ASCIA Guidelines - Acute management of anaphylaxis

These 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. The appendix includes additional information for health professionals working in emergency departments, ambulance services, and rural or regional areas, who provide emergency care.

pdfASCIA HP Guidelines Acute Management Anaphylaxis 2020267.98 KB

Anaphylaxis definitions

Signs and symptoms of allergic reactions 

Mild or moderate reactions (may not always occur before anaphylaxis):

Anaphylaxis – Indicated by any one of the following signs:

Immediate actions for anaphylaxis

  1. Remove allergen (if still present).
  2. Call for assistance.
  3. Lay patient flat. Do not allow them to stand or walk.
    Do not hold infants upright.
    If breathing is difficult, allow them to sit.
    Lay down, sit, do not stand
  4. Adrenaline (epinephrine) is the first line treatment for anaphylaxis. Give intramuscular injection (IMI) adrenaline into outer mid-thigh without delay using an adrenaline autoinjector if available OR adrenaline ampoule/syringe.
  5. Give oxygen (if available).
  6. Call ambulance to transport patient if not already in a hospital setting.
  7. If required at any time, commence CPR (cardiopulmonary resuscitation).

ALWAYS give adrenaline FIRST, then asthma reliever if someone with known asthma and allergy to food, insects or medication has SUDDEN BREATHING DIFFICULTY (including wheeze, persistent cough or hoarse voice) even if there are no skin symptoms. 

Anaphylaxis triggers and reaction times

The most common triggers of anaphylaxis are foods, insect stings and drugs (medications). Less common triggers include latex and ticks.

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.

Adrenaline administration and dosages

Adrenaline 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 follows: 

Adrenaline (epinephrine) dosages chart

Age (years)

Weight (kg)

Vol. adrenaline 1:1000

Adrenaline autoinjector

~<1

<7.5k

0.1 mL

Not available

~1-2

10

0.1 mL

7.5-20 kg (~<5yrs)

0.15mg device

(e.g. EpiPen Jr)

~2-3

15

0.15 mL

~4-6

20

0.2 mL

~7-10

30

0.3 mL

>20kg (~>5yrs)

0.3mg device

(e.g. EpiPen)

~10-12

40

0.4 mL

~>12 and adults

>50

0.5 mL

Note:

Anaphylaxis treatment for infants

Whilst 10-20kg was the previous weight guide for a 0.15mg adrenaline autoinjector device, a 0.15mg device may now also be prescribed for an infant weighting 7.5-10kg by health professionals who have made a considered assessment. Use of a 0.15mg device for treatment of infants weighing 7.5kg 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.

Management of anaphylaxis in pregnancy 

Management 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 (1:1000 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 for patients who are pregnant to reduce the risk of compression of the inferior vena cava by the pregnant uterus and thus impairing venous return to the heart. Refer to ASCIA Guidelines for further information: www.allergy.org.au/hp/papers/acute-management-of-anaphylaxis-in-pregnancy

Positioning of patient

Supportive management - when skills and equipment are available

See Appendix for additional information.

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/critical care 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.

See Appendix for additional information.

Additional measures to consider if IV adrenaline infusion is ineffective

For upper airway obstruction

  • Nebulised adrenaline (5mL e.g. 5 ampoules of 1:1000).
  • Consider need for advanced airway management if skills and equipment are available.

For persistent hypotension/ shock

  • Give normal saline (maximum of 50mL/kg in first 30 minutes).
  • Glucagon
  • In adults, selective vasoconstrictors only after advice from an emergency medicine/critical care specialist.

See Appendix for dosage and additional information.

For persistent wheeze

Bronchodilators: Salbutamol 8-12 puffs of 100µg (spacer) or 5mg (nebuliser).

Note: Bronchodilators must not be used as first line medication for anaphylaxis as they do not prevent or relieve upper airway obstruction, hypotension or shock.

Corticosteroids: Oral prednisolone 1 mg/kg (maximum of 50 mg) or intravenous hydrocortisone 5 mg/kg (maximum of 200 mg).

Note: Steroids must not be used as a first line medication in place of adrenaline.

 Antihistamines and corticosteroids

Antihistamines:

Corticosteroids:

Observe patient for at least 4 hours after last dose of adrenaline

Relapse, protracted and/or biphasic reactions may occur. Overnight observation is strongly recommended if they:

True biphasic reactions are estimated to occur following 3-20% of anaphylactic reactions.

Follow up treatment including advice for hospital discharge

Adrenaline autoinjector

Clinical immunology/allergy specialist referral

Documentation of episodes

Patients should be advised to document episodes of anaphylaxis. This facilitates identification of avoidable causes (e.g. food, medication, herbal remedies, bites and stings, co-factors like exercise) in the 6-8 hours preceding the onset of symptoms.

The ASCIA allergic reactions event record and clinical history forms can be used to collect and document this information.

www.allergy.org.au/hp/anaphylaxis/anaphylaxis-event-record

www.allergy.org.au/hp/anaphylaxis/clinical-history-form-allergic-reactions

Preparation: Equipment required for acute management of anaphylaxis

The equipment on your emergency trolley should include:

Acknowledgements

The information in these guidelines is consistent with the Australian Prescriber Anaphylaxis Management wall chart www.nps.org.au/australian-prescriber/articles/anaphylaxis-emergency-management-for-health-professionals 

These guidelines are also based on the following international guidelines:

Management of anaphylaxis in the community, including schools and early childhood education/care, is facilitated by regular training and the use of an ASCIA Action Plan for Anaphylaxis. The instructions in this plan are consistent with the information in these guidelines.  

To access ASCIA Action Plans and other anaphylaxis resources, including e-training courses, go to www.allergy.org.au/anaphylaxis

Appendix: Advanced Acute Management of Anaphylaxis

This 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 infusion

IV 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 settings

If 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 1000 mL normal saline is as follows:

Note:

Additional measures: IV adrenaline infusion for emergency departments/ tertiary hospitals only

This 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 ineffective

For 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:

© ASCIA 2020

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