Defibrillator Design and Usability May Be Impeding Timely Defibrillation

Timely defibrillation is the only rhythm-specific therapy proven to increase survival to hospital discharge following cardiac arrest secondary to ventricular tachyarrhythmia. Delayed defibrillation occurs in more than 30% of this population. A study was conducted to test the hypothesis that unintuitive defibrillator design and lack of usability are barriers to timely defibrillation, as measured by time to defibrillation and the proportion of defibrillations delivered within 2 minutes.

A mixed-methods (qualitative and quantitative) prospective usability study was performed to evaluate the use of a defibrillator in a simulated hospital environment. Participants were asked to perform two simulated tasks typical of in-hospital cardiac arrest care: defibrillation and synchronized cardioversion.

The average time to defibrillation was 4 minutes 21 seconds. Only 9.1% of participants (2/22) performed a defibrillation within 2 minutes. Participants had difficulty with several aspects of defibrillator use, including attaching the hands-free defibrillator electrode pads and selecting an appropriate display. Participants rated defibrillator design 4.2 ± 1.8 (mean, standard deviation) on a perceived usability scale (1 = "poorly designed"; 9 = "perfectly designed").

Most participants were unable to perform a simulated defibrillation within 2 minutes. This delay in defibrillation was likely at least partially the result of poor defibrillator design and lack of usability. Expert observation and participant feedback were largely congruent in terms of which aspects of defibrillator design do not suit the end user. Modification of future defibrillator design, along with improved education and training, may result in more timely defibrillation.