ASCIA guidelines for the acute management of severe allergic reactions (anaphylaxis) are intended for medical practitioners, nurses and other health professionals who provide first responder emergency care. Appendix A includes additional information for health professionals working in emergency departments, ambulance services, and rural or regional areas, who provide emergency care. Show
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Appendix A: Advanced Acute Management of Anaphylaxis 1. Definition and clinical diagnostic criteria for anaphylaxisASCIA defines anaphylaxis as:
The ASCIA definition is consistent with the following criteria published in the World Allergy Organisation Anaphylaxis Guidance Position Paper 2020. Anaphylaxis is highly likely when any one of the following two criteria are fulfilled: Criteria 1. Acute onset of an illness (minutes to several hours) with simultaneous involvement of the skin, mucosal tissue, or both (e.g. generalized hives, pruritus or flushing, swollen lips-tongue-uvula), and at least one of the following:a) Respiratory compromise (e.g. dyspnea, wheeze-bronchospasm, stridor, reduced peak expiratory flow, hypoxemia).b) Reduced blood pressure or associated symptoms of end-organ dysfunction (e.g. hypotonia [collapse], syncope, incontinence).c) Severe gastrointestinal symptoms (e.g. severe crampy abdominal pain, repetitive vomiting), especially after exposure to non-food allergens. Criteria 2. Acute onset of hypotension or bronchospasm or laryngeal involvement after exposure to a known or highly probable allergen for that patient (minutes to several hours), even in the absence of typical skin involvement. 2. Signs and symptoms of allergic reactionsMild or moderate reactions (may not always occur before anaphylaxis):
Anaphylaxis – Indicated by any one of the following signs:
3. Immediate actions for anaphylaxis
Note: If adrenaline is accidently injected (e.g. into a thumb) phone your local poisons information centre. Continue to follow this action plan for the person with the allergic reaction. 4. Anaphylaxis triggers and reaction timesThe most common triggers of anaphylaxis are foods, insect stings and drugs (medications). Less common triggers include latex, tick bites, exercise (with or without food), cold temperatures, radiocontrast agents, immunisation (rare) and unidentified (idiopathic). Anaphylaxis usually occurs within one to two hours of ingestion in food allergy. The onset of a reaction may occur rapidly (within 30 minutes) or may be delayed several hours (for example, in mammalian meat allergy and food dependent exercise induced anaphylaxis, where symptoms usually occur during exercise). Anaphylaxis to stings and injected medications (including radiocontrast agents and vaccines) usually occurs within 5-30 minutes but may be delayed. Anaphylaxis to oral medications can also occur but is less common than to injected medications. 5. Adrenaline administration and dosagesAdrenaline is the first line treatment for anaphylaxis and acts to reduce airway mucosal oedema, induce bronchodilation, induce vasoconstriction and increase strength of cardiac contraction. Give INTRAMUSCULAR INJECTION (IMI) OF ADRENALINE (1:1000) into outer mid-thigh (0.01mg per kg up to 0.5mg per dose) without delay using an adrenaline autoinjector if available OR adrenaline ampoule and syringe, as shown in the table below:
*Adrenaline 1:1,000 ampoules contain 1mg adrenaline per 1mL **EpiPen® Jr and Anapen® Junior 150 are examples of 150 microgram (0.15 mg) devices. ***EpiPen® and Anapen® 300 are examples of 300 microgram (0.3 mg) devices. ****Anapen® 500 is an example of a 500 microgram (0.5 mg) device. The adrenaline injector devices listed above are available in Australia on the Pharmaceutical Benefits Scheme (PBS). Adrenaline injector devices are not yet reimbursed by Pharmac in New Zealand. Note:
