Introduction
Methods
Setting and participants
Materials
Management of missing data
Statistics
Evaluation of system performance by random forest
Results
Variables | Units | Valid n | Mean | Standard deviation |
---|---|---|---|---|
Age | years | 1342 | 53.5 | 15.7 |
Body height | cm | 1342 | 165.0 | 8.5 |
Body weight | kg | 1342 | 68.9 | 16.5 |
Body mass index | kg/m2 | 1342 | 25.2 | 5.0 |
Glasgow coma scale | 1342 | 10.2 | 5.3 | |
Inotropic equivalent | 1342 | 28.9 | 44.2 | |
Preset ventilation rate | per minute | 1342 | 17.3 | 6.1 |
FiO2 | 1342 | 0.9 | 0.2 | |
Peak inspiratory pressure | cmH2O | 1342 | 27.8 | 8.8 |
Peak end-expiratory pressure | cmH2O | 1342 | 7.4 | 3.9 |
Mean airway pressure | cmH2O | 1342 | 14.0 | 5.1 |
Body temperature | degree Celsius | 1342 | 36.6 | 1.2 |
Respiratory rate | per minute | 1342 | 19.2 | 7.1 |
Heart rate | per minute | 1342 | 104.2 | 36.0 |
Systolic blood pressure | mmHg | 1342 | 95.7 | 31.4 |
Diastolic blood pressure | mmHg | 1342 | 57.5 | 18.1 |
24 h urine amount | dL | 1342 | 10.8 | 13.2 |
pH | 1342 | 7.3 | 0.2 | |
PaCO2 | mmHg | 1342 | 42.2 | 22.1 |
PaO2 | mmHg | 1342 | 120.7 | 100.3 |
PaO2/FiO2 | mmHg | 1342 | 166.8 | 171.1 |
Bicarbonate | mEq/L | 1342 | 20.1 | 6.7 |
Total bilirubin | mg/dL | 1035 | 2.4 | 4.1 |
Blood urine nitrogen | mg/dL | 1134 | 37.4 | 26.8 |
Creatinine | mg/dL | 1342 | 2.1 | 1.8 |
Sodium | mmole/L | 1342 | 139.3 | 6.9 |
Potassium | mmole/L | 1342 | 4.4 | 1.0 |
Lactate | mmole/L | 1068 | 8.3 | 6.4 |
White blood cell | per uL | 1342 | 13,610.9 | 7335.9 |
Hematocrit | % | 1342 | 36.3 | 7.6 |
Platelet | 103/uL | 1342 | 204.8 | 865.5 |
Prothrombin time | 981 | 1.5 | 1.0 | |
Creatine kinase | U/L | 864 | 1489.0 | 6561.2 |
Aspartate aminotransferase | U/L | 929 | 503.8 | 1615.9 |
Creatine kinase MB | U/L | 835 | 84.5 | 149.8 |
Troponin I | ng/mL | 665 | 19.0 | 174.8 |
Charlson | 929 | 4.3 | 3.1 | |
APACHE | 998 | 19.6 | 8.2 | |
SOFA | 841 | 12.0 | 4.4 | |
LODS | 820 | 9.9 | 3.7 | |
MODS | 774 | 9.1 | 3.7 | |
SAPS3 | 840 | 53.2 | 12.0 | |
SAVE | 429 | -5.4 | 5.7 |
Variables | Categories | Valid n | % |
---|---|---|---|
Sex | Male | 959 | 71.5 |
Female | 383 | 28.5 | |
ECMO categories | Cardiovascular | 1081 | 80.6 |
Respiratory | 252 | 18.8 | |
Others | 9 | 0.7 | |
ECMO mode | VA | 1119 | 83.4 |
VV | 223 | 16.6 | |
NYHA classification | n.a | 79 | 5.9 |
I | 600 | 44.7 | |
II | 314 | 23.4 | |
III | 218 | 16.2 | |
IV | 131 | 9.8 | |
Post-operative | No | 976 | 72.7 |
Yes | 366 | 27.3 | |
IABP use | No | 1104 | 82.3 |
Yes | 238 | 17.7 | |
Extracorporeal CPR | No | 819 | 61.0 |
Yes | 523 | 39.0 | |
Infection before ECMO | 950 | 70.8 | |
392 | 29.2 | ||
Pulmonary emboli | 1336 | 99.6 | |
6 | 0.4 | ||
Dialysis before ECMO | 1193 | 88.9 | |
149 | 11.1 | ||
LV ejection fraction | Missing | 728 | 54.2 |
< 55% | 438 | 32.6 | |
≥ 55% | 176 | 13.1 | |
Central venous pressure | Missing | 399 | 29.7 |
≤ 12 mmHg | 409 | 30.5 | |
> 12 mmHg | 534 | 39.8 | |
Bilirubin | Missing | 307 | 22.9 |
0–2 | 712 | 53.1 | |
2–5 | 226 | 16.8 | |
> 5 | 97 | 7.2 | |
Blood urine nitrogen | Missing | 208 | 15.5 |
0–20 | 323 | 24.1 | |
20–50 | 550 | 41.0 | |
> 50 | 261 | 19.4 | |
Lactate | Missing | 274 | 20.4 |
