Table 1.
Demographics, clinical characteristics and type of event by category of bleeding and thrombotic events
| Characteristic | All patients | Category of BTE | p value | |||
|---|---|---|---|---|---|---|
| None | Bleeding only | Thrombosis only | Both | |||
| n = 7579 | n = 4535 | n = 1127 | n = 1270 | n = 647 | ||
| Age, years—mean ± SD | 46.5 ± 15.4 | 47.3 ± 15.5 | 46 ± 15.1 | 45.6 ± 14.9 | 43.7 ± 15.1 | < 0.001 |
| Female sex—no. (%) | 2999 (39.6) | 1815 (40) | 460 (40.8) | 479 (37.7) | 245 (37.9) | 0.29 |
| Weight, kg—mean ± SD | 87.5 ± 28.3 | 86.9 ± 27.7 | 85.7 ± 27.8 | 90.5 ± 29.9 | 89.1 ± 29.7 | < 0.001 |
| White race—no. (%) | 4668 (61.6) | 2783 (61.4) | 694 (61.6) | 800 (63) | 391 (60.4) | 0.001 |
| Primary diagnosis—no. (%) | ||||||
| Non-viral pneumonia | 1905 (26.9) | 1090 (26.1) | 307 (27.8) | 318 (26.9) | 190 (30.3) | 0.14 |
| Viral pneumonia | 1463 (20.6) | 774 (18.5) | 263 (23.8) | 265 (22.5) | 161 (25.6) | < 0.001 |
| Trauma/burn | 1021 (14.4) | 539 (12.9) | 182 (16.5) | 181 (15.3) | 119 (18.9) | < 0.001 |
| Pneumonitis | 407 (5.7) | 234 (5.6) | 71 (6.4) | 65 (5.5) | 37 (5.9) | 0.73 |
| Asthma | 394 (5.6) | 272 (6.5) | 56 (5.1) | 45 (3.8) | 21 (3.3) | < 0.001 |
| Pulmonary hypertension | 179 (2.5) | 98 (2.3) | 25 (2.3) | 39 (3.3) | 17 (2.7) | 0.28 |
| Lung transplant complications | 170 (2.4) | 104 (2.5) | 28 (2.5) | 30 (2.5) | 8 (1.3) | 0.29 |
| Unspecified ARDS/ARF | 1387 (18.3) | 846 (18.7) | 182 (16.1) | 248 (19.5) | 111 (17.2) | 0.13 |
| Chronic respiratory conditions—no. (%) | ||||||
| ILD | 512 (7.2) | 317 (7.6) | 80 (7.3) | 69 (5.8) | 46 (7.3) | 0.24 |
| COPD | 250 (3.5) | 154 (3.7) | 47 (4.3) | 35 (3) | 14 (2.2) | 0.1 |
| Cystic fibrosis | 147 (2.1) | 87 (2.1) | 18 (1.6) | 27 (2.3) | 15 (2.4) | 0.65 |
| Cannulation strategy—no. (%) | ||||||
| Single cannulation site | 2778 (36.7) | 1677 (37) | 432 (38.3) | 415 (32.7) | 254 (39.3) | 0.007 |
| Pre-ECMO vasopressor—no. (%) | 4336 (57.2) | 2506 (55.3) | 722 (64.1) | 719 (56.6) | 389 (60.1) | < 0.001 |
| Pre-ECMO renal failure—no. (%) | 1192 (15.7) | 666 (14.7) | 230 (20.4) | 190 (15) | 106 (16.4) | < 0.001 |
| Pre-ECMO Cardiac Arrest-no. (%) | 538 (7.2) | 349 (7.9) | 66 (5.9) | 86 (6.8) | 37 (5.8) | 0.04 |
| Pre-ECMO pH—mean ± SD | 7.23 ± 0.15 | 7.22 ± 0.16 | 7.23 ± 0.14 | 7.24 ± 0.14 | 7.25 ± 0.13 | < 0.001 |
| Pre-ECMO PaCO2, mmHg—mean ± SD | 60.2 ± 32 | 60 ± 33 | 58.7 ± 34.1 | 61.9 ± 29.2 | 61 ± 26.5 | 0.11 |
| Pre-ECMO PaO2, mmHg—mean ± SD | 67.6 ± 54.1 | 68.8 ± 57.6 | 65 ± 56.3 | 67.9 ± 45.7 | 64.1 ± 39.7 | 0.08 |
