Spatial and Temporal Boundaries of Remote Areas in the Initial Management of Out-of-Hospital Cardiac Arrest.

Introduction: Besides well-described patient-related and event-related factors, time intervals during the initial management of out-of-hospital cardiac arrest (OHCA) and distance from the emergency call and collapse location are additional influencing elements usually underrepresented by the widely applied prognostic models. The aim of this study is to analyze the influence of time and distance as crucial factors on the success of pre-hospital care of patients with OHCA, as well as the influence of other variables defined by the EuReCa Study protocol, observed during the study period, on the positive pre-hospital outcomes.

Methods: According to the EuReCa Study protocol accepted by the EuReCa_Serbia protocol, the data on all cases of adult patients with witnessed cardiac-cause OHCA receiving bystander cardiopulmonary resuscitation (CPR) measures were prospectively collected during the period October 1, 2014 to December 31, 2023, and analyzed to compare the degree of influence of different patient- and OHCA-related predictors, including time- and distance-related factors, on initial OHCA outcomes - first recorded heart rhythm, return of spontaneous circulation on scene (any ROSC), and survival to hospital admission.