Predicting airway risk in angioedema: staging system based on presentation

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.

Airway Involvement and Intervention in Non-ACE-Inhibitor-Induced Angioedema

OBJECTIVES

Characterize the presentation of patients with non-angiotensin-converting enzyme inhibitor (ACEI)-induced angioedema and determine risk factors associated with patient disposition and possible need for airway intervention.

METHODS

The medical records of adult patients in the Emergency Department (ED) and diagnosed with non-ACEI-induced angioedema over 4.5 years were included. Demographics, vital signs, etiology, timeline, presenting symptoms, physical exam including flexible laryngoscopy, medical management, and disposition were examined. Statistical analyses were conducted using SPSS V 23.0 software calculating and comparing means, standard deviations, medians, and correlation of categorical and ordinate variables.

RESULTS

A total of 181 patients with non-ACEI-induced angioedema were evaluated with flexible laryngoscopy by otolaryngology. Notably, 11 patients (6.1%) required airway intervention and were successfully intubated. Statistically significant factors (p ≤ 0.05) associated with airway intervention included the diastolic blood pressure (DBP) and mean arterial pressure (MAP) (p = 0.006 and 0.01 respectively), symptoms of dysphonia (p = 0.018), the presence of oropharyngeal, supraglottic, and hypopharyngeal edema (p ≤ 0.001 for each site), and the number of edematous anatomic subsites documented on physical exam (p < 0.001). Other patient demographics, prior history of angioedema, heart rate, systolic blood pressure, symptom onset, number of symptoms at presentation, and medication administered in the ED did not correlate with airway intervention.

CONCLUSION

Dysphonia, DBP, MAP, anatomic location of edema and edema in multiple sites are associated with airway intervention and a higher level of care in non-ACEI-induced angioedema and can be useful in risk assessment in patient management.

LEVEL OF EVIDENCE

4 Laryngoscope, 134:2282-2287, 2024.

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.

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.

Isolated Angioedema: A Review of Classification and Update on Management

OBJECTIVE

The purpose of this article is to review the various types of angioedema including diagnosis and treatment.

DATA SOURCES

PubMed search of articles in the English language various types of angioedema STUDY SELECTION: Articles on the subject matter were selected and reviewed.

RESULTS

Herein, a case based approach is presented for discussing the major types of angioedema including: hereditary angioedema (HAE) TypesI/II and normal complement, acquired angioedema, Angiotensin converting enzyme (ACE) induced angioedema, as well as histaminergic and non-histaminergic angioedema. Emerging treatments of HAE including targets of pre-kalikrein, DNA vector technology replacing C1INH protein, and CRIPSR technology targeting PKK among many others are explored. In addition, other causes as well as mimickers of angioedema are briefly reviewed. Finally, a novel algorithm is proposed to help guide the treating physician through the work up and management of patients with suspected idiopathic angioedema unresponsive to conventional therapy with antihistamines.

CONCLUSION

Over the years, many strides have been made in both understanding the pathophysiology of various types of angioedema as well as expansion of treatment options. It is important for clinicians to be aware of current and emerging treatment options. We provide a novel practical algorithm to guide clinicians in challenging cases of idiopathic angioedema refractory to antihistamines.

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.

Recognition, Evaluation, and Management of Pediatric Hereditary Angioedema

ABSTRACT

Hereditary angioedema (HAE) is a rare, often underrecognized genetic disorder caused by either a C1 esterase inhibitor deficiency (type 1) or mutation (type 2). This leads to overproduction of bradykinin resulting in vasodilation, vascular leakage, and transient nonpitting angioedema occurring most frequently in the face, neck, upper airway, abdomen, and/or extremities. Involvement of the tongue and laryngopharynx has been associated with asphyxiation and death. Hereditary angioedema is an autosomal-dominant condition; therefore, there is a 50% chance an offspring will inherit this disorder. Any patient presenting with isolated angioedema should be screened with a C4 measurement, as 25% of cases have no family history of HAE. All patients with HAE will have a functional deficiency of C1 esterase inhibitor. Contributors that delay the diagnosis of HAE include recognition delay by clinicians who confuse this condition with histaminergic angioedema, the disease's varied presentations, and limitations to timely testing. Pediatric emergency clinicians should be knowledgeable about how to distinguish between bradykinin- and histamine-mediated angioedema, as there are significant differences in the diagnostic testing, treatment, and clinical response between these 2 different conditions. Evidence indicates that early diagnosis and treatment of HAE reduces morbidity and mortality. Clinician recognition of the mechanistically different problems will ensure patients are appropriately referred to an expert for outpatient management.

Recurrent angioedema: Experience at a tertiary care urban medical center

OBJECTIVE

To determine the demographics, presentation, management, and outcomes of patients with recurrent angioedema. To compare the findings to patients with ACE inhibitor related angioedema.

METHODS

Retrospective case series with chart review of patients who presented to a tertiary-care hospital between January 2010 and December 2017 with two or more episodes of angioedema. Excluded were patients with anaphylactic reaction, medication induced angioedema, or angioedema secondary to an infectious etiology. A group of 88 patients who presented during the same time period with ACE inhibitor related angioedema was used as a control. Statistical analysis was conducted using a two-tailed Fisher exact test and a multivariate logistical regression model to determine significant associations.

