Background and Advantages of a Tiered EMS Response in a Large, Fire-Based EMS Model

Abstract

HCCR, an open access journal Emergency medical services (EMS) has evolved greatly since its inception. The model has gone from a load-and-go philosophy to one that integrates high-level medical knowledge and techniques. As the practice of prehospital medicine evolves, these models must also evolve to provide good care. This requires efficient utilization of resources and placement of these resources in areas that are quickly accessible to those in need. A proposed solution has been to dispatch units based on screening by 911 call-takers. EMS response can be grouped into two categories: uniform and tiered. Uniform response means an advanced life support (ALS) unit is always dispatched. A tiered response sends first responders, basic life support (BLS) units, and/or ALS units depending on how the caller answers a series of questions asked by the dispatcher. Persse et al. investigated the difference in survival of patients in the uniform versus tiered response areas within a single, large system. Survival rates for those with out-of-hospital ventricular fibrillation arrest, as well as time to skilled procedures were compared. They found that survival rates were higher in patients treated in the tiered response group. Time to skilled procedures was shorter as well. In this article we aim to provide a background for Persse et al. 's study and underscore its relevance [1]. EMS Training Emergency medical technicians (EMTs) are trained at three main levels-basic, which fulfills first responder duties, intermediate, which incorporates some higher skills and knowledge, such as advanced airway techniques and intravenous line (i.v.) insertion, and paramedic, which includes advanced cardiac life support (ACLS) in addition to the aforementioned skills [2]. Training for paramedics is longer and requires a more advanced skill set that, in turn, requires more time and experience to master. ALS providers need repeated exposure to advanced interventions to maintain their skills [3]. Skill dilution has been an observed phenomenon in models with higher paramedic to population ratio, and some studies have shown a correlation between a smaller number of paramedics to BLS responders, and successful intubation rates [3-6]. Stout et al. similarly suggested that an all ALS response system causes skill dilution in paramedics, as most calls do not require ALS skills [7]. Uniform vs Tiered Response The uniform response (one that includes a paramedic) provides some advantages, most notably that there is always an advanced Abstract Emergency medical services (EMS) systems vary across country, state, and even county lines. Which model provides the most effective and safe care has been hotly debated. Some models employ a fire-based EMS response, whereas others are privately funded and are completely separate from other public responders. Response can be uniform or tiered, which means that either ALS units respond to every call or calls are triaged based on their severity and units are dispatched accordingly. This requires a sophisticated dispatch algorithm that screens for emergencies of highest priority. Persse et al. sought to determine the difference in survival in out-of-hospital ventricular fibrillation arrest between a tiered response EMS model and an all advanced life support (ALS) response model within the same system. Background and Advantages of a Tiered EMS Response in a Large, Fire-Based EMS Model