Clinical Reviews
Customizing Anaphylaxis Guidelines for Emergency Medicine

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Abstract

Background

Most episodes of anaphylaxis are managed in emergency medical settings, where the cardinal signs and symptoms often differ from those observed in the allergy clinic. Data suggest that low recognition of anaphylaxis in the emergency setting may relate to inaccurate coding and lack of a standard, practical definition.

Objective

Develop a simple, consistent definition of anaphylaxis for emergency medicine providers, supported by clinically relevant consensus statements.

Discussion

Definitions of anaphylaxis and criteria for diagnosis from current anaphylaxis guidelines were reviewed with regard to their utilization in emergency medical settings. The agreed-upon working definition is: Anaphylaxis is a serious reaction causing a combination of characteristic findings, and which is rapid in onset and may cause death. It is usually due to an allergic reaction but can be non-allergic. The definition is supported by Consensus Statements, each with referenced discussion. For a positive outcome, quick diagnosis and treatment of anaphylaxis are critical. However, even in the emergency setting, the patient may not present with life-threatening symptoms. Because mild initial symptoms can quickly progress to a severe, even fatal, reaction, the first-line treatment for any anaphylaxis episode—regardless of severity—is intramuscular injection of epinephrine into the anterolateral thigh; delaying its administration increases the potential for morbidity and mortality. When a reaction appears as “possible anaphylaxis,” it is generally better to err on the side of caution and administer epinephrine.

Conclusion

We believe that this working definition and the supporting Consensus Statements are a first step to better management of anaphylaxis in the emergency medical setting.

Introduction

Despite the recent release of a number of guidelines and updated emergency medicine (EM) practice parameters on the management of anaphylaxis, there remain significant knowledge and practice gaps in the United States (US) 1, 2, 3. This was the conclusion of a multidisciplinary group of experts attending a July 2011 Roundtable meeting, Anaphylaxis in Emergency Medicine (Chicago, IL), who were given the directive of reviewing the current guidelines and how they are applied in different emergency medical settings in the US (e.g., prehospital, community hospital, rural health care, academic medical center). The ensuing discussion identified gaps in knowledge and practice as well as barriers to care in each setting.

The group agreed that the root cause for many of the identified gaps in the treatment of anaphylaxis was the lack of a practical definition of anaphylaxis as it relates to EM. Although recent guidelines and practice parameters have published consensus definitions of anaphylaxis, there is a concern that emergency health professionals may not be fully utilizing them 1, 2, 3, 4, 5, 6. The poor concordance may reflect the lack of consensus among the various guidelines, as well as differences in the likelihood of several of the cardinal signs and symptoms of anaphylaxis actually being due to anaphylaxis in the Emergency Department (ED) as opposed to findings in the allergist's office. The current body of evidence from retrospective data reviews and surveys of ED and Emergency Medical Services (EMS) providers confirms that a variety of definitions of anaphylaxis are being utilized that vary across regions and health care systems 7, 8, 9. The “definitions” can be complex and confusing for clinical providers and can lead to inconsistency of care provided.

The lack of a standardized practical definition of anaphylaxis likely contributes to under-diagnosis, under-reporting, under-treatment, and subsequently, life-threatening complications that could potentially be avoided. The Roundtable faculty agreed that a simple and consistent definition might encourage ED and EMS providers to consider the diagnosis more frequently. It was also recognized that the definition had to have face validity with everyday EM practitioners, with both sensitivity and specificity for anaphylaxis, to become a part of common practice. It was not the intent to create a new definition, but to build upon those suggested by other groups to provide a more clinically relevant definition for emergency providers. Thus, as a starting point, the working definition is taken from current guidelines, with some minor modifications as follows: Anaphylaxis is a serious reaction causing a combination of characteristic findings, and which is rapid in onset and may cause death. It is usually due to an allergic reaction, but can be non-allergic. The characteristic findings are described in the listing of the clinical criteria for identification (Table 1).

After agreeing upon the working definition, the faculty developed consensus statements to summarize why the definition is needed and to encourage its practical application. This article presents those consensus statements, each with a brief discussion. It is not the intent to provide a comprehensive review of how to diagnose and manage anaphylaxis in the emergency medical setting. For that, the reader is directed to the current guidelines and other recent reviews 1, 2, 3, 10, 11. We wish to point out, however, that the consensus statements presented here expand the discussion and can be considered as a “call to action” for emergency health professionals.

The Roundtable meeting was chaired by the first author, Richard Nowak, and the expert faculty included all of the listed authors. All of the faculty met criteria for authorship and approved the Consensus Statements.

Section snippets

Consensus Statements

1. “The traditional mechanistic definition of anaphylaxis is not useful at the bedside.” When asked to define anaphylaxis, even some allergists have admitted that, “Anaphylaxis is hard to define, but I know it when I see it.” However, other clinicians might not recognize anaphylaxis on instinct alone (5).

Discussion: There is a “disconnect” in how anaphylaxis has historically been defined and how the term is used clinically. Traditionally, allergy textbooks and guidelines have defined

Conclusion

In conclusion, the current body of evidence indicates that most anaphylaxis cases are seen in an emergency medical setting, so proper diagnosis is critical. A critical factor contributing to failure of the emergency health professional to diagnose anaphylaxis may be the lack of a standard and practical definition applicable to the emergency medical setting. It is important to recognize that anaphylaxis may not appear life-threatening and that the patient may present without respiratory or

Acknowledgment

This manuscript was supported in part by an unrestricted educational grant from Mylan Pharmaceuticals. The company had no involvement in the development, writing, or review of the manuscript. All authors participated in the original Roundtable meeting, Anaphylaxis in Emergency Medicine, convened in Chicago, IL in July 2011, and agreed at that time that there exists a need for a standard definition of anaphylaxis that is appropriate for emergency medicine health professionals. Richard Nowak, md,

References (34)

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