Abstract 117: Effect of ‘Early Defibrillation’ on the Survival of Patients With Witnessed Cardiac Arrest From Ventricular Fibrillation in the Guideline 2005 Era in Japan
Background: In the management of sudden cardiac arrest (SCA) from ventricular fibrillation (VF), early defibrillation is vital along with early CPR. Here we assess the relation between the time from SCA to first defibrillation and the survival with favorable neurological function in defibrillation-treated SCA patients in the guideline 2005 era in Japan.
Methods: In a nationwide observational study, we enrolled individuals aged 18 years and older who had an out-of-hospital SCA witnessed by by-standers, and responded by Japanese official emergency medical system from Jan 1, 2006, to Dec 31, 2008. Collected data included age, sex, heart rhythm, bystander CPR and the time of witness and delivery of first defibrillation. The primary endpoint was favorable neurological outcome 1 month after an out-of-hospital SCA, defined as Glasgow-Pittsburgh cerebral performance category (CPC) 1 or 2.
Results: During 3 years after the guideline 2005 has taken effect, 13,053 patients were recorded as witnessed SCA, documented to have VF, whereas 2,150 (16.5%) patients survived with CPC 1 or 2. We excluded 738 (5.7%) subjects with recorded witness to defibrillation interval <0 min or >30 min to avoid potential errors in the records. Among 12,315 subjects, 5,862 (47.6%) did not, and 6,231 (50.6%) subjects did undergo bystander CPR. We analyzed the rate of survival with CPC 1 or 2 in the subjects without or with bystander CPR (figure). In subjects without bystander CPR, the chance of favorable outcome was 31.8% 1 min after witness, and decreased as the time to first defibrillation prolongs. By contrast, in subject with bystander CPR, the chance of favorable outcome sustained for the first 8 min after witness, and decreased later on by a similar decay.
Conclusions: We confirmed the effectiveness of ‘early defibrillation’ on the chance of survival after witnessed SCA from VF in the guideline 2005 era. Bystander CPR appears to maintain the chance to survive for several minutes after witnessed SCA.
- © 2010 by American Heart Association, Inc.