Epinephrine: the drug of choice for anaphylaxis. A statement of the World Allergy Organization

Integrated phase I pharmacokinetics and pharmacodynamics of epinephrine administered through sublingual film, autoinjector, or manual injection

BACKGROUND

Epinephrine is the first-line treatment for anaphylaxis and is administered through intramuscular or subcutaneous injection. AQST-109, a sublingual film containing the prodrug epinephrine, was developed as an alternative delivery method for treating severe allergic reactions, including anaphylaxis.

OBJECTIVE

To compare the pharmacokinetics (PK) and pharmacodynamics (PD) of epinephrine after the administration of AQST-109 with those of epinephrine delivered by manual intramuscular injection and epinephrine autoinjectors.

METHODS

Data were integrated from 2 randomized, open-label, phase I crossover trials that evaluated the PK and PD of epinephrine in 54 healthy volunteers. They had no previous medical conditions and were delivered either AQST-109 12 mg or 0.3 mg EpiPen, 0.3 mg generic EpiPen, 0.3 mg Auvi-Q, and 0.3 mg manual intramuscular injection.

RESULTS

AQST-109 yielded comparable epinephrine PK and exposure to both manual intramuscular injections and epinephrine autoinjectors. The median time to maximum concentration (Tmax) for AQST-109 was 15 minutes, compared with EpiPen (10 minutes), generic EpiPen (15 minutes), Auvi-Q (30 minutes), and manual intramuscular injection (50 minutes). There was also an early, rapid, and consistent increase in systolic blood pressure, diastolic blood pressure, and heart rate after the administration of AQST-109.

CONCLUSION

AQST-109 delivered epinephrine with PK and PD results within the bracketed range of approved intramuscular products. AQST-109 has promise as an innovative, needle-free, nondevice, portable, and orally delivered alternative for first-line treatment of type I allergic reactions, including anaphylaxis.

Discrepancies in anaphylaxis protocols across emergency medical services in the United States: Opportunities for improvement

BACKGROUND

Across the United States, there are significant inconsistencies in the protocols used by emergency medical services (EMS) in the prehospital treatment of anaphylaxis. These discrepancies include variations in the definition of anaphylaxis and treatment recommendations.

OBJECTIVE

To identify gaps in the recognition of anaphylaxis and to provide areas for improvement in prehospital management through an analysis of state-wide anaphylaxis protocols.

METHODS

States with mandatory or model state-wide protocols were included (total of 30). Each allergic reaction and/or anaphylaxis protocol was reviewed-emphasis was placed on the definitions used to identify reactions and treatment algorithms.

RESULTS

Of the 30 states, only 50% (15) included gastrointestinal symptoms in the definition of anaphylaxis and only 40% (12) included neurologic manifestations. In addition, 47% (14) used a 2-organ system definition. For anaphylactic reactions, 100% (30) of the protocols recommended diphenhydramine and epinephrine. However, 90% (27) recommended albuterol, if respiratory symptoms were present, and 60% (18) recommended steroids. Epinephrine was the first-line recommendation for anaphylaxis in 97% (29) of the protocols. Overall, 25 states (83%) allowed epinephrine autoinjectors and 17 (57%) provided autoinjectors.

CONCLUSION

Many EMS anaphylaxis protocols are incomplete and/or outdated. Many protocols do not consider gastrointestinal or neurologic manifestations. In addition, many contain outdated recommendations, including the use of steroids and first-generation antihistamines. Despite the convenience of epinephrine autoinjectors, many protocols do not permit or provide them. Given the frequency of EMS activation for allergic reactions, our communities would benefit from standardized protocols using current evidence-based guidelines for the management of anaphylaxis.

Management of anaphylaxis after pre-hospital epinephrine use in children with food-induced anaphylaxis

BACKGROUND

Previous guidelines recommend prompt epinephrine administration, followed by observation in the emergency department (ED). The need for transfer in all cases of anaphylaxis has recently been challenged.

OBJECTIVE

To evaluate the need for additional ED treatment among children with anaphylaxis who received prehospital epinephrine.

METHODS

Between 2011 and 2023, data were collected on symptoms, triggers, comorbidities, and prehospital and in-hospital management from children (<18 years) with food-induced anaphylaxis who received at least 1 dose of prehospital epinephrine presenting at 7 pediatric EDs. Multivariable logistic regression assessed factors associated with the use of 2 or more prehospital epinephrine autoinjectors (EAIs), epinephrine use in the ED, and hospital admission.

RESULTS

Of the 1127 children (mean 8.1 ± 5.3 years; 60.6% male sex) with food-induced anaphylaxis who used at least 1 EAI prehospital, the most common trigger was peanuts (25.3%). There were 209 (18.5%) children who received additional epinephrine in the ED, most of whom (88.0%) received 1 dose. A total of 30 (2.7%) patients were admitted to hospital. Among all patients, severe reactions (cardiovascular instability/cyanosis/loss of consciousness) (adjusted odds ratio [aOR] 1.22; 95% CI 1.12-1.33) and reactions to tree nuts (aOR 1.09; 95% CI 1.03-1.16) were associated with increased odds of in-hospital epinephrine use. Prehospital inhaled β-agonists (aOR 1.08; 95% CI 1.01-1.16) use and severe reactions (aOR 1.13; 95% CI 1.05-1.22) were associated with the use of 2 or more EAI prehospital.

CONCLUSION

A minority of anaphylaxis cases that used prehospital EAIs required additional treatment, supporting that shared decision making about transfer to ED works for most patients.

Non-pyrolytic synthesis of laccase-like iron based single-atom nanozymes for highly efficient dual-mode colorimetric and fluorescence detection of epinephrine

Single-atom nanozymes have garnered significant attention due to their exceptional atom utilization and ability to establish well-defined structure-activity relationships. However, conventional pyrolytic synthesis methods pose challenges such as high energy consumption and random local environments at the active sites, while achieving non-pyrolytic synthesis of single-atom nanozymes remains a formidable technical hurdle. The present study focuses on the synthesis of laccase-like iron-based single-atom nanozymes (Fe-SAzymes) using a non-pyrolysis method facilitated by microwave irradiation. Under low iron loading conditions, Fe-SAzymes exhibited significantly enhanced laccase activity (12.1 U/mg), surpassing that of laccase by 24-fold. Moreover, Fe-SAzymes demonstrated efficient catalytic oxidation of epinephrine (EP), enabling its colorimetric detection. Owing to the remarkable laccase activity of Fe-SAzymes, the conventional nanozymes EP detection time was reduced from 60 min to 20 min, with an impressive low detection limit as low as 2.95 μM. In addition, an ultra-sensitive fluorescence method for EP detection was developed using the internal filter effect of EP oxidation products and CDs combined with carbon dots probe. The detection limit of fluorescence method was only 0.39 μM. Therefore, an visual, fast, and highly sensitive dual-mode EP detection strategy has great potential in the clinical diagnostic industry.

