|NICE Clinical Guideline 134 on the assessment to confirm an anaphylactic episode and the decision to refer after emergency treatment for a suspected anaphylactic episode has been awarded the NHS Evidence Accreditation Mark.
This Mark identifies the most robustly produced guidance available. See evidence.nhs.uk/accreditation for further details.
Anaphylaxis is a severe, life-threatening, generalised or systemic hypersensitivity reaction. It is characterised by rapidly developing, life-threatening problems involving:1,2
- the airway (pharyngeal or laryngeal oedema) and/or
- breathing (bronchospasm with tachypnoea) and/or
- circulation (hypotension and/or tachycardia).
Most cases of anaphylaxis are associated with skin and mucosal changes.1,2
As anaphylaxis is a potentially fatal medical condition, there is often a huge emotional and psychological effect on patients who have experienced it, and their parents and families or carers.
There is no overall figure for the frequency of anaphylaxis in the UK because of inconsistencies in reporting and because it is often misdiagnosed. Available UK estimates suggest that approximately 1 in 1333 of the population of England has experienced anaphylaxis at some point in their lives, with approximately 20 deaths reported each year.1 Common food causes of anaphylactic reactions, especially in children, include nuts, eggs, shellfish, milk, fish, and some seeds such as sesame.1–3 Non-food causes include wasp or bee stings, natural latex (rubber), and penicillin. A significant proportion of anaphylactic reactions are classified as idiopathic, in which there are significant clinical effects, but no identifiable stimulus.1,2
In December 2011, NICE published a clinical guideline on assessment to confirm anaphylaxis, and the decision to refer patients, following emergency treatment for a suspected episode of anaphylaxis; the guideline also included advice on the issuing of adrenaline injectors.1,2 It is known that there is variation in both practice and service provision after a suspected anaphylactic episode.4 There are a number of possible reasons for this:
- Multiple diagnostic labels
- Variety of presentation routes
- Failure to recognise an at-risk patient or identify a potential cause
- Confusion over the provision of adrenaline injectors to patients
- Uncertainty of when or where to refer patients
- Variation in the availability of secondary care services in some areas.
The above factors can prevent an accurate diagnosis being made, which prevents appropriate treatment, management, and patient education being given. The NICE guideline is based on the most up-to-date evidence and represents best practice for the NHS on managing anaphylaxis after an emergency episode has been treated. This article highlights key recommendations and their implications from primary care.
Remit of the guideline
Most guidelines and algorithms concerning anaphylaxis focus on immediate and acute treatment.
Presentation can be varied—people may:
- present directly to an emergency department and be identified easily
- present following an episode to primary care, sometimes several days or even months after the episode
- be treated by ambulance services and have partially or completely recovered by the time they present to other healthcare professionals.
The new NICE recommendations focus on referral after emergency treatment for suspected anaphylaxis and assessment after the event to confirm an anaphylactic episode. They provide guidance on appropriate testing, management, and referral prior to discharge and include a care pathway (see Figure 1, below).1,2 Implementation of the guideline requires the involvement of primary care healthcare professionals in subsequent management of patients. Some patients may be discharged from emergency departments following recovery from anaphylaxis with no management plan for further investigation. In other cases, patients may present to primary care having experienced anaphylaxis without secondary care involvement.
Figure 1: Care pathway for anaphylaxis2
National Institute for Health and Care Excellence (NICE) (2011) CG134. Anaphylaxis: assessment to confirm an anaphylactic episode and the decision to refer after emergency treatment for a suspected anaphylactic episode. London: NICE. Available from www.nice.org.uk/guidance/CG134
Assessment and investigation
Careful history taking is essential in all patients to identify details of the anaphylactic episode and any possible trigger. Details of the acute clinical features of the suspected anaphylactic reaction, the time of onset, and the circumstances immediately before onset of symptoms should be recorded. During assessment of a patient following an anaphylactic reaction, it is important to take a good allergy focused history (see Box 1,below).1,2,5
|Box 1: Taking an allergy focused history5|
Mast cell tryptase
The NICE guideline includes recommendations on the use of timed blood samples to help confirm a suspected anaphylactic reaction. The Guideline Development Group (GDG) believed that the use of mast cell tryptase in testing for anaphylaxis was warranted.2
Mast cell tryptase:6
- is released with mast cell degranulation and is a marker for mast cell activation
- has a high specificity with clinical assessment for anaphylaxis
- helps differentiate between immunologically mediated conditions from other severe reactions.
