Adrenaline in the Acute Treatment of Anaphylaxis

[Prehospital care of anaphylactic reactions by the air rescue and ground-based emergency services Dresden : An analysis of treatment and outcome]

BACKGROUND

Anaphylaxis can lead to a life-threatening situation. Therefore, rapid diagnosis and emergency treatment is indicated. Immediate treatment with intramuscular adrenaline (or intravascularly with sufficient medical expertise) in anaphylaxis with cardiovascular and/or respiratory symptoms is recommended by various guidelines. Previous studies have shown that anaphylaxis is often not treated according to guidelines and that adrenaline in particular is rarely administered.

OBJECTIVE

The aim of the study was to investigate the data on emergency treatment and outcomes of patients with anaphylaxis by the air rescue and ground-based emergency services Dresden. Moreover, the results of the air- and ground-based services were compared. The focus was on administration of adrenaline and outcomes.

MATERIALS AND METHODS

Data from the ground-based emergency service Dresden (from 2012 to 2016) and the air rescue service Dresden (from 2008 to 2015) related to anaphylactic reactions were analyzed retrospectively. The severity of the anaphylaxis, the emergency medication administered, further monitoring, and outcomes were analyzed.

RESULTS

Data from 152 adults/29 children were analyzed for air rescue and 1131 adults/223 children for the ground-based emergency service. Adults with grade II-IV anaphylaxis received adrenaline in 19% (air rescue) and 7% (ground rescue) of cases. Children with grade II-IV anaphylaxis received adrenaline in 7% (air rescue) and 8% (ground rescue) of cases. Immediate drug therapy led to an improvement in general condition in 96-98% (air rescue) and 72-77% (ground-based emergency service) of cases. A significant correlation was found between the administration of adrenaline and the improvement in outcome in the ground-based emergency cohort.

CONCLUSION

Guideline-compliant first-line therapy with adrenaline was not performed in the majority of the cases analyzed in this study. The significant effect of adrenaline on outcome demonstrated in this study emphases the need to improve the emergency treatment of anaphylactic reactions.

Recombinant human diamine oxidase prevents hemodynamic effects of continuous histamine infusion in guinea pigs

OBJECTIVE

To test whether recombinant human diamine oxidase (rhDAO) with a mutated heparin-binding motif (mHBM), which shows an increased alpha-distribution half-life, prevents histamine-induced hemodynamic effects.

MATERIAL

Thirty-eight female guinea pigs were either pretreated with rhDOA_mHBM or buffer.

TREATMENT AND METHODS

Guinea pigs received a continuous infusion of histamine. Heart rate (HR), body core temperature and mean arterial pressure (MAP) were measured and blood was collected.

RESULTS

Continuous intravenous infusion of 8 µg/kg/min histamine increased mean peak plasma histamine levels from 5 (± 0.3 SEM) to 28 ng/mL (± 4.9 SEM) after 30 min but had no effect on oxygen saturation. Guinea pigs pretreated with 4 mg/kg rhDAO_mHBM showed lower mean HR (p = 0.008), histamine plasma concentrations (p = 0.002), and higher body core temperatures at the end of the histamine challenge (p = 0.02) compared to controls. Cessation of histamine infusion led to a rebound increase in MAP, but this hemodynamic instability was prevented by rhDAO_mHBM. Pretreatment with 4 mg/kg rhDAO_mHBM reduced urinary histamine (p = 0.004) and 1-Methylhistamine (p < 0.0001) concentrations compared to controls.

CONCLUSIONS

Prophylactic infusion of rhDAO_mHBM prevents hemodynamic effects in a guinea pig model of continuous histamine infusion. These findings might help in the translation from animals to humans and in the selection of the optimal dosing of rhDAO_mHBM during human histamine challenge studies.

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.

[Distributive shock]

In shock there is a significant mismatch between oxygen supply and consumption. In recent years the classification of forms of shock has been established based on pathophysiological and clinical aspects. The term distributive shock includes septic, anaphylactic and neurogenic shock. All these forms share a distinct vasoplegia with a relative volume deficiency. The adequate treatment of patients with distributive shock includes a rapid diagnosis and a consistent emergency treatment consisting of volume and catecholamine administration as well as additional specific emergency procedures when necessary.

Use of epinephrine in anaphylaxis: a retrospective cohort study at a Swiss university emergency department

AIMS OF THE STUDY

Anaphylaxis is a medical emergency and requires prompt treatment to prevent life-threatening conditions. Epinephrine, considered as the first-line drug, is often not administered. We aimed first to analyse the use of epinephrine in patients with anaphylaxis in the emergency department of a university hospital and secondly to identify factors that influence the use of epinephrine.

METHODS

We performed a retrospective analysis of all patients admitted with moderate or severe anaphylaxis to the emergency department between 1 January 2013 and 31 December 2018. Patient characteristics and treatment information were extracted from the electronic medical database of the emergency department.

