Response interval is important for survival until admission after prehospital cardiac arrest.

Introduction: An increasing distance to the nearest hospital must be expected as a result of centralization of acute care at a small number of hospitals. This may have important consequences in emergency situations, such as prehospital or out-of-hospital cardiac arrest (OHCA) where the aim is to obtain return of spontaneous circulation (ROSC), i.e. successful resuscitation. The aim of this study was to describe the impact of response interval on sustained ROSC, i.e. ROSC at hospital admission, after OHCA with presumed cardiac aetiology.
Material and Methods: We included all OHCA calls in which the Copenhagen Mobile Emergency Care Unit (MECU) was involved during the 2002-2008 period. Data were collected prospectively and the primary endpoint was sustained ROSC.
Results: Resuscitation was attempted in 2,678 OHCA cases. Among these, cardiac aetiology was presumed in 2,327 cases, and 745 patients (32.0%) achieved sustained ROSC. The mean response interval was significantly shorter for patients who obtained sustained ROSC (370 seconds) than for patients who did not (394 seconds) (p = 0.015).
Conclusion: A significantly shorter response interval was observed in patients who were successfully resuscitated after out-of-hospital cardiac arrest than in patients who were not successfully resuscitated.