Real-life time and distance covered by lay first responders alerted by means of smartphone application: implications for early initiation of cardiopulmonary resuscitation and access to automatic external defibrillators

Aim of the Study: To investigate the distance covered by lay first responders (LFR) alerted for an out-of- hospital cardiac arrest (OHCA), evaluate the time elapsed between mission acceptance and arrival at the OHCA site, as well as the distance between the LFRs to the closest automatic external defibrillator (AED). Methods: The LFR route, thus time, distance information, and the average speed of each responder were estimated. The same methodology was used to calculate the distance between the closest AED and the LFRs, as well as the distance between the AED and OHCA site. Results: Between June 1st, 2014 and December 31st, 2017, the LFR network was activated in occasion of 484 suspected OHCAs. 710 LFRs were automatically selected by the application and accepted the mission. On average 1.5 LFRs arrived at the OHCA site. LFRs covered a distance of 1196 m (IQR 596–2314) at a median speed of 6.9 m/s (IQR 4.5–9.8) or 24.8 Km/h. In 4.4% of the cases the speed of the LFRs was compatible with a brisk walk activity (<1.5 m/sec). The total intervention time of an LFR, who first retrieved an AED and then went to the OHCA site, was longer (275 s, IQR: 184 s–414 s) compared to the total intervention time of a LFR (197 s, IQR: 120 s–306 s; p < 0.001), who went to the OHCA site directly without retrieving an AED. Conclusions: The dispatch of LFRs directly to the OHCA site instead of first retrieving the AED, significantly decreases the time to CPR initiation. More studies are needed to assess the prognostic implications on survival and neurological outcome.