| Respiratory rate, rpm—mean ± SD | 22.9 ± 8.2 | 22.7 ± 8.1 | 22.7 ± 8.3 | 23.1 ± 8.4 | 24 ± 8.6 | 0.005 |
| FiO2, %—mean ± SD | 93.5 ± 14.1 | 93.3 ± 14.4 | 93.5 ± 13.9 | 94 ± 13.6 | 94.2 ± 13.1 | 0.32 |
| P/F ratio—mean ± SD | 75.7 ± 74.3 | 77.1 ± 78.2 | 72.8 ± 73.2 | 76.8 ± 73.7 | 69.9 ± 45.5 | 0.09 |
| PIP, cmH2O—mean ± SD | 34.9 ± 10.6 | 34.4 ± 9.9 | 35.4 ± 12.4 | 35.4 ± 10.9 | 36.4 ± 10.8 | < 0.001 |
| PEEP, cmH2O—mean ± SD | 13 ± 5.6 | 12.8 ± 5.6 | 12.9 ± 5.8 | 13.5 ± 5.4 | 13.4 ± 5.7 | < 0.001 |
| Mean airway pressure, cmH2O—mean ± SD | 24.5 ± 11.4 | 24.2 ± 11.3 | 25.7 ± 12.5 | 24.2 ± 10.6 | 25.5 ± 11.6 | 0.02 |
| Membrane oxygenator material | < 0.001 | |||||
| PMP | 4426 (58.4) | 2547 (56.2) | 693 (61.5) | 749 (59) | 437 (67.5) | |
| PP | 584 (7.7) | 321 (7.1) | 87 (7.7) | 120 (9.4) | 56 (8.7) | |
| Silicone | 6 (0.1) | 4 (0.1) | 0 (0) | 1 (0.1) | 1 (0.2) | |
| Time on ECMO, days—median (IQR) | 8 (5, 15) | 7 (4, 11) | 10 (6, 17) | 12 (7, 20) | 17 (10, 28) | < 0.001 |
| Cannulation site bleeding—no. (%) | 743 (9.8) | – | 466 (41.3) | – | 277 (42.8) | < 0.001 |
| Surgical site bleeding—no. (%) | 460 (6.1) | – | 289 (25.6) | – | 171 (26.4) | < 0.001 |
| Tamponade—no. (%) | 58 (0.8) | – | 36 (3.2) | – | 22 (3.4) | < 0.001 |
| Gastrointestinal bleeding—no. (%) | 397 (5.2) | – | 219 (19.4) | – | 178 (27.5) | < 0.001 |
| Pulmonary bleeding—no. (%) | 291 (3.8) | – | 167 (14.8) | – | 124 (19.2) | < 0.001 |
| Intracranial hemorrhage—no. (%) | 216 (2.8) | – | 161 (14.3) | – | 55 (8.5) | < 0.001 |
| Circuit clotting—no. (%) | 1276 (16.8) | – | – | 841 (66.2) | 435 (67.2) | < 0.001 |
| Oxygenator/pump failure—no. (%) | 575 (7.6) | – | – | 361 (28.4) | 214 (33.1) | < 0.001 |
| Hemolysis—no. (%) | 399 (5.3) | – | – | 255 (20.1) | 144 (22.3) | < 0.001 |
| Ischemic stroke—no. (%) | 92 (1.2) | – | – | 55 (4.3) | 37 (5.7) | < 0.001 |
Values are expressed as mean ± standard deviation or median (interquartile range) for continuous variables, and absolute frequency (percentages) for categorical variables. Continuous variables compared using one-way ANOVA and categorical variables compared using chi-square test
BTE, bleeding and thrombotic event; ARDS, acute respiratory distress syndrome; ARF, acute respiratory failure; ILD, interstitial lung disease; COPD, chronic obstructive pulmonary disease; ECMO, extracorporeal membrane oxygenation; FiO2, fraction of inspired oxygen; PaCO2, arterial partial pressure of carbon dioxide; PaO2, arterial partial pressure of oxygen; PIP, peak inspiratory pressure; PEEP, positive end-expiratory pressure; PMP, polymethylpentene; PP, polypropylene