0–2 | 156 | 11.6 | |
2–10 | 532 | 39.6 | |
> 10 | 380 | 28.3 | |
Prothrombin time | Missing | 361 | 26.9 |
0–2 | 873 | 65.1 | |
> 2 | 108 | 8.0 | |
Creatine kinase | Missing | 478 | 35.6 |
0–200 | 347 | 25.9 | |
200–1000 | 318 | 23.7 | |
> 1000 | 199 | 14.8 | |
Aspartate aminotransferase | Missing | 413 | 30.8 |
0–45 | 294 | 21.9 | |
45–135 | 286 | 21.3 | |
> 135 | 349 | 26.0 | |
Creatine kinase MB form | Missing | 507 | 37.8 |
0–23 | 276 | 20.6 | |
23–69 | 279 | 20.8 | |
> 69 | 280 | 20.9 | |
Troponin I | Missing | 677 | 50.4 |
0–23 | 564 | 42.0 | |
23–69 | 51 | 3.8 | |
69 | 50 | 3.7 | |
Charlson Comorbidity Index | Missing | 437 | 32.6 |
0–14 | 544 | 40.5 | |
15–22 | 325 | 24.2 | |
22–47 | 36 | 2.7 | |
APACHE Score | Missing | 344 | 25.6 |
0–14 | 304 | 22.7 | |
15–22 | 339 | 25.3 | |
22–47 | 355 | 26.5 | |
SOFA Score | Missing | 501 | 37.3 |
1–9 | 596 | 44.4 | |
10–13 | 244 | 18.2 | |
14–24 | 1 | 0.1 | |
LODS | Missing | 522 | 38.9 |
1–7 | 222 | 16.5 | |
8–11 | 341 | 25.4 | |
12–20 | 257 | 19.2 | |
MODS | Missing | 568 | 42.3 |
0–7 | 260 | 19.4 | |
8–10 | 252 | 18.8 | |
11–19 | 262 | 19.5 | |
SAPS3 | Missing | 522 | 38.9 |
24–46 | 277 | 20.6 | |
47–58 | 287 | 21.4 | |
59–98 | 256 | 19.1 | |
SAVE | Missing | 913 | 68.0 |
Class I | 7 | 0.5 | |
Class II | 52 | 3.9 | |
Class III | 149 | 11.1 | |
Class IV | 128 | 9.5 | |
Class V | 93 | 6.9 | |
Outcome | Survival to discharge | 506 | 37.7 |
In-hospital death | 836 | 62.3 |
The model used to estimate the probability of in-hospital death | ||||
Probability of in-hospital death = exp(Y)/(exp(Y) + 1), where | ||||
Y = logit (probability of in-hospital death) = | ||||
1.007 | ||||
+ 0.022 × Age | ||||
+ 0.035 × Ventilation rate | ||||
+ 0.007 × Inotropic equivalent | ||||
+ 0.591 × Extracorporeal ECPR | ||||
+ 0.767 × Infection before ECMO | ||||
− 0.005 × Systolic blood pressure | ||||
− 0.033 × Urine amount | ||||
− 0.071 × Glasgow coma scale | ||||
− 0.432 × [ECMO category = respiratory] | ||||
− 1.721 × [ECMO category = others] | ||||
− 0.573 × [Bil = missing] | ||||
− 1.150 × [Bil = 0–2 mg/dL] | ||||
− 0.733 × [Bil = 2–5 mg/dL] | ||||
− 0.101 × [CKMB = missing] | ||||
− 0.516 × [CKMB = 0–23 U/L] | ||||
− 0.538 × [CKMB = 23–69 U/L] |
Variables | Odds ratio | p | 95% confidence interval | |
---|---|---|---|---|
Age | 1.022 | < 0.001 | 1.014 | 1.03 |
Ventilation Rate | 1.035 | 0.004 | 1.011 | 1.06 |
Inotropic equivalent | 1.007 | 0.001 | 1.003 | 1.012 |
Extracorporeal CPR | 1.806 | < 0.001 | 1.356 | 2.407 |
Infection before ECMO | 2.152 | < 0.001 | 1.548 | 2.993 |
Systolic blood pressure | 0.995 | 0.017 | 0.991 | 0.999 |
Urine amount | 0.967 | < 0.001 | 0.957 | 0.977 |
Glasgow coma scale | 0.931 | < 0.001 | 0.909 | 0.954 |
ECMO category | 0.045 | |||
Respiratory | 0.649 | 0.045 | 0.425 | 0.991 |
Others | 0.179 | 0.119 | 0.021 | 1.558 |
Cardiovascular | Reference | |||
Bilirubin | < 0.001 | |||
Missing | 0.564 | 0.077 | 0.299 | 1.063 |
0–2 | 0.317 | < 0.001 | 0.174 | 0.577 |
2–5 | 0.48 | 0.025 | 0.253 | 0.913 |
> 5 | Reference | |||
Creatine kinase MB | 0.004 | |||
Missing | 0.904 | 0.599 | 0.622 | 1.316 |
0–23 | 0.597 | 0.01 | 0.403 | 0.884 |
23–69 | 0.584 | 0.007 | 0.396 | 0.862 |
> 69 | Reference |