Prevalence, outcome and pre-hospital management of anaphylaxis by first aiders and paramedical ambulance staff in Manchester, UK.

BACKGROUND: Anaphylaxis is of increasing prevalence and concern in Western communities. Ambulance services are often called to deal with these emergencies. There are few published studies that examine the demand and management of allergic reactions by emergency services. The aim of this study was to investigate the frequency, severity and outcome of calls, as well as whether intramuscular adrenaline was required for successful management of allergic reactions by paramedics and first aiders. METHOD: A retrospective study of all emergency calls for allergic reactions within Greater Manchester in a 12-month period by the North West Ambulance Service of the United Kingdom. RESULTS: 816 (0.2%) of 401,152 incidents were due to allergic reactions (32/100,000/year). No patients died. In 457 (56%) patients this was the first allergic reaction. Intramuscular adrenaline was administered to 116 (14%) patients. Patients with respiratory/circulatory compromise were significantly more likely to be given intramuscular adrenaline by paramedics (14 (4.4-45)), but not by first aiders (1.9 (0.98-3.6)). Administration of adrenaline by first aiders was more likely in patients with a past history of allergic reactions (4.3 (2.3-8.1)) and where reactions occurred at non-residential addresses (4.6 (2.6-8.2)). CONCLUSIONS: Emergency call-outs for allergic reactions made up <1% of total ambulance workload. Most cases were successfully managed without intramuscular adrenaline. Adrenaline appeared to be used appropriately by paramedics. The lack of correlation between clinical severity and adrenaline use by first aiders suggests that they may often not understand the correct clinical indications for this drug.