Relevance of Reversible Causes of Out-of-Hospital Cardiac Arrest: The "REBECCA" Interactive Checklist

Background/Objectives: Adequate cardiopulmonary resuscitation (CPR), defibrillation, and treatment of reversible causes are essential for improving the survival of patients suffering from out-of-hospital cardiac arrests (OHCAs). The Advanced Life Support (ALS) algorithm includes reversible causes for cardiac arrest. This study aimed to develop an interactive mobile checklist to identify reversible causes of OHCA (REBECCA) and evaluate their usability and usefulness among emergency physicians. Methods: This mixed-methods study was conducted at the Emergency Medical Service Vienna, Austria. All participants were emergency physicians from the Medical University of Vienna. An interactive mobile checklist was developed using a participatory design approach involving a focus group of 10 emergency physicians. Usability and applicability were assessed using structured questionnaires. Descriptive statistics were used to summarize participant characteristics and evaluation outcomes. Results: Among the included participants, 70% were specialists with a median prehospital experience of 2.0 (1.0-4.3) years. Although most participants were confident about their level of professional experience with OHCA, 85% still found the checklist to be helpful. The majority of the participants preferred the digital checklist over the paper-based checklist and appreciated its integration with the point-of-care ultrasound (POCUS) application. Although the participants did not communicate a significant need for further details on most causes, a small majority favored more information on intoxication and electrolyte disorders. Conclusions: The majority of the included emergency physicians found the REBECCA checklist helpful regardless of training level, whereas almost no physician needed further detailed information on the reversible causes. Our findings underscore the potential importance of future investigations aiming to reduce the cognitive load of emergency physicians during OHCA scenarios.