Remimazolam-Induced Anaphylaxis and Cardiovascular Collapse: A Narrative Systematic Review of Eleven Cases

Background and Objectives: Remimazolam, a novel benzodiazepine, is used for procedural sedation and general anesthesia due to its rapid onset and short duration of action. However, remimazolam-induced anaphylaxis (RIA) is a rare but severe complication. This study aimed to analyze RIA characteristics, focusing on cardiovascular collapse, and provide guidelines for safe remimazolam use. Methods: This study conducted a systematic review using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses 2020 guidelines. Research articles retrieved from PubMed on 26 May 2023, using the keywords 'remimazolam AND anaphylaxis' were evaluated based on the inclusion criteria of being written in English and aligning with the World Allergy Organization criteria for anaphylaxis, while studies not meeting these criteria were excluded. All published articles up to the search date were included without any date restrictions. The review analyzed factors such as age, sex, type of anesthesia, remimazolam dose (bolus/continuous), allergic symptoms and sign, epinephrine use, serum tryptase levels, and skin prick tests. Results: Among eleven cases, the mean age was 55.6 ± 19.6 years, with 81.8% male. Hypotension (81.8%) was the most common symptom, followed by bradycardia (54.5%) and desaturation (36.4%). Two patients experienced cardiac arrest. Serum tryptase levels confirmed anaphylaxis in ten cases. Epinephrine was the primary treatment, with intravenous doses ranging from 0.1 mg to 0.3 mg. Conclusions: Vigilance is crucial when administering remimazolam, adhering to recommended dosages, and promptly treating RIA with epinephrine. Further research is needed to understand the risk factors and refine the management strategies. Guidelines for safe remimazolam use are proposed.

A 13.2 mg epinephrine intranasal spray demonstrates comparable pharmacokinetics, pharmacodynamics, and safety to a 0.3 mg epinephrine autoinjector

Background

Recent acute anaphylaxis guideline updates have identified remaining unmet needs based on currently available therapeutic options as a critical focus.

Objective

We compared the pharmacokinetic, pharmacodynamic, safety, and tolerability profiles of intranasal epinephrine with intramuscular epinephrine administered by autoinjector and manual syringe.

Methods

An open-label, 3-period crossover study was conducted in 116 healthy adult volunteers to assess the bioavailability of a single 13.2 mg intranasal dose of epinephrine compared to a 0.3 mg intramuscular autoinjector and a 0.5 mg manual syringe. Patients with epinephrine concentrations of 50, 100, and 200 pg/mL at 10, 20, 30, and 60 minutes after dosing were also evaluated.

Results

Pharmacokinetic parameters for the 13.2 mg intranasal dose exceeded those of the 0.3 mg autoinjector with a rapid and higher maximum observed concentration (intranasal, 429.4 pg/mL; autoinjector, 328.6 pg/mL) and greater systemic exposure (AUC0-360; intranasal, 39,060 pg∙min/mL; autoinjector, 17,440 pg∙min/mL). Similar results were observed compared to the 0.5 mg manual syringe. Pharmacokinetic parameters for opposite-nostril and same-nostril dosing were higher than both intramuscular doses, except time to reach maximum observed concentration, which was bracketed between the 2 intramuscular doses (intranasal opposite and same nostril, 20 minutes; autoinjector, 14.9 minutes; manual syringe, 45 minutes). Similar effects on blood pressure and heart rate were observed for intranasal and autoinjector administration. Intranasal epinephrine was safe and well tolerated. No serious or unexpected adverse events were reported, confirming results from earlier clinical studies.

Conclusions

Bidose epinephrine spray addresses the unmet medical and patient needs for a needle-free, convenient, and effective dose-delivery system for self-administration of epinephrine that is as good as or better than the 0.3 mg autoinjector.

Australian and New Zealand Anaesthetic Allergy Group/Australian and New Zealand College of Anaesthetists perioperative anaphylaxis management guideline 2022

Perioperative anaphylaxis is a potentially life-threatening emergency that requires prompt recognition and institution of life-saving therapy. The Australian and New Zealand College of Anaesthetists and Australian and New Zealand Anaesthetic Allergy Group have partnered to develop the anaphylaxis management guideline along with crisis management cards that are recommended for use in suspected anaphylaxis in the perioperative setting. This is the third version of these guidelines with the second version having been published in 2016. This article contains the revised Australian and New Zealand Anaesthetic Allergy Group/Australian and New Zealand College of Anaesthetists perioperative anaphylaxis management guideline, with a brief review of the current evidence for the management of anaphylaxis in the perioperative environment.

The bradykinin-forming cascade in anaphylaxis and ACE-inhibitor induced angioedema/airway obstruction

Anaphylaxis is a potentially life-threatening multi-system allergic reaction to a biological trigger resulting in the release of potent inflammatory mediators from mast cells and basophils and causing symptoms in at least two organ systems that generally include skin, lungs, heart, or gastrointestinal tract in any combination. One exception is profound hypotension as an isolated symptom. There are two types of triggers of anaphylaxis: immunologic and non-Immunologic. Immunologic anaphylaxis is initiated when a foreign antigen directly binds to IgE expressed on mast cells or basophils and induces the release of histamine and other inflammatory substances resulting in vasodilation, vascular leakage, decreased peripheral vascular resistance, and heart muscle depression. If left untreated, death by shock (profound hypotension) or asphyxiation (airway obstruction) can occur. The non-immunologic pathway, on the other hand, can be initiated in many ways. A foreign substance can directly bind to receptors of mast cells and basophils leading to degranulation. There can be immune complex activation of the classical complement cascade with the release of anaphylatoxins C3a and C5a with subsequent recruitment of mast cells and basophils. Finally, hyperosmolar contrast agents can cause blood cell lysis, enzyme release, and complement activation, resulting in anaphylactoid (anaphylactic-like) symptoms. In this report we emphasize the recruitment of the bradykinin-forming cascade in mast cell dependent anaphylactic reactions as a potential mediator of severe hypotension, or airway compromise (asthma, laryngeal edema). We also consider airway obstruction due to inhibition of angiotensin converting enzyme with a diminished rate of endogenous bradykinin metabolism, leading not only to laryngeal edema, but massive tongue swelling with aspiration of secretions.

