Guidelines and updated emergency medicine (EM) practice parameters have been issued for the management of anaphylaxis in the ED, but research indicates that significant knowledge and practice gaps persist. In July 2011, a round-table meeting called Anaphylaxis in Emergency Medicine was conducted, consisting of a multidisciplinary group of experts who reviewed the current guidelines and how they are applied in different emergency medical settings in the United States. The experts agreed that the root cause for many treatment gaps for anaphylaxis was the lack of a practical definition of anaphylaxis as it relates to EM.

“There is concern that EM professionals may not be using current guidelines and practice parameters fully,” explains Richard Nowak, MD, who chaired the Anaphylaxis in Emergency Medicine roundtable panel. “This results from not having a consensus in published guidelines on the definition of anaphylaxis. Another key factor is that there are differences in signs and symptoms of how anaphylaxis presents in EDs, compared with those occurring in allergists’ offices.”

A Practical Definition of Anaphylaxis

In 2013, Dr. Nowak and colleagues published an article in the Journal of Emergency Medicine that customized anaphylaxis guidelines for EM. Articulating a simple standardized practical definition of anaphylaxis and describing characteristic findings in the clinical criteria for identifying it were an important emphasis (Table 1). The working definition was modified, building upon definitions suggested by other groups, so that it is clinically more relevant to emergency providers.

Anaphylaxis-ED-Callout

Dr. Nowak and colleagues also developed consensus statements that encouraged practical application of guidelines when managing anaphylaxis (Table 2). “These statements expand the discussion on how to diagnose and manage anaphylaxis in emergency settings rather than provide a comprehensive review,” Dr. Nowak says. “We view them as a ‘call to action’ for EM providers.”

Recognizing Anaphylaxis Is Key

“Diagnosing and managing anaphylaxis in the ED will be different from that of allergy clinics,” says Dr. Nowak. Much of the anaphylaxis literature is published in allergy journals, but the ED is the most common setting for treating it. The article also notes that anaphylaxis is underdiagnosed and undertreated in most pre-hospital care situations and EDs.

Dr. Nowak says that pre-hospital and EM providers must understand that patients may not present with life-threatening symptoms, he says. They may simply have gastrointestinal (GI) complaints plus hives, or they could have gastrointestinal distress with difficulty breathing. “That said, anaphylaxis occurs as a continuum,” explains Dr. Nowak. “Even when initial symptoms are mild, reactions can progress rapidly and become more severe. As such, it’s important to not delay appropriate treatment.”

About 1,500 people die each year in the U.S. from anaphylactic reactions to foods, drugs, latex, and insect stings. “Clinicians should recognize that severe reactions have the potential to be fatal,” Dr. Nowak says. “Those who die from anaphylaxis are oftentimes young and otherwise in good health.” Further complicating matters is that no single test can diagnose anaphylaxis or predict its outcome. As a result, EM providers should appreciate the potential morbidity and life-threatening nature of anaphylaxis and recognize that multiple factors can increase the likelihood of acute episodes.

Treatment Considerations: Epinephrine

Prompt recognition and aggressive treatment—particularly with early administration of intramuscular epinephrine—will typically reduce the severity and morbidity of acute anaphylaxis episodes. “Early administration of epinephrine is critical,” says Dr. Nowak. “If anaphylaxis is suspected, it’s generally better to err on the side of caution and administer epinephrine. The evidence shows that epinephrine should be the first-line treatment for all pre-hospital and ED patients with anaphylaxis.”

According to Dr. Nowak, anaphylaxis is a long-term diagnosis that requires patients to be managed even after they are discharged from the ED. “These patients are at risk for more episodes,” he says. “Patients should be prescribed self-injectable epinephrine at discharge from the ED and given an anaphylaxis emergency action plan. They need to be able to recognize symptoms and avoid triggers. Patients should also be educated on how to inject epinephrine and referred for follow-up and long-term care.”

Looking Ahead: Managing Anaphylaxis in the ED

Currently, there is limited evidence on practice gaps for managing anaphylaxis in the ED. “We still have several research gaps that must be addressed,” says Dr. Nowak. “We need data on the effects of not using epinephrine quickly in the atypical presentations of anaphylaxis. We also need to assess outcomes for patients who are given antihistamines first for anaphylaxis episodes and compare them with immediate epinephrine treatment. It would be helpful to find out if patients who don’t fill or refill epinephrine prescriptions fair worse than patients who maintain it and keep it with them. As these research gaps are addressed, it’s hoped that EM providers will be able to improve the management of anaphylaxis in the ED.”

References

Nowak R, Farrar JR, Brenner BE. Customizing anaphylaxis guidelines for emergency medicine. J Emerg Med. 2013;45:299-306.

Simons FE, Ardusso LR, Bilo MB, et al. World Allergy Organization guidelines for the assessment and management of anaphylaxis. J Allergy Clin Immunol. 2011;127:587-593.

Lieberman P, Nicklas RA, Oppenheimer J, et al. The diagnosis and management of anaphylaxis practice parameter: 2010 update. J Allergy Clin Immunol. 2010;126:477-480.

Boyce JA, Assa’ad A, Burks AW, et al. Guidelines for the diagnosis and management of food allergy in the United States: report of the NIAID-sponsored expert panel. J Allergy Clin Immunol. 2010;126(Suppl):S1-S58.