Table 1.
Baseline characteristic of patients who had initially nonshockable arrest rhythms
| Subsequently | Subsequently | ||
|---|---|---|---|
| Not Shockeda | Shockedb | ||
| (n = 10,960) | (n = 521) | P value | |
| Age (years) | 71.2 (16.9) | 68.0 (16.5) | <0.0001 |
| Sex (% male) | 58.5 | 65.3 | 0.0024 |
| Public location (%) | 18.8 | 20.9 | 0.24 |
| Witnessed arrest (%) | 42.2 | 54.5 | <0.0001 |
| Bystander CPR (%) | 30.7 | 28.1 | 0.21 |
| Call–response interval (minutes) | 8.0 (3.6) | 8.2 (3.8) | 0.18 |
| Initial rhythm PEA (n (%)) | 2455 (22.4) | 229 (44.0) | <0.0001 |
| Initial rhythm asystole (n (%)) | 8505 (77.6) | 292 (56.0) | <0.0001 |
| Shock delivery time (minutes) | – | 13.0 (9.8) | N/A |
| Etiology (n (%)) | |||
| Cardiac | 4748 (43.3) | 331 (63.5) | <0.0001 |
| Noncardiac | 6212 (56.7) | 190 (36.5) | |
| Asphyxia | 1469(13.4) | 39 (7.5) | |
| Trauma | 928 (8.5) | 11 (2.1) | |
| Aortic disease | 569 (5.2) | 24 (4.6) | |
| Drowning | 447 (4.1) | 12 (2.3) | |
| Cerebrovascular disease | 267 (2.4) | 11 (2.1) | |
| Drug overdose | 72 (0.7) | 3 (0.6) | |
| Others or unknown | 2460 (22.2) | 90 (17.3) |
Data are mean (standard deviation) for continuous variables. P values calculated using the t test and the chi-square test
aPatients who had initially nonshockable rhythms and received no shock(s) during EMS resuscitation
bPatients who had initially nonshockable arrest rhythms and subsequently received shock(s) owing to conversion to shockable rhythms during EMS resuscitation
CPR cardiopulmonary resuscitation, EMS emergency medical service, N/A not available, PEA pulseless electrical activity