Simulation and educationEffects of AED device features on performance by untrained laypersons☆,☆☆
Introduction
Sudden cardiac arrest (SCA) is the leading cause of death among adults in the United States, striking as many as 325,000 individuals per year.1 A common cardiac rhythm disturbance associated with sudden cardiac arrest is ventricular fibrillation (VF), for which the only effective treatment is rapid defibrillation.
New simplified automated external defibrillators (AEDs) enable untrained laypersons to deliver shocks to victims of cardiac arrest. A simulation study showed that sixth graders can deliver a rescue shock only 30 s slower than an experienced emergency medical technician or paramedic.2 Another study showed that a 30 min course in CPR and AED use was equivalent to the traditional full length course even after 6 months had passed, and that the AED was applied 93% of the time.3 Additionally, a recent study using three distinct methods of instruction to teach AED application and CPR, showed that all three methods were highly effective at instructing participants on AED use.4
There are many AED models available and these models have been shown to have varying success rates when used by laypersons. These models have similar functions, but features that affect the ease and speed of use vary among the devices. Simulation studies have shown marked variation in layperson operation.5, 6, 7, 8, 9 Since rapid defibrillation is of paramount importance in the treatment of SCA, it is important to identify what makes a device easy to use.
The majority of studies involving layperson AED use focus on the operation of the overall device and how quickly a shock can be delivered.5, 6, 7, 8, 9, 10 One study looked at pad placement and successful shock delivery,4 and another study looked at the time from first shock to the initiation of CPR.8
This study focuses on specific ergonomic features of AEDs and how they affect the ease and speed with which a shock can be delivered, and how quickly after a shock CPR is initiated. We hypothesized that successful device operation is based on the ability to rapidly perform these main steps: turning the device on, placing the pads, delivering a shock, and starting CPR.
Section snippets
Methods
This was a prospective, randomized, observational evaluation of features of selected trainer AEDs in a controlled simulation environment. Volunteer subjects were assigned to one of the devices using a computer generated randomization table (Microsoft Excel). Cross-over design was not used due to concern for learning effect. The study was conducted at a university-affiliated sports medicine clinic and at a university event center.
A “trainer AED” was defined for this study as a training device
Results
One hundred and twenty persons participated in the study. All but one completed high school and 45% had obtained a bachelor or post-graduate degree. Nearly half (42%) of participants reported prior CPR training (Table 2).
Most subjects (91%) were able to deliver shock. The most common individual step leading to failure to deliver shock was failure to power-on device (eight of 11 subjects) (Table 3). One hundred and eight (90%) subjects delivered shock within 180 s of starting the scenario. Median
Discussion
Many cardiac arrest victims who now die can be saved with prompt defibrillation.5 For this to occur, laypersons must be able to use AEDs quickly and effectively. Our study found that a high percentage of participants were able to deliver a shock within 180 s, which was also reported by other studies.5, 6, 7, 8, 9, 10, 11, 12 Other studies found that removing unnecessary voice prompts can shorten the amount of hands off time for the performance of CPR, and efforts to decrease the time to delivery
Conclusion
In a simulated cardiac arrest setting, most untrained AED users were able to deliver a shock within 180 s. Pad placement was often inadequate. Device features were found to have the most impact on time to power-on, accuracy of pad placement and initiation of CPR.
Conflicts of interest
VNM receives compensation for serving as medical director from the Sudden Cardiac Arrest Association, Washington, DC, a non-profit organization which promotes greater awareness and prevention and better treatment of sudden cardiac arrest.
Funding sources
AED devices were loaned and disposable supplies provided by the manufacturers of the six devices used in the study. The final study design and manuscript were solely determined by the authors. Manufacturers did not have access to the study database.
Acknowledgements
The authors express their appreciation to Matt Weaver for assistance with manuscript preparation and data management, Tom Dongilli and the WISER Institute of UPMC (Pittsburgh, PA) for simulation software and support, and to Cheryl Rickens, RN, Jon Rittenberger, MD, and Phil Vargo, EMT-P for evaluating pad placement.
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Cited by (45)
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2022, Resuscitation PlusCitation Excerpt :This requires laypersons to switch the AED settings from adult to pediatric mode or use pediatric defibrillation electrodes during resuscitation. Previous studies have reported that user-friendliness is a barrier for swift, effective, and safe defibrillation when using an AED in default adult mode.8,9 Accordingly, overall bystander AED usage remains low even when the nearest AED is close.10
Optimizing outcomes after out-of-hospital cardiac arrest with innovative approaches to public-access defibrillation: A scientific statement from the International Liaison Committee on Resuscitation
2022, ResuscitationCitation Excerpt :Simulation studies suggest that fully automated AEDs (in which shock is delivered without the need for the operator to press a button) increase operator safety152 and compliance with AED instructions, reducing the time to successful defibrillation.153 In simulation studies, untrained bystanders were often able to successfully deliver a shock,154 but device-specific differences in design have been observed to affect the time required to power on a device, the accuracy of AED pad placement, and whether CPR was initiated after rhythm analysis.155,156 We suggest that research be conducted to identify novel AED design features that facilitate the proper use of AEDs by laypeople and improve both the quality of resuscitation provided and the outcomes for patients with OHCA.
Layperson use of AEDs – What happens after shock delivery?
2021, Resuscitation
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A Spanish translated version of the abstract of this article appears as Appendix in the final online version at doi:10.1016/j.resuscitation.2009.07.016.
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Presented at National Association of EMS Physicians Annual Meeting, Naples, FL, 11 January 2007.