A consensus parameter for the evaluation and management of angioedema in the emergency department

Current and Emerging Therapeutics in Hereditary Angioedema

Angioedema is characterized by transient movement of fluid from the vasculature into the interstitial space leading to subcutaneous or submucosal non-pitting edema. Current evidence suggests that most angioedema conditions can be grouped into 2 categories: mast cell-mediated (previously termed histaminergic) or bradykinin-mediated angioedema. Although effective therapies for mast cell-mediated angioedema have existed for decades, specific therapies for bradykinin-mediated angioedema have more recently been developed. In recent years, rigorous studies of these therapies in treating hereditary angioedema (HAE) have led to regulatory approvals of medication for HAE management thereby greatly expanding HAE treatment options.

Corticosteroids in critically ill patients: A narrative review

Corticosteroids have been utilized in modern medicine for decades. Many indications have been investigated across various treatment settings with both benefit and harm observed. Given the instability of critically ill patients, the increased risk of corticosteroid-related complications, and the pervasive comorbidities, patients who receive corticosteroids must be carefully managed. Common critical care disease states in which corticosteroids have been studied and are routinely utilized include acute respiratory distress syndrome, adrenal insufficiency, angioedema, asthma, chronic obstructive pulmonary disease, community-acquired pneumonia, coronavirus disease 2019, septic shock, and spinal cord injury. Benefits of corticosteroids include an improvement in disease state-specific outcomes, decreased hospital length of stay, decreased mechanical ventilatory support, and decreased mortality. The harm of corticosteroids is well documented through adverse effects that include, but are not limited to, hyperglycemia, tachycardia, hypertension, agitation, delirium, anxiety, immunosuppression, gastrointestinal bleeding, fluid retention, and muscle weakness. Furthermore, corticosteroids are associated with increased health care costs through adverse effects as well as drug acquisition and administration costs. Given the assortment of agents, dosing, benefits, risks, and utilization in the critical care setting, there may be difficulty with identifying the appropriate places for use of corticosteroids in therapy. There currently exists no comprehensive report detailing the use of corticosteroids in the aforementioned disease states within the critical care setting. This narrative review sets out to describe these in detail.

Tranexamic acid for angiotensin converting enzyme inhibitor induced angioedema: A retrospective multicenter study

BACKGROUND

Angiotensin converting enzyme inhibitors (ACE-Is) prevent the breakdown of bradykinin and can lead to life threatening angioedema. Tranexamic acid is an antifibrinolytic that inhibits formation of precursors involved in bradykinin synthesis and, in case reports, has been described as a potential treatment for ACE-I angioedema.

METHODS

This retrospective study included patients who presented to the emergency department (ED) from January 2018 to August 2021 with angioedema while taking an ACE-I. Patients who received tranexamic acid (treatment group) were compared with patients who did not receive tranexamic acid (control group). Primary outcome was length of stay (LOS). Secondary outcomes evaluated included ICU admissions, intubations, and safety events.

RESULTS

A total of 262 patients were included in this study (73 treatment; 189 control). Overall, the median ED LOS was longer in the treatment group than controls (20.9 h vs 4.8 h, p < 0.001). ICU admission rates were higher in the treatment group (45% vs 16%, p < 0.001). More patients were intubated in the treatment group (12% vs 3%, p = 0.018). No difference was seen between the treatment group and the controls for return within 7 days, complications related to thrombosis, and death. In patients presenting with severe angioedema symptoms who were admitted to the hospital, median LOS was not different between the two groups (58.7 h vs 55.7 h, p = 0.61).

CONCLUSIONS

Patients who received tranexamic acid had increased ED LOS, rates of ICU admission, and need for intubation. This finding may be related to the severity of presentation. Administration of tranexamic acid appears safe to use in ACE-I angioedema. Prospective randomized controlled studies should be considered to determine whether tranexamic acid is an effective treatment for ACE-I angioedema.

Angiotensin-Converting Enzyme (ACE) Inhibitor-Induced Angioedema in an African American Male With Coronavirus Disease 2019 (COVID-19)

Angioedema is a condition characterized by non-pitting swelling of the subcutaneous or submucosal tissues in particular the face, lips, and oral cavity. Angiotensin-converting enzyme (ACE) inhibitors are known to contribute to the development of angioedema by increasing the levels of bradykinin and its active metabolites. Infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is hypothesized to contribute to the development of angioedema by modifying ACE II levels and further increasing the level of bradykinin in patients taking ACE inhibitors. African Americans may be at particular risk of developing angioedema with concomitant SARS-CoV-2 infection and ACE inhibitor use. This case involves a 31-year-old African American male diagnosed with coronavirus disease 2019 (COVID-19) who developed angioedema while taking an ACE inhibitor.

Pseudo-Allergies in the Emergency Department: A Common Misdiagnosis of Hypersensitivity Type 1 Allergic Reaction

Type-1 hypersensitivity reaction represents an acute IgE-mediated reaction that can cause life-threatening conditions, such as anaphylactic shock, angioedema, and airway obstruction. Other reactions that can mimic type-1 hypersensitivity reactions include IgE-independent mast cell degranulation, bradykinin-mediated reactions, leukotrienes-mediated reactions, and pseudo-allergies. We use the term pseudo-allergy in this article for histamine-mediated reactions that are mast cell-independent. We did not discuss pseudo-allergic reactions that are not acute or life-threatening, such as celiac disease, Heiner's syndrome, eosinophilic esophagitis, and food protein-induced enterocolitis in our article because the emergency department is not the primary location to diagnose or treat these reactions. Herein, we present some allergic-like reactions that can be life-threatening, such as scombroid food poisoning (SFP), bradykinin-induced angioedema, IgE-independent angioedema, opioid-induced angioedema, and non-steroidal anti-inflammatory drug (NSAID)-induced hypersensitivity and angioedema. These reactions may have different treatments based on their mechanism of reaction. Histamine-mediated reactions, such as SFP, histamine-mediated angioedema, and mast cell degranulation induced by NSAIDs, and opioids can be treated with antihistamines, epinephrine, and corticosteroids. Bradykinin-induced angioedema, including hereditary angioedema and acquired angioedema, can be treated with fresh frozen plasma. Hereditary angioedema can be treated with many FDA-approved targeted medications, such as plasma-derived C1-INH, plasma kallikrein inhibitor (Ecallantide), and selective bradykinin-2 receptor antagonist (Icatibant). However, these targeted agents are not well-studied enough to be used for acquired angioedema. It is crucial for emergency medicine physicians to be familiar with and predict these reactions to prevent misdiagnosis, be prepared to treat these life-threatening conditions appropriately without delay and eliminate patients' exposure to any unnecessary investigations or treatments.

Angiotensin-Converting Enzyme Inhibitor-Induced Angioedema

Angioedema is a well-recognized and potentially lethal complication of angiotensin-converting enzyme inhibitor (ACEi) therapy. In ACEi-induced angioedema, bradykinin accumulates due to a decrease in its metabolism by ACE, the enzyme that is primarily responsible for this function. The action of bradykinin at bradykinin type 2 receptors leads to increased vascular permeability and the accumulation of fluid in the subcutaneous and submucosal space. Patients with ACEi-induced angioedema are at risk for airway compromise because of the tendency for the face, lips, tongue, and airway structures to be affected. The emergency physician should focus on airway evaluation and management when treating patients with ACEi-induced angioedema.

