Anaphylaxis: acute treatment and management

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.

[Allergic emergencies]

Both anaphylactic reactions and angioedema in the head and neck area can be life-threatening and require emergency treatment. Therapy needed is primarily directed by the patient's symptoms. The first measures taken should consist of immediate disruption of the allergen contact, adequate positioning of the patient, the insertion of an intravenous catheter and an emergency call. In case of cardiovascular or respiratory involvement, intramuscular ± inhalative adrenalin is the treatment of choice. In case of cardiovascular involvement, volume substitution by intravenous catheter and oxygen administration are crucial and in lower airway obstruction, additionally short-acting beta mimetics should be inhaled. Intravenous H1-antihistamines and glucocorticoids are added. Allergic reaction confined to the skin and mucosal surfaces without respiratory involvement or to the gastrointestinal tract should also be treated with intravenous H1-antihistamines and glucocorticoids. Angioedema in the head and neck area can, however, also be associated with a life-threatening upper airway obstruction. Histamine-induced angioedema should be treated as anaphylaxis involving the upper respiratory tract. In hereditary angioedema, or in unclassified angioedema unresponsive to therapy, early airway maintenance and subcutaneous injection of bradykinin-receptor antagonist icatibant, intravenous injection of C1-inhibitor concentrate or fresh frozen plasma is recommended. The same approach should be taken for severe angiotensin converting enzyme inhibitor-induced angioedema with dyspnea. Intubation by skilled personal is indicated in inspiratory stridor and dyspnea at rest. In all cases of anaphylaxis or angioemdema, patients should be surveyed until a safe remission is achieved.

The influence of dexamethasone on postoperative swelling and neurosensory disturbances after orthognathic surgery: a randomized controlled clinical trial

BACKGROUND

Orthognathic surgery is associated with considerable swelling and neurosensory disturbances. Serious swelling can lead to great physical and psychological strain. A randomized, prospective, controlled clinical trial was realized in order to evaluate the effect of a preoperative intravenous dexamethasone injection of 40 mg on postoperative swelling and neurosensory disturbances after orthognathic surgery.

METHODS

Thirty-eight patients (27 male and 11 female) patients, all with the indication for an orthognathic surgery, were enrolled in this study (mean age: 27.63 years, range: 16-61 years) and randomly divided into two groups (study group/ control group). Both groups underwent either maxillary and/or mandibular osteotomies, resulting in three subgroups according to surgical technique (A: LeFort I osteotomy, B: bilateral sagittal split osteotomy (BSSO), C: bimaxillary osteotomy). The study group received a single preoperative intravenous injection of 40 mg dexamethasone. Facial edema was measured by 3D surface scans on the 1st, 2nd, 5th, 14th and 90th postoperative day. Furthermore, neurosensory disturbances on the 2nd, 5th, 14th and 90th postoperative day were investigated by thermal stimulation.

RESULTS

Facial edema after LeFort I osteotomy, BSSO and bimaxillary osteotomy showed a significant decrease in the study group compared to the control group (P = 0.048, P = 0.045, P < 0.001). The influence of dexamethasone on neurosensory disturbances was not significant for the inferior alveolar nerve (P = 0.746) or the infraorbital nerve (P = 0.465).

CONCLUSIONS

Patients undergoing orthognathic surgery should receive a preoperative injection of dexamethasone in order to control and reduce edema. However, there was no influence of dexamethasone on reduction of neurosensory disturbances.

TRIAL REGISTRATION

DRKS00009033 .

Hoffmann T, Bock B, Nordmann-Kleiner M, Trainotti S, Greve J. Angioedema

BACKGROUND

Acute angioedema of the upper airways can be life-threatening. An important distinction is drawn between mast-cell-mediated angioedema and bradykinin-mediated angioedema; the treatment of these two entities is fundamentally different.

METHODS

This review is based on pertinent articles retrieved by a selective search in PubMed and on guidelines concerning the treatment of angioedema. The authors draw on their own clinical experience in their assessment of the literature.

RESULTS

In the emergency clinical situation, the most important information comes from accompanying manifestations such as itching and urticaria and from the patient's drug history and family history. When angioedema affects the head and neck, securing the upper airways is the highest priority. Angioedema is most commonly caused by mast-cell mediators, such as histamine. This type of angioedema is sometimes accompanied by urticaria and can be effectively treated with antihistamines or glucocorticoids. In case of a severe allergic reaction or anaphylaxis, epinephrine is given intramuscularly in a dose that is adapted to the patient's weight (150 μg for body weight >10 kg, 300 μg for body weight >30 kg). Bradykinin-mediated angioedema may arise as either a hereditary or an acquired tendency. Acquired angioedema can be caused by angiotensin converting enzyme (ACE) inhibitors and by angiotensin II receptor blockers. Bradykinin-mediated angioedema should be treated specifically with C1-esterase inhibitor concentrates or bradykinin-2 receptor antagonists.

