Smartphone-based first aiders alerting shortens the no-flow-time in cardiac arrest

Background Smartphone-based alerting systems for voluntary first-aiders could make a contribution to improve the treatment of patients with cardiac arrest in the prehospital setting. For the first time in Germany, such a project named Mobile Rescuers has been evaluated regarding feasibility and outcome-related parameters. Methods Mobile Rescuers were alerted complementary to the regular emergency medical service (EMS). This was achieved by an app which connected the rescue coordination centre with the smartphone of the Mobile Rescuer via a central web service, navigating the first aider to the emergency scene. Primary endpoint was the time period between emergency call and arrival of adequate emergency care at the scene. Secondary endpoints were return of spontaneous circulation and frequency of alerting of Mobile Rescuers. Results During the observation period (30 months) 550 voluntary first aiders (1.6%. of the entire population) have been recruited and trained. Sixty percent of them had a rescue service-associated profession. The majority (81%) was male. In total, 477 resuscitations were registered. In 38% of them Mobile Rescuers took over the operation. In 59% of all cases Mobile Rescuers reached the scene before the EMS team. The average response time was significantly reduced as a result of the activity of Mobile Rescuers (4.4 min. vs. 8.7 min., p<0.01). Return of spontaneous circulation was seen in 63% of the patients resuscitated by Mobile Rescuers compared to 54% of patients initially treated by the EMS team (p=0.12). Conclusions In comparison with established EMS concepts, the Smartphone-based alerting system Mobile Rescuers is associated with a shorter response time and thus a reduced "no flow" time.