Hereditary Angioedema

Hereditary angioedema (HAE) is a rare autosomal dominant genetic disorder that usual results from a decreased level of functional C1-INH and clinically manifests with intermittent attacks of swelling of the subcutaneous tissue or submucosal layers of the respiratory or gastrointestinal tracts. Laboratory studies and radiographic imaging have limited roles in evaluation of patients with acute attacks of HAE except when the diagnosis is uncertain and other processes must be ruled out. Treatment begins with assessment of the airway to determine the need for immediate intervention. Emergency physicians should understand the pathophysiology of HAE to help guide management decisions.

Bradykinin Metabolism and Drug-Induced Angioedema

Bradykinin (BK) metabolism and its receptors play a central role in drug-induced angioedema (AE) without urticaria through increased vascular permeability. Many cardiovascular and diabetic drugs may cause BK-mediated AE. Angiotensin-converting enzyme inhibitors (ACEIs) and neprilysin inhibitors impair BK catabolism. Dipeptidyl peptidase-IV (DPP-IV) inhibitors reduce the breakdown of BK and substance P (SP). Moreover, angiotensin receptor blockers, thrombolytic agents, and statins may also induce BK-mediated AE. Understanding pathophysiological mechanisms is crucial for preventing and treating drug-induced AE.

The multifactorial impact of receiving a hereditary angioedema diagnosis

Hereditary angioedema (HAE) is a rare, chronic, debilitating genetic disorder characterized by recurrent, unpredictable, and potentially life-threatening episodes of swelling that typically affect the extremities, face, abdomen, genitals, and larynx. The most frequent cause of HAE is a mutation in the serpin family G member 1 (SERPING1) gene, which either leads to deficient plasma levels of the C1-esterase inhibitor (C1-INH) protein (type I HAE-C1-INH) or normal plasma levels of dysfunctional C1-INH protein (type II HAE-C1-INH). Mutations in SERPING1 are known to be associated with dysregulation of the kallikrein-bradykinin cascade leading to enhancement of bradykinin production and increased vascular permeability. However, some patients present with a third type of HAE (HAE-nl-C1-INH) that is characterized by normal plasma levels and functionality of the C1-INH protein. While mutations in the factor XII, angiopoietin-1, plasminogen, kininogen-1, myoferlin, and heparan sulfate-glucosamine 3-O-sulfotransferase-6 genes have been identified in some patients with HAE-nI-C1-INH, genetic cause remains unknown in many cases with further research required to fully elucidate the pathology of disease in these patients. Here we review the challenges that arise on the pathway to a confirmed diagnosis of HAE and explore the multifactorial impact of receiving a HAE diagnosis. We conclude that it is important to continue to raise awareness of HAE because delays to diagnosis have a direct impact upon patient suffering and quality of life. Since many patients will seek help from hospitals during their first swelling attack it is vital that emergency department staff are aware of the different pathological pathways that distinguish HAE from other forms of angioedema to ensure that the most appropriate treatment is administered. As disease awareness increases, it is hoped that patients will be diagnosed earlier and that pre-authorization and insurance coverage of HAE treatments will become easier to obtain, ultimately reducing the burden of treatment for these patients and their caregivers.

Hereditary Angioedema: Diagnosis, Clinical Implications, and Pathophysiology

Hereditary angioedema (HAE) is an autosomal dominant disorder caused by a mutation in the C1 esterase inhibitor gene. HAE affects 1/50,000 people worldwide. Three main types of HAE exist: type I, type II, and type III. Type I is characterized by a deficiency in C1-INH. C1-INH is important in the coagulation complement, contact systems, and fibrinolysis. Most HAE cases are type I. Type I and II HAE result from a mutation in the SERPING1 gene, which encodes C1-INH. Formally known as type III HAE is typically an estrogen-dependent or hereditary angioedema with normal C1-INH activity. Current guidelines now recommend subdividing hereditary angioedema with normal C1 esterase inhibitor gene (HAE-nl-C1-INH formerly known as HAE type III) based on underlying mutations such as in kininogen-1 (HAE-KNG1), plasminogen gene (PLG-HAE), myoferlin gene mutation (MYOF-HAE), heparan sulfate-glucosamine 3-sulfotransferase 6 (HS3ST6), mutation in Hageman factor (factor XII), and in angiopoietin-1 (HAE-ANGPT-1). The clinical presentation of HAE varies between patients, but it usually presents with nonpitting angioedema and occasionally abdominal pain. Young children are typically asymptomatic. Those affected by HAE usually present with symptoms in their early 20s. Symptoms can arise as a result of stress, infection, or trauma. Laboratory testing shows abnormal levels of C1-INH and high levels of bradykinin. C4 and D-dimer levels can also be monitored if an acute HAE attack is suspected. Acute treatment of HAE can include IV infusions of C1-INH, receptor antagonists, and kallikrein inhibitors. Short- and long-term prophylaxis can also be administered to patients with HAE. First-line therapies for long-term prophylaxis also include IV infusion of C1-INH. This review aims to thoroughly understand HAE, its clinical presentation, and how to treat it.

[Angioedema in the emergency department]

Acute angioedema is mostly found in the head and neck region. Therefore, it can be life threatening by potentially endangering air way patency. Pathophysiologically angioedemas can be divided into mast cell-mediated or bradykinin-mediated forms. Differentiation is essential due to the different therapeutic strategies. In cases of doubt, initial therapy with adrenalin, antihistamines, and glucocorticoids should be initiated. This initial emergency treatment is comparable to the treatment of allergic reactions. For diagnosed or suspected hereditary angioedema, specific treatments are available. For drug-associated forms, immediate and life-long cessation of the medication is crucial. In the emergency situation, diagnosis can only be based on medical history and clinical symptoms. Recognition of impending airway obstruction and securing the airway is of highest priority; final diagnosis must be confirmed later.

Clinical predictors of endotracheal intubation in patients presenting to the emergency department with angioedema

OBJECTIVES

The objective of this study is to identify predictors of airway compromise among patients presenting to the emergency department with angioedema in order to develop and validate a risk score to augment clinician gestalt regarding need for intubation.

METHODS

Retrospective chart review of emergency department patients with a diagnosis of angioedema. After data extraction they were randomly divided into a training and test set. The training set was used to identify factors associated with intubation and to develop a model and risk score to predict intubation. The model and risk score were then applied to the test set.

RESULTS

A total of 594 patients were included. Past medical history of hypertension, presence of shortness of breath, drooling, and anterior tongue or pharyngeal swelling were independent predictors included in our final model and risk score. The Area Under the Curve for the Receiver Operator Characteristic curve was 87.55% (83.42%-91.69%) for the training set and 86.1% (77.62%-94.60%) for the test set.

CONCLUSIONS

A simple scoring algorithm may aid in predicting angioedema patients at high and low risk for intubation. External validation of this score is necessary before wide-spread adoption of this decision aid.

