40 Long ambulance response time is associated with higher incidence of cardiopulmonary resuscitation and defibrillation by dispatched citizen first-responders

Background Dispatching citizen first-responders by a smartphone application (app) might increase incidence of bystander cardiopulmonary resuscitation (CPR) and defibrillation in out-of-hospital cardiac arrest (OHCA). We investigated citizen first-responder rates of CPR and defibrillation according to ambulance response time. Method From September 1, 2017 to September 1, 2018, 23 021 citizen first-responders registered through the app. After being dispatched, citizen first-responders reported whether they performed CPR or defibrillation. Distances were calculated as straight line. Ambulance response time was defined as time from dispatch to vehicle stop. Citizen first-responder CPR and defibrillation were calculated according to ambulance response times (10 min). Results The Emergency Dispatch Center activated the system in 837 suspected OHCAs where 51% (n=431) were confirmed as cardiac arrests eligible for inclusion. The median distance from citizen first-responder to OHCA was 628 meters (365,902; Q1,Q3), corresponding to 5 min and 14 s citizen first-responder response time (assumed speed of 2 m/s). For ambulance response times 10 min, citizen first-responders performed CPR in 29% (n=42), 40% (n=91), and 65% (n=39) of the cases, p Conclusion A total of 15% of all OHCA patients were defibrillated by citizen first-responders. Longer ambulance response times were associated with higher rates of citizen first-responder CPR and defibrillation. Conflict of interest Dr. CM. Hansen, Dr. F.Folke and Dr. F.Lippert have received research grants from the Laerdal Foundation. None of the other authors reported conflict of interest. Funding Dr. L. Andelius, Dr. L. Karlsson, Dr. CM. Hansen and Dr. F.Folke have received unrestricted funding from the Danish Foundation TrygFonden.