RESULTS

Ninety-one patients were identified; 61 met the selection criteria and had 217 total episodes of angioedema episodes presenting to the emergency department. Fifty percent were Caucasian or Hispanic. The average number of episodes was 3.5 (range: 2-23). The lips and tongue were the most commonly affected sites (37% and 39%). The larynx and floor of mouth were least likely to be involved (7% and 6%). Only 1 patient was found to have C1 esterase inhibitor deficiency. Twenty-eight percent of patients had asthma, allergic rhinitis, food allergies, or atopic dermatitis. Only 11% of episodes required airway intervention. No patients required airway intervention after admission.

CONCLUSION

Recurrent angioedema was primarily idiopathic, was less severe than ACE inhibitor angioedema, and was associated with an atopic history. There was less frequent worsening of symptoms after admission, and recurrences occurred more frequently are at the same anatomic subsite.

LEVEL OF EVIDENCE

IV.

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.

Severity grading system for acute allergic reactions: A multidisciplinary Delphi study

BACKGROUND

There is no widely adopted severity grading system for acute allergic reactions, including anaphylactic and nonanaphylactic reactions, thus limiting the ability to optimize and standardize management practices and advance research.

OBJECTIVE

The aim of this study was to develop a severity grading system for acute allergic reactions for use in clinical care and research.

METHODS

From May to September 2020, we convened a 21-member multidisciplinary panel of allergy and emergency care experts; 9 members formed a writing group to critically appraise and assess the strengths and limitations of prior severity grading systems and develop the structure and content for an optimal severity grading system. The entire study panel then revised the grading system and sought consensus by utilizing Delphi methodology.

RESULTS

The writing group recommended that an optimal grading system encompass the severity of acute allergic reactions on a continuum from mild allergic reactions to anaphylactic shock. Additionally, the severity grading system must be able to discriminate between clinically important differences in reaction severity to be relevant in research while also being intuitive and straightforward to apply in clinical care. Consensus was reached for all elements of the proposed severity grading system.

CONCLUSION

We developed a consensus severity grading system for acute allergic reactions, including anaphylactic and nonanaphylactic reactions. Successful international validation, refinement, dissemination, and application of the grading system will improve communication among providers and patients about the severity of allergic reactions and will help advance future research.

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.

Acquired complement C1 esterase inhibitor deficiency in a patient with a rare SERPING1 variant with unknown significance

Angioedema (AE) is caused by a wide range of diseases and pharmaceuticals; it can become life-threatening when located to the airways. Patients with deficiency or malfunction of complement C1 esterase inhibitor (hereditary or acquired) experience recurrent AE due to an accumulation of the vasoactive mediator bradykinin (BK). Complement C1 inhibitor normally decreases BK production, so a reduced function hereof causes increased levels. The diagnosis of hereditary or acquired AE can be difficult due to similarities to allergic reactions (swelling, abdominal pain, rash). We describe a 35-year-old man presenting with upper-airway AE progressing rapidly and promptly required cricothyroidotomy. Complement and autoantibody screening together with sequencing of SERPING1 were performed and gave the diagnosis of acquired complement C1 esterase inhibitor deficiency. The patient is unusual to have this disease before the age of 40 years. No associated comorbidities were found. It is important to know that antiallergic medication is not effective in BK-mediated AE.

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.

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.

Development of the Hereditary Angioedema Rapid Triage Tool

BACKGROUND

Patients with hereditary angioedema (HAE) present to the emergency department (ED), where their symptoms are often incorrectly attributed to common allergic and gastrointestinal conditions, resulting in major delays in diagnosis and treatment.

OBJECTIVE

To develop a rapid triage HAE (Hereditary AngioEdema Rapid Triage [HAE-RT]) tool for ED settings.

METHODS

A mixed-methods approach was used in 3 phases: Phase 1: A literature review on the current management of patients with HAE in the ED. Phase 2: A Delphi study with HAE specialists (N = 9) and Patient Advocacy Group Members (N = 3) to reach consensus on the predictor variables (PVs) to be included in the HAE-RT tool. Phase 3: A retrospective chart review to assess the performance of the PVs for HAE.

RESULTS

The literature review informed the final list of PVs included in the HAE-RT prototype. Nine experts participated in the Delphi study. Of 8 identified HAE-specific PVs, 3 reached consensus: (1) absence of urticaria, (2) recurrent abdominal pain/swelling, and (3) lack of response to allergic-directed therapy. The retrospective study included 107 patients (N = 66 with HAE; N = 41 non-HAE). Patients with HAE were more likely to have a family history of HAE (71%; P < .0001), previous recurrent angioedema (96%; P < .002), and previous recurrent abdominal pain (77%; P < .0001), and only 6% responded to allergy treatments (P < .0001). The HAE-RT tool had 98% sensitivity and specificity.

CONCLUSIONS

Expert consensus led to the identification and prioritization of variables that when incorporated into an HAE-RT tool were associated with a high level of sensitivity and specificity when applied to known patients.

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.

Intraoperative angioedema induced by angiotensin II receptor blocker: a case report

Background

Angiotensin II receptor blockers are a class of antihypertensive agent that is developed to exclude the adverse effects of angiotensin converting enzyme inhibitors. However, as angiotensin II receptor blockers have begun to be more widely prescribed, cases of angiotensin II receptor blocker-induced angioedema have been reported. Rare cases of angioedema following surgery in patients using angiotensin converting enzyme inhibitors have been published.

