Abstract 16101: The Stockholm Automated External Defibrillator and Mobile Bystander Activation Trial - Results From the Run-in Period

Introduction: Survival in Out of Hospital Cardiac Arrest (OHCA) is highly dependent on time from arrest to defibrillation. In a recent Stockholm study, a mobile positioning system (MPS) was used for dispatch of lay CPR-trained responders to nearby OHCA, and bystander CPR rates increased with 30%. The MPS is now integrated with a national AED register and a smartphone application for dispatch of lay volunteers to also bring AEDs. Aim: To investigate if an MPS and a smartphone application can be used to alert CPR-trained laymen to suspected OHCA before EMS arrival, to perform CPR, and to use public AEDs. Methods: GPS-technology and integration of the Swedish AED registry within a smartphone application was used to position and recruit CPR-trained laymen (SMS-lifesavers) to nearby suspected OHCAs. The dispatcher triggered the MPS in response to suspected OHCAs. Dependent on their location, SMS-lifesavers were dispatched by the MPS to either perform CPR or to retrieve nearby AEDs. For follow up, an online-survey was sent to all SMS-lifesavers that had responded to a mission. We here present data from the run-in period in Stockholm County, February to June 2016. Results: During the study period the number of SMS-lifesavers increased from 17206 to 20784. The MPS was triggered in 410 cases of suspected OHCAs, and of these, 103 cases were true EMS-treated OHCAs. In true cases, SMS-lifesavers arrived to the patient in 56% (n=58) and prior to the EMS-services in 27% (n=28). AEDs were attached in 8% (n=8) and used in 2% (n=2). CPR was performed in 31% (n=32). SMS-lifesavers were alerted to OHCAs within a mean distance of 1488 m for AED-retrievers, and 799 m for CPR-performers. The survey-answering rate was 80%. Conclusions: With a new MPS-system and a smartphone application, CPR trained laymen can be dispatched to OHCAs before arrival of the EMS for CPR and AED use. A future randomized controlled trial -The SAMBA trial - will investigate the impact on survival from this system.