The Scandinavian AED and Mobile Bystander Activation Trial

Overview

Sudden cardiac death is a major health problem in the western world. In Europe alone nearly 300 000 patients are affected annually. The majority of victims suffering from an Out-of-Hospital Cardiac Arrest (OHCA have an initial cardiac rhythm that can be treated by means of defibrillation. In most emergency medical systems (EMS) time to defibrillation is too long and survival averages 10 %.However, when laymen operated Automated External Defibrillators (AEDs) are used within the first minutes, 7 out of 10 may survive. The aim of "The Scandinavian AED and Mobile Bystander Activation" (SAMBA) trial is to evaluate if a Mobile Phone Positioning system and a smartphone application will increase the proportions of patients with an attached Automated External Defibrillator (AED) before arrival of the Emergence Medical System (EMS). Mobile phone technology and a smartphone application will be used identify and recruit nearby CPR-trained lay people and automated external defibrillators (AEDs) to patients suffering out-of-hospital cardiac arrest (OHCA). The system is currently running in Stockholm Sweden and in the Gothenburg region.

Early defibrillation in out-of-hospital cardiac arrest is associated with high survival rates. If the operator at the dispatch center suspects an out-of-hospital cardiac arrest he or she will activate the mobile positioning system (MPS) wich is integrated in the operators computer environment. After activation, the system will locate all CPR-trained volunteers nearby the suspected OHCA. By computer based 1:1 randomization lay volunteers will be alerted and dispatched in 50 % of all suspected OHCAs in where the system is triggered by the dispatchers. In the intervention group, the activation of the system is supposed to result in lay volunteers to be alerted and directed to fetch the nearest AED and commence early defibrillation. Dependent on geographical and logistical circumstances, at a minimum one lay volunteer or more will be alerted to provide bystander CPR only. In the control group the MPS will be activated and lay responders will be dispatched to suspected OHCA to perform CPR only. In both groups the ordinary EMS services are dispatched in a regular fashion.