Suspected Anaphylactic Reactions Associated with Anaesthesia

This is a consensus document produced by expert members of a Working Party established by the Association of Anaesthetists of Great Britain and Ireland (AAGBI). It updates and replaces previous guidance published in 2003. The AAGBI has published guidance on management of anaphylaxis during anaesthesia in 1990, 1995 and 2003. This 2008 update was necessary to disseminate new information. Death or permanent disability from anaphylaxis in anaesthesia may be avoidable if the reaction is recognised early and managed optimally. Recognition of anaphylaxis during anaesthesia is usually delayed because key features such as hypotension and bronchospasm more commonly have a different cause. Initial management of anaphylaxis should follow the ABC approach. Adrenaline (epinephrine) is the most effective drug in anaphylaxis and should be given as early as possible. If anaphylaxis is suspected during anaesthesia, it is the anaesthetist’s responsibility to ensure the patient is referred for investigation. Serum mast cell tryptase levels may help the retrospective diagnosis of anaphylaxis: appropriate blood samples should be sent for analysis. Specialist (allergist) knowledge is needed to interpret investigations for anaesthetic anaphylaxis, including sensitivity and specificity of each test used. Specialist (anaesthetist) knowledge is needed to recognise possible non-allergic causes for the ‘reaction’. Optimal investigation of suspected reactions is therefore more likely with the collaboration of both specialties. Details of specialist centres for the investigation of suspected anaphylaxis during anaesthesia may be found on the AAGBI website http://www.aagbi.org. Cases of anaphylaxis occurring during anaesthesia should be reported to the Medicines Control Agency and the AAGBI National Anaesthetic Anaphylaxis Database. Reports are more valuable if the diagnosis is recorded following specialist investigation of the reaction. This guidance recommends that all Departments of Anaesthesia should identify a Consultant Anaesthetist who is Clinical Lead for anaesthetic anaphylaxis. The AAGBI published its first guidelines on suspected anaphylactic reactions in 1990. Subsequent revisions were published in 1995 and 2003. The current guidelines incorporate advice from a large number of clinical immunologists, allergists and anaesthetists throughout the UK. In common with the 1995 and the 2003 editions, this report is published jointly with the British Society for Allergy and Clinical Immunology (BSACI). This document is intended to be concordant with, and complementary to, the 2007 Scandinavian Clinical Practice Guidelines, the 2008 Resuscitation Council UK guidelines and the BSACI guidelines: Investigation of suspected anaphylaxis during anaesthesia. These guidelines apply only to suspected anaphylactic reactions associated with anaesthesia and it is presupposed that the patient is in the care of a trained anaesthetist. To clarify the definitions used in allergy and anaphylaxis. To review the epidemiology of anaesthesia-related anaphylaxis. To provide advice on the recognition of anaesthetic anaphylaxis. To make recommendations on the immediate management and initial investigation of suspected anaesthetic anaphylaxis. To make recommendations concerning the further investigation of suspected anaesthetic anaphylaxis. To assist anaesthetists in obtaining access to a specialist centre for comprehensive investigation of suspected anaesthetic anaphylaxis. To assist anaesthetists to provide appropriate information to the specialist centre. To make recommendations about the reporting and collection of data on anaesthetic anaphylaxis in Great Britain and Ireland. The term ‘anaphylaxis’ has been used for all types of acute life-threatening illness triggered by abnormal sensitivity (hypersensitivity) to a trigger agent, and for apparently spontaneous attacks with similar features (idiopathic anaphylaxis). This has made it difficult to define. The EAACI Nomenclature Committee proposed the following broad definition [1]: Anaphylaxis is a severe, life-threatening, generalized or systemic hypersensitivity reaction. Minor, localised or non-systemic reactions are outside the definition of anaphylaxis. Anaphylaxis may be divided into ‘allergic anaphylaxis’ and ‘non-allergic anaphylaxis’. The clinical features of allergic anaphylaxis and non-allergic anaphylaxis may be identical. The EAACI committee proposed the term ‘allergic anaphylaxis’ should be used only when the reaction is mediated by an immunological mechanism (such as IgE, IgG, or complement activation by immune complexes). An anaphylactic reaction mediated by IgE antibodies, such as to amoxicillin, is referred to as ‘IgE-mediated allergic anaphylaxis’. The term ‘anaphylactoid’ reaction had been introduced for non-IgE-mediated anaphylactic reactions but the EAACI committee has recommended this term should no longer be used. This proposal has not been universally accepted. An authoritative recent American practice parameter [2] states: ‘Anaphylaxis is defined … as a condition caused by an IgE-mediated reaction [2]. Anaphylactoid reactions are defined as those reactions that produce the same clinical picture as anaphylaxis but are not IgE mediated.’ In these guidelines we will follow the European (EAACI) nomenclature. Anaphylaxis is not a homogeneous process: the pathways, mediators, time course and response to treatment depend on the trigger agent, its route and rate of administration, the nature of the patient’s hypersensitivity and the state of health of the patient, including incidental pathology such as respiratory or cardiovascular disease and the effects of concomitant medication such as β-blockers and ACE inhibitors. Although anaphylaxis commonly involves respiratory, cutaneous and circulatory changes, variations such as shock with gastrointestinal disturbance or shock alone are possible. Alternatively, reactions may be fatal without significant shock except as the terminal event following respiratory arrest [3]. Angioedema and urticaria may be features of anaphylaxis but commonly result from mechanisms other than anaphylaxis. Intravascular volume redistribution is an important component of anaphylactic shock. Cardiac output may be decreased as a result of reduced coronary artery perfusion pressure as well as impaired venous return. Local release of mediators may cause coronary artery spasm and there may be features of acute left or right ventricular failure. Myocardial ischaemia with ECG changes is expected within minutes of anaphylactic shock becoming severe. Asphyxia may be due to upper airway occlusion caused by angioedema, or bronchospasm with mucus plugging of the lower airways; the latter most commonly occurs in patients taking daily treatment for asthma. Both these processes may occur simultaneously in patients reacting to foods, latex, β-lactam antibiotics or aspirin. Anaphylaxis usually resolves in 2–8 h but secondary pathology arising from the reaction or its treatment may prolong this. Resolution is complete except when cerebral hypoxia at the peak of the reaction has caused significant brain damage, or when disordered clotting leads to bleeding. The involvement of the British Society for Allergy and Clinical Immunology and the Clinical Immunology and Allergy section of the British Society for Immunology is gratefully acknowledged. In addition, the working party wishes to acknowledge the assistance of the following: Sr Alex Farragher Specialist Immunology Nurse Mr Chris Hirst AAGBI Anaphylaxis website designer Dr David Noble Dr Martin Shields Most reports on anaesthesia-related anaphylaxis originate from France, Australia, New Zealand and the United Kingdom. Other case series have been described from Scandinavia and the USA. The true incidence and their associated morbidity and mortality remain poorly defined. Both the accuracy and completeness of reporting is not optimal. 10% of anaesthesia-related reactions reported to the UK Medicines Control Agency (MCA) were fatal. These data should be interpreted with caution because it is likely that many less-severe reactions are not reported [1]. Reactions that are accepted as side-effects of certain drugs, for instance, histaminergic reactions due to atracurium and mivacurium, may be under-reported. During a time period of over 6 years only 361 reactions were reported to the MCA. In a 2-year period 789 reactions were reported in France in a comparable population where there is a well-established culture of reporting anaesthesia-related reactions [2]. Based on studies in Australia and France, the incidence of anaphylaxis during anaesthesia has been at in and The true incidence of anaphylaxis during anaesthesia in the UK is not the and data to the it is that there are reactions in the UK each reactions are more common when are given In large an immune was in of patients for anaphylaxis the non-allergic anaphylaxis and mechanisms other than anaphylaxis. The for the diagnosis of anaesthetic anaphylaxis are and blood have sensitivity and specificity and their and and to cause anaphylaxis more commonly in to be a and anaphylaxis, because may by to of antibiotics for respiratory with a of or allergy to to be at of allergy but not anaphylaxis to or antibiotics Anaphylaxis associated with to be associated with with or taking may a more reaction. of these reactions may be to The of anaphylactic reactions to is reported to be at more in it is more common in than in are proposed to be the in such as and these with the for a to to and be at of anaphylaxis to during