Transient Neurologic Deficits Following Intramuscular Epinephrine Administration for the Treatment of Anaphylaxis

Anaphylaxis is an acute, potentially life-threatening severe allergic reaction commonly caused by foods, insect stings, and medications. Intramuscular epinephrine is the cornerstone of treatment for anaphylaxis in order to reverse immediate symptoms and prevent progression to life-threatening hemodynamic or respiratory collapse. By nature of its mechanism of action, epinephrine may induce a number of neurovascular-related adverse effects; even at usual therapeutic doses. Rarely described adverse events include transient ischemic attacks, ischemic stroke, intracerebral hemorrhage, and myocardial infarction. These events may be observed more frequently in patients with cardiovascular risk factors including hypertension, hyperlipidemia, and diabetes mellitus. We present a case of transient neurologic deficits in a patient with underlying cardiovascular disease related to intramuscular epinephrine use for the treatment of anaphylaxis. This case serves to further highlight serious adverse neurologic events that may result from intramuscular epinephrine administration.

Refractory cardiac arrest caused by type I Kounis syndrome treated with adrenaline and nicorandil: A case report

RATIONALE

Kounis syndrome is a rare but life-threatening anaphylactic reaction that can lead to acute coronary syndrome and cardiac arrest, and requires prompt diagnosis. Adrenaline, which is used to treat anaphylaxis, may cause coronary vasoconstriction and worsen ischemia, whereas coronary vasodilators may dilate systemic vessels and exacerbate hypotension. Delayed diagnosis of Kounis syndrome and inadequate therapeutic intervention may thus lead to a poor outcome.

PATIENT CONCERNS

A 59-year-old man was treated for sepsis due to a liver abscess. Following administration of daptomycin, the patient developed severe anaphylactic shock leading to refractory cardiac arrest. Because conventional cardiopulmonary resuscitation was ineffective, extracorporeal cardiopulmonary resuscitation was considered as an alternative approach.

DIAGNOSES

On bedside monitoring during cardiopulmonary resuscitation, unexpected ST-segment elevation was found on lead II electrocardiogram. Accordingly, the patient was clinically diagnosed with Kounis syndrome.

INTERVENTIONS

Nicorandil (6 mg/h), a coronary vasodilator with minimal blood pressure effects, was administered along with high doses of vasopressors, including adrenaline 0.2 µg/kg/min.

OUTCOMES

After the initiation of nicorandil administration, the patient achieved return of spontaneous circulation and did not require extracorporeal cardiopulmonary resuscitation. Based on the elevated serum tryptase level, normal creatine kinase-MB range, and lack of stenosis on coronary angiography, the patient was definitively diagnosed with type I (coronary vasospasm) Kounis syndrome. He was subsequently transferred to the referring hospital without neurological sequelae.

LESSONS

If anaphylaxis leads to refractory shock and cardiac arrest, ischemic changes on the electrocardiogram should be investigated to identify underlying Kounis syndrome. In addition to adrenaline, coronary dilators are the definitive treatment. Nicorandil may be a useful treatment option because of its minimal effect on blood pressure.

Drug Hypersensitivity Reactions

Drug hypersensitivity reactions are a diverse group of reactions mediated by the immune system after exposure to a drug. The Gell and Coombs classification divides immunologic DHRs into 4 major pathophysiologic categories based on immunologic mechanism. Anaphylaxis is a Type I hypersensitivity reaction that requires immediate recognition and treatment. Severe cutaneous adverse reactions (SCARs) are a group of dermatologic diseases that result from a Type IV hypersensitivity process and include drug reaction with eosinophilia and systemic symptom (DRESS) syndrome, Stevens-Johnson Syndrome (SJS), toxic epidermal necrolysis (TEN), and acute generalized exanthematous pustulosis (AGEP). Other types of reactions are slow to develop and do not always require rapid treatment. Emergency physicians should have a good understanding of these various types of drug hypersensitivity reactions and how to approach the patient regarding evaluation and treatment.

Anaphylaxis: Emergency Department Treatment

Anaphylaxis is a potentially life-threatening, multisystem allergic reaction that can cause airway, breathing, or circulatory compromise. Intramuscular epinephrine is the immediate treatment of all patients. Intravenous epinephrine should be used in patients in shock, either as a bolus or infusion, along with fluid resuscitation. Airway obstruction must be recognized, and early intubation may be necessary. For shock that is refractory to epinephrine, additional vasopressors may be needed. Disposition depends on patient presentation and response to treatment. Mandatory observation periods are not necessary, because biphasic reactions are difficult to predict and may occur outside of typical observation periods.

Adrenaline-resistant anaphylactic shock caused by contrast medium in a patient after risperidone overdose: a case report

BACKGROUND

In Japan, the use of risperidone in combination with adrenaline is contraindicated, except in cases of anaphylaxis. Therefore, there is limited clinical evidence regarding the interaction of these two drugs. Here, we report the clinical course of a case of adrenaline-resistant anaphylactic shock induced by a contrast medium injection after a risperidone overdose.

CASE PRESENTATION

A man in his 30s was transported to our hospital after attempting suicide by taking 10 mg of risperidone and jumping from a height of 10 m. To determine the location and severity of his injuries, he was injected with an iodinated contrast medium, after which he developed generalized erythema and hypotension and was diagnosed with anaphylactic shock. A 0.5 mg dose of adrenaline was administered with no improvement, followed by another 0.5 mg dose that did not change his blood pressure. After infusion of a sodium bicarbonate solution (8.4%), administration of fresh frozen plasma, and additional administration of adrenaline (0.6-1.2 µg/min), his blood pressure improved, and he recovered from the anaphylactic shock.

