Table 1.
Clinical characteristics of study cohort
| n | Level | Overall—n (%) | Survivor—n (%) | Non-survivor—n (%) | p |
|---|---|---|---|---|---|
| 673 (100) | 211 (31.4) | 462 (68.6) | |||
| (1) Demographics, Risk factors, comorbidities | |||||
| Date of hospital admission | 04/2020–06/2020 | 186 (27.6) | 75 (35.5) | 111 (24.0) | 0.0019 |
| 07/2020–03/2021 | 487 (72.4) | 136 (64.5) | 351 (76.0) | ||
| Age [years] | 19–40 | 50 (7.4) | 29 (13.7) | 21 (4.6) | < 0.0001 |
| 41–70 | 578 (85.9) | 178 (84.4) | 400 (86.6) | ||
| > 70 | 42 (6.2) | 4 (1.9) | 38 (8.2) | ||
| Missing | 3 (0.4) | 0 (0.00) | 3 (0.7) | ||
| Sex | m | 535 (79.5) | 161 (76.3) | 374 (81,095) | 0.3661 |
| w | 131 (19.5) | 48 (22.8) | 83 (18.0) | ||
| Missing | 7 (1.0) | 2 (0.9) | 5 (1.1) | ||
| BMI [kg/m2] | < 25 | 81 (12.0) | 21 (10.0) | 60 (13.0) | 0.0414 |
| 25–30 | 263 (39.1) | 83 (39.3) | 180 (39.0) | ||
| 30–35 | 147 (21.8) | 43 (20.4) | 104 (22.5) | ||
| ≥ 35 | 157 (23.3) | 61 (28.9) | 96 (20.8) | ||
| Missing | 25 (3.7) | 3 (1.4) | 22 (4.8) | ||
| Cardiovascular disease | No | 226 (33.6) | 82 (38.9) | 144 (31.2) | 0.1323 |
| Yes | 416 (61.8) | 119 (56.4) | 297 (64.3) | ||
| Missing | 31 (4.6) | 10 (4.7) | 21 (4.6) | ||
| Chronic pulmonary disease | No | 564 (83.8) | 179 (84.8) | 385 (83.3) | 0.8043 |
| Yes | 103 (15.3) | 31 (14.7) | 72 (15.6) | ||
| Missing | 6 (0.9) | 1 (0.5) | 5 (1.1) | ||
| Diabetes mellitus | No | 483 (71.8) | 153 (72.5) | 330 (71.4) | 0.9401 |
| Yes | 186 (27.6) | 57 (27.0) | 129 (27.9) | ||
| Missing | 4 (0.6) | 1 (0.5) | 3 (0.7) | ||
| Moderate to severe kidney disease | No | 619 (92.0) | 192 (91.0) | 427 (92.4) | 0.6161 |
| Yes | 49 (7.3) | 18 (8.5) | 31 (6.7) | ||
| Missing | 5 (0.7) | 1 (0.5) | 4 (0.9) | ||
| Immunosuppression within 6 months prior to admission | No | 523 (77.7) | 158 (74.9) | 365 (79.0) | 0.0334 |
| Yes | 39 (5.8) | 8 (3.8) | 31 (6.7) | ||
| Unknown | 111 (16.5) | 45 (21.3) | 66 (14.3) | ||
| (2) Severity of disease, laboratory parameters (day 1) | |||||
| EOLIA criteria | Met | 284 (42.2) | 108 (51.2) | 176 (38.1) | 0.0014 |
| Not met | 389 (57.8) | 103 (48.8) | 286 (61.9) | ||
| Indication of ECMO | Hypoxemia | 419 (62.3) | 126 (59.7) | 293 (63.4) | 0.5229 |
| Hypercapnia | 141 (21.0) | 43 (20.4) | 98 (21.2) | ||
| Lung protective ventilation | 48 (7.1) | 16 (7.6) | 32 (6.9) | ||
| Right heart failure | 2 (0.3) | 1 (0.5) | 1 (0.2) | ||
| Left heart failure | 4 (0.6) | 1 (0.5) | 3 (0.6) | ||
| Cardiopulmonary resuscitation | 6 (0.9) | 0 (0.0) | 6 (1.3) | ||
| Pulmonary embolism | 3 (0.4) | 3 (1.4) | 0 (0.0) | ||
| Other | 9 (1.3) | 5 (2.4) | 4 (0.9) | ||
| Intubation prior to ECMO [days] | < 5 | 275 (40.9) | 102 (48.3) | 173 (37.4) | 0.0004 |
| 5–7 | 102 (15.2) | 20 (9.5) | 82 (17.7) | ||
| ≥ 8 | 179 (26.6) | 44 (20.9) | 135 (29.2) | ||
| No prior intubation | 75 (11.1) | 33 (15.6) | 42 (9.1) | ||
| Missing | 42 (6.2) | 12 (5.7) | 30 (6.5) | ||
