Shortening Time to Arrival in Out-of-Hospital Cardiac Arrest by Implementing a Dual Dispatch Strategy of EMS and Volunteer Fire Service-A Simulation Study

Background/Objectives: Survival after out-of-hospital cardiac arrest (OHCA) is strongly influenced by the no-flow interval-the time between cardiac arrest and initiation of cardio-pulmonary resuscitation (CPR)-with the probability of good neurological outcome decreasing by 13% per minute without circulation. Rapid mobilization of all available responders is therefore critical. Fire services, due to their widespread local presence, can shorten response times, but turnout times-particularly in departments staffed with volunteers-may limit their benefit. In sparsely populated regions, dual dispatch of emergency medical service (EMS) and fire services may help reduce arrival times and thus improve outcomes. Methods: Response times to 1000 hypothetical OHCAs in Lower Austria (19,000 km2, 1.73 million population) were modelled. Travel times were calculated from 121 EMS stations and 1590 fire stations using the fastest route. Turnout times were set at two minutes for EMS and five minutes for fire services, with a sensitivity analysis for eight minutes for fire services. For each event, the shortest travel time was compared for both single EMS and dual EMS and fire service dispatch. Results: Mean response time was 10.6 min (SD 4.7) for EMS alone vs. 7.2 min (SD 2.2) with dual dispatch (p < 0.0001). At the 90th percentile, times were 16.8 vs. 9.7 min. Within 10 min, 49.0% of cases were reached by EMS alone vs. 92.6% with dual dispatch; fire services arrived first in 62.7% of all simulations. With an 8 min turnout, mean dual-dispatch arrival increased to 8.8 min (SD 2.9), with 68.2% of all patients reached within 10 min and firefighters arriving first in 42.9%. Conclusions: Dual dispatch of fire services and EMS significantly reduced response times, particularly in areas with a low population density. Using a dual dispatch strategy, response times were below 10 min in nearly all of the patients.