CONCLUSION

Angioedema of the upper airways requires a well-coordinated diagnostic and therapeutic approach. Steroids and antihistamines are very effective against mast-cell-mediated angioedema, but nearly useless against bradykinin-mediated angioedema. For angioedema induced by ACE inhibitors, no causally directed treatment has yet been approved.

Hypersensitivity to intravenous iron: classification, terminology, mechanisms and management

Intravenous (IV) iron therapy is widely used in iron deficiency anaemias when oral iron is not tolerated or ineffective. Administration of IV-iron is considered a safe procedure, but severe hypersensitivity reactions (HSRs) can occur at a very low frequency. Recently, new guidelines have been published by the European Medicines Agency with the intention of making IV-iron therapy safer; however, the current protocols are still non-specific, non-evidence-based empirical measures which neglect the fact that the majority of IV-iron reactions are not IgE-mediated anaphylactic reactions. The field would benefit from new specific and effective methods for the prevention and treatment of these HSRs, and the main goal of this review was to highlight a possible new approach based on the assumption that IV-iron reactions represent complement activation-related pseudo-allergy (CARPA), at least in part. The review compares the features of IV-iron reactions to those of immune and non-immune HSRs caused by a variety of other infused drugs and thus make indirect inferences on IV-iron reactions. The process of comparison highlights many unresolved issues in allergy research, such as the unsettled terminology, multiple redundant classifications and a lack of validated animal models and lege artis clinical studies. Facts and arguments are listed in support of the involvement of CARPA in IV-iron reactions, and the review addresses the mechanism of low reactogenic administration protocols (LRPs) based on slow infusion. It is suggested that consideration of CARPA and the use of LRPs might lead to useful new additions to the management of high-risk IV-iron patients.

Hypersensitivity reactions to intravenous iron: guidance for risk minimization and management

Intravenous iron is widely used for the treatment of iron deficiency anemia when oral iron is inappropriate, ineffective or poorly tolerated. Acute hypersensitivity reactions during iron infusions are very rare but can be life-threatening. This paper reviews their frequency, pathogenesis and risk factors, and provides recommendations about their management and prevention. Complement activation-related pseudo-allergy triggered by iron nanoparticles is probably a more frequent pathogenetic mechanism in acute reactions to current formulations of intravenous iron than is an immunological IgE-mediated response. Major risk factors for hypersensitivity reactions include a previous reaction to an iron infusion, a fast iron infusion rate, multiple drug allergies, severe atopy, and possibly systemic inflammatory diseases. Early pregnancy is a contraindication to iron infusions, while old age and serious co-morbidity may worsen the impact of acute reactions if they occur. Management of iron infusions requires meticulous observation, and, in the event of an adverse reaction, prompt recognition and severity-related interventions by well-trained medical and nursing staff.

Complement activation as a bioequivalence issue relevant to the development of generic liposomes and other nanoparticulate drugs

Liposomes are known to activate the complement (C) system, which can lead in vivo to a hypersensitivity syndrome called C activation-related pseudoallergy (CARPA). CARPA has been getting increasing attention as a safety risk of i.v. therapy with liposomes, whose testing is now recommended in bioequivalence evaluations of generic liposomal drug candidates. This review highlights the adverse consequences of C activation, the unique symptoms of CARPA triggered by essentially all i.v. administered liposomal drugs, and the various features of vesicles influencing this adverse immune effect. For the case of Doxil, we also address the mechanism of C activation and the opsonization vs. long circulation (stealth) paradox. In reviewing the methods of assessing C activation and CARPA, we delineate the most sensitive porcine model and an algorithm for stepwise evaluation of the CARPA risk of i.v. liposomes, which are proposed for standardization for preclinical toxicology evaluation of liposomal and other nanoparticulate drug candidates.

Triggers and treatment of anaphylaxis: an analysis of 4,000 cases from Germany, Austria and Switzerland

BACKGROUND

Anaphylaxis is the most severe manifestation of a mast cell-dependent immediate reaction and may be fatal. According to data from the Berlin region, its incidence is 2-3 cases per 100 000 persons per year.

METHOD

We evaluated data from the anaphylaxis registry of the German-speaking countries for 2006-2013 and data from the protocols of the ADAC air rescue service for 2010-2011 to study the triggers, clinical manifestations, and treatment of anaphylaxis.