Large Predominance of Off-Label Prescriptions of C1-Inhibitor Concentrates and Icatibant in a Real-Life Setting: A Retrospective Clinical Study

C1-inhibitor (C1INH) concentrates and the selective bradykinin B2 receptor antagonist icatibant are approved only for treating hereditary angioedema with C1INH deficiency. Yet, they are regularly prescribed off label in other types of bradykinin-mediated angioedema including angiotensin-converting enzyme inhibitor (ACEi)-related and undetermined angioedema. We conducted a retrospective chart review of inpatient prescriptions of C1INH concentrates and icatibant between 2016 and 2020 in the University Hospital of Angers. The first outcome was the proportion of prescriptions with explicit indication. Then, we determined the compliance of prescriptions with European Medicines Agency approvals and the French bradykinin-mediated angioedema reference center guidelines. Finally, we estimated the economic impact of inappropriate prescribing. The therapeutic indication was explicit in 90.4% of prescriptions (n = 66/73). Only 17.8% of prescriptions were for hereditary angioedema with C1INH deficiency, while 31.5% were for ACEi-related and 28.7% for undetermined angioedema. However, most off-label prescriptions were consistent with the French bradykinin-mediated angioedema reference center guidelines (73.3%). We estimated that 13% of drug expenditures were potentially excessive. The predominance of off-label prescriptions may be explained by the infrequency of hereditary angioedema and the absence of approved alternatives in other types of bradykinin-mediated angioedema. Most attacks were related to ACEis. Epinephrine was rarely prescribed as first-line therapy in attacks of unknown origin. Given the high prices of these drugs, we advocate the development of a readily available management algorithm of angioedema to reduce inappropriate prescriptions in our center. In addition, we think that the drug prescription circuit should be redesigned to ensure the traceability of prescribed vials in the dispensing areas.

A Comprehensive Review of Bradykinin-Induced Angioedema Versus Histamine-Induced Angioedema in the Emergency Department

Angioedema (AE) is a condition that is frequently encountered in the emergency department (ED). It is a rare condition with localized, asymmetrical swelling of the skin and/or mucosa that is frequently nonpruritic and primarily affects locations with loose connective tissue. Physicians must have a thorough understanding of this condition since it can cause fatal airway compromise, which might be the presenting symptom. Histamine-mediated AE is the most common type of AE seen in EDs. However, ED physicians must be on the lookout for the less common bradykinin-mediated types of AE as these do not respond to the same therapy as histamine-mediated AE. Hospitals may lack specialized drugs or protocols, and many ED staff may be unable to identify or treat bradykinin-mediated AE. It is crucial to understand the pathophysiology of the various kinds of AE in order to optimize treatment. The goal of this review paper is to provide an overview of the pathophysiology, clinical manifestations, and treatment options for bradykinin and histamine-induced AE in the ED.

Atorvastatin as a Rare Primary Cause of Drug-Induced Angioedema: A Case Report

In patients with hyperlipidemia and cardiovascular disease, statin remains the primary medication for risk reduction. Statins are primarily associated with adverse outcomes like myoglobinuria and deranged liver function tests (LFTs). Angioedema is a life-threatening reaction characterized by mucosal and submucosal swelling. It is rarely known for its association with statins. However, we present a rare case of a 59-year-old man presenting with recurrent angioedema of the face and tongue after starting on 40mg of atorvastatin, within one week of the treatment. He had no previous history of hypersensitivity and rash. He denied any food or medication allergy in the past. The Naranjo scale probability and the abrupt nature of these episodes upon starting statin and completely resolving after discontinuing the drug made statin-induced angioedema the primary diagnosis in this case.

Bradykinin-induced angioedema in the emergency department

Background

Acute airway angioedema commonly occurs through two distinct mechanisms: histamine- and bradykinin-dependent. Although they respond to distinct treatments, these two potentially life-threatening states present similarly. Poor recognition of the bradykinin-dependent pathway leads to treatment errors in the emergency department (ED), despite the availability of multiple pharmacologic options for hereditary angioedema (HAE) and other forms of bradykinin-induced angioedema. Here, we consider the pathophysiology and clinical features of bradykinin-induced angioedema, and we present a systematic literature review exploring the effectiveness of the available therapies for managing such cases.

Methods

PubMed searches using ‘emergency’, ‘bradykinin’ and various therapeutic product names identified studies reporting the efficacy of treatments for bradykinin-induced angioedema in the ED setting. In all, 22 studies met prespecified criteria and are analysed here.

Findings

Whereas histamine-induced angioedema has a faster onset and often presents with urticaria, bradykinin-induced angioedema is slower in onset, with greater incidence of abdominal symptoms. Acute airway angioedema in the ED should initially be treated with anaphylactic protocols, focusing on airway management and treatment with epinephrine, antihistamine and systemic steroids. Bradykinin-induced angioedema should be considered if this standard treatment is not effective, despite proper dosing and regard of beta-adrenergic blockade. Therapeutics currently approved for HAE appear as promising options for this and other forms of bradykinin-induced angioedema encountered in the ED.

Conclusion

Diagnostic algorithms of bradykinin-induced angioedema should be followed in the ED, with early use of approved therapies to improve patient outcomes.

Pediatric Emergency Department Management of C1 Inhibitor Deficiency

INTRODUCTION

C1 inhibitor deficiency is a rare, potentially life-threatening syndrome. Acute attacks of angioedema may occur at any time, so the emergency department (ED) constitutes an indispensable component of its care.

AIM

To describe the reasons for consultation by children with C1 inhibitor deficiency at the ED, as well as its management and complications.

PATIENTS AND METHODS

This is a longitudinal retrospective study conducted in a pediatric ED of a tertiary care hospital in Madrid. The study includes children with C1 inhibitor deficiency, aged 0 to 16 years, who had consulted the ED for whatever reason, over a span of 9 years (2011-2020). Analyzed data include the following: age, sex, type of disease, reason for query, complementary examinations, established diagnosis, treatment, number of visits to the ED, length of ED stay, and admissions.

RESULTS

Sixteen patients, amounting a total of 83 ED visits, were analyzed. Fifty-six percent were boys, and the median age was 6.9 years (5 months to 15.9 years). The median and mean of number of visits to the ED per patient was 2 (1-22) and 5.2 ± 6.11, respectively. There were 85.5% of the ED visits initially attributed to acute angioedema attacks. Additional tests were conducted in 30.1%, and 31.3% required C1 inhibitor concentrate. Three episodes required hospital admission (3.6%), and there were no complications. The stay in the ED was longer for patients who needed specific intravenous treatment.

CONCLUSIONS

C1 inhibitor deficiency is a rare disease that may require ED care. The main reasons for ED visits were respiratory problems, and the main location of the acute attacks of angioedema were abdominal and cutaneous. Almost one third of the ED visits needed specific treatment, resulting in longer stays. A proper management in the ED and the specific treatment with C1 inhibitor concentrate were effective in 96.2% of the acute attacks of angioedema. Knowledge of this disease in the ED is key to prevent complications.

