Risk Factors for Refractory Anaphylaxis in the Emergency Department

Background: Anaphylaxis is a serious allergic reaction that has a rapid onset and can result in death. Identifying the factors that trigger anaphylaxis and increase its severity is important for preventing refractory anaphylaxis (RA). In this study, we aimed to determine the factors associated with an increased risk of developing RA. Preventive measures to reduce the frequency and intensity of anaphylactic events are essential to provide the best care for allergic patients. Aggravating factors can trigger or increase the severity of anaphylaxis and therefore need to be recognized and avoided. Methods: We retrospectively analyzed the data of 1378 patients over the age of 18 who were diagnosed with anaphylaxis in our clinic between January 1, 2020, and December 31, 2024. We divided the patients into two groups: anaphylaxis and RA. We evaluated the patients' clinical characteristics in the ED, demographic information, and elicitors that caused anaphylaxis. Results: Of the 1384 anaphylaxis patients included in the study, 46 (3.3%) were diagnosed as RA. We determined that having a history of anaphylaxis is the most important determinant of the increased risk of RA. Having a history of anaphylaxis (OR: 2.87, 95% CI: 1.71-5.72), beta-blockers/ACEI use (OR: 2.47, 95% CI: 1.71-5.42), IV contrast agent (OR: 2.33, 95% CI: 1.64-5.39), and low blood pressure or related symptoms (OR: 2.34, 95% CI: 1.67-5.43) were more frequently associated with severe reactions. Conclusion: We found that having low blood pressure or related symptoms, a known history of anaphylaxis, beta-blockers/ACEI, and IV contrast agent are risk factors for RA. To prevent mortality and morbidity in patients with this risk factor, early interventions such as rapidly repeating epinephrine doses and rapid fluid resuscitation should not be avoided.