CONCLUSIONS

This was a rare case of a risperidone overdose followed by adrenaline-resistant anaphylactic shock. The resistance is likely associated with the high blood concentration of risperidone. Our findings indicate that the potential for decreased adrenergic responsiveness should be considered in patients undergoing risperidone treatment in the event of anaphylactic shock.

Epinephrine treatment of food-induced and other cause anaphylaxis in United States and Canadian Emergency Departments: a systematic review and meta-analysis

INTRODUCTION

Studies from more than 10 years ago showed epinephrine treatment of food-induced anaphylaxis in the emergency department (ED) was unacceptably low. We investigated whether epinephrine treatment of food-induced and other cause anaphylaxis in United States and Canadian EDs has changed over time.

METHODS

Guided by a health sciences librarian, we performed a systematic search in Medline, Embase, and Web of Science on 11 January 2023. We included observational studies that reported epinephrine use to treat anaphylaxis in the ED. We stratified by anaphylaxis etiology (food-, venom-, medication-induced, or any cause). Associations between year and epinephrine use were tested using Spearman correlation and proportional meta-analysis.

RESULTS

Of 2458 records identified in our initial search, 40 met inclusion criteria. Of these, 14 examined food-induced, 4 venom-induced, 0 medication-induced, and 24 any cause anaphylaxis. For epinephrine treatment of food-induced anaphylaxis in the ED, among studies using similar definition of anaphylaxis, meta-analysis showed a pooled value of 20.7% (95% CI 17.8, 23.8) for studies performed >10 years ago and 45.1% (95% CI 38.4, 52.0) from those in the last 10 years. For anaphylaxis of any cause, there was no change over time, with a pooled value of 45.0% (95% CI 39.8, 50.3) over the last 10 years.

DISCUSSION

Epinephrine treatment of food-induced anaphylaxis in the ED has increased over time. There was no clear change for anaphylaxis of any cause. Over the last 10 years, approximately 45% of ED patients with anaphylaxis received epinephrine. A limitation of the evidence is heterogeneity in anaphylaxis definitions.

Intraoperative cardiac arrest due to allergic acute coronary syndrome (Kounis syndrome) triggered by cephalosporin

An acute coronary syndrome due to mast-cell activation in the presence of an allergen is known as Kounis Syndrome (KS). This relatively new entity of KS is being increasingly recognized among allergists, cardiologists, and emergency physicians; however, it is not well-known among anesthesiologists. We report here, a case of type 2 KS due to antibiotic administration causing sudden perioperative cardiac arrest.

Peanut-Induced Anaphylaxis in Children: A Literature Review

Peanut allergy has become more common among children and is considered one of the most common triggers for fatal anaphylaxis. Treatment of symptoms during a reaction is only one aspect of managing anaphylaxis; other elements include rigorous dietary avoidance and education about settings that could put the patient at a high risk of unintentional exposure. We aimed to review the prevalence, mechanism, diagnosis, treatment, and emergency action of peanut-induced anaphylaxis among children. We used a web-based literature search using the advanced features of databases such as PubMed, Scopus, Directory of Open Access Journals (DOAJ), Embase, Google Scholar, and Cochrane electronic databases. The most common food to cause fatal anaphylaxis and a common cause of food allergies is peanuts. Over the past two years, our knowledge improved more about peanut allergens, their prevalence, causes, diagnoses, and treatments. The research cited in this review demonstrates that the peanut allergens are most closely associated with disease differ across cultures, that early oral peanut exposure may reduce the occurrence of peanut allergy while early non-oral exposure may have the opposite effect, that complement activation by peanut constituents appears to promote peanut-induced anaphylaxis, and that oral immunotherapy, anti-IgE antibody, and a herbal formulation are all demonstrating promise as treatments. To conclude, peanut allergies have increased frequently during the past 10 years, especially in Westernized nations. Given that peanut allergy poses a danger for fatal anaphylaxis, response management is crucial. The current standard of care for those with nut allergies comprises complete food avoidance and the administration of injectable epinephrine to treat systemic symptoms.

Pathophysiological, Cellular, and Molecular Events of the Vascular System in Anaphylaxis

Anaphylaxis is a systemic hypersensitivity reaction that can be life threatening. Mechanistically, it results from the immune activation and release of a variety of mediators that give rise to the signs and symptoms of this pathological event. For years, most of the research in anaphylaxis has focused on the contribution of the immune component. However, approaches that shed light on the participation of other cellular and molecular agents are necessary. Among them, the vascular niche receives the various signals (e.g., histamine) that elicit the range of anaphylactic events. Cardiovascular manifestations such as increased vascular permeability, vasodilation, hypotension, vasoconstriction, and cardiac alterations are crucial in the pathophysiology of anaphylaxis and are highly involved to the development of the most severe cases. Specifically, the endothelium, vascular smooth muscle cells, and their molecular signaling outcomes play an essential role downstream of the immune reaction. Therefore, in this review, we synthesized the vascular changes observed during anaphylaxis as well as its cellular and molecular components. As the risk of anaphylaxis exists both in clinical procedures and in routine life, increasing our knowledge of the vascular physiology and their molecular mechanism will enable us to improve the clinical management and how to treat or prevent anaphylaxis.

Key Message

Anaphylaxis, the most severe allergic reaction, involves a variety of immune and non-immune molecular signals that give rise to its pathophysiological manifestations. Importantly, the vascular system is engaged in processes relevant to anaphylactic events such as increased vascular permeability, vasodilation, hypotension, vasoconstriction, and decreased cardiac output. The novelty of this review focuses on the fact that new studies will greatly improve the understanding of anaphylaxis when viewed from a vascular molecular angle and specifically from the endothelium. This knowledge will improve therapeutic options to treat or prevent anaphylaxis.

Fatal noncardiogenic pulmonary edema related to nonionic, iso-osmolar iodine contrast medium: one case report

Background

Noncardiogenic pulmonary edema (NCPE) is a rare and life-threatening allergy-like reaction to the intravascular injection of a nonionic radiographic agent. We first describe a very rare case of fatal NCPE after the intravenous injection of nonionic, iso-osmolar iodine contrast media.