6. Management of anaphylaxis in pregnancy and infantsManagement of anaphylaxis in pregnancyManagement of anaphylaxis in pregnant women is the same as for non-pregnant women. Adrenaline should be the first line treatment for anaphylaxis in pregnancy, and prompt administration of adrenaline (1:1,000 IM adrenaline 0.01mg per kg up to 0.5mg per dose) should not be withheld due to a fear of causing reduced placental perfusion. The left lateral position is recommended, as shown below. For more information go to www.allergy.org.au/hp/papers/acute-management-of-anaphylaxis-in-pregnancy Management of anaphylaxis in infantsWhilst 10-20kg was the previous weight guide for a 150 microgram adrenaline injector device, a 150 microgram device may now also be prescribed for an infant weighting 7.5-10 kg by health professionals who have made a considered assessment. Use of a 150 microgram device for treatment of infants weighing 7.5 kg or more poses less risk, particularly when used without medical training, than use of an adrenaline ampoule and syringe. Infants with anaphylaxis may retain pallor despite 2-3 doses of adrenaline, and this can resolve without further doses. More than 2-3 doses of adrenaline in infants may cause hypertension and tachycardia, which is often misinterpreted as an ongoing cardiovascular compromise or anaphylaxis. Blood pressure measurement can provide a guide to the effectiveness of treatment, to check if additional doses of adrenaline are required. The correct way to hold an infant is flat, as shown below. 7. Positioning of patients with anaphylaxis
8. Equipment required for acute management of anaphylaxisThe equipment on your emergency trolley should include:• Adrenaline 1:1,000 (consider adrenaline injector availability for initial administration by nursing staff) • 1mL syringes; 22-25 G needles (25mm length) are recommended for IM injections for all ages* (consistent with Australian Immunisation Handbook). *Exceptions are preterm/very small infants (23-25G needle length 16mm) and very large adults (22-25G and needle length up to 38mm). • Oxygen, airway equipment, including rebreather oxygen masks, nebuliser masks and suction• Defibrillator• Manual blood pressure cuff• IV access equipment (including large bore cannulae)• At least 3 litres of normal saline• A hands-free phone in resuscitation room, to allow health care providers in remote locations to receive instructions by phone whilst keeping hands free for resuscitation. 9. Supportive management and additional measures - see Appendix A for additional informationSupportive management - when skills and equipment are available:
Additional measures - IV adrenaline infusion in clinical setting:If there is an inadequate response after 2-3 adrenaline doses, or deterioration of the patient, start IV adrenaline infusion, given by staff trained in its use or in liaison with an emergency specialist. IV adrenaline infusions should be used with a dedicated line, infusion pump and anti-reflux valves wherever possible. CAUTION: IV boluses of adrenaline are NOT recommended without specialised training as they may increase the risk of cardiac arrhythmia. Additional measures to consider if IV adrenaline infusion is ineffective
Antihistamines have no role in treating or preventing respiratory or cardiovascular symptoms of anaphylaxis. Do not use oral sedating antihistamines as side effects (drowsiness or lethargy) may mimic some signs of anaphylaxis. Injectable promethazine should not be used in anaphylaxis as it can worsen hypotension and cause muscle necrosis. 10. Actions after administration of adrenalineObservation of patient for at least 4 hours after last dose of adrenalineRelapse, protracted and/or biphasic reactions may occur and overnight observation is strongly recommended if they:
True biphasic reactions are estimated to occur following 3-20% of anaphylactic reactions. Adrenaline injector prescription and trainingIf there is a risk of re-exposure to allergens such as stings or foods, or if the cause of anaphylaxis is unknown (idiopathic) then prescribe and if possible dispense an adrenaline injector before discharge, pending specialist review. It is important to teach the patient how to use the adrenaline injector using a trainer device and provide them with an ASCIA Action Plan for Anaphylaxis which can be completed online and printed from the ASCIA website allergy.org.au/anaphylaxis Clinical immunology/allergy specialist referralIt is important that ALL patients who present with anaphylaxis are referrred to a clinical immunology/allergy specialist listed at www.allergy.org.au/patients/locate-a-specialist who will:.
