Table 2.
Patient characteristics in the matched cohort
| Initial shockable rhythm | Initial non-shockable rhythm | |||||
|---|---|---|---|---|---|---|
| Characteristics | ECPR (N = 913) | Control (N = 913) | SMD | ECPR (N = 370) | Control (N = 370) | SMD |
| Sex (men) | 784 (86%) | 778 (85%) | 0.02 | 284 (77%) | 278 (75%) | 0.04 |
| Age | 59 (48, 68) | 59 (48, 70) | − 0.04 | 60 (47, 69) | 58 (45, 69) | 0.08 |
| Witnessed | 714 (78%) | 717 (79%) | − 0.01 | 285 (77%) | 296 (80%) | − 0.07 |
| Bystander CPR | 506 (55%) | 510 (56%) | − 0.01 | 160 (43%) | 178 (48%) | − 0.10 |
| Initial cardiac rhythm | 0.00 | 0.01 | ||||
| Initial VF/VT | 913 (100%) | 913 (100%) | – | – | ||
| PEA | – | – | – | 237 (64%) | 239 (65%) | |
| Asystole | – | – | – | 133 (36%) | 131 (35%) | |
| Bystander AED | 77 (8.4%) | 74 (8.1%) | 0.01 | 20 (5.4%) | 20 (5.4%) | 0.00 |
| Physician-staffed heli/ ambulance | 237 (26%) | 246 (27%) | − 0.02 | 86 (23%) | 105 (28%) | − 0.12 |
| Shock by paramedic | 907 (99%) | 896 (98%) | 0.11 | 133 (36%) | 114 (31%) | 0.11 |
| Advanced airway | 0.08 | 0.09 | ||||
| Intubation | 121 (13%) | 126 (14%) | 35 (9.5%) | 41 (11%) | ||
| None | 349 (38%) | 379 (42%) | 151 (41%) | 160 (43%) | ||
| SGA | 443 (49%) | 408 (45%) | 184 (50%) | 169 (46%) | ||
| Number of IV adrenaline | 0.02 | − 0.05 | ||||
| 0 | 533 (58%) | 538 (59%) | 226 (61%) | 212 (57%) | ||
| 1 | 121 (13%) | 135 (15%) | 38 (10%) | 56 (15%) | ||
| 2 | 99 (11%) | 93 (10%) | 44 (12%) | 48 (13%) | ||
| 3 | 91 (10.0%) | 72 (7.9%) | 36 (9.7%) | 22 (5.9%) | ||
| 4 | 33 (3.6%) | 34 (3.7%) | 21 (5.7%) | 10 (2.7%) | ||
| ≥ 5 | 36 (3.9%) | 41 (4.5%) | 5 (1.4%) | 22 (5.9%) | ||
| Pre-hospital ROSC | 70 (7.7%) | 67 (7.3%) | 0.01 | 30 (8.1%) | 25 (6.8%) | 0.05 |
| Time from call to hospital | 31 (26, 39) | 31 (25, 38) | 0.06 | 33 (27, 40) | 34 (27, 41) | − 0.03 |
| Initial cardiac rhythm on arrival | 0.09 | 0.11 | ||||
| Asystole | 151 (17%) | 133 (15%) | 110 (30%) | 104 (28%) | ||
| PEA | 162 (18%) | 143 (16%) | 169 (46%) | 188 (51%) | ||
| VF/VT | 600 (66%) | 637 (70%) | 91 (25%) | 78 (21%) | ||
| Shock in hospital | 472 (52%) | 551 (60%) | − 0.17 | 133 (36%) | 133 (36%) | 0.00 |
| Adrenaline in hospital | 776 (85%) | 838 (92%) | − 0.21 | 332 (90%) | 346 (94%) | − 0.14 |
| Intubation in hospital | 711 (78%) | 761 (83%) | − 0.14 | 303 (82%) | 323 (87%) | − 0.15 |
| ECPR case volume | 0.12 | 0.19 | ||||
| High volume | 668 (73%) | 664 (73%) | 269 (73%) | 277 (75%) | ||
| Middle volume | 202 (22%) | 181 (20%) | 85 (23%) | 64 (17%) | ||
| Low volume | 43 (4.7%) | 68 (7.4%) | 16 (4.3%) | 29 (7.8%) | ||
Continuous variables are expressed as medians and interquartile ranges, and categorical variables are expressed as numbers and percentages (%)
SMD, standardized mean difference. ECPR, Extracorporeal cardiopulmonary resuscitation; CPR, Cardiopulmonary resuscitation; VF, Ventricular fibrillation; VT, Ventricular tachycardia; PEA: Pulseless electrical activity; ROSC, Return of spontaneous circulation; AED, Automated external defibrillator; SGA, Supraglottic airway; IV, intravenous. Variables were included in the model to generate propensity scores