RESULTS

A total of 531 (0.2%) patients with moderate or severe anaphylaxis out of 260,485 patients admitted to the emergency department were included. Epinephrine was administered in 252 patients (47.3%). In a multivariate logistic regression, cardiovascular (Odds Ratio [OR] = 2.94, CI 1.96-4.46, p <0.001) and respiratory symptoms (OR = 3.14, CI 1.95-5.14, p<0.001) were associated with increased likelihood of epinephrine administration, in contrast to integumentary symptoms (OR = 0.98, CI 0.54-1.81, p = 0.961) and gastrointestinal symptoms (OR = 0.62, CI 0.39-1.00, p = 0.053).

CONCLUSIONS

Less than half of the patients with moderate and severe anaphylaxis received epinephrine according to guidelines. In particular, gastrointestinal symptoms seem to be misrecognised as serious symptoms of anaphylaxis. Training of the emergency medical services and emergency department medical staff and further awareness are crucial to increase the administration rate of epinephrine in anaphylaxis.

A Conceptual Framework for Instructional Design of a High Acuity and Low Occurrence Event - Simulation Based Education Training of Residents, Medical Students, and Nurses in Anaphylaxis Utilizing Curated Educational Theories

The broad goal of this educational curriculum is utilization and optimization of Simulation-Based Education (SBE) in the training of residents, medical students, and nursing staff involved in the rapid and timely recognition of Anaphylaxis and its optimized treatment. A critical gap in Anaphylaxis Diagnosis, Management, and Treatment (ADAM) has been well established across medical disciplines. It is imperative to include all members of the healthcare team, as nurses and pharmacists play key roles in anaphylaxis recognition and care. Nurses and pharmacists are proficiently trained in the initial assessment of acute patient complaints, status, and in proper dosing/administration considerations. Anaphylaxis is a High Acuity and Low Occurrence (HALO) event. Delayed recognition and administration of epinephrine-autoinjector (EAI) is a patient safety concern. Suboptimal technique and expertise in this regard is common. Literature abounds with reports of physician trainee doubts and uncertainties in the recognition and optimized management of Anaphylaxis. Importantly, Anaphylaxis is frequently misdiagnosed in hospital emergency departments. SBE methodologies are ideal for instructing HALO experiences. The framework of the "Zone of Simulation Matrix" supports the utilization of a simulation experience in this instance. Learning will be effective, enhanced, and made durable by embedding numerous specifically curated educational theories. Given the paucity in training of residents and nursing staff in Anaphylaxis, such instruction is imperative. Of note, a special emphasis in this curricular framework is the debriefing experience. Considerations will be given to the psychological safety of the trainees and the importance of the heterogeneity of prior experiences. Precise diagnosis minimizes mortality. In the hospital setting, nurses are the first responders to critical HALO events, and there is a lack of awareness of ADAM by nursing students.

Idiopathic Anaphylaxis? Analysis of Data from the Anaphylaxis Registry for West Pomerania Province, Poland

The most common causes of anaphylaxis, according to various authors and depending on the age of the studied groups, are: Hymenoptera venom, food, and medications. Unfortunately, we are not always able to indicate the cause of anaphylaxis. There are data in the literature where as many as 41% of all cases are idiopathic anaphylaxis. Since the introduction of new diagnostic methods such as molecular diagnostics (MD) in our centre, the percentage of idiopathic anaphylaxis in the Anaphylaxis Register has significantly decreased. The purpose of this study was to identify possible causes of idiopathic anaphylaxis in patients with a history of moderate to severe anaphylactic reactions. After using MD, the causative agent was found in another 29 people. The proportion of people with idiopathic anaphylaxis in the Registry decreased from 9.2% to 3.5%. There were no significant differences in the incidence, although men appear to be slightly more common in primary idiopathic anaphylaxis. The mean age of primary idiopathic anaphylaxis was 40 years, but this was as high as 51 for anaphylaxis with alpha-gal allergy. Exercise may or may not be present as a cofactor despite its established role, e.g., in wheat-dependent exercise-induced anaphylaxis (WDEIA). In most of the analyzed cases, i.e., 70%, the reaction took place within an hour. The longest time interval from exposure to the development of symptoms is in the case of alpha-gal allergy; in this analysis, it was at least 5 h after ingestion of the so-called "red meat". Patients are not aware of the disease, or further attacks cannot be prevented. As many as 80% had idiopathic anaphylaxis prior to visiting the centre, and 80% developed anaphylaxis after visiting the centre, which emphasizes the need to not stop the medical team in their search for the causes. As many as 93% of cases required medical intervention, of which adrenaline was used only in 34.5%, antihistamines in 86%, systemic glucocorticosteroids (sCS) in 75%, and fluids in 62% of cases. A total of 83% of patients received an emergency kit for self-administration. Idiopathic anaphylaxis can be resolved as known-cause anaphylaxis after a thorough medical history and, if possible, without exposing the patient after using appropriate, modern in vitro diagnostic methods, including molecular diagnostics. The diagnosis of idiopathic anaphylaxis should extend the diagnosis to include alpha-gal syndrome, LTP syndrome and WDEIA.

