Abstract 286: Survival to Hospital Discharge With Fixed 360 Joules Versus 200 Escalating to 360 Joules Defibrillation Strategies in Out-of-Hospital Cardiac Arrest of Presumed Cardiac Etiology
Background: There is lack of evidence for fixed or escalating shock energy levels impact on survival to hospital discharge during CPR. According to the 2010 CPR consensus “maintaining the same initial energy level during subsequent shocks is acceptable. It is reasonable to increase the energy level when possible.” We studied shock success and survival to hospital discharge with fixed 360 Joules (J) versus escalating 200 to 360 J shocks, in patients in the Circulation Improving Resuscitation Care (CIRC) trial.
Methods: Initial rhythm, pre-shock rhythm, rhythm 5 seconds after shock, shock energy levels and number of shocks were recorded. Patients uncategorizable as fixed or escalating shock energy protocol, without any indicated shocks or without any analyzable result from the shock were excluded from analysis. Shock success was defined as VF/VT termination at least 5 seconds after shock. Shock success between groups was calculated using chi-square test. Logistic regression determined the association between defibrillation strategy and survival to hospital discharge, after adjusting for age, initial rhythm, number of shocks, and witnessed arrests.
Results: In CIRC 1657 (39%) of 4231 patients received at least one shock with analyzable defibrillator data. We included 914 fixed and 411 escalating patients. Median number of shocks per patient was 2 (IQR 1-4) in both groups. These patients received 3819 indicated shocks, 2662 in the fixed group and 1157 in the escalating group. There were 2178 (81.8%) successful shocks in the fixed group versus 963 (83.2%) in the escalating group (OR 0.91, 95% CI 0.76-1.09, p=0.29). A sub-analysis of patients whose initial rhythm was VF/VT found first shock success for 409 (83.1%) of the 492 in the fixed group versus 237 (86.5%) of the 274 in the escalating group (OR 0.77, 95% CI 0.51-1.17, p=0.22). Survival to hospital discharge for patients in the fixed group had an unadjusted OR 0.83, (95% CI 0.62-1.12, p=0.23) and adjusted OR 1.10 (95% CI 0.78-1.54, p=0.61) compared to the escalating group.
Conclusion: There was no difference in individual shock success between defibrillation strategies. Further, there was no difference in patient survival to hospital discharge between the fixed versus escalating defibrillation strategies.
- © 2013 by American Heart Association, Inc.