[Implementation of a smartphone-based first-responder alerting system].

Background Shortening the resuscitation-free interval in cardiac arrest increases the survival rate. Smartphone-based systems can locate and alert nearby rescuers. Objectives Implementation of a first responder system, technical development and adaption to regional structures. Materials and methods The system Region der Lebensretter was successfully established in July 2018 in Freiburg. The need of optimization was evaluated every half year and realized according to the PDCA (plan-do-check-act) cycle. The necessary functions were specified (plan), programmed, tested and released (do). Afterwards the changes were evaluated (check) and, if necessary, further optimizations were implemented (act). Results The number of registered rescuers increased from 276 (2nd half year 2018) to 794 (1st half year 2020). The rate of alarm acceptance increased from 30% (2nd half year 2018) to 49% (1st half year 2020). The following features were designed and released: dynamic adjustment of the alarm radius (DAA), critical alert function, connection to automated external defibrillator (AED) database, digital rescuer identification (ID), feedback button arrived on scene, choice of means of transport for algorithm optimization. The number of existing AEDs increased from 190 to 270. Conclusion The resuscitation-free interval can be shortened by smartphone-based alerting systems. For successful operation, the total number of rescuers and the technical realization is crucial. Further studies are necessary to investigate whether the survival rate of out-of-hospital cardiac arrest can be increased. It appears extremely appropriate to adapt these systems to databases of quality management or research registers.