Energy levels in manual defibrillation after prior AED shock

Abstract

Aim: European guidelines suggest an escalating defibrillation energy protocol for cases of out-of-hospital cardiac arrest (OHCA) with a shockable rhythm. Our regional manual defibrillators are by default set to deliver 200 J for the initial shock and 360 J for subsequent shocks. In case of a prior AED shock, Emergency Medical Services (EMS) personnel need to deliberately adjust the energy level to 360 J before delivering the first shock with their manual defibrillator to adhere to the escalating energy protocol. We investigated adherence to this escalating energy protocol by EMS and the association with clinical outcomes.

Methods: Data were collected from the ARREST-registry in (the) Netherlands. We analysed OHCA cases in adults with shockable rhythms who had received at least one shock from an AED and from a manual defibrillator. The primary outcome was the adherence to the escalating energy protocol. Secondary outcomes were the relationships of adherence with various clinical outcomes.

Results: In 827 cases, adherence to the escalating energy protocol was 20.3 % (95 % CI 17.7 %-23.2 %). No baseline characteristics were significantly associated with increased adherence. Shockable rhythms were terminated by the first manual defibrillator shock in 521/659 (79.1 %) cases with 200 J and 139/168 (82.7 %) cases with 360 J (p = 0.33). Overall 30-day survival rate was 38.4 %. Adherence to protocol was not significantly associated with differences in clinical outcomes after multivariable analyses.

Conclusion: Adherence to escalating energy protocol by EMS during transition from defibrillation with AED to manual defibrillator is limited. Our data did not provide evidence for a relationship between adherence and clinical outcomes.

Keywords: Advanced life support; Automated external defibrillator; Cardiopulmonary resuscitation; Defibrillation; Manual defibrillator; Out-of-hospital cardiac arrest; Prehospital care.