Case presentation

A 55-year-old male patient was admitted to the hospital with esophageal cancer. After the intravenous administration of 100 mL iodixanol, the patient first exhibited digestive tract symptoms, including abdominal pain, diarrhea, and vomiting, with no dyspnea, rash, itching, or throat edema. He received anti-allergy treatment, but his symptoms did not improve; instead, he further developed pulmonary edema. Arterial blood gas analysis results were as follows: pH, 7.08; PO₂, 70 mm Hg; PCO₂, 40 mm Hg; and SaO₂, 52%. Then, the patient received emergent tracheal intubation and ventilation to assist breathing, and he was transferred to the intensive care unit (ICU) for further treatment. In the ICU, the patient developed shock and respiratory and circulatory failure; therefore, he received shock resuscitation, acidosis correction, muscle relaxants to lower the work of breathing, and cardiotonic therapy. The patient eventually died. During the ICU period, emergency bedside color ultrasound showed a diffuse B line in both lungs, and the size of the cardiac cavity was normal, but the ventricular rate was extremely fast. Chest radiography showed pulmonary edema with a normal cardiac silhouette, and the brain natriuretic peptide (BNP) level was in the normal range.

Conclusions

NCPE is a rare and critical allergy-like reaction to the use of a nonionic iso-osmolar radiocontrast contrast medium. Clinicians should pay very close attention to digestive tract manifestations during the medical observation of patients, as gastrointestinal manifestations may be the prodromal symptoms of NCPE caused by iso-osmolar contrast medium injection.

Potential prophylactic efficacy of mast cell stabilizers against COVID-19 vaccine-induced anaphylaxis

To fight against coronavirus disease 2019 (COVID-19), the vaccination is currently the most effective approach. However, in addition to common systemic side effects, the vaccines can cause serious allergic reactions or anaphylaxis. In anaphylaxis, the exposure to the allergen causes a sudden release of chemical mediators from mast cells, for which adrenaline is the drug of first choice. In our previous basic studies, in addition to adrenaline, anti-allergic drugs (olopatadine, loratadine, tranilast and ketotifen), antibiotics (clarithromycin), corticosteroids (hydrocortisone and dexamethasone) and certain food constituents (caffeine and catechin) inhibited the process of exocytosis and showed their effectiveness as highly potent mast cell stabilizers. In these studies, since mast cells were pre-incubated with these drugs or the food constituents before exocytosis was induced, the findings strongly indicated their prophylactic efficacy in stabilizing mast cells. Considering such pharmacological properties of these commonly prescribed medications or the food constituents, their prophylactic use may potentially be beneficial in preventing anaphylaxis caused by COVID-19 vaccination.

Drug Hypersensitivity Reactions

Drug hypersensitivity reactions are a diverse group of reactions mediated by the immune system after exposure to a drug. The Gell and Coombs classification divides immunologic DHRs into 4 major pathophysiologic categories based on immunologic mechanism. Anaphylaxis is a Type I hypersensitivity reaction that requires immediate recognition and treatment. Severe cutaneous adverse reactions (SCARs) are a group of dermatologic diseases that result from a Type IV hypersensitivity process and include drug reaction with eosinophilia and systemic symptom (DRESS) syndrome, Stevens-Johnson Syndrome (SJS), toxic epidermal necrolysis (TEN), and acute generalized exanthematous pustulosis (AGEP). Other types of reactions are slow to develop and do not always require rapid treatment. Emergency physicians should have a good understanding of these various types of drug hypersensitivity reactions and how to approach the patient regarding evaluation and treatment.

Anaphylaxis: Emergency Department Treatment

Anaphylaxis is a potentially life-threatening, multisystem allergic reaction that can cause airway, breathing, or circulatory compromise. Intramuscular epinephrine is the immediate treatment of all patients. Intravenous epinephrine should be used in patients in shock, either as a bolus or infusion, along with fluid resuscitation. Airway obstruction must be recognized, and early intubation may be necessary. For shock that is refractory to epinephrine, additional vasopressors may be needed. Disposition depends on patient presentation and response to treatment. Mandatory observation periods are not necessary, because biphasic reactions are difficult to predict and may occur outside of typical observation periods.

Autoinjector - A smart device for emergency cum personal therapy

Autoinjectors are self-injectable devices; they are important class of medical devices which can deliver drugs through subcutaneous or intramuscular route. They enclose prefilled syringes or cartridges which are driven by a spring system. The major benefits of this device are easy self-administration, improved patient compliance, reduced anxiety, and dosage accuracy. Immediate treatment during emergency conditions such as anaphylaxis, migraine, and status epilepticus or for chronic conditions like psoriasis, diabetes, multiple sclerosis, and rheumatoid arthritis, Reformulation of first-generation biologics, technical advancements, innovative designs, patient compliance, overwhelming interest for self-administration all these made entry of more and more autoinjectors into use. In this review, intensive efforts have been made for exploring the different types of currently available autoinjectors for the management of emergency and chronic diseases.

Anaphylactic shock in a patient with severe aortic stenosis treated with adrenaline and landiolol for circulatory management: A case report

RATIONALE

We present the first case of a patient with severe aortic stenosis who developed anaphylactic shock and was successfully treated with adrenaline and landiolol, a highly selective β1-receptor blocker, to prevent disruption of the myocardial oxygen supply-demand balance caused by tachycardia.

PATIENT CONCERNS

An 86-year-old woman was scheduled for simultaneous anterior-posterior fixation for a burst fracture of the 12th thoracic vertebra; 200 mg sugammadex, a neuromuscular blocking agent antagonist, was administered postoperatively, and she was extubated without complications. However, 6 min after extubation, her blood pressure decreased abruptly to 55/29 mm Hg, and her heart rate increased to 78 bpm. Then, we intervened with fluid loading, an increased dose of noradrenaline, and phenylephrine administration. However, her blood pressure did not increase.

DIAGNOSES

A general observation revealed urticaria on the lower leg; thus, we suspected anaphylactic shock due to sugammadex administration.

INTERVENTIONS

We carefully administered 2 doses of 0.05 mg adrenaline and simultaneously administered landiolol at 60 μg/kg/min to suppress adrenaline-induced tachycardia. Adrenaline administration resulted in a rapid increase in blood pressure to 103/66 mm Hg and a maximum heart rate of 100 bpm, suppressing excessive tachycardia.