RESULTS

The registry contained data on 4141 patients, and the ADAC air rescue protocols concerned 1123 patients. In the registry, the most common triggers for anaphylaxis were insect venom (n = 2074; 50.1%), foods (n = 1039; 25.1%), and drugs (n = 627; 15.1%). Within these groups, the most common triggers were wasp (n = 1460) and bee stings (n = 412), legumes (n = 241), animal proteins (n = 225), and analgesic drugs (n = 277). Food anaphylaxis was most frequently induced by peanuts, cow milk, and hen's egg in children and by wheat and shellfish in adults. An analysis of the medical emergency cases revealed that epinephrine was given for grade 3 or 4 anaphylaxis to 14.5% and 43.9% (respectively) of the patients in the anaphylaxis registry and to 19% and 78% of the patients in the air rescue protocols.

CONCLUSION

Wasp and bee venom, legumes, animal proteins, and analgesic drugs were the commonest triggers of anaphylaxis. Their relative frequency was age-dependent. Epinephrine was given too rarely, as it is recommended in the guidelines for all cases of grade 2 and above.

[Emergency treatment and management of anaphylaxis]

Anaphylaxis, the maximal manifestation of an immediate allergic reaction, is a life-threatening systemic reaction. The immediate therapy is chosen according to the clinical manifestations and new German guidelines are in preparation. Required measures include immediate removal of allergen, adequate positioning, assessment of severity and organ involvement and activation of emergency medical services. In anaphylaxis with primarily cardiovascular involvement, epinephrine is the treatment of choice and given together with volume substitution, oxygen, H(1)-antihistamines and corticosteroids. Obstruction of the airways is treated with intramuscular and inhaled epinephrine, or alternatively β(2)-sympathicomimetics, and oxygen. Abdominal or cutaneous involvement, such as generalized urticaria, usually can be treated with intravenous H(1)-antihistamines, glucocorticoids and surveillance. In patients with anaphylaxis, the elicitor of the reaction has to be diagnosed by allergy testing. Patients with sustained risk for anaphylaxis should receive a self-medication kit and should be educated about behavioral patterns needed for prophylaxis and therapy of anaphylactic reactions. Patient educational intervention increases knowledge about anaphylaxis, and practical competence and thus, is a basis of a successful management of anaphylaxis.

Common features of anaphylaxis in children

OBJECTIVE

We aimed to establish the characteristics of anaphylaxis in childhood.

METHODS

Forty-four patients who had experienced anaphylaxis in a period of 10 years (from 1999 to 2009), were included in the study. Parameters analysed were age, gender, concomitant allergic disease, trigger, setting, clinical symptoms, treatment, prognosis and prophylaxis.

RESULTS

The total numbers of anaphylaxis cases were 44 in a ten-year period. The ages of patients ranged from 3 to 14 years (11.50 ± 3.87 years) and the majority were male. 33 of the patients (75%) had a concomitant allergic disease. The trigger was determined in 93.2% of the cases, being most frequent: food (27.3%), and SIT (25%), followed by bee sting, medications and others. Respiratory (95.5%), dermatological (90.9%), cardiovascular (20.5%), neuropsychiatric (25%), and gastrointestinal (11.4%) symptoms were seen most frequently. For anaphylaxis triggered by food, the duration of anaphylactic episode was significantly longer (p<0.05). No biphasic reaction was observed during these attacks. Of our patients, only one developed respiratory failure and cardiac arrest due to SIT, and intensive care support was required.

DISCUSSION

As a trigger for anaphylaxis, the frequency of SIT is so high that it cannot be described by the study group including patients who were followed up in an outpatient allergy clinic.

Rapid desensitization induces internalization of antigen-specific IgE on mouse mast cells

BACKGROUND

Rapid desensitization transiently prevents severe allergic reactions, allowing administration of life-saving therapies in previously sensitized patients. However, the mechanisms underlying successful rapid desensitization are not fully understood.

OBJECTIVES

We sought to investigate whether the mast cell (MC) is an important target of rapid desensitization in mice sensitized to exhibit IgE-dependent passive systemic anaphylaxis in vivo and to investigate the antigen specificity and underlying mechanisms of rapid desensitization in our mouse model.

METHODS

C57BL/6 mice (in vivo) or primary isolated C57BL/6 mouse peritoneal mast cells (PMCs; in vitro) were passively sensitized with antigen-specific anti-2,4-dinitrophenyl IgE, anti-ovalbumin IgE, or both. MCs were exposed over a short period of time to increasing amounts of antigen (2,4-dinitrophenyl-human serum albumin or ovalbumin) in the presence of extracellular calcium in vitro or by means of intravenous administration to sensitized mice in vivo before challenging the mice with or exposing the PMCs to optimal amounts of specific or irrelevant antigen.