The Role of Cetirizine in the Changing Landscape of IV Antihistamines: A Narrative Review

Since 1955, the only available H1 antihistamines for intravenous administration have been first-generation formulations and, of those, only intravenously administered (IV) diphenhydramine is still approved in the USA. Orally administered cetirizine hydrochloride, a second-generation H1 antihistamine, has been safely used over-the-counter for many years. In 2019, IV cetirizine was approved for the treatment of acute urticaria. In light of this approval, this narrative review discusses the changing landscape of IV antihistamines for the treatment of histamine-mediated conditions. Specifically, IV antihistamines will be discussed as a treatment option for acute urticaria and angioedema, as premedication to prevent infusion reactions related to anticancer agents and other biologics, and as an adjunct treatment for anaphylaxis and other allergic reactions. Before the development of IV cetirizine, randomized controlled trials of IV antihistamines for these indications were lacking. Three randomized controlled trials have been conducted with IV cetirizine versus IV diphenhydramine in the ambulatory care setting. A phase 3 trial of IV cetirizine 10 mg versus IV diphenhydramine 50 mg was conducted in 262 adults who presented to the urgent care/emergency department with acute urticaria requiring antihistamines. For the primary efficacy endpoint, defined as change from baseline in a 2-h patient-rated pruritus score, non-inferiority of IV cetirizine to IV diphenhydramine was demonstrated (score - 1.6 vs - 1.5, respectively; 95% CI - 0.1, 0.3). Compared with IV diphenhydramine, IV cetirizine demonstrated fewer adverse effects including less sedation, a significantly shorter length of stay in the treatment center, and fewer returns to the treatment center at 24 and 48 h. Similar findings were demonstrated in another phase 2 acute urticaria trial and in a phase 2 trial assessing IV cetirizine for pretreatment for infusion reactions in the oncology/immunology setting. IV cetirizine is associated with similar patient outcomes, fewer adverse effects, and increased treatment center efficiency than IV diphenhydramine.

Hereditary Angioedema

Hereditary angioedema (HAE) is a rare autosomal dominant genetic disorder that usual results from a decreased level of functional C1-INH and clinically manifests with intermittent attacks of swelling of the subcutaneous tissue or submucosal layers of the respiratory or gastrointestinal tracts. Laboratory studies and radiographic imaging have limited roles in evaluation of patients with acute attacks of HAE except when the diagnosis is uncertain and other processes must be ruled out. Treatment begins with assessment of the airway to determine the need for immediate intervention. Emergency physicians should understand the pathophysiology of HAE to help guide management decisions.

Angiotensin-Converting Enzyme Inhibitor-Induced Angioedema

Angioedema is a well-recognized and potentially lethal complication of angiotensin-converting enzyme inhibitor (ACEi) therapy. In ACEi-induced angioedema, bradykinin accumulates due to a decrease in its metabolism by ACE, the enzyme that is primarily responsible for this function. The action of bradykinin at bradykinin type 2 receptors leads to increased vascular permeability and the accumulation of fluid in the subcutaneous and submucosal space. Patients with ACEi-induced angioedema are at risk for airway compromise because of the tendency for the face, lips, tongue, and airway structures to be affected. The emergency physician should focus on airway evaluation and management when treating patients with ACEi-induced angioedema.

A Case Report of Delayed Post-operative Angioedema Associated With Angiotensin-Converting Enzyme Inhibitor Use

Angiotensin-converting enzyme inhibitors are known to precipitate angioedema. Drug-induced angioedema is rare in the perioperative setting. Even fewer cases described hours following a minor procedure. In this case report, we present a 45-year-old female who developed drug-induced angioedema hours following an obstetric procedure.

Emergency Department Intubations in Patients With Angioedema: A Report from the National Emergency Airway Registry

BACKGROUND

Angioedema, a localized swelling of subcutaneous and submucosal tissues, may involve the upper airway. A subset of patients presenting for emergent evaluation of angioedema will require intubation. Little is known about airway management practices in patients with angioedema requiring intubation in the emergency department (ED).

OBJECTIVE

To describe airway management practices in patients intubated for angioedema in the ED.

METHODS

We analyzed data from the National Emergency Airway Registry. All patients with an intubation attempt for angioedema between January 1, 2016 and December 31, 2018 were included. We report univariate descriptive data as proportions with cluster-adjusted 95% confidence intervals.

RESULTS

Of 19,071 patient encounters, intubation was performed for angioedema in 98 (0.5%). First-attempt success was achieved in 81%, with emergency physicians performing the procedure in 94% of encounters. The most common device used was a flexible endoscope (49%), and 42% of attempts were via a nasal route. Pharmacologic methods included sedation with paralysis (61%), topical anesthesia with or without sedation (13% and 13%, respectively), and sedation only (10%). Among 19 (19%) patients requiring additional attempts, intubation was achieved on second attempt in 10 (53%). The most common adverse events were hypotension (13%) and hypoxemia (12%). Cricothyrotomy occurred in 2 patients (2%). No deaths were observed.

CONCLUSIONS

Angioedema was a rare indication for intubation in the ED setting. Emergency physicians achieved first-attempt success in 81% of encounters and used a broad range of intubation devices and methods, including flexible endoscopic techniques. Cricothyrotomy was rare, and no ED deaths were reported. © 2021 Elsevier Inc.

Tranexamic Acid for the Emergency Treatment of Angiotensin-Converting Enzyme Inhibitor-Induced Angioedema

INTRODUCTION

Angioedema is a rare but potentially life-threatening adverse effect associated with the use of angiotensin-converting enzyme (ACE) inhibitors. Various therapies, including ecallantide, icatibant, complement-1 esterase inhibitors, and fresh frozen plasma, have been used for treatment with inconsistent results and significant adverse effects. Tranexamic acid (TXA) is used as an alternative for the treatment of hereditary angioedema and it may be an attractive option for the treatment of ACE inhibitor-induced angioedema (ACEi-AE) in the emergency department (ED). The purpose of this study was to evaluate the impact of TXA administration on rates of intubation in patients presenting to the ED with suspected ACEi-AE.

METHODS

This was an institutional review board-approved, retrospective cohort study conducted at a single-site ED. All patients who received TXA for ACEi-AE in the ED between January 1, 2019 and March 31, 2021 were eligible for inclusion. The primary outcome was the proportion of patients who required intubation for suspected ACEi-AE.

RESULTS

A total of 16 patients received TXA in the ED for suspected ACEi-AE during the study timeframe. Of these, two patients were intubated prior to administration of TXA. The remaining 14 patients did not require intubation following TXA administration.

CONCLUSION

Administration of TXA was associated with a low rate of adverse effects and did not contribute to further morbidity when added to standard care in patients presenting to the ED with suspected ACEi-AE.

Risk Factors Associated with Intubation and Readmissions in patients with Angioedema: A Single Center Experience

BACKGROUND

Given the heterogeneity of etiologies, pathophysiology and presentation of angioedema, variations in clinical outcomes, such as intubation and hospital readmissions, need further clarification.

OBJECTIVE

To determine factors associated with intubation and hospital readmissions in patients with angioedema.

METHODS

Retrospective study of patients evaluated with a diagnosis of angioedema over a 6year period. Demographic and clinical data such as medication use, family history, comorbidities, and symptoms were recorded. Multivariable logistic regression was used to analyze factors associated with intubation, while Cox regression was used to analyze readmissions.

RESULTS

From 636 patients, the most common etiology of angioedema was angiotensin converting enzyme inhibitor (ACEI) induced at 58%. The overall mortality was 0.5%. After adjusting for gender, race, comorbidities, and type of angioedema, smoking (OR=1.79, 95% CI=1.10-2.93, p=0.02), calcium channel blocker (CCB) therapy (OR=1.91, 95% CI=1.18-3.10, p=0.009), histaminergic symptoms (OR=3.21, 95% CI=1.93-5.33, p<0.001) and age (OR=1.02, 95% CI=1.00-1.04, p=0.023) were independently associated with increased odds of intubation. Involvement of either the pharynx, larynx or tongue was associated with higher odds of intubation (OR=20.96, 95% CI=10.63-41.33, p<0.001). 10% of patients had a readmission for angioedema within 90 days and 75% occurred within 30 days. After Multivariable Cox Regression analysis, only COPD/asthma (OR=2.13, 95% CI=1.12-4.07, p=0.022) and ACEI related angioedema (OR=2.93, 95% CI=1.33-6.47, p=0.008) were significantly associated with readmissions.