OUTCOMES

The patient's general condition was stable after the intervention, and circulatory agonists could be discontinued the following day. She was discharged from the intensive care unit on the fourth postoperative day.

LESSONS

Landiolol may help control the heart rate of patients with aortic stenosis and anaphylactic shock. The combined use of landiolol and adrenaline may improve patient outcomes; however, their efficacy and risks must be evaluated by studying additional cases.

Emergency medicine updates: Anaphylaxis

INTRODUCTION

Anaphylaxis is a potentially deadly condition that requires emergent therapy. While frequently treated in the emergency department (ED), recent evidence updates may improve the diagnosis and management of this condition.

OBJECTIVE

This paper evaluates key evidence-based updates concerning the diagnosis and management of anaphylaxis for the emergency clinician.

DISCUSSION

The presentation of anaphylaxis can vary. Current diagnostic criteria can be helpful when evaluating patients for anaphylaxis, though multiple criteria exist. While the most common causes of anaphylaxis include medications, insect venom, and foods, recent literature has identified an IgE antibody response to mammalian galactose alpha-1,3-galactose, known as alpha-gal anaphylaxis. Epinephrine is the first-line therapy and is given in doses of 0.01 mg/kg (up to 0.5 mg in adults) intramuscularly (IM) in the anterolateral thigh. Intravenous (IV) epinephrine administration is recommended in patients refractory to IM epinephrine and IV fluids, or those with cardiovascular collapse. Antihistamines and glucocorticoids should not delay administration of epinephrine and do not demonstrate a significant reduction in risk of biphasic reactions. Biphasic reactions may affect 1-7% of patients with anaphylaxis. Risk factors for biphasic reaction include severe initial presentation and repeated doses of epinephrine. Disposition of patients with anaphylaxis requires consideration of several factors.

CONCLUSIONS

Emergency clinicians must be aware of current updates in the evaluation and management of this disease.

Fatal anaphylaxis to intravenous ondansetron: A case report

The safety and efficacy of ondansetron has led to its wider clinical use and this could increase unusual serious adverse events. Therefore, we emphasize the need for cautious use of ondansetron and beware and prepare for unusual adverse events.

The pharmacokinetics of epinephrine/adrenaline autoinjectors

Background

For a century, epinephrine has been the drug of choice for acute treatment of systemic allergic reactions/anaphylaxis. For 40 years, autoinjectors have been used for the treatment of anaphylaxis. Over the last 20 years, intramuscular epinephrine injected into the thigh has been recommended for optimal effect.

Objective

To review the literature on pharmacokinetics of epinephrine autoinjectors.

Results

Six studies assessing epinephrine autoinjector pharmacokinetics were identified. The studies, all on healthy volunteers, were completed by Simons, Edwards, Duvauchelle, Worm and Turner over the span of 2 decades. Simons et al. published two small studies that suggested that intramuscular injection was superior to subcutaneous injection. These findings were partially supported by Duvauchelle. Duvauchelle showed a proportional increase in C_max and AUC_0-20 when increasing the dose from 0.3 to 0.5 mg epinephrine intramuscularly. Turner confirmed these findings. Simons, Edwards and Duvauchelle documented the impact of epinephrine on heart rate and blood pressure. Turner confirmed a dose-dependent increase in heart rate, cardiac output and stroke volume. Based on limited data, confirmed intramuscular injections appeared to lead to faster C_max. Two discernable C_max’s were identified in most of the studies. We identified similarities and discrepancies in a number of variables in the aforementioned studies.

Conclusions

Intramuscular injection with higher doses of epinephrine appears to lead to a higher C_max. There is a dose dependent increase in plasma concentration and AUC_0-20. Most investigators found two C_max’s with T_max 5–10 min and 30–50 min, respectively. There is a need for conclusive trials to evaluate the differences between intramuscular and subcutaneous injections with the epinephrine delivery site confirmed with ultrasound.

Electrochemical Sensors Based on Conducting Polymers for the Aqueous Detection of Biologically Relevant Molecules

Electrochemical sensors appear as low-cost, rapid, easy to use, and in situ devices for determination of diverse analytes in a liquid solution. In that context, conducting polymers are much-explored sensor building materials because of their semiconductivity, structural versatility, multiple synthetic pathways, and stability in environmental conditions. In this state-of-the-art review, synthetic processes, morphological characterization, and nanostructure formation are analyzed for relevant literature about electrochemical sensors based on conducting polymers for the determination of molecules that (i) have a fundamental role in the human body function regulation, and (ii) are considered as water emergent pollutants. Special focus is put on the different types of micro- and nanostructures generated for the polymer itself or the combination with different materials in a composite, and how the rough morphology of the conducting polymers based electrochemical sensors affect their limit of detection. Polypyrroles, polyanilines, and polythiophenes appear as the most recurrent conducting polymers for the construction of electrochemical sensors. These conducting polymers are usually built starting from bifunctional precursor monomers resulting in linear and branched polymer structures; however, opportunities for sensitivity enhancement in electrochemical sensors have been recently reported by using conjugated microporous polymers synthesized from multifunctional monomers.

Got a Pen for Allergen Immunotherapy? Lessons from Near-Fatal Anaphylaxis with Pulmonary Edema

On our pediatric intensive care unit, we successfully treated a 10-year-old boy with severe pulmonary edema due to anaphylaxis after his last injection of a 3-year course of allergen immunotherapy (AIT). In view of the severity of the adverse event, we initiated a case analysis with all involved medical professionals. The evaluation revealed delayed administration of epinephrine due to dosing uncertainty and underestimation of severity. Consequently, all involved institutions established epinephrine auto-injectors (EAIs) in their emergency equipment. We suggest providing EAIs in every practice conducting AIT, as well as in pediatric emergency rooms and ambulances. We would like to remind readers of the risk of anaphylaxis, even on the last day of AIT.

