Simulation of Health and Economic Benefits of Extended Observation of Resolved Anaphylaxis

To the ER? Can Patients Treat Their Anaphylaxis at Home?

PURPOSE OF REVIEW

To discuss if all patients who use self-injectable epinephrine outside the hospital setting require immediate emergency care.

RECENT FINDINGS

Prior to 2023, anaphylaxis management guidance universally recommended that patients who use self-injectable epinephrine outside of the hospital or clinic setting immediately activate emergency medical services and seek further care. Additional food-induced anaphylaxis management recommendations specified that all patients always carry 2 auto-injector devices and give a second dose of epinephrine if there was not immediate response within 5 min of injection. Patients presenting for emergency care after epinephrine are often observed for up to 4-6 h afterwards, even when completely asymptomatic. These management steps have lacked evidence for improving outcomes, and universal implementation of these approaches is not cost-effective as guidance for food allergic patients. Epinephrine pharmacokinetics and pharmacodynamics suggest that peak physiologic response is more likely to occur closer to 15 min than before 5 min, that few patients require a second dose of epinephrine as most stabilize within 15 min of use, that 60 min of observation after a patient stabilizes after epinephrine use may be adequate as patients infrequently have further sequelae, and that not everyone needs to carry 2 epinephrine auto-injectors on their person at all times. The most recent anaphylaxis practice parameter promotes a contextualized approach to these management questions, outlining the option for watchful waiting to gauge response to epinephrine before seeking emergency care, which has been proven as a more cost-effective management strategy. The recent updated anaphylaxis care guidelines support the evolution of anaphylaxis care, in that universal, immediate activation of emergency services is not required for using self-injectable epinephrine outside the hospital setting.

Anaphylaxis: Definition and criteria

Anaphylaxis is a systemic allergic reaction that may be severe and life-threatening. With more than a dozen anaphylaxis definitions proposed over the past several decades and several diagnostic criteria in circulation, there is a need for a multinational consensus definition to simplify management across specialties. Anaphylaxis diagnostic criteria are more alike than they are different, and approaches of the National Institute of Allergy and Infectious Disease, World Allergy Organization, and Brighton Collaborative help to add granularity and perspective to patient management. Anaphylaxis occurs across a spectrum of severity within populations, although, among individual patients, there is some evidence to suggest more consistency for an individual allergen. Still, severity is influenced by a number of factors that demonstrate variability: factors that relate to allergen triggers, patient characteristics, and treatments received. Severity of anaphylaxis impacts management, and recent guidelines provide approaches that consider individual factors to inform both strong and conditional recommendations. Conditional recommendations serve as navigational signals for shared decision-making when patient expertise is leveraged to inform individual preferences and values together with clinician expertise in anaphylaxis management to provide patient care bespoke to each patient. As novel approaches to both prevention and treatment of anaphylaxis emerge, an understanding of the significance of strong and conditional recommendations becomes critical to providing individualized and appropriate care for patients at risk for anaphylaxis.

Global disparities in availability of epinephrine auto-injectors

Background

Anaphylaxis is the most severe clinical presentation of acute systemic allergic reactions and can cause death. Given the prevalence of anaphylaxis within healthcare systems, it is a high priority public health issue. However, management of anaphylaxis - both acute and preventative - varies by region.

Methods

The World Allergy Organization (WAO) Anaphylaxis Committee and the WAO Junior Members Steering Group undertook a global online survey to evaluate local practice in the diagnosis and management of anaphylaxis across regions.

Results

Responses were received from WAO members in 66 countries. While intramuscular epinephrine (adrenaline) is first-line treatment for anaphylaxis, some countries continue to recommend alternative routes in contrast to guidelines. Epinephrine auto-injector (EAI) devices, prescribed to individuals at ongoing risk of anaphylaxis in the community setting, are only available in 60% of countries surveyed, mainly in high-income countries. Many countries in South America, Africa/Middle-East and Asian-Pacific regions do not have EAI available, or depend on individual importation. In countries where EAIs are commercially available, national policies regarding the availability of EAIs in public settings are limited to few countries (16%). There is no consensus regarding the time patients should be observed following emergency treatment of anaphylaxis.