Case presentation

A 38-year-old man with past history of hypertension was admitted for an elective lumbosacral spine surgery. He had been taking Valsartan 160 mg a day for the past 4 years.At the end of the surgical procedure and turning the patient into supine position, we noticed severe swelling in the neck and the face with.an edematous tongue, floor of the mouth, glottis, and supraglottic areas. A diagnosis of drug induced angioedema was made and intravenous dexamethasone, diphenhydramine and ranitidine were given. The patient remained intubated and was transferred to the intensive care unit. The valsartan was suspected to be the precipitating factor for the angioedema and was therefore discontinued.The swelling started to regress after 2 h, and resolved completely by the third day.

Conclusion

The precise mechanism of angiotensin II receptor blocker-induced angioedema is still unknown and should be thoroughly investigated. This report demonstrates a unique case of intraoperative angiotensin II receptor blocker-induced angioedema. Potential differential diagnoses of postoperative facial edema are discussed in detail, including the prolonged prone positioning for posterior spine surgery. Anesthesiologists should be aware of such rare, but potentially dangerous, perioperative adverse reaction that can occur with angiotensin II receptor blockers use.

Quantification of human C1 esterase inhibitor protein using an automated turbidimetric immunoassay

Background

Impaired levels or function of C1 inhibitor (C1‐INH) results in angioedema due to increased bradykinin. It is important to distinguish between angioedema related to C1‐INH deficiency and that caused by other mechanisms, as treatment options are different. In hereditary (HAE) and acquired (AAE) angioedema, C1‐INH concentration is measured to aid patient diagnosis. Here, we describe an automated turbidimetric assay to measure C1‐INH concentration on the Optilite^® analyzer.

Methods

Linearity, precision, and interference were established over a range of C1‐INH concentrations. The 95th percentile reference interval was generated from 120 healthy adult donors. To compare the Optilite C1‐INH assay with a predicate assay used in a clinical laboratory, samples sent for C1‐INH investigation were used. The predicate results were provided to allow comparison.

Results

The Optilite C1‐INH assay was linear across the measuring range at the standard sample dilution. Intra and interassay variability was <6%. The 95th percentile adult reference interval for the assay was 0.21‐0.38 g/L. There was a strong correlation between the Optilite concentrations and those generated with the predicate assay (R² = 0.94, P < 0.0001, slope y = 0.83x). All patients with Type I HAE (n = 24) and AAE (n = 3) tested had concentrations below the measuring range in both assays, while all patients with unspecified angioedema (UAE), not diagnosed with HAE or AAE had values within the reference range.

Conclusion

The Optilite assay allows the automated and precise quantification of C1‐INH concentrations in patient samples. It could therefore be used as a tool to aid the investigation of patients with angioedema.

Otolaryngology in Critical Care

Diseases affecting the ear, nose, and throat are prevalent in intensive care settings and often require combined medical and surgical management. Upper airway occlusion can occur as a result of malignant tumor growth, allergic reactions, and bleeding events and may require close monitoring and interventions by intensivists, sometimes necessitating surgical management. With the increased prevalence of immunocompromised patients, aggressive infections of the head and neck likewise require prompt recognition and treatment. In addition, procedure-specific complications of major otolaryngologic procedures can be highly morbid, necessitating vigilant postoperative monitoring. For optimal outcomes, intensivists need a broad understanding of the pathophysiology and management of life-threatening otolaryngologic disease.

Diagnosis and treatment of upper airway oedema caused by acute angio-oedema in the emergency department: a French consensus statement

Angio-oedema is a transitory, localized, noninflammatory oedema of subcutaneous tissue or mucous. When the oedema affects the mouth, lips, tongue or larynx, it can result in fatal asphyxiation in the absence of specific treatment. Oedema secondary to plasma extravasation is usually mediated by either histamine or bradykinin. As laboratory tests are not available in an emergency setting, the implicated mediator cannot be readily determined. The challenge for the emergency physician is to determine the aetiological type, evaluate severity and initiate adapted treatment by means of a structured approach. A team of experts from the French Reference Centre for Angio-oedema reached a consensus for recommendations for the diagnostic and therapeutic strategy to be adopted by emergency departments faced with angio-oedema of the upper airways in adults. The experts defined 11 important questions. Responses were rated using a two-round Delphi methodology. The 11 recommendations were related to triage on admission, a step-by-step diagnostic protocol, definition of attack severity, discouragement of instrumental examination, prioritization of treatment for severe attacks according to clinical signs and anticipation of access to specific treatments by the hospital. Angio-oedema of the upper airways can be fatal and requires anticipation by the emergency department. A search for the aetiology, an evaluation of clinical symptoms and the availability of the treatments are challenges justifying these recommendations.

Inhalant allergen sensitization is an independent risk factor for the development of angioedema

BACKGROUND/OBJECTIVE

The etiology and risk factors for angioedema remain poorly understood with causative triggers often going undiagnosed despite repeated reactions. The purpose of this study was to determine the relationship between inhalant allergen sensitization and angioedema.

METHODS

A retrospective review of patients who had in vitro inhalant allergy testing from 2006 to 2010 was performed. Patients with a diagnosis of angioedema who underwent inhalant allergy testing were identified. Analyses for co-morbidities, class of sensitization, seasonal timing of angioedema, and concurrent use of known hypertensive medications that can cause angioedema were performed.

