Table 1 Demographic, pre-hospital, and in-hospital characteristics of the study population divided into groups based on initial partial pressure of arterial oxygen levels after the start of extracorporeal membrane oxygenation
Variables | Total (n = 847) | Normoxia (n = 277) | Moderate hyperoxia (n = 313) | Extreme hyperoxia (n = 257) | p value |
|---|---|---|---|---|---|
Pre-hospital variables | |||||
Age (years) | 62 (49–69) | 58 (49–68) | 62 (49–69) | 64 (52–72) | 0.017 |
Male, n (%) | 670 (79.1) | 223 (80.5) | 258 (82.4) | 189 (73.5) | 0.091 |
Witness, n (%) | Â | Â | Â | Â | 0.95 |
 EMS personnel | 115 (15.7) | 38 (16.2) | 42 (16.1) | 35 (14.8) |  |
 Others | 464 (63.5) | 148 (63.2) | 162 (62.1) | 154 (65.3) |  |
Bystander CPR, n (%) | 326 (44.6) | 102 (43.6) | 120 (46.0) | 104 (44.1) | 0.74 |
Initial cardiac rhythm monitored, n (%) | Â | Â | Â | Â | 0.55 |
 Vf/pulseless VT | 463 (63.3) | 141 (60.3) | 177 (67.8) | 145 (61.4) |  |
 PEA | 149 (20.4) | 43 (18.4) | 52 (19.9) | 54 (22.9) |  |
 Asystole | 66 (9.0) | 29 (12.4) | 18 (6.9) | 19 (8.1) |  |
 Others | 53 (7.3) | 21 (9.0) | 14 (5.4) | 18 (7.6) |  |
Pre-hospital shock delivery, n (%) | 548 (75.0) | 168 (71.8) | 207 (79.3) | 173 (73.3) | 0.32 |
Pre-hospital adrenaline administration, n (%) | 253 (34.6) | 75 (32.1) | 89 (34.1) | 89 (37.7) | 0.48 |
Pre-hospital advanced airway management, n (%) | 378 (51.8) | 117 (50.0) | 145 (55.8) | 116 (49.2) | 0.51 |
Time from call to scene (mins) | 7 (5–8) | 7 (5–8) | 7 (5–8) | 7 (5–8) | 0.86 |
Time from scene to hospital arrival (mins) | 25 (19–32) | 24 (19–31) | 25 (19–34) | 24 (19–30) | 0.46 |
Cardiac origin, n (%) | 715 (84.4) | 226 (81.6) | 266 (85.0) | 223 (86.8) | 0.059 |
In-hospital variables | |||||
Cardiac rhythm on arrival, n (%) | Â | Â | Â | Â | 0.003 |
 Vf/pulseless VT | 374 (44.2) | 102 (36.8) | 144 (46.0) | 128 (49.8) |  |
 PEA | 241 (28.5) | 74 (26.7) | 96 (30.7) | 71 (27.6) |  |
 Asystole | 164 (19.4) | 69 (24.9) | 51 (16.3) | 44 (17.1) |  |
 Others | 68 (8.0) | 32 (11.6) | 22 (7.0) | 14 (5.4) |  |
In-hospital shock delivery, n (%) | 539 (63.6) | 151 (54.5) | 220 (70.3) | 168 (65.4) | < 0.001 |
In-hospital adrenaline administration, n (%) | 747 (88.5) | 236 (85.8) | 273 (87.5) | 238 (92.6) | 0.031 |
Antiarrhythmic drug administration, n (%) | 406 (48.3) | 110 (40.0) | 159 (51.5) | 137 (53.3) | 0.002 |
Transient ROSC before ECMO pump-on, n (%) | 312 (37.1) | 143 (51.8) | 97 (31.4) | 72 (28.0) | < 0.001 |
Time from hospital arrival to ECMO pump-on (mins) | 32 (21–47) | 35 (24–61) | 30 (20–46) | 30 (20–40) | < 0.001 |
Time from hospital arrival to BGA (mins) | 60.5 (29–159) | 40 (18–151) | 78 (39–192) | 60 (35–123.5) | < 0.001 |
pH | 7.14 (6.95–7.29) | 7.07 (6.88–7.25) | 7.2 (7.01–7.31) | 7.16 (6.96–7.30) | < 0.001 |
PaO2 (mmHg) | 300 (148–427) | 106 (83–145) | 311 (254–351) | 489 (439–537) | < 0.001 |
PaCO2 (mmHg) | 39 (31–52) | 48 (36–71) | 37 (31–47) | 36 (29–45) | < 0.001 |
HCO3− (mEq/L) | 13.3 (9.7–17.2) | 14.0 (10.4–17.3) | 13.5 (9.9–17.5) | 12.3 (8.5–15.8) | 0.002 |
Lactate (mEq/L) | 11.8 (6.9–16.0) | 11.2 (6.1–15.9) | 11.8 (6.6–16.0) | 12.8 (8.3–16.0) | 0.076 |
Intra-aortic balloon pump use, n (%) | 531 (62.7) | 180 (65.0) | 191 (61.0) | 160 (62.3) | 0.53 |
Percutaneous coronary intervention, n (%) | 348 (41.1) | 122 (44.0) | 112 (35.8) | 114 (44.4) | 0.004 |
Targeted temperature management, n (%) | 469 (55.4) | 161 (58.1) | 165 (52.7) | 143 (55.6) | 0.39 |