely ARDS (n = 14) | |||
| Age, yr, mean (SD) | 62 (17) | 62 (13) | 63 (15) | 66 (12) |
| Male, n (%) | 27 (58.7) | 12 (48.0) | 10 (71.4) | 32 (72.7) |
| BMI, kg/m2, median (IQR) | 24.0 (22.7, 27.2) | 27.3 (24.5, 29.4) | 24.8 (23.6, 28.0) | 26.5 (23.6, 28.6) |
| APACHE II score, median (IQR) | 24 (16, 26) | 22 (15, 25) | 24 (17, 26) | 16 (13, 24) |
| LIPS, median (IQR) | 5 (4, 7) | 5 (4, 6) | 5 (3, 6) | 6 (5, 6) |
| SOFA score, median (IQR) | 7 (5, 10) | 8 (7, 9) | 8 (6, 9) | 8 (7, 10) |
| Global LUS score, median (IQR) | 5 (3, 8) | 7 (3, 11) | 8 (5, 13) | 14 (10, 17) |
| Pre-ICU LOS, d, median (IQR) | 2 (1, 3) | 2 (1, 4) | 3 (1, 9) | 3 (2, 7) |
| Duration MV, h, median (IQR) | 24 (17, 38) | 24 (17, 30) | 21 (17, 26) | 23 (17, 34) |
| Admission type, n (%) | ||||
| Emergency surgical | 11 (23.9) | 2 (8.0) | 2 (14.3) | 0 (0.0) |
| Medical | 27 (58.7) | 20 (80.0) | 10 (71.4) | 44 (100.0) |
| Planned surgical | 8 (17.4) | 3 (12.0) | 2 (14.3) | 0 (0.0) |
| Pneumonia, n (%) | 2 (4.3) | 2 (8.0) | 2 (14.3) | 33 (75.0) |
| COVID-19, n (%) | 0 (0.0) | 0 (0.0) | 0 (0.0) | 18 (40.9) |
| ARDS severity, n (%) | ||||
| Mild | NA | NA | 7 (50.0) | 3 (7.0) |
| Moderate | NA | NA | 7 (50.0) | 25 (58.1) |
| Severe | NA | NA | 0 (0.0) | 15 (34.9) |
| Cause of ARDS | ||||
| Nonpulmonary, n (%) | NA | NA | 12 (85.7) | 3 (7.0) |
| Pulmonary, n (%) | NA | NA | 2 (14.3) | 37 (84.1) |
| ICU LOS, d, median (IQR) | 6 (4, 13) | 8 (4, 17) | 5 (4, 9) | 11 (6, 25) |
| 30 d mortality, n (%) | 19 (41.3) | 9 (36.0) | 4 (30.8) | 18 (40.9) |
| ICU mortality, n (%) | 16 (35.6) | 7 (28.0) | 2 (14.3) | 18 (40.9) |
| Ventilation characteristics | ||||
| PaO2/FiO2 ratio, mm Hg, median (IQR) | 307 (195, 388) | 157 (128, 239) | 203 (188, 234) | 120 (82, 143) |
| PEEP, cm H2O, median (IQR) | 8 (6, 8) | 8 (8, 8) | 8 (7, 10) | 11 (10, 12) |
| RR, breaths/min, median (IQR) | 16 (14, 20) | 17 (13, 20) | 18 (15, 22) | 20 (18, 24) |
| VT/PBW, ml/kg, median (IQR) | 7.2 (5.7, 8.6) | 7.0 (6.6, 8.9) | 7.3 (6.4, 9.6) | 6.9 (5.9, 7.7) |
| Ventilatory ratio, median (IQR) | 1.1 (1.0, 1.4) | 1.2 (1.0, 1.4) | 1.3 (1.2, 1.7) | 1.4 (1.2, 1.7) |
| Mechanical power, J/min, median (IQR) | 15.3 (10.9, 23.1) | 16.3 (11.6, 21.5) | 19.6 (12.1, 22.2) | 24.8 (19.6, 32.2) |
| Driving pressure, cm H2O, median (IQR) | 15 (12, 19) | 14 (10, 19) | 15 (11, 19) | 18 (15, 22) |
| Compliance, mL/cm H2O, median (IQR) | 26.6 (19.8, 34.9) | 32.4 (24.9, 39.1) | 28.4 (24.3, 42.2) | 24.0 (19.3, 30.7) |
For definition of abbreviations, see Table 1.
Data are presented as n (%) or median (IQR), unless indicated otherwise. Duration of MV is the time between intubation and LUS. The PaO2/FiO2 ratio is defined as the lowest PaO2/FiO2 ratio in the 24 hours before LUS. Ventilation parameters were collected during LUS, and laboratory parameters were collected closest to LUS. PBW is calculated as follows: PBWmale = 50 + 0.91 ⋅ (cm of height – 152.4) and PBWfemale = 45.5 + 0.91 ⋅ (cm of height – 152.4). Ventilatory ratio (VR) is calculated as follows: VR = [minute volume (ml/min) ⋅ PaCO2]/(PBW ⋅ 100 ⋅ 37.5). Mechanical power (MP) is calculated as follows: MP = 0.098 ⋅ RR ⋅ VT ⋅ [PEEP + (Pmax − PEEP)]. Driving pressure (DP) is calculated as DP = Pmax − PEEP. Additional characteristics are presented in the online supplement.