CONCLUSION

Smoking, CCB use, histaminergic symptoms, age, and upper airway involvement were significantly associated with intubation. Presence of COPD/asthma and ACEI related angioedema were independently associated with increased odds of readmission.

The importance of recognizing and managing a rare form of angioedema: hereditary angioedema due to C1-inhibitor deficiency

The majority of angioedema cases encountered in clinical practice are histamine-mediated (allergic); however, some cases are bradykinin-related (non-allergic) and do not respond to standard anti-allergy medications. Among bradykinin-related angioedema, hereditary angioedema (HAE) is a rare, but chronic and debilitating condition. The majority of HAE is caused by deficiency (type 1) or abnormal function (type 2) of the naturally occurring protein, C1-inhibitor (C1-INH)-a major inhibitor of proteases in the contact (kallikrein-bradykinin cascade), fibrinolytic pathway, and complement systems. Failure to recognize HAE and initiate appropriate intervention can lead to years of pain, disability, impaired quality of life (QoL) and, in cases of laryngeal involvement, it can be life-threatening. HAE must be considered in the differential diagnosis of non-urticarial angioedema, particularly for patients with a history of recurrent angioedema attacks, family history of HAE, symptom onset in childhood/adolescence, prodromal signs/symptoms before swellings, recurrent/painful abdominal symptoms, and upper airway edema. Management strategies for HAE include on-demand treatment for acute attacks, short-term prophylaxis prior to attack-triggering events/procedures, and long-term or routine prophylaxis for attack prevention. Patients should be evaluated at least annually to assess need for routine prophylaxis. HAE specific medications like plasma-derived and recombinant C1-INH products, kallikrein inhibitors, and bradykinin B2 receptor antagonists, have improved management of HAE. While the introduction of intravenous C1-INH represented a major breakthrough in routine HAE prophylaxis, some patients fail to achieve adequate control and others have psychological barriers or experience complications related to intravenous administration. Subcutaneous (SC) C1-INH, SC monoclonal antibody (mAb)-based therapies, and an oral kallikrein inhibitor offer effective alternatives for HAE attack prevention and may facilitate self-administration. HAE management should be individualized, with QoL improvement being a key goal. This can be achieved with broader availability of existing options for routine prophylaxis, including greater global availability of C1-INH(SC), mAb-based therapy, oral treatments, and multiple on-demand therapies.

Angioedema with severe acute abdominal pain: Think of hereditary angioedema

Angioedema can be either mast cell-(histamine-)mediated or bradykinin-mediated. Treatment approaches for the two types are very different, making differential diagnosis critical. Severe acute abdominal pain caused by intestinal angioedema is commonly misdiagnosed, especially when associated with bradykinin-mediated angioedema. After describing a typical clinical scenario and diagnostic journey of a patient with recurrent, undiagnosed abdominal pain due to hereditary angioedema (HAE), a rare variant of bradykinin-mediated angioedema, we delve into the classification and differential diagnosis of the various types of angioedema and provide an overview of appropriate management with an emphasis on the bradykinin-mediated types. Bradykinin-induced angioedema may be inherited or acquired and is infrequent compared to mast cell-mediated angioedema. HAE is a rare disease characterized by recurrent attacks of non-urticarial, nonpruritic edema usually affecting the face, respiratory tract, extremities, gastrointestinal tract, and genitalia. Unlike mast cell-mediated angioedema, painful abdominal symptoms are prevalent in bradykinin-mediated angioedema and are sometimes the only manifestation of an attack, increasing the likelihood of initial misdiagnosis as appendicitis or other forms of acute abdomen. It is important for gastroenterologists to be vigilant for the possibility of angioedema pathology in patients presenting with undiagnosed, recurrent, abdominal symptoms to facilitate accurate diagnosis and effective treatment.

Assessment of disease activity and quality of life in patients with recurrent bradykinin-mediated versus mast cell-mediated angioedema

Objective

Recurrent Angioedema (RAE) is characterized by sudden swelling of mucosal surfaces or deep dermis and is either mast cell-(MMAE) or bradykinin-mediated (BMAE). How patients with BMAE and MMAE differ in terms of disease activity and impact remains largely unknown. Here, we determined validity, reliability, and sensitivity to change of Turkish versions of angioedema activity score (AAS) and quality of life questionnaire (AE-QoL) and used both instruments to investigate and compare patients with BMAE and MMAE.

Methods

Turkish versions of AAS28 and AE-QoL were applied to 94 patients with RAE (18–72 years). Patients’ global self-assessment of QoL (PGA-QoL), disease activity (PGA-DA-VRS, PatGA-DA-VAS), and 12-Item-Short Form Survey were used at week 4 (visit 2), and week 8 (visit 3). Demographic characteristics, clinical features, and AAS28 and AE-QoL values were compared between 31 patients with BMAE and 63 patients with MMAE.

Results

Turkish AAS28 and AE-QoL showed excellent internal consistency, high reproducibility and known-groups validity. Compared to patients with MMAE, BMAE patients were younger (34.6 ± 10.7 vs. 40.7 ± 13.3 years), had longer disease duration (236 ± 178 vs. 51 ± 78 months), high prevalence of family history (63% vs 14%), longer duration of attacks (65 ± 20 vs. 40 ± 25 h), and they were more commonly affected by upper airway angioedema (70% vs 23%). Disease activity (AAS28) was lower (29.3 ± 24.6 vs 55.2 ± 52.9), but AE-QoL was higher (44.2 ± 16.1 vs 34.5 ± 22.5) in BMAE patients as compared to MMAE patients.

Conclusions

Patients with BMAE and MMAE have distinct disease characteristics. Recurrent bradykinin-mediated angioedema impacts quality of life more than mast cell-mediated angioedema. The discriminating characteristics of patients with BMAE and MMAE may help to improve the diagnosis and management of patients with RAE.

Mitigating Disparity in Health-care Resources Between Countries for Management of Hereditary Angioedema

Hereditary angioedema (HAE) is a rare genetic disorder characterized by recurrent episodes of skin and mucosal edema. The main treatment goal is to enable a “normal life” for all patients. However, due to high costs, there are limited options for the management of HAE in most developing and low-income countries. As a result, most of the recommended first-line treatments are not available. In this review, we attempt to highlight the disparities in health-care resources for the management of patients with HAE amongst different countries. Data was collected from HAE experts in countries who provide tabulated information regarding management and availability of HAE treatments in their countries. We reviewed the two most recent international HAE guidelines. Using India, the world’s second most populous country, as a paradigm for HAE management in lower-income countries, we reviewed the evidence for second-line and non-recommended practices reported by HAE experts. Results suggest significant inequities in provision of HAE services and treatments. HAE patients in low-income countries do not have access to life-saving acute drugs or recently developed highly effective prophylactic medications. Most low-income countries do not have specialized HAE services or diagnostic facilities, resulting in consequent long delays in diagnosis. Suggestions for optimizing the use of limited resources as a basis for future discussion and reaching a global consensus are provided. There is an urgent need to improve HAE services, diagnostics and treatments currently available to lower-income countries. We recommend that all HAE stakeholders support the need for global equity and access to these essential measures.

