Prehospital rearrest following resuscitation from out-of-hospital cardiac arrest (OHCA) has been estimated to afflict 30 % of patients with return of spontaneous circulation (ROSC) and is associated with a 70 % reduction in the odds of survival to hospital discharge [1]. Delayed recognition and treatment of rearrest may contribute to adverse outcomes, but limited data exists characterizing the duration of these delays.

In the prehospital setting, emergency medical services (EMS) clinicians have many competing responsibilities while caring for post-ROSC patients: tasks such as administration of vasopressors, coordinating movement to the ambulance, and airway management may occupy their attention and contribute to delayed rearrest recognition. Previously published data exist to support the assertion that these delays exist. One single-center study reported delayed EMS recognition of ∼20 % of rearrest events, with a median delay of 2.6 min [2]. Similarly, there are treatment delays in initial OHCA, with one study demonstrating an average delay of approximately 7 min from EMS arrival on scene to defibrillation of initial shockable rhythms [3]. The previous study of prehospital rearrest treatment delays did not stratify by initial rhythm (ventricular fibrillation (VF) vs. asystole) or treatment type (defibrillation delivery vs. cardiopulmonary resuscitation (CPR) initiation). Additionally, while it has been hypothesized that treatment delays may be related to transport, [2] previous research has not related the timing of rearrest or duration of delays to patient movement.

In this retrospective study, we aimed to determine the frequency and magnitude of delays to defibrillation and chest compressions following prehospital rearrest for patients with a rearrest rhythm of asystole or VF. Secondarily, we aimed to characterize the timing of rearrest in relation to patient movement using a novel exploratory methodology.