Knowledge, Attitude, and Practice regarding Anaphylaxis among Pediatric Health Care Providers in a Teaching Hospital

Anaphylaxis is a severe, life threatening generalized or systemic hypersensitivity reaction which requires prompt, accurate diagnosis, and appropriate management. The objective of the study is to assess the extent of knowledge, management skills, and attitude on anaphylaxis among pediatric health care providers of a tertiary care teaching hospital. This was a cross-sectional study done in the department of pediatrics, which included faculty, residents, interns, and nurses. The knowledge, attitude, and practice were assessed using a standardized questionnaire comprised of 35 questions. The questionnaire was distributed and collected in person to all the participants. Informed consent was obtained from all participants and confidentiality was ensured at all stages. Collected data were analyzed using SPSS version 20. The mean of total knowledge score (TKS) was 7.36 ± 1.42. TKS of faculty was 8.36 ± 1.15, in residents 7.81 ± 1.25, in interns 7.46 ± 1.15, and in nurses 6.69 ± 1.57. Knowledge scores of faculty, residents, and interns were significantly higher than that of nurses while there was no significant difference between faculty, residents, and interns. The majority of participants have positive attitude toward anaphylaxis. Incorrect practice is followed by most of the participants. The extent of knowledge about anaphylaxis among pediatric health care providers is moderate but management skills remains suboptimal. Thus, proper training, through continued medical educations and programs to improve abilities to recognize and manage anaphylaxis are very crucial. Differential approach may be followed to different groups; nurses need extra training for optimal management of anaphylaxis.

[Update on perioperative hypersensitivity reactions: joint document of the Brazilian Society of Anesthesiology (SBA) and Brazilian Association of Allergy and Immunology (ASBAI) - Part I: post-crisis guidelines and treatment]

Experts from the Brazilian Association of Allergy and Immunology (ASBAI) and the Brazilian Society of Anesthesiology (SBA) interested in the issue of perioperative anaphylaxis, and aiming to strengthen the collaboration between the two societies, combined efforts to study the topic and to prepare a joint document to guide specialists in both areas. The purpose of the present series of two articles was to report the most recent evidence based on the collaborative assessment between both societies. This first article will consider the updated definitions, treatment and guidelines after a perioperative crisis. The following article will discuss the major etiologic agents, how to proceed with the investigation, and the appropriate tests.

Who Bites Me? A Tentative Discriminative Key to Diagnose Hematophagous Ectoparasites Biting Using Clinical Manifestations

Arthropod blood feeders are vectors of several human pathogenic agents, including viruses (e.g., yellow fever, chikungunya, dengue fever), parasites (e.g., malaria, leishmaniasis, lymphatic filariasis), or bacteria (e.g., plague). Besides their role as a vector of pathogens, their biting activities cause a nuisance to humans. Herein, we document clinical symptoms associated with the biting of ten clusters of hematophagous arthropods, including mosquitoes, biting midges and sandflies, lice, ticks, tsetse flies, blackflies, horse flies, fleas, triatomine and bed bugs. Within the framework of clinical history and entomo-epidemiological information, we propose a tentative discriminative key that can be helpful for practicing physicians in identifying hematophagous arthropods biting humans and delivering treatment for the associated clinical disorders.

Fill rates and access to self-injectable epinephrine prescribed in a pediatric emergency department

BACKGROUND

Despite its life-saving potential in anaphylaxis, self-injectable epinephrine (SIE) is frequently not administered by caregivers prior to arrival in the emergency department (ED). Prescriptions from the ED often go unfilled which may contribute to the failure to receive SIE when needed.

OBJECTIVE

To determine the prescription filling rate and accessibility of SIE devices among families discharged from the Pediatric ED with an SIE prescription.

METHODS

A phone survey was administered to parents of children <18 years of age prescribed SIE in the pediatric ED over 12 months. The survey inquired if they own an SIE device, the device's expiration date as confirmation, and details of their child's allergy. Variables were analyzed for association with owning SIE, having SIE accessible when prompted, and having unexpired SIE accessible.

RESULTS

170 children received prescriptions for SIE and 100 (59%) completed the survey. Eighty-four of 100 (84%) had filled the initial SIE prescription. Sixty-five of 100 (65%) had proof of having SIE, of which 29% (19/65) were expired. Only 46% (46/100) of all respondents had an accessible unexpired SIE. Patients with food allergies and those who'd visited an allergist after their ED visit had higher odds of having unexpired accessible devices.

CONCLUSION

A majority of patients prescribed SIE from the ED fill their prescription; however, less than half have unexpired SIE readily available despite high rates of recurrent anaphylactic emergencies. Focusing on post-discharge planning, particularly follow-up, may prevent children with allergies from being left dangerously unprepared.

Chronic infection with a tissue-invasive helminth attenuates sublethal anaphylaxis and reduces granularity and number of mast cells

BACKGROUND

Immunoglobulin E (IgE)-mediated anaphylaxis is a potentially fatal condition in which allergy effector cells rapidly discharge pre-formed inflammatory mediators. Treatments that address the immune component of allergic anaphylaxis are inadequate. Helminths have been previously shown to suppress effector cell function; however, their ability to treat pre-existing allergy remains unclear.

OBJECTIVE

To evaluate the ability of chronic helminth infection to protect against anaphylaxis in previously sensitized mice.

METHODS

A sublethal model of anaphylaxis was used, in which BALB/c mice were sensitized by three intraperitoneal (i.p.) injections of OVA/alum. Temperature drop was then monitored after systemic OVA challenge in uninfected mice and in mice infected chronically with Litomosoides sigmodontis, a tissue-invasive filarial nematode.

RESULTS

Litomosoides sigmodontis-infected mice exhibited significantly lower serum levels of mMCP-1 and were less hypothermic at 30-minute post-challenge compared to uninfected OVA-challenged controls. Characterization of anaphylaxis revealed that FcԑR1 and mast cells were required for hypothermia and elevated serum mMCP-1. OVA-IgE and OVA-IgG1 serum levels were not significantly altered by L sigmodontis infection, and experiments with IL-10^-/- mice demonstrated that IL-10 was not required for protection against anaphylaxis. However, peritoneal mast cell numbers were significantly lower in infected mice, and those that were present exhibited decreased granularity by flow cytometry and marked depletion of intracytoplasmic granules by light microscopy. Mast cells from infected mice had lower expression of the activation markers CD200R and CD63 and contained significantly lower basal stores of histamine.

CONCLUSIONS

Chronic L sigmodontis infection protects against anaphylaxis, likely due to reduction in mast cell numbers and depletion of pre-formed inflammatory mediators in remaining mast cells.