Hereditary angioedema: how to approach it at the emergency department?

Angioedema attacks are common causes of emergency care, and due to the potential for severity, it is important that professionals who work in these services know their causes and management. The mechanisms involved in angioedema without urticaria may be histamine- or bradykinin-mediated. The most common causes of histamine-mediated angioedema are foods, medications, insect sting and idiopathic. When the mediator is bradykinin, the triggers are angiotensin-converting enzyme inhibitors and factors related to acquired angioedema with deficiency of C1-inhibitor or hereditary angioedema, which are less common, but very important because of the possibility of fatal outcome. Hereditary angioedema is a rare disease characterized by attacks of edema that affect the subcutaneous tissue and mucous membranes of various organs, manifesting mainly by angioedema and abdominal pain. This type of angioedema does not respond to the usual treatment with epinephrine, antihistamines and corticosteroids. Thus, if not identified and treated appropriately, these patients have an estimated risk of mortality from laryngeal edema of 25% to 40%. Hereditary angioedema treatment has changed dramatically in recent years with the development of new and efficient drugs for attack management: plasma-derived C1 inhibitor, recombinant human C1-inhibitor, bradykinin B2 receptor antagonist (icatibant), and the kallikrein inhibitor (ecallantide). In Brazil, plasma-derived C1 inhibitor and icatibant have already been approved for use. Proper management of these patients in the emergency department avoids unnecessary surgery and, especially, fatal outcomes.

Angiotensin-Converting Enzyme Inhibitor Angioedema

Angioedema from angiotensin-converting enzyme inhibitors (ACEIs) is a potential, emergent, and frightening problem that presents to the emergency department. This article focuses on angioedema caused by using ACEIs. The presentation, pathology, diagnostic testing, treatment, and patient education of angioedema are explored. This article explores using fresh frozen plasma as an initial approach to the treatment of ACEI angioedema.

Evaluation of staging criteria for disposition and airway intervention in emergency department angioedema patients

AIM

Angioedema is a nonpitting edema that can lead to death secondary to airway obstruction. Previously, a staging system based on localization of the angioedema was proposed for risk stratification of likelihood of need for admission or airway intervention. This study aims to evaluate a staging system based on angioedema localization as a method of predicting need for admission or airway intervention.

METHODS

This was a retrospective chart review of angioedema cases that presented to an academic emergency department (ED) from August 1, 2006, to January 31, 2018. Data were collected on location of swelling, treatment setting, and medical and procedural interventions. Cases were categorized by modified Ishoo criteria, defined as follows: 1, lips, face, periorbital, extremities, total body/diffuse swelling; 2, soft palate, posterior pharynx; 3, tongue; 4, larynx. Predictive probability of disposition by stage was then compared.

RESULTS

A total of 320 patients were included in this study (median age, 44 years; 54.4% female). Stage 4 was more likely to require intensive care unit care without (probability 17%) and with (67%) airway intervention compared with stage 1 without (2.5%) and with (0.1%) airway intervention. Conversely, stage 1 was more likely to be treated in ED and discharged (85%) compared with stage 4 (0%). Stage 4 was also more likely to require airway intervention (67%) compared with other stages (1, 0.1%; 2, 8.6%; 3, 16%).

CONCLUSION

Higher-stage patients were more likely to require higher levels of care and airway intervention. Thus, the staging system appears to be a valid method of predicting risk among ED angioedema patients.

Recognition and Differential Diagnosis of Hereditary Angioedema in the Emergency Department

BACKGROUND

Angioedema (AE) is a clinical syndrome marked by localized swelling of the subcutaneous layer of the skin or the submucosal layer of the respiratory or gastrointestinal tracts. While AE is commonly mediated by histamine (allergic AE), some types result from excessive bradykinin activity, including hereditary AE (HAE), acquired AE, and angiotensin-converting enzyme inhibitor-induced AE. These are less common but important to consider given different treatment requirements and potentially serious outcomes, including death from laryngeal swelling.

OBJECTIVE

This review describes the pathophysiology and clinical features of AE as well as the diagnosis and treatment of AE in the emergency department (ED).

DISCUSSION

Bradykinin-mediated AE does not respond to antihistamines and corticosteroids. By contrast, several targeted, effective therapies are available, including C1-inhibitor (C1-INH) concentrates, which replace the missing protein activity underlying some bradykinin-mediated AE, and medications that directly lessen bradykinin activity (eg, ecallantide and icatibant). Urticaria is generally absent in bradykinin-mediated AE and serves as a primary differentiating factor in the clinical diagnosis. Relevant laboratory assessments may include C1-INH levels, C1-INH function, and C4 complement. Patients with HAE or a family member can communicate their known diagnosis when presenting to the ED, and some may even bring their own medication(s) with them. Patients newly diagnosed with HAE in the ED should be referred for specialized outpatient care upon ED discharge.

CONCLUSIONS

There is a great need for ED clinicians to be aware of HAE, its differential diagnosis, and appropriate treatment to ensure that patients receive optimal and timely treatment.

The High-Risk Airway

The high-risk airway is a common presentation and a frequent cause of anxiety for emergency physicians. Preparation and planning are essential to ensure that these challenging situations are managed successfully. Difficult airways typically present as either physiologic or anatomic, each type requiring a specialized approach. Primary physiologic considerations are oxygenation, hemodynamics, and acid-base, whereas anatomic difficulty is overcome using proper positioning and skilled laryngoscopy to ensure success. It is essential to be comfortable performing alternative techniques to address varying presentations. Ultimately, competence in airway management hinges on consistent training, deliberate practice, and a dedication to excellence.

ACE inhibitor angioedema: characterization and treatment versus non-ACE angioedema in acute hospitalized patients

Background

ACE angioedema has not been characterized in comparison with angioedema from other causes in acute hospitalized patients.

Methods

We retrospectively compared ACE-angioedema and non-ACE angioedema patients from January 2013 to May 2017.

Results

Of 855 cases screened, 575 met the inclusion criteria of angioedema diagnosis and an electronic medical record. Of these, 297 (51.7%) had ACE angioedema and 278 had angioedema from other causes, of these 31 who were taking an ACE inhibitor that was not considered to be the cause of angioedema (ACE other cause). At least 80% of cases in all groups were African American. Epinephrine was prescribed in 21% of ACE angioedema cases. One-third of patients in all groups were admitted to the ICU, and about 25% required intubation. Previous history of ACE inhibitor-induced angioedema was found in 63 of 278 non-ACE cause angioedema patients (23%) and in 23 (8%) in the ACE cause group.

Conclusion

ACE angioedema was the cause of half of angioedema admissions over a 4.5-year period. Mortality, morbidity, and treatment did not differ between the groups. Patients on ACE inhibitors were often treated with medications known not to be effective for ACE angioedema. Over one-fourth of patients not taking an ACE inhibitor had a previous history of ACE angioedema, and 31 patients taking ACE inhibitors were diagnosed with non-ACE angioedema. Regardless of the etiology of angioedema, 25% of patients required airway protection in the form of intubation.

