Epinephrine use by emergency medical technicians for presumed anaphylaxis

Abstract

Objective The use of epinephrine for the treatment of anaphylaxis by emergency medical technicians (EMTs) has not been rigorously evaluated. The aim of this study was to determine whether first-tier EMTs use epinephrine safely and appropriately for anaphylactic reactions. Methods The study used a case–control design. Cases were persons treated by EMTs with epinephrine for presumed anaphylaxis from January 1, 2000, through January 31, 2003, in King County, Washington ( n = 22). Controls were emergency medical services (EMS)-treated persons matched to cases by diagnosis category, patient age, fire department, and year, but who had not been administered epinephrine by EMTs ( n = 44). Cases and controls were compared with regard to history, symptoms, and examination characteristics. In a second assessment, physicians blinded to treatment (case/control) status reviewed events to determine whether they would have treated the patient with epinephrine. Results When cases were compared with controls, cases were more likely to report a history of anaphylaxis (27% vs. 2%), upper airway symptoms (59% vs. 18%), and shortness of breath (77% vs. 27%). Cases were also more likely to have tachypnea (32% vs. 5%), hypotension (41% vs. 9%), decreased level of consciousness (32% vs. 2%), abnormal breath sounds (46% vs. 16%), and rash (50% vs. 23%) (p ≤ 0.01 for all comparisons). The physicians agreed with the EMTs' decisions regarding epinephrine use (or nonuse) in 86% (57/66) of events: 86% (19/22) in which the EMTs used epinephrine and 86% (38/44) in which the EMTs did not use epinephrine. Conclusion In this EMS system, the EMTs used epinephrine for presumed anaphylaxis in a discriminating manner that typically agreed with physician review.