Conclusion

This survey provides a global snapshot view of the current management of anaphylaxis, and highlights key unmet needs including the global availability of epinephrine for self-injection as a key component of anaphylaxis management.

Trends and Variation in Pediatric Anaphylaxis Care From 2016 to 2022

BACKGROUND

Variation in the use of treatments and hospitalization for anaphylaxis would suggest a lack of consensus in therapeutic approach.

OBJECTIVE

To evaluate trends and practice variation in the emergency department (ED) care of children with anaphylaxis in a large US cohort.

METHODS

We conducted a 48-site retrospective cohort study using the Pediatric Health Information System from January 2016 through September 2022. Children younger than 18 years with a primary diagnosis of anaphylaxis were included. Care trends were assessed using negative binomial regression modeling. Rates of medication use, hospitalizations, and revisits were reported as medians with interquartile ranges (IQRs).

RESULTS

There were 42,909 ED visits for anaphylaxis, with a 4.2% per-year increase in visit incidence (95% CI, 1.8-6.7) during the study period. The median hospitalization rate was 3.5% (IQR, 2.2-6.0), and the 3-day ED revisit rate was 0.6% (IQR, 0.4-0.9). The hospital-level median use of therapies included intramuscular epinephrine (55.3%; IQR, 50.1-59.9), systemic steroids (73.8%; IQR, 63.9-81.4), antihistamines (59.9%; IQR, 53.5-65.5), H2-receptor antagonists (56.8%; IQR, 42.3-66.2), bronchodilators (15.1%; IQR, 12.5-17.0), inhaled epinephrine (1.1%; IQR, 0.6-1.9), and fluid boluses (19.8%; IQR, 11.3-29.3). Severe reactions requiring intensive care unit admission (1.5%; IQR, 0.8-2.2), vasopressors (0.3%; IQR, 0.0-0.6), and intubation (0.2%; IQR, 0.0-0.3) were rare.

CONCLUSIONS

ED visits for anaphylaxis increased during the study period, but hospitalization rates were low. Substantial variation exists between EDs regarding the use of anaphylaxis therapies, supporting the need for future research to evaluate the efficacy of these medications.

Biphasic Allergic Reactions at a Dutch Emergency Department: A 5-Year Retrospective Cohort Study

BACKGROUND

A biphasic allergic reaction develops in 0.4-20% of patients with an allergic reaction, but the incidence of severe biphasic reactions is unknown OBJECTIVE: Our objective was to assess the incidence and time of onset of clinically relevant biphasic reactions in a Dutch emergency department (ED) cohort. Furthermore, the characteristics of patients with a biphasic reaction and the mean observation time after an allergy-related ED visit were assessed.

METHODS

This was a single-center retrospective cohort study. We collected data from clinical records of adult patients presenting with an allergic reaction to the ED between January 2015 and December 2019. We defined clinically relevant biphasic reactions as biphasic reactions in which the criteria for anaphylaxis were met.

RESULTS

Five hundred fifty-seven patients were included. Eight patients (1.4%) developed a biphasic reaction, of which 1 (0.2% of the total inclusions) was clinically relevant. In the subgroup of patients with an anaphylactic reaction (n = 258), those percentages were 2.3% and 0.4%, respectively. The mean time between the initial allergic reaction and the biphasic allergic reaction was 25.4 h (95% CI 13.2-37.6 h). The single clinically relevant biphasic reaction occurred 30 h after the initial reaction.

CONCLUSIONS

The incidence of clinically relevant biphasic reactions in our cohort was low, with a mean time between the initial allergic reaction and the biphasic reaction of > 24 h. Based on these single-center retrospective data, routine inpatient monitoring for several hours does not seem warranted for all patients.

Canadian Anaphylaxis Network-Predicting Recurrence after Emergency Presentation for Allergic REaction (CAN-PREPARE): a prospective, cohort study protocol

INTRODUCTION

Anaphylaxis is a severe, potentially fatal multiorgan system manifestation of an allergic reaction. The highest incidence of anaphylaxis is in children and adolescents. Biphasic anaphylaxis (BA) is defined as the recurrence of allergic symptoms after resolution of an initial reaction. It has been reported to occur in 10%-20% of cases within 1-48 hours from the onset of the initial reaction. The dilemma for physicians is determining which patients with resolved anaphylaxis should be observed for BA and for how long. Guidelines for duration of postanaphylaxis monitoring vary, are based on limited evidence and can have unintended negative impacts on patient safety, quality of life and healthcare resources. The objectives of this study are to derive a prognostic model for BA and to develop a risk-scoring system that informs disposition decisions of children who present to emergency departments (ED) with anaphylaxis.

