Table 1 Baseline characteristics of included patients and clinical characteristics and biological differences between the 2 classes
Baseline Characteristic | All patients (n = 1104) | Class1 (n = 866) | Class2 (n = 238) | P value |
|---|---|---|---|---|
Age, year | 63 ± 18 | 64 ± 18 | 61 ± 18 | 0.0258 |
Gender, n (%) | Â | Â | Â | 0.14 |
 female | 501(45.4%) | 403(46.54%) | 98(41.18%) |  |
 male | 603(54.6%) | 463(53.46%) | 140(58.82%) |  |
Height, cm | 168.8 ± 10 | 168.7 ± 10 | 169.0 ± 10 | 0.6295 |
Weight, kg | 85.8 ± 24 | 85.4 ± 24 | 87.3 ± 24 | 0.2809 |
The risk of ARDS, n (%) |  |  |  | < 0.001 |
 pneumonia | 319(28.9%) | 240(27.71%) | 79(33.19%) |  |
 trauma | 378(34.2%) | 203(23.44%) | 52(21.85%) |  |
 sepsis | 247(22.4%) | 87(10.05%) | 49(20.59%) |  |
 aspiration | 14(1.3%) | 9(1.04%) | 3(1.26%) |  |
 other | 382(34.6%) | 327(37.76%) | 55(23.11%) |  |
Vasopressor Use, n (%) | Â | Â | Â | Â |
 vaso_use_24h#1 | 119(10.8%) | 44(5.08%) | 75(31.51%) | < 0.001 |
 vaso_use_48h#2 | 150(13.6%) | 64(7.39%) | 86(36.13%) | < 0.001 |
 vaso_use_all#3 | 217(19.7%) | 116(13.39%) | 101(42.44%) | < 0.001 |
Corticosteroids, n (%) | 172(15.6%) | 125(14.13%) | 47(19.75%) | 0.045 |
Race, n (%) | Â | Â | Â | 0.009 |
 White | 696(63.04%) | 568(65.59%) | 128(53.78%) |  |
 BLACK/AFRICAN | 75(6.79%) | 53(6.12%) | 22(9.24%) |  |
 HISPANIC/LATINO | 45(4.08%) | 31(3.58%) | 14(5.88%) |  |
 Asian | 29(2.63) | 24(2.77%) | 5(2.10%) |  |
 other | 259(23.46%) | 190(21.94%) | 69(28.99%) |  |
PaO2fiO2ratio | 161.8(98.9-246.8) | 175(115–263) | 113(75–193) | < 0.0001 |
PcO2, mmHg | 49(43–56) | 49(43–55) | 52(44–60) | 0.0039 |
PO2, mmHg | 80(66–108) | 81(68–113) | 74(61–90) | < 0.0001 |
Aado2, mmHg | 356.2(216.0-528.6) | 324(205–492) | 503(293–577) | < 0.0001 |
Totalco2, mEq/L | 21(18–24) | 22(20–25) | 16(14–18) | < 0.0001 |
 min volume, L/min | 11.5 ± 3 | 11.1 ± 3 | 12.8 ± 3 | < 0.0001 |
Tidal volume, mL | 410(345.5-482.5) | 410(341–480) | 419(351–490) | 0.2167 |
Plateau pressure, cmH2O | 22(18–26) | 21(18–25) | 26(21–30) | < 0.0001 |
Peep, cm H2O | 8(5–11) | 7(5–10) | 10(6–15) | < 0.0001 |
FiO2, % | 100(60–100) | 100(60–100) | 100(100–100) | < 0.0001 |
Lactate, mg/dl | 3(1.7–4.9) | 2.6(1.6–3.9) | 6.4(4.1–8.7) | < 0.0001 |
Be, mmol/L | -5(-8–1) | -3(-6-0) | -12(-15–9) | < 0.0001 |
Hematocrit, % | 35.7 ± 6 | 35.4 ± 6 | 36.8 ± 7 | 0.0018 |
Hemoglobin, mg/dL | 9.7 ± 2 | 9.9 ± 2 | 9.1 ± 2 | < 0.0001 |
Platelets, 109/L | 155.5(103–216) | 169(114–226) | 117(73–172) | < 0.0001 |
Wbc, 109/L | 14.9(11.2–20.0) | 14.1(10.9–18.8) | 17.6(12.7–23.3) | < 0.0001 |
Glucose, mg/dL | 179(146–223) | 171(142–207) | 233(181–301) | < 0.0001 |
AG, mmol/L | 16(13–19) | 15(13–17) | 21(18–24) | < 0.0001 |
Bicarbonate, mmol/L | 21 ± 4 | 22 ± 4 | 16 ± 4 | < 0.0001 |
Bun, mmol/L | 21(15–30) | 19(14–26) | 31(20–46) | < 0.0001 |
Calcium, mg/dL | 7.9 ± 0.9 | 8.0 ± 0.8 | 7.5 ± 1.0 | < 0.0001 |
Chloride, mmol/L | 108(105–112) | 108(105–111) | 110(105–113) | < 0.0001 |
Creatinine, mg/dL | 1.1(0.8–1.6) | 1.0(0.8–1.3) | 1.8(1.3–2.7) | < 0.0001 |
Sodium, mmol/L | 141 ± 4 | 140 ± 4 | 142 ± 5 | 0.0005 |
Potassium, mmol/L | 3.9 ± 0.5 | 3.9 ± 0.5 | 3.9 ± 0.6 | 0.4217 |
 h, beats per min | 108(93–123) | 105(91–119) | 120(105–135) | < 0.0001 |
Temperature, °C | 37.7 ± 0.8 | 37.7 ± 0.8 | 37.7 ± 0.8 | 0.6690 |
Sbp, mmHg | 85 ± 14 | 87 ± 14 | 80 ± 14 | < 0.0001 |
RR, breaths per min | 27(24–32) | 27(23–31) | 29(25–34) | < 0.0001 |
Urine output, L | 1.5(0.9–2.3) | 1.6(1-2.4) | 1.0(0.5–1.8) | < 0.0001 |
Scoring systems | Â | Â | Â | Â |
 SAPSII | 41(33–51) | 39(31–48) | 49(40–62) | < 0.0001 |
 SOFA | 8(5–11) | 7(5–9) | 12(10–14) | < 0.0001 |