Immediate injection of intramuscular adrenaline

If a clinician believes you are experiencing anaphylaxis, they will immediately give you an injection of adrenaline into the outer mid-thigh muscle.

When you recognise the signs of anaphylaxis, use your adrenaline injector without delay (if you have been prescribed one) and call for help immediately. Give the intramuscular injection of adrenaline into your outer mid-thigh. Using your adrenaline injector when you first have symptoms of anaphylaxis can help reverse the allergic reaction and prevent it from becoming life-threatening. If you are not sure, it is safer to use adrenaline than to wait for your symptoms to get worse. The adrenaline injection should work within minutes. If you do not start to feel better after 5 minutes, use a second adrenaline injector, if you have one.

Adrenaline lessens the effects of anaphylaxis by reducing throat swelling, opening the airways, and maintaining heart function and blood pressure.

Other medicines (including non-sedating antihistamines and asthma medicines) that relieve symptoms such as itchy or red skin and breathlessness should only be used after adrenaline, and will be prescribed and/or given if considered necessary.

Immediately on diagnosis of anaphylaxis, administer adrenaline via intramuscular (IM) injection into the mid-anterolateral thigh using a needle of appropriate length. Subcutaneous or inhaled routes for adrenaline are not recommended as they are less effective. Pregnant women experiencing anaphylaxis require the same dose of IM adrenaline as other patients. The recommended doses for IM adrenaline are indicated in Table 3.

Delayed administration of adrenaline is a risk factor for fatal anaphylaxis. If anaphylaxis is suspected in the presence of an allergy or anaphylaxis history, or following exposure to a potential allergen, it is safer to administer adrenaline early than to wait for progression, which may be hard to reverse. There are no absolute contraindications to adrenaline administration in anaphylaxis.

In most situations, IM adrenaline is preferred and is safer than the intravenous (IV) route. Adverse events have been reported in adult patients who received overdoses of IV adrenaline, but these are rare with IM adrenaline.

An IV adrenaline infusion should only be administered when clinically appropriate, and:

• By clinicians trained in the use of IV adrenaline
• In a critical care setting where there is appropriate haemodynamic monitoring available.

Repeated IM adrenaline injections can be given at five-minute intervals if the patient’s symptoms are not improving. Escalate care as per organisational protocols if the patient’s condition is not improving after two to three doses of adrenaline.

Do not administer corticosteroids or antihistamines first-line, as they are not effective in treating anaphylaxis. Corticosteroids have a delayed effect of 4–6 hours and are adjuncts in the management of anaphylaxis – they do not replace adrenaline. Antihistamines are only helpful for relieving associated urticaria (hives), angioedema and itch. Do not give promethazine or other sedating antihistamines, as the sedating effect can mask deterioration or a biphasic reaction. Injecting promethazine can worsen hypotension and cause muscle necrosis.

Consider the implications of the treatment provided in the healthcare facility and what this communicates regarding adrenaline use. Avoiding adrenaline use in the case of a severe allergic reaction, or preferentially using corticosteroids, bronchodilators or antihistamines, may inadvertently give a message to patients that they should delay using their adrenaline injector, thus increasing potential risk in a subsequent anaphylaxis.

Include a ‘when required’ (prn) order for IM adrenaline on an admitted patient’s medication chart if they have a known allergy and have been prescribed an adrenaline injector. This can expedite the administration of IM adrenaline if the patient experiences anaphylaxis while in care.

Ensure that there is a protocol for the management of anaphylaxis in place that supports prompt administration of IM adrenaline by all relevant clinicians, including nurses. The use of protocols can significantly improve IM adrenaline injection rates for anaphylaxis.

Ensure that all clinical areas have access to adrenaline for the treatment of anaphylaxis, and specify access arrangements in the protocol for the management of anaphylaxis. This will ensure that adrenaline is readily accessible to any clinician who may administer it, including prn orders for IM adrenaline.

Ensure that clinicians have training in the management of anaphylaxis and are practised using adrenaline injector or pen devices. Ensure adrenaline injector practise devices are available; the closest adrenaline may be the patient’s own injector device.

The use of ‘anaphylaxis management’ cards for an anaphylaxis event can serve as a cognitive aid when rehearsing the protocol for an event.

Consider providing access to adrenaline in readily identifiable anaphylaxis kits for emergency use, to reduce the time to administration of intramuscular adrenaline. The anaphylaxis kit may be placed on the resuscitation trolley and should be easily distinguished from the intravenous adrenaline for cardiac emergencies. An anaphylaxis kit also reduces the risk of an inadvertent IV overdose of adrenaline for anaphylaxis.

• Adrenaline injector practise devices are available and commonly sourced from the Allergy & Anaphylaxis Australia website: allergyfacts.org.au/shop/training-accessories
  
   
• EpiPen and Anapen training videos are available on Allergy & Anaphylaxis Australia website: allergyfacts.org.au/resources/videos-from-a-aa/how-to-give-epipen