| Creatinine [mg/dl] | ≤ 1.17 | 313 (46.5) | 99 (46.9) | 214 (46.3) | 0.8757 |
| > 1.17 | 304 (45.2) | 93 (44.1) | 211 (45.7) | ||
| Missing | 56 (8.3) | 19 (9.00) | 37 (8.0) | ||
| Mode of ventilation | Spontaneous | 18 (2.67) | 9 (4.27) | 9 (1.95) | 0.3042 |
| Assisted | 71 (10.55) | 19 (9.00) | 52 (11.26) | ||
| Controlled | 544 (80.83) | 170 (80.57) | 374 (80.95) | ||
| Missing | 40 (5.94) | 13 (6.16) | 27 (5.84) | ||
| Lung compliance [ml/cm H2O] | 25.5 [18.1, 34.2] | 26.0 [17.6, 35.7] | 25.4 [18.4, 33.9] | 0.7168 | |
| (3) ECMO and adjunct therapy | |||||
| Mode of ECMO | VV | 651 (96.7) | 205 (97.2) | 446 (96.5) | 0.5104 |
| VA | 12 (1.8) | 2 (0.9) | 10 (2.2) | ||
| VVA | 10 (1.5) | 4 (1.9) | 6 (1.3) | ||
| Cannula | Single lumen | 544 (80.8) | 153 (72.5) | 391 (84.6) | 0.0028 |
| Double lumen | 52 (7.7) | 22 (10.4) | 30 (6.5) | ||
| Unknown | 70 (10.4) | 33 (15.6) | 37 (8.0) | ||
| Missing | 7 (1.0) | 3 (1.4) | 4 (0.9) | ||
| Case volume ECMO center [n/year] | Low (< 20) | 96 (14.3) | 19 (9.0) | 77 (16.7) | 0.0024 |
| Intermediate (20–49) | 329 (48.9) | 97 (46.0) | 232 (50.2) | ||
| High (≥ 50) | 248 (36.9) | 95 (45.0) | 153 (33.1) | ||
| Duration of ECMO support [h] | 312.5 [144.0, 528.0] | 336.0 [178.2, 560.8] | 300.0 [120.0, 502.5] | 0.0046 | |
| Prone positioning | No | 240 (35.7) | 64 (30.3) | 176 (38.1) | 0.1314 |
| Yes | 333 (49.5) | 111 (52.6) | 222 (48.1) | ||
| Missing | 100 (14.9) | 36 (17.1) | 64 (13.9) | ||
| Therapeutic Anticoagulation | No | 53 (7.9) | 22 (10.4) | 31 (6.7) | 0.0968 |
| Yes | 620 (92.1) | 189 (89.6) | 431 (93.3) | ||
| (4) Complications during ECMO | |||||
| Major bleeding or thromboembolic event | No | 231 (34.3) | 97 (46.0) | 134 (29.0) | < 0.0001 |
| Yes | 442 (65.7) | 114 (54.0) | 328 (71.0) | ||
| Secondary bacterial infection (respiratory tract or bloodstream) | No | 239 (35.5) | 81 (38.4) | 158 (34.2) | 0.2921 |
| Yes | 434 (64.5) | 130 (61.6) | 304 (65.8) | ||
| Renal replacement therapy | No | 282 (41.9) | 123 (58.3) | 159 (34.4) | < 0.0001 |
| Yes | 391 (58.1) | 88 (41.7) | 303 (65.6) | ||
Clinical characteristics of study cohort. Clinical characteristics in total population (n = 673) and survivor (n = 211) vs. non-survivor (n = 462). Parameters were slit up into blocks: (1) Demographics, Risk factors, Comorbidities; (2) Severity of Disease, Laboratory Parameters (day 1); (3) ECMO and adjunct therapy; (4) Complications during ECMO. Descriptive statistics are expressed as frequencies for categorical variables (including a category for missing data). Lung compliance is expressed as median (IQR) and data are missing for 34%, since the parameter was recorded in controlled ventilated patients only. Differences between groups were tested using the Mann–Whitney U test (continuous variables), χ2 test (categorical variables) or Fisher’s exact test (categorical variables with observed frequencies < 5), as appropriate