METHODS AND ANALYSIS

This prospective multicentre cohort study will enrol 1682 patients from seven paediatric EDs that are members of the Paediatric Emergency Research Canada network. We will enrol patients younger than 18 years of age with an allergic reaction meeting anaphylaxis diagnostic criteria. Trained ED research assistants will screen, obtain consent and prospectively collect study data. Research assistants will follow patients during their ED visit and ascertain, in conjunction with the medical team, if the patient develops BA. A standardised follow-up survey conducted following study enrolment will determine if a biphasic reaction occurred after ED disposition. Model development will conform to the broad principles of the PROGRESS (Prognosis Research Strategy) framework and reporting will follow the Transparent Reporting of a multivariable prediction model for Individual Prognosis or Diagnosis Statement.

ETHICS AND DISSEMINATION

Ethics approval has been received from all participating centres. Our dissemination plan focuses on informing clinicians, policy makers and parents of the results through publication in peer-reviewed journals and broadcasting on multiple media platforms.

TRIAL REGISTRATION NUMBER

NCT05135377.

Anaphylaxis in Children

ABSTRACT

Anaphylaxis is a potentially life-threatening event in children, commonly encountered in the prehospital and emergency department settings. Recently published clinical guidelines emphasize early recognition of anaphylaxis and administration of epinephrine as the mainstay of management. Literature regarding adjuvant therapies, biphasic reactions, observation times, and disposition of patients with anaphylaxis remains controversial. In this article, we will review the background and pathophysiology of anaphylaxis, as well as the diagnostic approach, management, and future directions of anaphylaxis in children.

Anaphylaxis knowledge gaps and future research priorities: A consensus report

BACKGROUND

Despite a better understanding of the epidemiology, pathogenesis, and management of patients with anaphylaxis, there remain knowledge gaps. Enumerating and prioritizing these gaps would allow limited scientific resources to be directed more effectively.

OBJECTIVE

We sought to systematically describe and appraise anaphylaxis knowledge gaps and future research priorities based on their potential impact and feasibility.

METHODS

We convened a 25-member multidisciplinary panel of anaphylaxis experts. Panelists formulated knowledge gaps/research priority statements in an anonymous electronic survey. Four anaphylaxis themed writing groups were formed to refine statements: (1) Population Science, (2) Basic and Translational Sciences, (3) Emergency Department Care/Acute Management, and (4) Long-Term Management Strategies and Prevention. Revised statements were incorporated into an anonymous electronic survey, and panelists were asked to rate the impact and feasibility of addressing statements on a continuous 0 to 100 scale.

RESULTS

The panel generated 98 statements across the 4 anaphylaxis themes: Population Science (29), Basic and Translational Sciences (27), Emergency Department Care/Acute Management (24), and Long-Term Management Strategies and Prevention (18). Median scores for impact and feasibility ranged from 50.0 to 95.0 and from 40.0 to 90.0, respectively. Key statements based on median rating for impact/feasibility included the need to refine anaphylaxis diagnostic criteria, identify reliable diagnostic, predictive, and prognostic anaphylaxis bioassays, develop clinical prediction models to standardize postanaphylaxis observation periods and hospitalization criteria, and determine immunotherapy best practices.

CONCLUSIONS

We identified and systematically appraised anaphylaxis knowledge gaps and future research priorities. This study reinforces the need to harmonize scientific pursuits to optimize the outcomes of patients with and at risk of anaphylaxis.