Anaphylaxis diagnosis and management in the Emergency Department of a tertiary hospital in the Philippines

Background

In the Emergency Department (ED), diagnosis and management of anaphylaxis are challenging with at least 50% of anaphylaxis episodes misdiagnosed when the diagnostic criteria of current guidelines are not used.

Objective

Objective of our study was to assess anaphylaxis diagnosis and management in patients presenting to the ED.

Methods

Retrospective chart review conducted on patients presenting to The Medical City Hospital ED, the Philippines from 2013–2015 was done. Cases were identified based on International Statistical Classification of Diseases, 10th revision coding for either anaphylaxis or other allergic related diagnosis. Cases fitting the definition of anaphylaxis as identified by the National Institute of Allergy and Infectious Disease and the Food Allergy and Anaphylaxis Network (NIAID/FAAN) were included. Data collected included demographics, signs and symptoms, triggers and management.

Results

A total of 105 cases were evaluated. Incidence of anaphylaxis for the 3-year study period was 0.03%. Of the 105 cases, 35 (33%) were diagnosed as “urticaria” or “hypersensitivity reaction” despite fulfilling the NIAID/FAAN anaphylaxis criteria. There was a significant difference in epinephrine administration between those given the diagnosis of anaphylaxis versus misdiagnosed cases (61 [87%] vs. 12 [34%], χ² = 30.77, p < 0.01); and a significant difference in time interval from arrival at the ED to epinephrine administration, with those diagnosed as anaphylaxis (48%) receiving epinephrine within 10 minutes, versus ≥ 60 minutes for most of the misdiagnosed group (χ² = 52.97, p < 0.01).

Conclusion

Despite current guidelines, anaphylaxis is still misdiagnosed in the ED. Having an ED diagnosis of anaphylaxis significantly increases the likelihood of epinephrine administration, and at a shorter time interval.

Childrens' and Parents' Willingness to Join a Smartphone-Based Emergency Response Community for Anaphylaxis: Survey

BACKGROUND

Medical emergencies such as anaphylaxis may require immediate use of emergency medication. Because of the low adherence of chronic patients (ie, carrying anti-anaphylactic medication) and the potentially long response time of emergency medical services (EMSs), alternative approaches to provide immediate first aid are required. A smartphone-based emergency response community (ERC) was established for patients with allergies to enable members to share their automatic adrenaline injector (AAI) with other patients who do not have their AAI at the onset of anaphylactic symptoms. The community is operated by a national EMS. In the first stage of the trial, children with food allergies and their parents were invited to join.

OBJECTIVE

This study aimed to identify the factors that influence the willingness to join an ERC for a group of patients at risk of anaphylaxis.

METHODS

The willingness to join an ERC was studied from different perspectives: the willingness of children with severe allergies to join an ERC, the willingness of their parents to join an ERC, the willingness of parents to enroll their children in an ERC, and the opinions of parents and children about the minimum age to join an ERC. Several types of independent variables were used: demographics, medical data, adherence, parenting style, and children's autonomy. A convenience sample of children and their parents who attended an annual meeting of a nonprofit organization for patients with food allergies was used.

RESULTS

A total of 96 questionnaires, 73 by parents and 23 by children, were collected. Response rates were approximately 95%. Adherence was high: 22 out of 23 children (96%) and 22 out of 52 parents (42%) had their AAI when asked. Willingness to join the community was high among parents (95%) and among children (78%). Willingness of parents to enroll their children was 49% (36/73). The minimum age to join an ERC was 12.27 years (SD 3.02) in the parents' opinion and 13.15 years (SD 3.44) in the children's opinion.

CONCLUSIONS

Parents' willingness to join an ERC was negatively correlated with parents' age, child's age, and parents' adherence. This can be explained by the free-rider effect: parents who carried an AAI for their young child, but had low adherence, wanted to join the ERC to get an additional layer of emergency response. Children's willingness to join the community was positively correlated with age and negatively correlated with the child's emotional autonomy. Parents' willingness to enroll their children in an ERC was positively correlated with child's age and negatively correlated with parents' adherence: again, this can be explained by the aforementioned free-rider effect. Parents' and children's opinions about the minimum age to join an ERC were negatively correlated with protective parenting style and positively correlated with monitoring parenting style.

A biotinylated peptide, BP21, alleviates hypotension in anaphylactic mice

Platelet-activating factor (PAF) is known as an important mediator of anaphylaxis and, therefore, may possibly serve as a direct target for anti-anaphylactic drugs. We recently reported that a synthetic N-terminally biotinylated peptide, BP21, alleviates hypothermia and vascular hyperpermeability during anaphylactic reactions in a mouse model of anaphylaxis via the direct binding of a Tyr-Lys-Asp-Gly sequence in the peptide to PAF. In this study, we investigated the effect of BP21 on in vivo anaphylactic hypotension. Results showed that BP21 significantly inhibited anaphylactic hypotension in a dose-dependent manner, with peak severity being reached within 20 minutes. Adrenaline, which is the recommended first line treatment for anaphylactic patients, did not inhibit anaphylactic hypothermia. The combined administration of BP21 with adrenaline inhibited both hypotension and hypothermia, even at both low doses, more effectively compared with solo administration of BP21 or adrenaline. These results suggested that BP21 could potentially be a novel anti-anaphylactic agent for targeting PAF in vivo.

Non-Auto-Injector Epinephrine Administration by Basic Life Support Providers: A Literature Review and Consensus Process

Anaphylaxis is a life-threatening condition with a known effective prehospital intervention: parenteral epinephrine. The National Association of EMS Physicians (NAEMSP) advocates for emergency medical services (EMS) providers to be allowed to carry and administer epinephrine. Some states constrain epinephrine administration by basic life support (BLS) providers to administration using epinephrine auto-injectors (EAIs), but the cost and supply of EAIs limits the ability of some EMS agencies to provide epinephrine for anaphylaxis. This literature review and consensus report describes the extant literature and the practical and policy issues related to non-EAI administration of epinephrine for anaphylaxis, and serves as a supplementary resource document for the revised NAEMSP position statement on the use of epinephrine in the out-of-hospital treatment of anaphylaxis, complementing (but not replacing) prior resource documents. The report concludes that there is some evidence that intramuscular injection of epinephrine drawn up from a vial or ampule by appropriately trained EMS providers-without limitation to specific certification levels-is safe, facilitates timely treatment of patients, and reduces costs.