Abstract 96: Randomized Trial to Shorten Perishock Pauses During AED Use
Objective: Retrospective studies show that interruption of CPR for shocks and long pre-shock pauses for ventricular fibrillation (VF) have a negative association with shock success and survival. Guidelines changes in 2005 eliminated long post-shock pauses. We tested a new AED protocol that also eliminated long pre-shock pauses and increased CPR for patients with out-of-hospital cardiac arrest (OHCA) and VF.
Materials and Methods: In a per-patient randomized controlled trial, patients with OHCA with shockable initial rhythm were treated with two AED protocols. In the control protocol (A), based on Guidelines 2000, no CPR was given during analysis of the heart rhythm and charging. Rhythm analysis followed every shock, followed by a pulse check or if needed a second (200J) or third (360J) shock. If no pulse was detected, CPR was resumed immediately for 1 min. In the study protocol (B), a modification of the Guidelines 2005, a 15 second period of CPR during and after charging was added to the voice prompts, no pulse check, no rhythm analysis after a single shock, followed by CPR for 2 minutes. In both protocols, C:V ratio was 30:2.
Results: In 1043 OHCA patients were connected to an AED and resuscitation started, 415 were included in the final analysis. Study patients (n=202) had short pre- and postshock pauses, received more CPR and fewer shocks than control patients (n=213) (Table). VF was terminated after the first shock in similar proportions (A:87% vs. B:89%; P=0.61). No significant difference was found in survival to hospital admission (A:64% vs. B:61%; P=0.66) and survival to discharge (A: 37% vs. study: 41%; P=0.48).
Conclusion: An AED protocol with a period of CPR immediately before the shock and shortened pre- and postshock pauses, increased overall hands-on time and more compressions delivered, but did not increase the percentage of patients in which VF was terminated after the first shock, survival to hospital admission or survival to discharge.
Author Disclosures: S.G. Beesems: None. M. Hulleman: None. J. Berdowski: None. R.W. Koster: Research Grant; Significant; Physio-Control.
- © 2014 by American Heart Association, Inc.