Health-care resource utilization associated with peanut allergy management under allergen avoidance among commercially insured individuals

Background: Until recently, the standard approach to care for individuals with peanut allergy (PA) was limited to allergen avoidance and treatment of reactions with emergency medicines. Objectives: To assess health-care resource utilization (HRU) and costs associated with PA management under allergen avoidance and to identify risk factors associated with peanut reactions that resulted in inpatient (IP) and/or emergency department (ED) visits. Methods: Privately insured individuals with PA diagnosis codes were identified from a large U.S. administrative claims data base (January 1, 1999, to March 31, 2017). PA-related HRU, indicated by a PA diagnosis and/or diagnostic procedure codes and by epinephrine autoinjectors (EAI) prescription fills in medical and pharmacy claims, respectively, and all-cause costs were described per patient-year (PPY). Risk factors associated with peanut reactions in an IP and/or ED setting were identified by using a multivariable logistic regression model. Results: A total of 86,483 patient-years from 14,136 individuals with PA were included. At the patient-year level, 28.1% were ages 0-3 years, 43.6% were ages 4-11 years, 13.7% were ages 12-17 years, and 14.5% were ages ≥ 18 years; 35.6% had PA-related outpatient visits; 50.6% had EAI fills; and 2.4% had PA-related IP and/or ED visits PPY. Younger individuals had more PA-related outpatient visits and EAI fills, with peak intensive use at ages 4-11 years. The proportion of individuals with PA-related IP and/or ED visits was highest among those aged ≥ 18 years. Mean all-cause costs were $3084 PPY; individuals with PA-related IP and/or ED visits incurred $8902 PPY ($17,451 for those with one or more IP visits). Risk factors associated with peanut reactions that resulted in IP and/or ED visits included young adults (odds ratio [OR] 3.19 [95% confidence interval {CI}, 2.66-3.83]), previous peanut reaction(s) (OR 1.66 [95% CI, 1.23-2.24]), asthma (OR 1.33 [95% CI, 1.18-1.51]), and male sex (OR 1.14 [95% CI, 1.01-1.28]). Conclusion: Individuals with PA and under allergen avoidance had significant HRU that varied across all age groups, with more PA-related outpatient visits during preschool and/or school age and PA-related urgent care among adults. Individuals with previous peanut reaction(s), asthma, and males had a higher risk of peanut reactions that resulted in IP and/or ED visits.

Factors influencing emergency department observation time following anaphylaxis: a systematic review

OBJECTIVE

Anaphylaxis is a condition that warrants an observation period after symptoms resolution to detect rare but life-threatening delayed complications. There is a need for evidence to identify patients who would benefit from prolonged observation time. The purpose of this review was to identify factors that may influence the need for longer observation in the emergency department.

METHODS

PubMed, Embase, EBM Review, and Cochrane Library were searched using controlled vocabulary and keywords to cover all relevant data. Titles, abstract, and full text were reviewed for inclusion and exclusion criteria. Data were extracted from the included articles regarding case definitions, prognosis, treatment and time factors, and recommended observation time. Factors linked to observation time or complications were tabulated and compared between studies.

RESULTS

The search retrieved 2443 citations of which 49 were included. Twenty-one were primary studies and were used to identify factors influencing observation time or complications. Biphasic anaphylaxis was the only adverse event that warranted prolonged observation. The five risk factors often associated with biphasic reactions were time to first epinephrine, history of anaphylaxis, symptom severity, number of epinephrine doses, and unknown trigger. Biphasic reactions happened mostly within the first 72 h with most severe reactions occurring earlier than the milder ones. Heterogeneity in the definition of biphasic anaphylaxis made comparisons challenging.

CONCLUSIONS

Observation time should be based on the provider's best estimation of the risk of biphasic anaphylaxis, although no single factor can predict their occurrence. The identified factors will allow the development of an early discharge screening tool.

