Table 1.
Baseline characteristics by time interval between defibrillation attempts in patients with cardiac arrest in hospital. Figures are numbers (percentage) of patients unless otherwise specified
| Characteristic | Second defibrillation attempt | P value | |
|---|---|---|---|
| Early (≤1 min between attempts) (n=1612, 59%) | Deferred (>1 min between attempts) (n=1121, 41%) | ||
| Mean (SD) age (years) | 64.22 (15.2) | 65.22 (14.7) | 0.09 |
| Men | 1059 (65.7) | 733 (65.4) | 0.9 |
| White | 1209 (75.0) | 820 (73.2) | 0.7 |
| Pre-existing conditions: | |||
| Heart failure this admission | 277 (17.2) | 193 (17.2) | 0.9 |
| Previous heart failure | 307 (19.0) | 243 (21.7) | 0.09 |
| Myocardial infarction this admission | 467 (29.0) | 276 (24.6) | 0.01 |
| Previous myocardial infarction | 328 (20.4) | 237 (21.1) | 0.6 |
| Arrhythmia | 660 (40.9) | 448 (40.0) | 0.6 |
| Hypotension | 413 (25.6) | 227 (20.3) | 0.001 |
| Respiratory insufficiency | 559 (34.7) | 376 (33.5) | 0.5 |
| Hepatic insufficiency | 86 (5.3) | 60 (5.4) | 0.9 |
| Metabolic or electrolyte abnormality | 197 (12.2) | 153 (13.7) | 0.3 |
| Diabetes mellitus | 459 (28.5) | 350 (31.2) | 0.1 |
| Baseline depression in CNS function | 170 (10.6) | 105 (9.4) | 0.3 |
| Acute stroke | 50 (3.1) | 44 (3.9) | 0.3 |
| Pneumonia | 109 (6.8) | 88 (7.9) | 0.3 |
| Septicemia | 159 (9.9) | 165 (14.7) | <0.001 |
| Major trauma | 55 (3.4) | 33 (2.9) | 0.5 |
| Metastatic cancer | 124 (7.7) | 109 (9.7) | 0.06 |
| Interventions in place before arrest: | |||
| Mechanical ventilation | 592 (36.7) | 368 (32.8) | 0.04 |
| Intravenous vasopressor medication | 549 (34.1) | 327 (29.2) | 0.007 |
| Dialysis | 47 (2.9) | 41 (3.7) | 0.3 |
| Intra-aortic balloon pump | 72 (4.5) | 31 (2.8) | 0.02 |
| Pulmonary artery catheter | 105 (6.5) | 49 (4.4) | 0.02 |
| Characteristics of cardiac arrest | |||
| Initial cardiac arrest rhythm: | |||
| Ventricular fibrillation | 1029 (63.8) | 741 (66.1) | 0.2 |
| Pulseless ventricular tachycardia | 583 (36.2) | 380 (33.9) | |
| Median time (mins) to first defibrillation attempt (IQR) | 1 (0-4) | 2 (0-5) | <0.001 |
| Hospital location of arrest: | |||
| Intensive care unit | 418 (25.9) | 343 (30.6) | <0.001 |
| Monitored unit | 168 (10.4) | 190 (17.0) | |
| Non-monitored unit | 146 (9.1) | 126 (11.2) | |
| Procedural area | 265 (73.2) | 97 (26.8) | |
| Hospital-wide response activated | 1141 (70.8) | 817 (72.9) | 0.2 |
| Assessed with AED | 287 (17.8) | 248 (22.1) | 0.01 |
| Time of arrest: | |||
| Arrest at night (11 pm to 7 am) | 283 (17.6) | 247 (22.0) | 0.01 |
| Arrest on weekend | 429 (26.6) | 275 (24.5) | |
| Hospital characteristics | |||
| Geographic region: | |||
| North and Mid-Atlantic | 231 (14.3) | 161 (14.4) | 0.7 |
| South Atlantic | 403 (25.0) | 268 (23.9) | |
| North central | 369 (22.9) | 243 (21.7) | |
| South central | 287 (17.8) | 224 (20.0) | |
| Mountain/Pacific | 286 (17.7) | 196 (17.5) | |
| Hospital size (No of beds): | |||
| <250 | 229 (14.2) | 154 (13.7) | 0.3 |
| 250-499 | 741 (46.0) | 463 (41.3) | |
| ≥500 | 606 (37.6) | 475 (42.4) | |
AED=automated external defibrillator, CNS=central nervous system, IQR=interquartile range.