CG04 VERSION 1.0 1/5 Guideline ID CG04 Version 1.0 Title Approved by Allergic Reactions Clinical Effectiveness Group Date Issued 01/01/2013 Review Date 31/12/2016 Directorate Authorised Staff Clinical Ambulance Care Assistant Emergency Care Assistant Student Paramedic Advanced Technician Paramedic (non-ecp) Nurse (non-ecp) ECP Doctor Clinical Publication Category Guidance (Green) - Deviation permissible; Apply clinical judgement 1. Scope 1.1 This guideline aims to provide advice on the assessment and management of patients who present with anaphylaxis, in order to improve the outcome for patients who suffer from this potentially life-threatening condition. 2. Background and Definitions 2.1 The UK incidence of anaphylactic reactions is increasing. The mortality associated with anaphylaxis is estimated to be <1%, which equates to approximately 20 deaths each year in the UK. Death occurs quickly after contact with the trigger or allergen, normally due to respiratory arrest from airway obstruction. Despite being potentially life-threatening, if treated promptly, most people will make a full recovery and experience no long term complications. However, many people do not receive optimal management of their acute anaphylactic reaction; misdiagnosis is common, and there is lack of understanding around when or where to refer patients. 2.2 People with other allergic conditions, such as asthma or atopic eczema, are most at risk of developing anaphylaxis. The risk of an individual suffering a recurrent anaphylactic reaction is estimated to be approximately 1:12 per year. 2.3 Patients who have experienced previous episodes of anaphylaxis may wear a Medic Alert bracelet or necklace and carry an adrenaline pen.
CG04 VERSION 1.0 2/5 2.4 Anaphylaxis can be defined as a severe, life-threatening, generalised or systemic hypersensitivity reaction. This is characterised by rapidly developing life-threatening airway and/or breathing and/or circulation problems, usually associated with skin and mucosal changes. 1 3. Guidance 3.1 Triggers 3.1.1 Anaphylaxis can be caused by a broad range of triggers including food, drugs and insect stings. Food is a common trigger in children, while drugs are a more common trigger in older people. Virtually any food or class of drug can be implicated, although the classes of foods and drugs responsible for the majority of reactions are well described. 3.1.2 Anaphylaxis can occur despite a long history of previously safe exposure to a potential trigger. 3.1.3 Common triggers of anaphylaxis include: Foods; nuts, pulses, sesame seeds, milk, eggs and fish/shellfish; Venom; insect stings and bites (e.g. wasp and bees); Drugs; antibiotics (e.g. penicillin), NSAIDS, ACE inhibitors, local anaesthetics and opiates; Other causes; latex, hair dye. 3.2. Signs and Symptoms 3.2.1 The time it takes for the symptoms of anaphylaxis to develop depends on how the trigger enters the body. The longer it takes for anaphylactic symptoms to develop, the less severe the overall reaction. When anaphylaxis is fatal, death usually occurs soon after contact with the trigger. Fatal food reactions cause respiratory arrest after 30-35 minutes, insect stings cause collapse from shock after 10-15 minutes and deaths caused by intravenous medication often occur within just five minutes. 3.2.2 Angioedema is a swelling in the dermis, subcutaneous and submucosal tissues. It most commonly occurs with urticaria, but may occur in isolation. Swelling can occur anywhere on the body, but most often involves the eye, lips, hands and feet. Less commonly, submucosal swelling affects the airway. Angioedema may be considered part of the continuum of anaphylaxis, but in isolation, without respiratory difficulty or circulatory collapse, is not anaphylaxis. 3.2.3 The mechanism for angioedema and anaphylaxis is the same; both histamine and bradykinin are involved. However, in anaphylaxis the reaction is more
CG04 VERSION 1.0 3/5 marked, resulting in an increase in vascular permeability and circulatory collapse. 2 3.2.4 Anaphylaxis is likely when all of the following 3 criteria are met (exposure to a known allergen for the patient also supports the diagnosis): Sudden onset and rapid progression of symptoms; Life-threatening airway and/or breathing and/or circulation problems; Skin and/or mucosal changes (flushing, urticaria, angioedema). 3.2.5 Symptoms of anaphylaxis include rapidly developing life-threatening problems: Airway - throat and tongue swelling causes: Difficulty in breathing and swallowing; Hoarse voice; Stridor (high-pitched inspiratory noise caused by upper airway obstruction). Breathing - bronchospasm causes: Tachypnoea (Shortness of breath); Wheeze; Fatigue; Confusion caused by hypoxia; Cyanosis (appears blue) - this is usually a late sign; SpO 2 <92%; Respiratory arrest. Circulation - hypotension and/or tachycardia pale and clammy Dizziness; Decreased conscious level; Myocardial ischaemia; Bradycardia (usually a late feature); Cardiac arrest. 3.2.6 The skin and/or mucosal changes that occur in anaphylaxis include erythema, urticaria (also called hives, nettle rash, weals or welts) and angioedema (swelling of eyelids, lips and tongue). Skin changes without life-threatening airway, breathing or circulation problems do not signify an anaphylactic reaction. 3.3 Assessment and Management 3.3.1 Quickly remove the patient from the trigger if possible e.g. environmental, infusion etc. Do not delay definitive treatment if removing the trigger is not feasible. 3.3.2 Assess CABCDE. If time critical features are present - correct A and B and transfer to the nearest appropriate Emergency Department, providing an ATMIST
