Differing operational outcomes with six commercially available automated external defibrillators

Introduction: In general automated external defibrillators (AED) are handled easily, but some untrained lay rescuers may have major problems with the use of such products. This may result in delayed shock delivery and delay in basic life support (BLS) after use of the AED. To study the effect of voice prompts and design solutions we tested the time from the first shock to the initiation of BLS for six defibrillators available in Austria. Methods: Volunteers, who had no AED training, were evaluated to see when they delivered the first shock and how often BLS was started after the voice prompts were given by the defibrillators. Results: Time to first shock delivered ranged from 78 (95% CI: 68-89) to 128 (95% CI: 110-146) s. The defibrillator-type had a significant influence on the time to first shock delivered (P < 0.0001). The proportion of volunteers who started BLS after defibrillation ranged from 93 to 33% and differed significantly between the AEDs used (P < 0.03). Conclusions: We demonstrated that there are significant differences between AEDs, concerning important operational outcomes like time to first shock and the start of BLS. Further research and development is urgently required to optimise user-friendliness and operational outcomes. (C) 2004 Elsevier Ireland Ltd. All rights reserved.