Prescriptions for self-injectable epinephrine in emergency department angioedema management

Background: Angioedema is often treated in the emergency department (ED). Few studies have evaluated self-injectable epinephrine (SIE) prescribing patterns for angioedema. Objectives: To describe presentation and management of ED patients with angioedema and determine factors associated with epinephrine administration, hospital admission and SIE prescription. Methods: We conducted a retrospective cohort study of all ED patients with angioedema between January 2005 and December 2006. Results: Of 63 patients, 39 (61.9%) were female. Median age was 49 years. Precipitating factors were identified in 36 (57.1%) patients. History of other allergic conditions was seen in 37 (58.7%) patients. Seventeen (27.0%) patients received epinephrine, 55 (87.3%) received antihistamines, and 51 (81.0%) received steroids. Epinephrine was administered more commonly in patients with edema of the tongue (risk ratio [RR], 5.28, 95% confidence interval [CI] 1.95-14.33, P = .0003), tightness/fullness of throat (RR, 3.31, 95% CI 1.62-6.76, P = .006), and dyspnea/wheeze (RR, 3.04, 95% CI 1.41-6.59, P = .005). Hospitalization was more common in patients with dyspnea/wheeze (P = .028) and allergic history (P = .006). Thirteen patients (22.0%) were discharged with SIE. An SIE prescription was associated with younger patients (median age, 26 years [interquartile range (IQR) 15-50] vs a median age 57.5 years [IQR 43-68], P = .004) and patients with throat tightness/fullness (RR, 4.2, 95% CI 1.8-9.8, P = .005). Conclusion: Patients with respiratory symptoms and allergic history were likely to be admitted. Epinephrine use was more frequent in patients with signs and symptoms of oropharyngeal edema. Younger patients and those with tightness/fullness of throat were likely to be prescribed SIE. Further studies are needed to determine who would benefit from epinephrine use and SIE prescription.