RESULTS

There were 1000 patients who underwent inhalant allergy testing and qualified for the study. 37/1000 had at least one episode of angioedema and of these patients, 34 had positive inhalant sensitization testing results. Multivariate regression models showed overall sensitization status, seasonal allergen and epidermal/mite sensitization as independent risk factors (p<0.001, p=0.005, p=0.025 respectively) when controlling for ACE inhibitor use and other covariates. Tree, and epidermal/mite sensitizations were independent risk factors for angioedema in mono-sensitized subject analysis (p=0.028, p=0.029, respectively).

CONCLUSION

Both seasonal and perennial allergen sensitizations are independent risk factors for the development of angioedema. In patients with angioedema and an unknown trigger, inhalant allergen sensitization should be considered as a potential contributing factor to the development of angioedema.

Pharmacotherapy for Angiotensin-Converting Enzyme Inhibitor–Induced Angioedema: A Systematic Review

Objective

Angioedema is a potentially life-threatening complication of angiotensin-converting enzyme inhibitor (ACEI) use, occurring in up to 0.5% of users. Although the pathophysiology of ACEI-induced angioedema is attributable to elevated serum bradykinin, standard management typically includes corticosteroids and antihistamines. We sought to summarize the evidence supporting pharmacotherapy for ACEI-induced angioedema.

Data Sources

PubMed, MEDLINE, and Embase portals.

Methods

A systematic literature review was conducted according to the PRISMA guidelines. Databases were queried by 3 independent reviewers for English-language studies published between 1980 and 2017. The initial search screened for all occurrences of “angioedema” and then was further refined to include studies of ACEI-related cases and exclude hereditary angioedema.

Results

Five articles representing 218 cases were identified, including 3 randomized controlled trials and 2 prospective case series with historical controls. One of 2 studies of icatibant (bradykinin B2 receptor antagonist) found more rapid symptom improvement than that with a control group of corticosteroids and antihistamines. Two studies of ecallantide (plasma kallikrein inhibitor) and 1 study of C1 inhibitor replacement found no significant benefit over control. No studies were identified that compared the efficacy of corticosteroids with antihistamines, of one dose with another, of fresh frozen plasma, or of combination therapy.

Conclusion

The efficacy of treatment of ACEI-induced angioedema with bradykinin antagonists, kallikrein inhibitor, and C1 inhibitor warrants further study. Although consistent benefit of these medications has not been demonstrated, their use has not caused harm. One study examining off-label use of icatibant has demonstrated efficacy over control. In addition, further study is needed to establish the efficacy and mechanism of action of standard pharmacotherapy such as corticosteroids and antihistamines in treatment of this condition.

Pathogenesis of Drug Induced Non-Allergic Angioedema: A Review of Unusual Etiologies

Angioedema is the swelling of mucosal and sub-mucosal tissue. Typically, it manifests as the swelling of the face, lips, and tongue. Angioedema can be severe and life threatening when it involves the respiratory tract. Drug induced allergic angioedema and drug induced non-allergic angioedema differ in their mediator, their clinical presentations, and their management. In drug induced non-allergic angioedema, symptoms are resistant to antihistamine and corticosteroid treatment. The aim of the analysis was to identify which medications are associated with drug-induced non-allergic angioedema and to understand the mechanism of action via which of these medication cause angioedema.

Development and validation of the angiotensin-converting enzyme inhibitor (ACEI) induced angioedema investigator rating scale and proposed discharge criteria

BACKGROUND

The use of angiotensin-converting enzyme inhibitors (ACEI) has been associated with the development of bradykinin-mediated angioedema. With ever-widening indications for ACEI in diseases including hypertension, congestive heart failure and diabetic nephropathy, a concomitant increase in ACEI-Angioedema (ACEI-A) has been reported. At present there is no validated severity scoring or discharge criteria for ACEI-A. We sought to develop and validate an investigator rating scale with corresponding discharge criteria using clinicians experienced in treating ACEI-A.

METHODS

In-depth, 60-min qualitative telephone interviews were conducted with 12 US-based emergency physicians. Beforehand, clinicians were sent four case studies describing patients experiencing different severities of angioedema attacks. Clinicians were initially asked open-ended questions about their experience of patients' symptoms, treatment and discharge decisions. Clinicians then rated each patient case study and discussed patient diagnoses, ratings of symptom severity and discharge evaluation. The ratings were used to assess inter-rater reliability of the scale using the intra-class correlation coefficient (ICC) using IBM SPSS analysis Version 19 software.

RESULTS

The findings provide support focusing on four key symptoms of airway compromise scored on a 0-4 scale: 1) Difficulty Breathing, 2) Difficulty Swallowing, 3) Voice Changes and 4) Tongue Swelling and the corresponding discharge criteria of a score of 0 or 'No symptoms' for Difficulty Breathing and Difficulty Swallowing and a score of 0 or 1 indicating mild or absence of symptoms for Voice Change and Tongue Swelling. Eleven clinicians agreed the absence of standardized discharge criteria supported the use of this scale. All physicians concurred with the recommended discharge criteria. The clinician ratings provided evidence of strong inter-rater reliability for the rating scale (ICC > 0.80).

CONCLUSION

The investigator rating scale and discharge criteria are clinically valid, relevant and reliable. Moreover, both address the current unmet need for standardized ED discharge criteria.