In people aged 16 years or older, a blood sample for mast cell tryptase should be taken as soon as possible after emergency treatment is started, with a second sample being taken ideally within 1–2 hours (but no later than 4 hours) from the onset of symptoms. Healthcare professionals should also consider taking blood samples for mast cell tryptase from children aged younger than 16 years if the cause is thought to be venom-related, drug-related, or idiopathic. It is likely that the majority of these samples will be taken in the emergency department setting.1,2
Adults and young people aged 16 years or older who have had emergency treatment for suspected anaphylaxis should be observed for 6–12 hours from the onset of symptoms, depending on their response to emergency treatment.1,2 A shorter observation period can be considered in people with reactions that are controlled promptly and easily as long as they receive appropriate post-reaction care prior to discharge. Patients below the age of 16 years who have had emergency treatment for suspected anaphylaxis, should be admitted to hospital under the care of a paediatric medical team.1,2
Management after suspected anaphylaxis
After emergency treatment for suspected anaphylaxis, patients should be offered referral to a specialist allergy service (age-appropriate where possible) consisting of healthcare professionals with the skills and competencies necessary to investigate, diagnose, monitor, and provide ongoing management of suspected anaphylaxis, along with patient education.1,2
Following emergency treatment for suspected anaphylaxis, people (or their parent or carer) should be offered an appropriate adrenaline injector as an interim measure before their specialist appointment; training on the use of such injectors should be provided.1,2
One of the most important and relevant sections of the guideline for primary care stresses the need for onward referral and appropriate patient/carer education. All patients should be advised on:1,2
- the signs and symptoms of anaphylaxis and what to do if an episode occurs (e.g. use the adrenaline injector and call emergency services)
- avoiding the suspected trigger (if known)
- the possibility of biphasic reactions, which can occur up to 72 hours later with no re-exposure to the trigger
- how to use the adrenaline injector correctly and when to use it
- patient support groups.
Implications for primary care
The NICE guideline on anaphylaxis is likely to affect primary care in a number of ways. It stresses the importance of taking an allergy focused history, a skill that is rarely covered in standard GP vocational training (see Box 1). The recommendation on specialist allergy service referral for all patients may be problematic to implement. Although some areas of the UK are well represented with both adult and paediatric services, this is not the case for all parts of the country. Other constraints, such as limitations on consultant-to-consultant referrals, may affect the NICE recommendation that a referral be offered to the patient before they leave the hospital. Commissioning groups and existing services will need to implement separate referral pathways (unless already in place) for suspected anaphylaxis in adults (and young people) and children.
The guideline recommends that all patients are offered an appropriate adrenaline injector.1,2 There are currently three devices available in the UK,7 accompanied by simulator injectors for training and demonstration. The manufacturers offer online registration of the injectors to patients, which allows them to receive mobile phone or email alerts when the expiry date of the injector is approaching.8
One of the difficulties facing primary care is the question of how many injectors should be provided for each patient. The full NICE guideline states that: ‘The GDG was unable to state the exact number of adrenaline injectors to be prescribed per person because this would depend on various individual factors. Instead any decision should be taken by the clinician in question.’2 For example, an adult may find it relatively easy to have a single injector and to keep it with them at all times. A child may need several injectors for use at: home, school, child-minding service, or nursery, and at the home of any relatives with whom they spend time (e.g. grandparents). Additionally, other carers will need education and advice on appropriate and correct use of such devices; involvement of school nurses and other community services may be very helpful in achieving this. Providers of primary care should be able to offer patient education and training in the appropriate use of adrenaline injectors with the aid of demonstrations.