CG04 VERSION 1.0 4/5 pre-alert and continuing patient management en-route. Time critical features include: Major CABCD deficits; Extreme breathing difficulty; Cyanosis; Hypoxia - SpO 2 <95% or not responding to oxygen therapy; Loss of consciousness. 3.3.3 Administer intramuscularly (IM) adrenaline (1:1,000) in accordance with JRCALC guidelines; adrenaline must never be administered intravenously (IV). In anaphylaxis, adrenaline is the first drug to be administered. 3.3.4 Repeat the IM adrenaline dose if there is no improvement in the patient s condition. Further doses can be given at 5 minute intervals according to the patient s response, as the benefit of using repeated doses far exceeds any risk. 3.3.5 For patients taking tricyclic anti-depressants (e.g. amitriptyline, imipramine) administer half doses of adrenaline. 3.3.6 Administer high flow oxygen. 3.3.7 Administer IM/IV hydrocortisone in accordance with JRCALC guidelines. Whilst the preferred route is IV, IM may be used when IV access cannot be obtained or where a paramedic is not present. To reduce the likelihood of the patient experiencing the side effect of a burning or itching sensation in the groin, when given IV, administer slowly over approximately 2 minutes. 3.3.8 If the patient is haemodynamically compromised, administer a rapid IV fluid challenge of 0.9% saline (20 ml/kg in a child or 500-1000 ml in an adult) and monitor the response, giving further doses as necessary. If intravenous access is delayed or impossible, the intra-osseous route should be considered. 3.3.9 Where bronchospasm is present, consider the administration of nebulised salbutamol in accordance with JRCALC guidelines. 3.3.10 Administer IM/IV chlorphenamine in accordance with JRCALC guidelines. Whilst the preferred route is IV, IM may be used when IV access cannot be obtained or where a paramedic is not present. 3.3.11 Continually monitor and re-assess ABCs, pulseoximetry, peak expiratory flow rate (PEFR), BP and ECG.
CG04 VERSION 1.0 5/5 3.3.12 Some patients relapse hours after an apparent recovery from anaphylaxis (biphasic response). Therefore all patients suffering anaphylaxis should be advised that NICE guidance recommends that they are transferred to hospital for further assessment. 1 3.4 Mild/Moderate Allergic Reactions 3.4.1 Consider a mild/moderate allergic reaction if the onset of the presentation has progressed over minutes to hours, and there are cutaneous findings (e.g. urticaria and/or angioedema) in the absence of life-threatening features. In this scenario, adrenaline is not appropriate. 3.4.2 Chlorphenamine is the treatment of choice; in moderate reactions consider IM administration. 3.4.3 In the case of a mild reaction not requiring IM chlorphenamine, consider the appropriateness of advising the patients to purchase their own over-the-counter anti-histamine. If this is not possible consider referral to an Emergency Care Practitioner for oral chlorphenamine supply. 4. Episode Closure 4.1 Patients who remain on-scene should be advised to see their GP or local NHS Walk In Centre for consideration of oral steroids (where not already prescribed), as a useful adjunct to chlorphenamine. The patient must be left with a copy of the PCR and supplied with a patient information leaflet. 5. Documentation 5.1 In line with Trust Policy, a Patient Clinical Record must be completed and annotated appropriately, with the supply of medicines recorded within the drugs section. Any deviation from this guideline must be recorded, with any potential or actual adverse event reported through the incident reporting system. 6. References 1. National Institute Clinical Excellence (2011) Anaphylaxis CG134. Available from: http://guidance.nice.org.uk/cg134/niceguidance/pdf/english [Accessed 8th November 2011]. 2. Clinical Knowledge Summaries (2012) angioedema and anaphylaxis. Available from: http://www.cks.nhs.uk [Accessed 4th November]. 3. Joint Royal Colleges Ambulance Liaison Committee (2006) Pre-Hospital Guidelines. JRCALC. 4. Resuscitation Council UK (2008) Emergency treatment of anaphylactic reactions, Guidelines for healthcare providers. Available from: http://www.resus.org.uk/ pages/reaction.pdf [Accessed 3th November 2011].