RESULTS

Rapidly exposing mice or PMCs to progressively increasing amounts of specific antigen inhibited the development of antigen-induced hypothermia in sensitized mice in vivo and inhibited antigen-induced PMC degranulation and prostaglandin D2 synthesis in vitro. Such MC hyporesponsiveness was induced antigen-specifically and was associated with a significant reduction in antigen-specific IgE levels on MC surfaces.

CONCLUSIONS

Rapidly exposing MCs to progressively increasing amounts of antigen can both enhance the internalization of antigen-specific IgE on the MC surface and also desensitize these cells in an antigen-specific manner in vivo and in vitro.

Why glucocorticosteroids should remain in the list of prohibited substances: a sports medicine viewpoint

In addition to their therapeutic applications, glucocorticosteroids have been widely used and abused in the belief that these substances may enhance athletic performance. Analysis of athlete urine samples by antidoping laboratories around the world support this conclusion. It is commonly accepted in medical practice to use local glucocorticosteroid injections in the treatment of non-infectious local musculotendinous inflammatory conditions conveying symptom relief and often a speedier return to sporting activity. This practice is not to be considered illicit, but sports physicians must accept that such an intervention is not in itself an immediate cure and that an athlete will still require a period of recuperation before continuing sporting activity. How long such a period of recuperation should last is a matter of conjecture and there is little concrete data to support what is, or what is not, an acceptable period of inactivity. In the interest of athlete safety, we would propose to maintain systemic glucocorticosteroids on the World Anti-Doping Agency&apos;s (WADA) list of prohibited substances, both in and out-of-competition as well as a mandatory period of 48 hours of rest from play after receiving a local glucocorticosteroid injection.

IgE and mast cells in allergic disease

Immunoglobulin E (IgE) antibodies and mast cells have been so convincingly linked to the pathophysiology of anaphylaxis and other acute allergic reactions that it can be difficult to think of them in other contexts. However, a large body of evidence now suggests that both IgE and mast cells are also key drivers of the long-term pathophysiological changes and tissue remodeling associated with chronic allergic inflammation in asthma and other settings. Such potential roles include IgE-dependent regulation of mast-cell functions, actions of IgE that are largely independent of mast cells and roles of mast cells that do not directly involve IgE. In this review, we discuss findings supporting the conclusion that IgE and mast cells can have both interdependent and independent roles in the complex immune responses that manifest clinically as asthma and other allergic disorders.

Allergy as an epithelial barrier disease

The objective of this review is to focus on putative modified epithelial functions related to allergy. The dysregulation of the epithelial barrier might result in the allergen uptake, which could be the primary defect in the pathogenesis of allergic reaction. We review the literature of the role of respiratory epithelium as an active barrier, how allergens are transported through it and how it senses the hostile environmental allergens and other dangerous stimuli.

World allergy organization guidelines for the assessment and management of anaphylaxis

The illustrated World Allergy Organization (WAO) Anaphylaxis Guidelines were created in response to absence of global guidelines for anaphylaxis. Uniquely, before they were developed, lack of worldwide availability of essentials for the diagnosis and treatment of anaphylaxis was documented. They incorporate contributions from more than 100 allergy/immunology specialists on 6 continents. Recommendations are based on the best evidence available, supported by references published to the end of December 2010. The Guidelines review patient risk factors for severe or fatal anaphylaxis, co-factors that amplify anaphylaxis, and anaphylaxis in vulnerable patients, including pregnant women, infants, the elderly, and those with cardiovascular disease. They focus on the supreme importance of making a prompt clinical diagnosis and on the basic initial treatment that is urgently needed and should be possible even in a low resource environment. This involves having a written emergency protocol and rehearsing it regularly; then, as soon as anaphylaxis is diagnosed, promptly and simultaneously calling for help, injecting epinephrine (adrenaline) intramuscularly, and placing the patient on the back or in a position of comfort with the lower extremities elevated. When indicated, additional critically important steps include administering supplemental oxygen and maintaining the airway, establishing intravenous access and giving fluid resuscitation, and initiating cardiopulmonary resuscitation with continuous chest compressions. Vital signs and cardiorespiratory status should be monitored frequently and regularly (preferably, continuously). The Guidelines briefly review management of anaphylaxis refractory to basic initial treatment. They also emphasize preparation of the patient for self-treatment of anaphylaxis recurrences in the community, confirmation of anaphylaxis triggers, and prevention of recurrences through trigger avoidance and immunomodulation. Novel strategies for dissemination and implementation are summarized. A global agenda for anaphylaxis research is proposed.