Angioedema in the emergency department: a practical guide to differential diagnosis and management

Background

Angioedema is a common presentation in the emergency department (ED). Airway angioedema can be fatal; therefore, prompt diagnosis and correct treatment are vital.

Objective of the review

Based on the findings of two expert panels attended by international experts in angioedema and emergency medicine, this review aims to provide practical guidance on the diagnosis, differentiation, and management of histamine- and bradykinin-mediated angioedema in the ED.

Review

The most common pathophysiology underlying angioedema is mediated by histamine; however, ED staff must be alert for the less common bradykinin-mediated forms of angioedema. Crucially, bradykinin-mediated angioedema does not respond to the same treatment as histamine-mediated angioedema. Bradykinin-mediated angioedema can result from many causes, including hereditary defects in C1 esterase inhibitor (C1-INH), side effects of angiotensin-converting enzyme inhibitors (ACEis), or acquired deficiency in C1-INH. The increased use of ACEis in recent decades has resulted in more frequent encounters with ACEi-induced angioedema in the ED; however, surveys have shown that many ED staff may not know how to recognize or manage bradykinin-mediated angioedema, and hospitals may not have specific medications or protocols in place.

Conclusion

ED physicians must be aware of the different pathophysiologic pathways that lead to angioedema in order to efficiently and effectively manage these potentially fatal conditions.

Assessment of 105 Patients with Angiotensin Converting Enzyme-Inhibitor Induced Angioedema

Objective. To asses a cohort of 105 consecutive patients with angiotensin converting enzyme-inhibitor induced angioedema with regard to demographics, risk factors, family history of angioedema, hospitalization, airway management, outcome, and use of diagnostic codes used for the condition. Study Design. Cohort study. Methods. This was a retrospective cohort study of 105 patients with angiotensin converting enzyme-inhibitor induced angioedema in the period 1995-2014. Results. The cohort consisted of 67 females and 38 males (F : M ratio 1.8), with a mean age of 63 [range 26-86] years. Female gender was associated with a significantly higher risk of angiotensin converting enzyme-inhibitor induced angioedema. 6.7% had a positive family history of angioedema. Diabetes seemed to be a protective factor with regard to angioedema. 95% experienced angioedema of the head and neck. 4.7% needed intubation or tracheostomy. 74 admissions took place during the study period with a total of 143 days spent in the hospital. The diagnosis codes most often used for this condition were "DT783 Quincke's oedema" and "DT78.4 Allergy unspecified". Complement C1 inhibitor was normal in all tested patients. Conclusion. Female gender predisposes to angiotensin converting enzyme-inhibitor induced angioedema, whereas diabetes seems to be a protective factor.

Emergency Department Airway Management of Severe Angioedema: A Video Review of 45 Intubations

STUDY OBJECTIVE

Angioedema is an uncommon but important cause of airway obstruction. Emergency airway management of angioedema is difficult. We seek to describe the course and outcomes of emergency airway management for severe angioedema in our institution.

METHODS

We performed a retrospective, observational study of all intubations for angioedema performed in an urban academic emergency department (ED) between November 2007 and June 2015. We performed a structured review of video recordings of each intubation. We identified the methods of airway management, the success of each method, and the outcomes and complications of the effort.

RESULTS

We identified 52 patients with angioedema who were intubated in the ED; 7 were excluded because of missing videos, leaving 45 patients in the analysis. Median time from arrival to the ED to the first intubation attempt was 33 minutes (interquartile range 17 to 79 minutes). Nasotracheal intubation was the most common first method (33/45; 73%), followed by video laryngoscopy (7/45; 16%). Two patients required attempts at more invasive airway procedures (retrograde intubation and cricothyrotomy). The intubating laryngeal mask airway was used as a rescue method 5 times after failure of multiple methods, with successful oxygenation, ventilation, and intubation through the laryngeal mask airway in all 5 patients. All patients were successfully intubated.

CONCLUSION

In this series of ED patients who were intubated because of angioedema, emergency physicians used a range of methods to successfully manage the airway. These observations provide key lessons for the emergency airway management of these critical patients.

Angioedema: Classification, management and emerging therapies for the perioperative physician

Angioedema is a rare condition which manifests as sudden localised, non-pitting swelling of certain body parts including skin and mucous membranes. It is vital that anaesthesiologists understand this condition, as it may present suddenly in the perioperative period with airway compromise. To identify literature for this review, the authors searched the PubMed, Medline, Embase, Scopus and Web of Science databases for English language articles covering a 10-year period, 2006 through 2016. Angioedema can be either mast-cell mediated or bradykinin-induced. Older therapies for histaminergic symptoms are well known to anaesthesiologists (e.g., adrenaline, anti-histamines and steroids), whereas older therapies for bradykinin-induced symptoms include plasma and attenuated androgens. New classes of drugs for bradykinin-induced symptoms are now available, including anti-bradykinin, plasma kallikrein inhibitor and C1 esterase inhibitors. These can be used prophylactically or as rescue medications. Anaesthesiologists are in a unique position to coordinate perioperative care for this complex group of patients.

The role of serial physical examinations in the management of angioedema involving the head and neck: A prospective observational study

Objective

To elucidate the progression of angioedema of the head and neck with routine management and to assess the utility of serial physical exams and fiberoptic laryngoscopy in its management.