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.

Case Report: "Killer Bee" Swarm Attacks in French Guiana: The Importance of Prompt Care

In French Guiana, a French overseas region partly located in the Amazon, "Africanized" bees, a hybrid species of Brazilian bees known as "killer bees," have been observed since 1975. Since then, several cases requiring long hospitalization times have been described, allowing for a better understanding of the physiopathological mechanisms of this particular envenomation. Here, we report on a series of 10 cases of patients simultaneously attacked by hundreds of killer bees and immediately treated by a prehospital medical team already on site. Between 75 and 650 stingers were removed per victim. The reference treatment for anaphylaxis using intramuscular injection of epinephrine, vascular filling, and oxygen therapy was administered to all patients without delay. A clinical description was provided, and biological tests were performed immediately after the envenomation. We therefore observe the existence of a two-phase, medically well-controlled systemic toxic reaction. Thus, all our patients left the hospital after 44 hours of monitoring with no complications or sequelae, despite levels of intoxication described as potentially fatal elsewhere in the literature.

Case Report: Acute Kidney Failure due to Massive Envenomation of a Two-Year-Old Child Caused by Killer Bee Stings

A hybrid species of Brazilian bee has proliferated on the South American continent since 1956. We describe a “killer bee” swarm attack on a 2-year-old girl in French Guiana. The patient weighed 10 kg, and approximately hundreds of bees’ stingers were removed, that is, 10 stings/kg. Our patient survived without long-term sequelae. The management of her condition required admission into intensive care for renal failure due to acute tubular necrosis and severe rhabdomyolysis. We emphasize the importance of early medical intervention, clinical surveillance, and biological monitoring at the hospital to prevent a toxic chain reaction that could prove fatal within 72 hours.

Adrenaline May Contribute to Prothrombotic Condition via Augmentation of Platelet Procoagulant Response, Enhancement of Fibrin Formation, and Attenuation of Fibrinolysis

Background: Adrenaline is believed to play a role in thrombosis and hemostasis. The complex effect of its clinically relevant concentrations on thrombus formation, coagulation and fibrinolysis in human blood has never been specifically studied. Methods: Confocal microscopy was used to study thrombus formation under flow, exposure of phosphatidylserine (PS) in adhered platelets, to evaluate clots density, and to measure kinetics of fibrin formation and external fibrinolysis under flow. Flow cytometry was utilized to assess PS exposure in non-adhered platelets. Kinetics of clot formation and internal fibrinolysis was evaluated by thromboelastometry. Platelet aggregation was measured by optical aggremometry. Kinetics of clot retraction was assessed by using digital camera. Results: We found that adrenaline (1-10 nM) is able to enhance platelet activation evoked by subthreshold collagen (150 ng/ml), resulting in augmentation of platelet aggregation, thrombus formation under arterial flow conditions, platelet PS exposure, and formation of platelet-fibrin clots. The development of platelet procoagulant response evoked by adrenaline + low collagen was associated with the formation of denser platelet-fibrin clots and the decrease in rate of fibrinolysis despite whether lysis was initiated inside (internal fibrinolysis) or outside the clot (external fibrinolysis). The above phenomena were abolished by the α₂-adrenergic receptor antagonist, rauwolscine. Adrenaline-collagen synergism, expressed as PS exposure, was significantly reduced by cyclooxygenase inhibitor (acetylsalicic acid), GPIIb/IIIa receptor blocker (tirofiban), and P2Y₁₂ receptor antagonist (PSB 0739). Conclusion: Clinically relevant concentrations of adrenaline may significantly augment responses of human platelets in the presence of subthreshold concentrations of collagen, which should be considered during therapies involving adrenaline infusion. Routinely used antiplatelet drugs may reduce the prothrombotic state evoked by adrenaline-collagen synergism.

Allergische Reaktionen auf COVID-19-Impfungen – Was HNO-Ärzte wissen sollten – Teil 1: Immunologische Grundlagen von Allergien auf Impfstoffe, Immunmechanismen von allergischen und pseudoallergischen Reaktionen; Teil 2: Charakteristika der mRNA-Impfstoffe BNT162b2- und mRNA-1273 zur Prophylaxe von COVID-19 und assoziierte Immunphänomene; Teil 3: Praktische Aspekte der Prophylaxe, Diagnostik und Therapie von Allergien auf COVID-19-Impfstoffe

Allergic reactions against mRNA COVID-19 vaccine are yet uncommon, but due to the high number of people who get this vaccination anaphylaxis will be seen. This is especially so in people who are sensitized to components of the vaccine. This article focuses on practical aspects of diagnostic possibilities, prevention, recognition and therapy of anaphylactic reactions. High-risk population, who should not get vaccinated; as well as people who need allergy diagnostics before vaccinations are discussed. In opinion of allergy experts patients with atopic allergies or venom allergies do not have a higher risk regarding anaphylaxic reaction due to COVID vaccination.