NICE has developed the following tools to support implementation of Clinical Guideline 134 on Anaphylaxis: assessment to confirm an anaphylactic episode and the decision to refer after emergency treatment for a suspected anaphylactic episode. The tools are now available to download from the NICE website: www.nice.org.uk/CG134
Baseline assessment tool
The baseline assessment tool is an Excel spreadsheet that can be used by organisations to identify if they are in line with practice recommended in NICE guidance and to help them plan activity that will help them meet the recommendations.
Clinical audit tools
Audit tools aim to assist organisations with the audit process, thereby helping to ensure that practice is in line with the NICE recommendations. They consist of audit criteria and data collection tool(s) and can be edited or adapted for local use.
The costing statement estimates the financial impact to the NHS of implementing this clinical guideline. This statement focuses on the financial impact of the recommendations that require most change in resources to implement in England.
Electronic audit tool
Electronic audit tools are developed to assist organisations with clinical audit and to ensure that practice is in line with the NICE recommendations.
The slides provide a framework for discussing the NICE guideline with a variety of audiences and can assist in local dissemination. This information does not supersede or replace the guidance itself.
The NICE guideline provides comprehensive recommendations on the assessment and referral of patients who have experienced an anaphylactic episode, based on the best current available evidence. It includes advice regarding onward referral and provision of adrenaline injectors to patients. This is the first national guideline for England, Wales, and Northern Ireland on the assessment after the event to confirm an anaphylactic episode and on the decision to refer after emergency treatment. It is likely to improve and help standardise the care and management of patients with this life-threatening and potentially recurrent condition.
For further information and to download the guideline, please visit the NICE website at: www.nice.org.uk/CG134 This link also includes the NICE Pathway on Anaphylaxis, the ‘Understanding NICE guidance’ summary for patients and carers, as well as a number of tools and resources designed to help organisations implement this guideline (see the Implementation tools box below).
View the Guidelines summary of the NICE guideline on Anaphylaxis: assessment to confirm an anaphylactic episode and the decision to refer after emergency treatment for a suspected anaphylactic episode at: egln.co.uk/link/34573
- National Institute for Health and Care Excellence. Anaphylaxis: assessment to confirm an anaphylactic episode and the decision to refer after emergency treatment for a suspected anaphylactic episode. Clinical Guideline 134. London: NICE, 2011. Available at: www.nice.org.uk/CG134
- National Institute for Health and Care Excellence. Anaphylaxis: assessment to confirm an anaphylactic episode and the decision to refer after emergency treatment for a suspected anaphylactic episode. Full guideline. London: NICE, 2011. Available at: www.nice.org.uk/CG134
- Guenova E, Genova S, Voykov B et al. Immunoglobulin E-mediated anaphylaxis to sesame. World Allergy Organization J 2008; 1 (8): 134.
- Arya V, Shrivastava A. Prescribing epinephrine injection (EPIPEN) for anaphylaxis in primary care—a survey. Arch Dis Child 2011; 96: A50–A51.
- National Institute for Health and Care Excellence. Food allergy in children and young people: diagnosis and assessment of food allergy in children and young people in primary care and community settings. Clinical Guideline 116. London: NICE, 2011. Available at: www.nice.org.uk/CG116
- Payne V, Kam P. Mast cell tryptase: a review of its physiology and clinical significance. Anaesthesia 2004; 59 (7): 695–703.
- British National Formulary. BNF 62. London: Royal Pharmaceutical Society, 2011.
- Anaphylaxis Campaign website. About—adrenaline auto-injectors (AAIs).
www.anaphylaxis.org.uk/information/patients/adrenaline-injectors.aspx (accessed 20 February 2012). G