Methods

This study was a prospective observational research. From 2013 to 2014, a prospective observational study was conducted at a tertiary referral center. Forty patient were approached, 7 refused, 33 (18–90 years old) were enrolled. Patients presented with angioedema involving the head and neck over a 12 month period were asked to participate in the study. Physical examination and fiberoptic laryngoscopy were performed at presentation and then repeated at least 1 h later.

Results

Thirty-three patients with head and neck angioedema from any cause were enrolled (mean age 58, range 23–89 years). The upper lip was the most commonly involved site (58%). On reevaluation, 82% of patients reported subjective improvement in symptoms. The association between subjective improvement and the physical exam, including fiberoptic laryngoscopy findings, was statistically significant (P < 0.001).

Conclusion

In stable patients with angioedema of any head and neck subsite, self-reported symptoms are associated with clinical stability or improvement as assessed by physical signs and fiberoptic laryngoscopy. Patients' symptoms may be an appropriate surrogate to monitor clinical status without the need for routine serial physical examinations or fiberoptic laryngoscopy, though further study is needed.

Patient Admission Preferences and Perceptions

INTRODUCTION

Understanding patient perceptions and preferences of hospital care is important to improve patients' hospitalization experiences and satisfaction. The objective of this study was to investigate patient preferences and perceptions of hospital care, specifically differences between intensive care unit (ICU) and hospital floor admissions.

METHODS

This was a cross-sectional survey of emergency department (ED) patients who were presented with a hypothetical scenario of a patient with mild traumatic brain injury (TBI). We surveyed their preferences and perceptions of hospital care related to this scenario. A closed-ended questionnaire provided quantitative data on patient preferences and perceptions of hospital care and an open-ended questionnaire evaluated factors that may not have been captured with the closed-ended questionnaire.

RESULTS

Out of 302 study patients, the ability for family and friends to visit (83%), nurse availability (80%), and physician availability (79%) were the factors most commonly rated "very important," while the cost of hospitalization (62%) and length of hospitalization (59%) were the factors least commonly rated "very important." When asked to choose between the ICU and the floor if they were the patient in the scenario, 33 patients (10.9%) choose the ICU, 133 chose the floor (44.0%), and 136 (45.0%) had no preference.

CONCLUSION

Based on a hypothetical scenario of mild TBI, the majority of patients preferred admission to the floor or had no preference compared to admission to the ICU. Humanistic factors such as the availability of doctors and nurses and the ability to interact with family appear to have a greater priority than systematic factors of hospitalization, such as length and cost of hospitalization or length of time in the ED waiting for an in-patient bed.

Predictors of Airway Intervention in Angiotensin-Converting Enzyme Inhibitor–Induced Angioedema

Objectives

Identify factors associated with angiotensin-converting enzyme inhibitor–induced angioedema (AIIA), including (1) time of presentation, (2) clinical symptoms, and (3) anatomical regions in the head and neck, that may indicate need for airway intervention.

Study Design

Case series with chart review.

Setting

Three university tertiary care hospitals.

Subjects and Methods

Medical records of adult patients presenting to the emergency department (ED) diagnosed with AIIA within a 3-year period were reviewed. Time at presentation, presenting symptoms, physical examination findings, treatment, length of hospitalization, and outcomes were examined. Univariate analysis was performed.

Results

311 patients were diagnosed with AIIA and evaluated with flexible laryngoscopy by an otolaryngologist. Patients requiring airway intervention most often presented within 4 hours of onset. Dysphagia, dysphonia, drooling, respiratory distress, and globus sensation were associated with airway intervention (χ2 range, 9.1-47.1). Patients with edema of the face, lower lip, and upper lip were at low risk for airway intervention (odds ratio = 0.4, 0.3, and 0.4, respectively; all P values <.05), while those with involvement of the tongue, soft palate, vallecula, aryepiglottic folds, and true vocal cords were associated with highest risk (odds ratio = 11.1, 12.3, 9.9, 8.5, and 33.5, respectively; all P values < .001).

Conclusion

This is the largest patient series to date of AIIA patients evaluated with flexible laryngoscopy. Physicians should be aware of certain risk factors that will require a higher acuity level of care, including (1) presentation within 4 hours of symptom onset, (2) symptoms such as drooling and respiratory distress, (3) and involvement of the tongue, soft palate, and larynx.

Hyperelastic modeling of swelling in fibrous soft tissue with application to tracheal angioedema

Angioedema, the rapid swelling of under-skin tissue, is typically triggered by complex biochemical processes that disrupt an original steady state filtration of liquid through the tissue. Swelling stabilizes once a new steady state is achieved in which the tissue has significantly increased liquid content. These processes are controlled by events at the molecular to the cellular length scale. For describing consequences at organ level length scales it is useful to invoke consolidated continuum mechanics treatments within a generalized hyperelastic framework. We describe the challenges associated with such modeling and demonstrate their use in the context of tracheal angioedema. The trachea is modeled as a two layered cylindrical tube. The inner layer and outer layer represent the soft mucosal tissue and the stiffer cartilaginous tissue respectively. Axially oriented fibers contribute anisotropy to the inner layer, and the swelling is largely confined to this layer. A boundary value problem is formulated; existence and uniqueness is verified. Numerical solutions track airway constriction as a function of mucosal swelling.