A Case of Prolonged Angioedema After Cardiac Surgery

Angioedema (AE) is a transient capillary leak syndrome, caused by either histamine or bradykinin, that presents as an acute nonpitting swelling of the skin, subcutaneous tissues, and mucous membranes of the face, lips, tongue, upper airways, and gastrointestinal tract, with or without a rash. A lack of response to antihistamines, steroids, and epinephrine suggests a bradykinin-mediated AE. Bradykinin-AE may be inherited, acquired, or drug related. Mechanism of increased bradykinin can include decreased C1-esterase inhibitor (C1-INH) levels or activity, increased bradykinin production, or decreased bradykinin breakdown, the latter occurring during angiotensin converting enzyme inhibitor (ACEi). A 65-year-old woman had coronary artery bypass grafting, which was complicated by prolonged bradykinin-AE owing to ACEi, requiring prolonged endotracheal tube intubation. Treatment with a C1-esterase inhibitor (Berinert) on postoperative day 7 resulted in a dramatic improvement in airway edema and tongue swelling within 7 hours, and the patient was subsequently extubated. The case is unusual because of the prolonged course of AE and the benefit of late administration of C1-INH concentrate.

Recurrent Angiotensin-Converting Enzyme Inhibitor-Induced Angioedema Refractory to Fresh Frozen Plasma

The case of a patient with refractory angioedema who was treated with fresh frozen plasma without success raises concern for its effectiveness.

The International/Canadian Hereditary Angioedema Guideline

This is an update to the 2014 Canadian Hereditary Angioedema Guideline with an expanded scope to include the management of hereditary angioedema (HAE) patients worldwide. It is a collaboration of Canadian and international HAE experts and patient groups led by the Canadian Hereditary Angioedema Network. The objective of this guideline is to provide evidence-based recommendations, using the GRADE system, for the management of patients with HAE. This includes the treatment of attacks, short-term prophylaxis, long-term prophylaxis, and recommendations for self-administration, individualized therapy, quality of life, and comprehensive care. New to the 2019 version of this guideline are sections covering the diagnosis and recommended therapies for acute treatment in HAE patients with normal C1-INH, as well as sections on pregnant and paediatric patients, patient associations and an HAE registry. Hereditary angioedema results in random and often unpredictable attacks of painful swelling typically affecting the extremities, bowel mucosa, genitals, face and upper airway. Attacks are associated with significant functional impairment, decreased health-related quality of life, and mortality in the case of laryngeal attacks. Caring for patients with HAE can be challenging due to the complexity of this disease. The care of patients with HAE in Canada, as in many countries, continues to be neither optimal nor uniform. It lags behind some other countries where there are more organized models for HAE management, and greater availability of additional licensed therapeutic options. It is anticipated that providing this guideline to caregivers, policy makers, patients, and advocates will not only optimize the management of HAE, but also promote the importance of individualized care. The primary target users of this guideline are healthcare providers who are managing patients with HAE. Other healthcare providers who may use this guideline are emergency and intensive care physicians, primary care physicians, gastroenterologists, dentists, otolaryngologists, paediatricians, and gynaecologists who will encounter patients with HAE and need to be aware of this condition. Hospital administrators, insurers and policy makers may also find this guideline helpful.

Hereditary angioedema, emergency management of attacks by a call center

OBJECTIVE

Hereditary angiœdema (HAE) is a rare autosomal dominant disease characterized by recurrent, unpredictable, potentially life-threatening swelling. Objective is to assess the management of the acute HAE attacks in the real life setting through a call center in France.

METHODS

A pre-specified ancillary study of SOS-HAE, a cluster-randomized prospective multicenter trial, was conducted. HAE patients were recruited from 8 participating reference centers. The outcome of interest was the rate of hospitalization.

RESULTS

onerhundred patients were included. The median (quartile) age was 38 (29-53) years, and 66 (66%) were female. Eighty (80%) patients had HAE type I, 8 (8%) had HAE type II and 12 (12%) patients had FXII-HAE. Fifty-one (51%) patients had experienced at least one time the call center during the follow-up. Nine over 166 (5%) attacks for 9 different patients resulted in hospital admission to the hospital (in the short-stay unit, ie, <24 h) during the follow-up period. During 2 years, there were 166 calls to call center for 166 attacks. All attacks were treated at home after call center contact.

CONCLUSIONS

Use of emergency departments and hospitalizations are reduced by the use of a coordinated national call center in HAE after therapeutic education program that promoted self-administration of specific treatment and use of call to call center.

TRIAL REGISTRATION

clinicalTrials.gov identifier: NCT01679912.

An 82-year-old man with recurrent angioedema

Angioedema is a potentially life-threatening swelling condition that can occur either in isolation or in the context of other syndromes, e.g., anaphylaxis. Angioedema is typically asymmetric, lasts for hours to days, is not gravity dependent, and is often nonpitting. Recurrent angioedema is typically associated with histaminergic and bradykinin-mediated causes, some of which can indicate underlying etiologies with high morbidity or mortality. The differential diagnosis for acute angioedema can include anaphylaxis, chronic urticaria with angioedema, medications such as angiotensin-converting-enzyme inhibitors, hereditary C1 esterase inhibitor defects, and acquired defects; however, the cause is often idiopathic, and effective therapy can be elusive. In this article, we described a unique etiology of a case of isolated recurrent angioedema that improved when the possible underlying cause was successfully treated.

Lupus anticoagulant-hypoprothrombinemia syndrome and immunoglobulin-A vasculitis: a report of Japanese sibling cases and review of the literature

Lupus anticoagulant-hypoprothrombinemia syndrome (LAHPS) is a rare bleeding disorder caused by antiprothrombin antibodies. LAHPS is associated with systemic lupus erythematosus (SLE) or infections. We describe two Japanese brothers with immunoglobulin-A vasculitis (IgAV) who met the diagnostic criteria of LAHPS. They presented with palpable purpura and abdominal pain, and had a prolonged activated partial thromboplastin time (APTT) and prothrombin deficiency with the presence of lupus anticoagulant. Pediatric LAHPS was reviewed in abstracts from the Japan Medical Abstracts Society that were written in Japanese and PubMed or Web of Science-listed articles in English between 1996 and 2019. Including our cases, pediatric LAHPS has been reported in 40 Japanese and 46 non-Japanese patients. We summarized the clinical and laboratory characteristics of all 86 cases, and found only one Japanese LAHPS case with IgAV, except for our cases. Of the 86 cases, most were associated with infections followed by SLE. The presence of SLE, older age, lower prothrombin levels, severe bleeding symptoms, and positivity of immunoglobulin G anticardiolipin antibodies and anticardiolipin/β₂-glycoprotein I antibodies and/or β₂-glycoprotein I-dependent anticardiolipin antibodies had higher odds of requiring treatment. Measuring the APTT and prothrombin time (PT) might be required in patients with IgAV when they do not have a typical clinical course or distinctive symptoms. LAHPS should be considered with prolongation of the APTT and/or PT. Additionally, it is important to maintain a balance between the risk of thrombosis and hemorrhage when normalization of the PT and FII levels occurs in LAHPS cases under treatment.

Clinical Features and Outcomes Associated with Angioedema in the Emergency Department

Introduction

Angioedema represents self-limited, localized swelling of submucosal or subcutaneous tissues. While the underlying etiology may be undeterminable in the emergent setting, nonhistaminergic and histaminergic angioedema respond differently to therapeutic interventions, with implications for empiric treatment. Clinical features and outcome differences among nonhistaminergic vs histaminergic angioedema patients in the emergency department (ED) are poorly characterized. We aim to describe the clinical characteristics and outcomes among ED patients with angioedema by suspected etiology.