ASCIA anaphylaxis resources Management of anaphylaxis in the community (including the home, schools and children’s education/care) is facilitated by regular training and the use of an ASCIA Action Plan for Anaphylaxis, which includes instructions that are consistent with these guidelines. To access ASCIA Action Plans and other anaphylaxis resources, including e-training courses, go to www.allergy.org.au/anaphylaxis Documentation of episodesPatients should be advised to document episodes of anaphylaxis, and the ASCIA allergic reactions event record can be used to collect this information www.allergy.org.au/hp/anaphylaxis#ap1 This facilitates identification of avoidable causes (such as food, medication, herbal remedies, bites and stings, co-factors like exercise) in the 6-8 hours preceding the onset of symptoms. Patient supportPatients should be referred to patient/consumer support organisations for information on daily management and support whilst they await clinical immunology/allergy specialist review. Allergy & Anaphylaxis Australia www.allergyfacts.org.au or Allergy New Zealand www.allergy.org.nz Appendix A: Advanced Acute Management of AnaphylaxisThis additional information is intended for health professionals working in emergency departments, ambulance services, and rural or regional areas, who provide emergency care. Supportive management (when skills and equipment available)
During severe anaphylaxis with hypotension, marked fluid extravasation into the tissues can occur: DO NOT FORGET FLUID RESUSCITATION. Assess circulation to reduce risk of overtreatment
Note: If a patient is nauseous, shaky, vomiting, or tachycardic but has a normal or elevated SBP, this may be adrenaline toxicity rather than worsening anaphylaxis. Additional measures - IV adrenaline infusionIV adrenaline infusions should only be given by, or in liaison with, an emergency medicine/critical care specialist. If your centre has a protocol for IV adrenaline infusion for critical care, this should be utilised and titrated to response with close cardio-respiratory monitoring. If there is not an established protocol for your centre, two protocols for IV adrenaline infusion are provided, one for pre-hospital settings and a second for emergency departments/tertiary hospital settings only. It is important to note that the two infusion protocols have different concentrations and different rates of IV fluid infusion, resulting in the same initial rate of adrenaline infusion. It is vital that IV adrenaline infusions should be used with the following equipment wherever possible:
Additional measures - IV adrenaline infusion for pre-hospital settingsIf there is inadequate response to IMI adrenaline or deterioration, start an intravenous adrenaline infusion. IV adrenaline infusions should only be given by, or in liaison with, an emergency medicine/critical care specialist. The protocol for 1,000 mL normal saline is as follows:
Note:
Additional measures: IV adrenaline infusion for emergency departments/ tertiary hospitals onlyThis infusion will facilitate a more rapid delivery through a peripheral line and should only be used in emergency departments and tertiary hospital settings. The protocol for 100 mL normal saline is as follows:
Additional measures to consider if IV adrenaline infusion is ineffectiveFor persistent hypotension/shock:
In children, metaraminol 10 micrograms/kg/dose can be used. Noradrenaline infusion may be used in the critical care setting, only with invasive blood pressure monitoring. Advanced airway management
If unable to maintain an airway and the patient's oxygen saturations are falling, further approaches to the airway (e.g. cricothyrotomy) should be considered in accordance with established difficult airway management protocols. Specific training is required to perform these procedures. Special situation: Overwhelming anaphylaxis (cardiac arrest) Key points:
Appendix B: AcknowledgementsA list of anaphylaxis references is available on the ASCIA website www.allergy.org.au/hp/papers#p1 The information in these guidelines is consistent with the following publications: These guidelines are also based on the following international guidelines: © ASCIA 2021 ASCIA is the peak professional body of clinical immunology/allergy specialists in Australia and New Zealand. ASCIA resources are based on published literature and expert review, however, they are not intended to replace medical advice. The content of ASCIA resources is not influenced by any commercial organisations. For more information go to www.allergy.org.au To donate to allergy and immunology research go to www.allergyimmunology.org.au |