anaesthesia. In a recent Scandinavian of certain was found to be the only significant in In but not are without to were in of a population in but not in of of anaesthesia-related anaphylaxis are on the of to be due to and atracurium are associated with non-allergic anaphylaxis in release of mediators from mast allergic anaphylaxis. a is not associated with non-allergic anaphylaxis, of allergic anaphylaxis have been It is accepted that is the most likely to be associated with allergic anaphylaxis, has been in a similar number of in The of to in the is than the incidence of reactions In 10% of the population to an incidence that the incidence of anaphylaxis on of these during anaesthesia previous of drug is not for of previous is found in than of patients who are allergic to an may an to of the different is because a If anaphylaxis to an is the patient should with all the in current If a patient a test to an the patient should be to all if possible. 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Anaphylaxis has when was used as an for and as well as of venous and The of certain venous has been in such It is to to an Anaphylaxis to as or as an for occurs but is to patients may be during anaesthesia may be associated with anaphylaxis, including and Anaphylaxis to and may occur In a patient such as during anaesthesia, when a in blood in rate or with are anaphylaxis is the cause that treatment is given for diagnosis anaphylaxis is the response to this treatment has commonly delayed or recognition of the true cause. It is therefore that many and acute allergic reactions to anaesthetic are a cause other than allergic anaphylaxis more likely in of the patients referred to specialist centres for investigation of suspected anaphylaxis during anaesthesia. that of anaphylaxis will be previous of reaction to anaesthetic drugs, other drugs, or should to appropriate it is possible the trigger was the of to previous reaction should be during the such as or such as and has been proposed as the of sensitivity to and a of cutaneous sensitivity to or from should Anaphylaxis to and is in who have had of these antibiotics without the of anaphylaxis in such a patient are likely to be as those expected from anaesthesia in an Although anaesthesia-related anaphylaxis usually from drug administration, by other for or may be Clinical features or cutaneous or and If an event such as hypotension or bronchospasm occurs during anaesthesia it is appropriate to anaphylaxis there a more likely cause. is not is in 10% of patients with allergic anaphylaxis during anaesthesia. is the clinical in 10% of patients and is likely to be in patients anaesthesia with or urticaria is in the of patients but the of cutaneous not anaphylaxis. may be more common in patients with asthma. 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and or respiratory disease should be in with It may be possible to allergy by taking a from the If this is a should be are likely to be the previous was due to If previous are It be appropriate to all given during the previous anaesthetic the of with the of If the patient a drug the all should be if possible because is If previous are not It be appropriate to all if possible will to the of used in and anaesthesia are likely to be allergy to anaesthetic is It be appropriate to if allergy to is common than allergy to The previous reaction may have been the result of non-allergic it be appropriate to that are to release for is no that with or will the of anaphylaxis. is a from the of a found in with during anaesthesia may occur including the and An anaphylactic reaction to during anaesthesia may be or may be delayed for to an The clinical of anaphylaxis during anaesthesia to be than anaphylaxis due to of the population is to but only of the population The following are at with such as or 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This will the blood and causes a in the of tryptase This be into when the the and tryptase is no longer from the samples are in the terminal were to anaphylaxis. tryptase found at has lower than a during may be in or The Association of Anaesthetists of Great Britain and Ireland The British Society for Allergy and Clinical Immunology The British Society for Immunology Resuscitation Council UK The European of and Clinical Immunology The Medicines and Agency further blood investigations depend on the drug in and the of the samples for IgE may be at the time of the or during that If the are these should be when the patient is at the specialist centre in case the initial be due to possible of IgE during the reaction. The most commonly used test for IgE or drug a or and a The a it is used but the has in common IgE be in but the sensitivity is for IgE other are not in the UK. 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