Effectiveness of ecallantide in treating angiotensin-converting enzyme inhibitor-induced angioedema in the emergency department

BACKGROUND

Angiotensin-converting enzyme inhibitor-induced angioedema (ACEI-AE) is mediated by bradykinin. There remains an unmet treatment need because these patients, when presenting to the emergency department (ED), do not respond to conventional therapies, such as antihistamines and corticosteroids.

OBJECTIVE

To estimate the treatment effect of ecallantide, a recombinant plasma kallikrein inhibitor, in ED patients with ACEI-AE in whom conventional therapy fails.

METHODS

This was a triple-blind (patient, physician, and statistician), randomized, controlled, phase 2 study to estimate the magnitude of safety and efficacy signals for designing a definitive phase 3 trial comparing conventional therapy with ecallantide to conventional therapy with placebo. Patients were enrolled from April 1, 2010, through January 31, 2013. The primary efficacy study end point was achieving discharge criteria from the ED within 4 hours after initiating study-related treatment.

RESULTS

Discharge criteria from the ED was met in 4 hours or less for 8 (31%) of 26 patients receiving ecallantide vs 5 of (21%) 24 patients receiving placebo (difference in proportions, 10%; 95% confidence interval, -14% to 34%). Ecallantide was well tolerated in both groups.

CONCLUSION

The results from this preliminary study reveal that ecallantide is safe to use and may increase the proportion of patients who meet early discharge criteria by approximately10%. A larger phase 3 study is necessary to confirm the efficacy and evaluate the cost-effectiveness of ecallantide use for ACEI-AE in the ED setting.

TRIAL REGISTRATION

clinicaltrials.gov Identifier: NCT01036659.

Management of angioedema without urticaria in the emergency department

Angioedema refers to a localized, transient swelling of the deep skin layers or the upper respiratory or gastrointestinal mucosa. It develops as a result of mainly two different vasoactive peptides, histamine or bradykinin. Pathophysiology, as well as treatment, is different in each case; nevertheless, the resulting signs and symptoms may be similar and difficult to distinguish. Angioedema may occur at any location. When the affected area involves the upper respiratory tract, both forms of angioedema can lead to an imminent upper airway obstruction and a life-threatening emergency. Emergency physicians must have a basic understanding of the pathophysiology underlying this process. Angioedema evaluation in the emergency department (ED) should aim to distinguish between histamine- and bradykinin-induced angioedema, in order to provide appropriate treatment to patients. However, diagnostic methods are not available at the ED setting, neither to confirm one mechanism or the other, nor to identify a cause. For this reason, the management of angioedema should rely on clinical data depending on the particular features of the episode and the patient in each case. The history-taking should be addressed to identify a possible etiology or triggering agent, recording complete information for an ulterior diagnostic study in the outpatient clinic. It is mandatory quickly to recognize and treat a potential life-threatening upper airway obstruction or anaphylaxis. This review focuses on the underlying mechanisms and management of histamine- and bradykinin-induced angioedema at the emergency department and provides an update on the currently available treatments.

Angioedema in the neurointerventional suite

A 68-year-old woman with acute ischemic stroke presented for mechanical thrombectomy, after failed thrombolysis with intravenous recombinant tissue plasminogen activator. The procedure was completed successfully with dexmedetomidine infusion. However, she developed acute angioedema toward the end of the procedure requiring emergent fiberoptic-guided endotracheal intubation. Angioedema has been reported to occur after administering intravenous recombinant tissue plasminogen activator with an incidence of 1.3%-5.1% in patients with acute stroke.

Isolated oedema of the uvula induced by intense snoring and ACE inhibitor

A case of snoring-induced angioedema of uvula is described in a patient who was treated with ACE inhibitor. The patient partially responded to complement C1-inhibitor concentrate and did not suffer any recurrences after the medication was withdrawn. When encountering a patient suffering from swellings of the orofacial area it should be considered whether the mechanism is mast-cell associated or not, as classical antiallergic treatment is ineffective in non-mast-cell-associated disease (ie, bradykinin-mediated angioedema). Other causes of uvular oedema are also discussed.

Angiotensin converting enzyme inhibitor-related angioedema: onset, presentation, and management

OBJECTIVE

This study aimed to determine the duration of use, presentation, and management of angiotensin converting enzyme (ACE) inhibitor-related angioedema patients at an urban academic medical center.

METHODS

Retrospective chart review.

RESULTS

Eighty-eight patients who presented with ACE inhibitor-related angioedema between January 1, 2012, and December 31, 2012, were identified. They presented anywhere from 1 day to 20 years after starting an ACE inhibitor. About half the patients (50.7%) presented after taking an ACE inhibitor for at least 1 year. Fifty-five patients were female (62.5%). Twenty-eight patients (31.8%) had an airway intervention with 27 intubated and 1 requiring cricothyroidotomy. Six patients were intubated after more than 1 flexible laryngoscopy. The percentage of patients with involvement of the face, lips, tongue, floor of mouth, soft palate/uvula, and larynx were 12.5%, 60.2%, 39.7%, 6.8%, 17.0%, and 29.5%, respectively. Sixty-eight percent of patients with laryngeal edema were intubated. The majority of patients were treated with a corticosteroid and H1 and H2 receptor antagonists.

CONCLUSION

Angioedema can occur at any time after starting ACE inhibitor use, with nearly half occurring after 1 year of use. Laryngeal involvement occurred in a minority of patients, but most of these patients were felt to require airway protection.

