To shock or not to shock - The accuracy of cardiac arrest rhythm assessment by paramedics in a simulated environment.

Purpose: Defibrillation in shockable rhythm is a well-known key intervention in cardiopulmonary resuscitation (CPR). The aim of this study was to analyze accuracy (the sum of the numbers of true positive results and true negative results, divided by the number of total results) of deciding by paramedics whether the rhythm was shockable or non-shockable.

Methods: In this study 103 paramedics from various regions of Poland participated voluntarily. Study participants were presented with 22 simulated various electrocardiogram (ECG) recordings based on 10-s videos. These rhythms were also assessed using a manual defibrillator with shock-advisory mode known as automated external defibrillator (AED) mode.

Results: Among the 103 participants, the mean of correct answers (correct decision to defibrillate or correct decision not to defibrillate) was 18/22 (83.7 ​%). The highest possible score was achieved by the participant with 22/22 (100 ​%) correct answers, while the lowest was 10/22 (45.5 ​%). The highest score obtained for single rhythm was 97.1 ​% and the lowest was 32 ​%. Mean accuracy of shock-advisory mode was 77.3 ​%.

Conclusions: Improving the quality of paramedic training and continuous quality monitoring (e.g., by analyzing ECG recordings from resuscitations) is essential to improve the accuracy of defibrillation rhythm recognition. The role of the AED mode can be advisory, but is not a substitute for assessment by medical professionals in Emergency Medical Service.