Methods

This was a 10-year retrospective study of adult ED patients with angioedema, using data abstracted from the electronic health record. We evaluated univariable associations of select clinical features with etiology and used them to develop a multivariable logistic regression model for nonhistaminergic vs histaminergic angioedema.

Results

Among 450 adult angioedema patients, the mean +/− standard deviation age was 57 +/− 18 years, and 264 (59%) were female. Among patients, 30% had suspected nonhistaminergic angioedema, 30% had suspected histaminergic angioedema, and 40% were of unknown etiology. As compared to histaminergic angioedema, nonhistaminergic angioedema was associated with angiotensin-converting enzyme inhibitors (ACEI) or use of angiotensin II receptor blockers (ARB) (odds ratio [OR] [60.9]; 95% confidence interval [CI], 23.16–160.14) and time of onset one hour or more prior to ED arrival (OR [5.91]; 95% CI,1.87–18.70) and was inversely associated with urticaria (OR [0.05]; 95% CI, 0.02–0.15), dyspnea (OR [0.23]; 95% CI, 0.08–0.67), and periorbital or lip edema (OR [0.25]; 95% CI, 0.08–0.79 and OR [0.32]; 95% CI, 0.13–0.79, respectively).

Conclusion

As compared to histaminergic angioedema, patients with nonhistaminergic angioedema were more likely to present one hour or more after symptom onset and take ACEI or ARB medications, and were less likely to have urticaria, dyspnea, or periorbital or lip angioedema. Identification of characteristics associated with the etiology of angioedema may assist providers in more rapidly initiating targeted therapies.

Non-Vitamin K Antagonist Oral Anticoagulants and Angioedema: A Cohort and Case-Crossover Study

INTRODUCTION

Patients taking non-vitamin K antagonist oral anticoagulants (NOACs) such as dabigatran, rivaroxaban, and apixaban have reported experiencing angioedema in randomized trials and routine care.

OBJECTIVE

The aim of this study was to quantify the association between NOACs and angioedema relative to warfarin among routinely treated patients with atrial fibrillation in a cohort study. We also compared warfarin users with non-users in a case-crossover study.

METHODS

We utilized a cohort design that drew eligible patients from the Truven Health MarketScan Commercial database, the Optum^© Clinformatics^® Data Mart, and Medicare. Within each database, we compared the 6-month relative rate of angioedema among new users of NOACs (dabigatran, rivaroxaban, apixaban) and new users of warfarin. We estimated hazard ratios (HRs) and 95% confidence intervals (CIs) after adjusting for confounders using propensity score stratification, and meta-analyzed the database-specific HRs using a random-effects model. We also estimated an odds ratio (OR) for the association between warfarin and angioedema using a case-crossover design, a self-controlled design that controls for time-invariant confounders.

RESULTS

In the cohort study, we observed 249 incident angioedema events among 267,681 NOAC initiators and 281,143 warfarin initiators across all databases. The meta-analyzed HR for angioedema comparing any NOAC versus warfarin was 0.98 (95% CI 0.76-1.27). In the case-crossover design, the OR for the association between warfarin and angioedema was 0.91 (95% CI 0.68-1.21) based on 431 cases.

CONCLUSIONS

Our estimates were inconsistent with substantial short-term relative increases in the rate of angioedema associated with oral anticoagulant therapy.

Evaluation and Management of Angioedema in the Emergency Department

Angioedema is defined by non-dependent, non-pitting edema that affects several different sites and is potentially life-threatening due to laryngeal edema. This narrative review provides emergency physicians with a focused overview of the evaluation and management of angioedema. Two primary forms include histamine-mediated and bradykinin-mediated angioedema. Histamine-mediated forms present similarly to anaphylaxis, while bradykinin-mediated angioedema presents with greater face and oropharyngeal involvement and higher risk of progression. Initial evaluation and management should focus on evaluation of the airway, followed by obtaining relevant historical features, including family history, medications, and prior episodes. Histamine-mediated angioedema should be treated with epinephrine intramuscularly, antihistaminergic medications, and steroids. These medications are not effective for bradykinin-mediated forms. Other medications include C1-INH protein replacement, kallikrein inhibitor, and bradykinin receptor antagonists. Evidence is controversial concerning the efficacy of these medications in an acute episode, and airway management is the most important intervention when indicated. Airway intervention may require fiberoptic or video laryngoscopy, with preparation for cricothyrotomy. Disposition is dependent on patient's airway and respiratory status, as well as the sites involved.

Diagnosis and treatment of urticaria in primary care

Urticaria, also known as hives among people, is a very common disease characterized by erythematous, edematous, itchy, and transient plaques that involve skin and mucous membranes. It is classified as acute spontaneous urticaria, chronic spontaneous urticaria, chronic inducible urticaria, and episodic chronic urticaria. Many factors such as infections, medicines, food, psychogenic factors, and respiratory allergens are accused of etiology, but sometimes, it is idiopathic. Clinical presentation involves red, swelling, and itchy plaques. The lesions usually resolve spontaneously within 2-3 h without a trace. The patients are sometimes confronted with an angioedema that can also involve the respiratory tract. In this case mucous membranes, such as eyelids, lips, swell with some pain and burning sensation. If respiratory tracts are involved, it may be life threatening and should be treated urgently. The diagnosis is usually straightforward, urticarial vasculitis, drug eruptions, viral eruptions, and urticaria pigmentosa must also be considered. H1 antihistamines and, sometimes, short-term systemic corticosteroids are preferred for the treatment; H2 antagonists may be added during resistant cases, although other treatment options, such as omalizumab, cyclosporine, and leukotriene receptor antagonists, may be considered during missed events.

Angioedema and emergency medicine: From pathophysiology to diagnosis and treatment

Angioedema is a self-limiting edema of the subcutaneous or submucosal tissues due to localised increase of microvascular permeability whose mediator may be histamine or bradykinin. Patients present to emergency department when angioedema involves oral cavity and larynx (life-threatening conditions) or gut (mimicking an acute abdomen). After initial evaluation of consciousness and vital signs to manage breathing and to support circulation if necessary, a simple approach can be applied for a correct diagnosis and treatment. Forms of edema such as anasarca, myxedema, superior vena cava syndrome and acute dermatitis should be ruled out. Then, effort should be done to differentiate histaminergic from non-histaminergic angioedema. Concomitant urticaria and pruritus suggest a histaminergic origin. Exposure to allergens and drugs (mainly ACE inhibitors and non steroidal anti-inflammatory drugs) should be investigated as well as a family history of similar symptoms. Allergic histaminergic angioedema has a rapid course (minutes) whereas non histaminergic angioedema is slower (hours). Since frequently the intervention needs to be immediate, the initial diagnosis is only clinical. However, laboratory tests can be subsequently confirmatory. Allergic angioedema is sensitive to standard therapies such as epinephrine, glucocorticoids and antihistamines whereas non histaminergic angioedema is often resistant to these drugs. Therapeutic options for angioedema due C1-inhibitor deficiencies are C1-inhibitor concentrates, icatibant and ecallantide. If these drugs are not available, fresh frozen plasma can be considered. All these medications have been used also in ACE inhibitor-induced angioedema with variable results thus they are not currently recommended whereas experts agree on the discontinuation of the causative drug.