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

Despite its relatively common occurrence and life-threatening potential, the management of angioedema in the emergency department (ED) is lacking in terms of a structured approach. It is paramount to distinguish the different etiologies of angioedema from one another and more specifically differentiate histaminergic-mediated angioedema from bradykinin-mediated angioedema, especially in lieu of the more novel treatments that have recently become available for bradykinin-mediated angioedema. With this background in mind, this consensus parameter for the evaluation and management of angioedema attempts to provide a working framework for emergency physicians (EPs) in approaching the patient with angioedema in terms of diagnosis and management in the ED. This consensus parameter was developed from a collaborative effort among a group of EPs and leading allergists with expertise in angioedema. After rigorous debate, review of the literature, and expert opinion, the following consensus guideline document was created. The document has been endorsed by the American College of Allergy, Asthma & Immunology (ACAAI) and the Society for Academic Emergency Medicine (SAEM).

Angioedema of the upper aerodigestive tract: risk factors associated with airway intervention and management algorithm

BACKGROUND

Angioedema of the upper aerodigestive tract can lead to significant airway obstruction. To date no articles have delineated risk factors for progression after initial evaluation.

METHODS

This article presents the results of a retrospective study of patients with angioedema at a single institution. Patients included were consecutive otolaryngology consultations for angioedema in the emergency department (ED) from 1999 to 2003. All patients were evaluated by an otolaryngologist and underwent fiber-optic laryngoscopy, which was repeated serially depending on findings. Data was collected on demographics, comorbidities, intubation, disposition, and progression of angioedema.

RESULTS

A total of 177 patients were included in the study: 32 (18%) patients required intubation; 25 (14%) on initial presentation and 7 (4%) who progressed from an initially stable airway to requiring intervention after reevaluation. Analysis of variance (ANOVA) demonstrated a statistically significant variance between location of edema and rate of intubation, with higher rates in the pharynx and larynx vs the lip and face. Patients who required intubation after progression between serial evaluations were statistically more likely to have edema that involved deeper portions of the aerodigestive tract. Patients who required intubation were statistically more likely to be older (average age 61.8 vs 55.1 years, p = 0.03).

CONCLUSION

In this large series of patients managed for aerodigestive angioedema we demonstrate risk factors associated with airway intervention, and risk factors associated with clinical progression on serial examination to airway intervention. In addition, we demonstrate a successful management algorithm for patients with aerodigestive angioedema.

Intubation of patients with angioedema: A retrospective study of different methods over three year period

Background:

Angioedema (AE) is edema of the skin, subcutaneous tissue and/or submucosal tissues, resulting from extravasation of intravascular fluid. Swelling of the supraglottic mucosa can lead to airway obstruction with consequent hypoxia, brain damage and death. To date, fiberoptic bronchoscope (FOB) intubation of the spontaneously breathing patient is the preferred method for an anticipated difficult intubation. However, other alternative devices can be utilized to intubate angioedema successfully.

Materials and Methods:

A retrospective chart review was performed over a three-year period (2008-2010) of all patients with angioedema that required airway intervention. We hypothesized that fiberoptic intubation would have a higher success rate for intubation attempts; however, would take longer to perform when compared to videolaryngoscopic (VL) intubation. Outcomes for FOB versus VL intubations were reviewed, along with alternative miscellaneous methods of tracheal intubation in the setting of angioedema.

Results:

Thirty-three patients were grouped, according to the chosen method of intubation into FOB (n=12), VL (n=11), and miscellaneous (n=10) groups. No significant difference was found in first intubation attempts or number of intubation attempts between the three groups. Duration of time to perform successful intubation revealed a significantly shorter intubation time (P<0.05) in the VL group (6.9±0.9 min) and miscellaneous group (9.1±2.0 min) than that of the FOB group (10.4±0.7 min).

Conclusion:

This retrospective review of intubation methods showed that VL could be performed faster than FOB without an increase in adverse events.

Diagnosis and management of hereditary angioedema: an emergency medicine perspective

BACKGROUND

Hereditary angioedema (HAE) is a rare and often debilitating condition associated with substantial morbidity and mortality in the absence of appropriate intervention. An underlying deficiency in functional C1-inhibitor (C1-INH) protein induces a vulnerability to unchecked activation of the complement, contact, and coagulation/fibrinolytic systems. The clinical consequence is a pattern of recurring attacks of non-pitting, non-pruritic edema, the urgency of which varies by the affected site. Laryngeal edema can escalate rapidly to asphyxiation, and severe cases of abdominal swelling can lead to hypovolemic shock.

OBJECTIVES

This report reviews the emergency diagnosis and treatment of hereditary angioedema and the impact of recently introduced treatments on treatment in the United States.

DISCUSSION

Until recently, emergency physicians in the United States were hindered by the lack of rapidly effective treatment options for HAE attacks. In this article, general clinical and laboratory diagnostic procedures are reviewed against the backdrop of two case studies: one patient presenting with a known history of HAE and one with previously undiagnosed HAE. In many countries outside the United States, plasma-derived C1-INH concentrate has for decades been the first-line treatment for acute attacks. The end of 2009 ushered in a new era in the pharmacologic management of HAE attacks in the United States with the approval of two new treatment options for acute treatment: a plasma-derived C1-INH concentrate and a kallikrein inhibitor.

CONCLUSION

With access to targeted and effective treatments, emergency physicians are now better equipped for successful and rapid intervention in urgent HAE cases.