The Revenge of Unintended Consequences of Anaphylaxis-Risk Overdiagnosis: How Far We Have Come and How Far We Have to Go

Overdiagnosis of anaphylaxis risk is an underappreciated aspect of anaphylaxis prevention. Whereas the benefits of anaphylaxis-risk prevention are well known, potential harms resulting from preemptive approaches to mitigate anaphylaxis-risk are not insignificant. Still, great progress has been made in recent years to avoid the unintended consequences of anaphylaxis-risk overdiagnosis. Reflection on recent advances in the use of diagnostic testing, as well as the application of diagnostic labels, provides an important perspective to understand how far the specialty of allergy and immunology has come in improving the lives of patients and families. Examples of recent paradigm shifts in anaphylaxis-risk management include approaches to peanut allergy prevention without screening, deferral of corticosteroids to prevent biphasic anaphylaxis reactions, reevaluation of reflex use of emergency medical services for resolved community anaphylaxis, and an approach to penicillin allergy delabeling with direct oral challenge. Routine medical practices to decrease anaphylaxis risk can have lifelong impacts for patients-beyond just preventing anaphylaxis. As our understanding of these trade-offs evolves, it becomes necessary to weigh both the benefits and the harms of past management approaches. Because medicine remains a science of uncertainty and an art of probability, a critical approach to risk mitigation remains necessary to find the often-elusive balance in anaphylaxis prevention.

Food allergy: how expensive are they?

PURPOSE OF REVIEW

Food allergy remains a disease of global public health significance well known to impact social, emotional, and financial well being. This review aims to summarize the existing literature focused on the direct, indirect, and intangible costs of food allergy at the household and healthcare system levels, and begin to discuss how emerging treatment and prevention strategies may be leveraged to comprehensively care for the food allergic population with the efficient use of health resources.

RECENT FINDINGS

Food allergy imposes significant costs to multiple stakeholders and largely impact families at the household level. Recent studies elucidate the need to balance the household management of food allergy with the efficient use of health resources. Overall, it remains critical that safe foods and medications remain affordable while further exploring the cost-effectiveness of early introduction, emerging food allergy therapies, and the wider use of stock epinephrine to adequately meet the public health needs of the food-allergic community.

SUMMARY

Better understanding how the cost of food allergy impacts populations will help to inform more progressive policies aimed at lessening socioeconomic disparities and ultimately improve quality of life for children and adults with food allergies.

Evidence update for the treatment of anaphylaxis

The Resuscitation Council UK has updated its Guideline for healthcare providers on the Emergency treatment of anaphylaxis. As part of this process, an evidence review was undertaken by the Guideline Working Group, using an internationally-accepted approach for adoption, adaptation, and de novo guideline development based on the Grading of Recommendations Assessment, Development and Evaluation (GRADE) evidence to decision (EtD) framework, referred to as GRADE-ADOLOPMENT. A number of significant changes have been made, which will be reflected in the updated Guideline. These include: emphasis on repeating intramuscular adrenaline doses after 5 min if symptoms of anaphylaxis do not resolve; corticosteroids (e.g. hydrocortisone) no longer being routinely recommended for the emergency treatment of anaphylaxis; interventions for reactions which are refractory to initial treatment with adrenaline; a recommendation against the use of antihistamines for the acute management of anaphylaxis; and guidance relating to the duration of observation following anaphylaxis, and timing of discharge.

What the COVID-19 Pandemic Can Teach Us About Resource Stewardship and Quality in Health Care

The coronavirus disease 2019 pandemic has forever changed how we view health care service delivery. Although there are undoubtedly some unintended consequences that will result from current health care service reallocation, it provides a unique opportunity to consider how to deliver quality care currently, and after the pandemic. In the context of lessons learned, moving forward some of what was previously routine could remain reserved for more exceptional circumstances. To determine what is "routine," what is "essential," and what is "exceptional," it is necessary to view medical decisions within the paradigm of high-quality care. The Institute for Healthcare Improvement definition of the dimensions of quality is based on whether the care is safe, effective, patient-centered, timely, efficient, and equitable. This type of stewardship has been applied to many interventions already deemed unnecessary by organizations such as the Choosing Wisely initiative, but the coronavirus disease 2019 pandemic provides a lens from which to consider other aspects of care. The following will provide examples from Allergy/Immunology that outline how we can reconsider what quality means in the post-coronavirus disease health care system.

Clinical Guideline Highlights for the Hospitalist: Anaphylaxis Management in Adults and Children

Anaphylaxis-A 2020 practice parameter update, systematic review, and Grading of Recommendations, Assessment, Development and Evaluation (GRADE) analysis RELEASE DATE: April 2020 PRIOR VERSION: Anaphylaxis - a 2019 practice parameter and GRADE analysis DEVELOPER: American Academy of Allergy, Asthma & Immunology (AAAAI) and the American College of Allergy, Asthma, and Immunology (ACAAI) FUNDING SOURCE: None TARGET POPULATION: Adult and pediatric patients with anaphylaxis.

