Table 1.
Out of hospital cardiac arrest patient characteristics.
| All Patients | Patients w/out any Metronome Used |
Patients w/ Metronome Ever Used |
||
|---|---|---|---|---|
| Demographics | Median/n (IQR/%) | Median/n (IQR/%) | Median/n (IQR/%) | p |
| Total patients | 2,132 | 1,043 | 1,089 | |
| Age, years | 63 (50–75) | 63 (50–75) | 63 (50–75) | 0.95 |
| Sex, male | 1,412 (66.3%) | 682 (65.4%) | 730 (67.0%) | 0.45 |
| Clinical Features | ||||
| Presumed Etiology | 0.19 | |||
| Primary Cardiac | 1,673 (78.5%) | 826 (79.2%) | 847 (77.9%) | |
| Primary Respiratory - non toxic | 109 (5.1%) | 50 (4.8%) | 59 (5.4%) | |
| Primary Respiratory - toxic | 208 (9.8%) | 111 (10.6%) | 97 (8.9%) | |
| Medical | 120 (5.6%) | 47 (4.5%) | 73 (6.7%) | |
| Other / Unknown | 22 (1.0%) | 9 (0.9%) | 13 (1.2%) | |
| Arrest Location | 0.043 | |||
| Home/Other Residence | 1,304 (61.2%) | 603 (57.8%) | 701 (64.4%) | |
| Public | 565 (26.5%) | 308 (29.5%) | 257 (23.6%) | |
| Healthcare Facility | 249 (11.7%) | 126 (12.0%) | 123 (11.3%) | |
| Other / Unknown | 14 (0.7%) | 6 (0.6%) | 8 (0.7%) | |
| Bystander Witnessed | 785 (36.8%) | 381 (36.5%) | 404 (37.1%) | 0.13 |
| Bystander CPR | 1,283 (60.2%) | 593 (56.8%) | 690 (63.4%) | <0.0001 |
| Initial Rhythm on EMS Arrival | 0.24 | |||
| VF or VT | 502 (23.6%) | 263 (25.2%) | 239 (21.9%) | |
| PEA | 482 (22.6%) | 235 (22.5%) | 247 (22.7%) | |
| Asystole | 1,052 (49.4%) | 505 (48.4%) | 547 (50.3%) | |
| Non-Shockable | 43 (2.0% | 14 (1.3%) | 29 (2.7%) | |
| Pulses on First Check | 36 (1.7%) | 16 (1.5%) | 20 (1.8%) | |
| Unknown | 17 (0.7%) | 10 (1.0%) | 7 (0.6%) | |
| Case Features | ||||
| Call to Dispatch, minutes | 0.63 (0.47–0.88) | 0.62 (0.47–0.85) | 0.65 (0.48–0.92) | 0.0006 |
| Call to Start EMS Compressions, minutes | 6.7 (5.6–8.1) | 6.5 (5.4–7.9) | 6.8 (5.7–8.2) | 0.0006 |
| Length of Resuscitation, minutes | 30.3 (22.2–39.4) | 30.0 (20.8–38.9) | 30.5 (23.4–39.7) | 0.012 |
| EMS Compressions to Metronome Start, minutes | 1.3 (0.6–3.2) |
There were significant differences observed between groups for Arrest Location, Bystander CPR, Call to Dispatch, Call to Start EMS Compressions, and Length of Resuscitation. There were no significant differences observed between other groups.
Data was missing from 10 cases for Age; 21 cases from Call to Start EMS Compressions; 32 cases from Length of Resuscitation, minutes; and 7 cases from EMS Compressions to Metronome Start.
Abbreviations: CPR: cardiopulmonary resuscitation, EMS: emergency medical services, VF/VT: ventricular fibrillation/ventricular tachycardia, PEA: pulseless electrical activity.