Achieving the Quadruple Aim to deliver value-based allergy care in an ever-evolving health care system

OBJECTIVE

To define the concept of value-based care in allergy, and to review challenges and opportunities in value-based health care delivery for allergists and immunologists.

DATA SOURCES

Articles describing practice variation, health care financing and reimbursement, shared decision-making, cost-effective health care delivery, patient-reported outcome measures, social determinants of health, and screening.

STUDY SELECTIONS

A narrative review detailing concepts and approaches to improve value-based health care in the context of the Quadruple Aim to address the patient and physician experience, cost, and population health.

RESULTS

Efforts to improve cost-effective care can be informed by understanding unwarranted geographic practice variation and benchmarking best practices. Although evidence suggests that shared decision-making and addressing social determinants of health have critical roles in high-quality care, some practices such as routine laboratory screening for urticaria, premedication to prevent recurrent low- or iso-osmolar contrast reactions, extended observation of resolved anaphylaxis, food allergy screening, and penicillin allergy overdiagnosis have high costs in relation to overall societal benefit. Food allergy prevention, newborn screening for severe combined immune deficiency, and penicillin delabeling are examples of population-based opportunities in which allergists and immunologists can assist in creating health care value. Although efforts to incentivize value-based care have emerged in recent years, the degree to which process measures improve patient-important outcomes remain uncertain. Clinician wellness must be made a priority for continued effective practice.

CONCLUSION

As health care systems continue to evolve, allergists and immunologists will play a key role in optimizing value by translating emerging evidence into practice and communicating novel approaches to prevent and treat allergic diseases.

Engaging patient partners in state-of-the-art allergy care: Finding balance when discussing risk

OBJECTIVE

To review risk communication in the context of shared decision making.

DATA SOURCES

Articles describing risk communication, shared decision making, and cost-effective healthcare delivery.

STUDY SELECTIONS

A narrative review detailing approaches to improve risk communication and shared decision making to optimize patient-centered cost-effective practice.

RESULTS

Risk communication must occur on a foundation of mutual trust and can be improved by keeping risk in perspective of everyday hazards, such as using pictograms when possible, providing numeric likelihoods of risks and benefits, and discussing absolute risks. Variability in patient-perceived quality of life for allergic and nonallergic health states may affect the health and economic outcomes of many allergy therapies. Shared decision making improves patient knowledge and risk perception, engagement, and adherence. Patient decision aids can be time-consuming to develop and validate, but their use is associated with a more accurate understanding of patient-oriented outcomes.

CONCLUSION

Communicating risk is complex, and validated patient decision aids using visual aids, presenting essential information, using knowledge checks, and incorporating values clarification can reduce decisional conflict and improve decisional self-efficacy.

Anaphylaxis-a 2020 practice parameter update, systematic review, and Grading of Recommendations, Assessment, Development and Evaluation (GRADE) analysis

Anaphylaxis is an acute, potential life-threatening systemic allergic reaction that may have a wide range of clinical manifestations. Severe anaphylaxis and/or the need for repeated doses of epinephrine to treat anaphylaxis are risk factors for biphasic anaphylaxis. Antihistamines and/or glucocorticoids are not reliable interventions to prevent biphasic anaphylaxis, although evidence supports a role for antihistamine and/or glucocorticoid premedication in specific chemotherapy protocols and rush aeroallergen immunotherapy. Evidence is lacking to support the role of antihistamines and/or glucocorticoid routine premedication in patients receiving low- or iso-osmolar contrast material to prevent recurrent radiocontrast media anaphylaxis. Epinephrine is the first-line pharmacotherapy for uniphasic and/or biphasic anaphylaxis. After diagnosis and treatment of anaphylaxis, all patients should be kept under observation until symptoms have fully resolved. All patients with anaphylaxis should receive education on anaphylaxis and risk of recurrence, trigger avoidance, self-injectable epinephrine education, referral to an allergist, and be educated about thresholds for further care.