Anaphylaxis represents one of the most serious medical emergencies you may encounter. This severe allergic reaction can occur within minutes of exposure to an allergen and can be fatal without prompt emergency treatment. Understanding how to use adrenaline auto-injectors correctly can save lives and forms an essential component of workplace first aid training.
Anaphylaxis and Severe Allergic Reactions
Anaphylaxis is a severe, life-threatening allergic reaction that affects multiple body systems simultaneously. Unlike mild allergic reactions that might cause localised symptoms, anaphylaxis can cause breathing difficulties, cardiovascular collapse, and loss of consciousness. The Australasian Society of Clinical Immunology and Allergy (ASCIA) defines anaphylaxis as a serious allergic reaction that is rapid in onset and may cause death.
People at risk of anaphylaxis may have known allergies to foods, medications, insect stings, or other substances. However, anaphylaxis can also occur in individuals with no previous history of severe allergic reactions. Food allergies are among the most common triggers, particularly nuts, shellfish, eggs, and milk. Other triggers include medications, latex, and insect venom.
Adrenaline: The First-Line Treatment for Anaphylaxis
Adrenaline, also known as epinephrine, is the only medication that can effectively treat anaphylaxis and is delivered through an adrenaline auto-injector device. This naturally occurring hormone and neurotransmitter acts as both an alpha and beta-adrenergic receptor agonist, producing multiple physiological effects crucial for reversing anaphylaxis.
During anaphylaxis, adrenaline works through several mechanisms to counteract life-threatening symptoms. It stimulates alpha-1 adrenergic receptors, causing vasoconstriction that reverses the dangerous drop in blood pressure and reduces tissue swelling. Through beta-1 receptor stimulation, it increases heart rate and cardiac output, improving circulation to vital organs. Beta-2 receptor activation causes bronchodilation, relieving the airway constriction that makes breathing difficult during severe allergic reactions.
Adrenaline also stabilises mast cells and basophils, preventing further release of inflammatory mediators like histamine, leukotrienes, and cytokines that drive the allergic cascade. This dual action of treating existing symptoms whilst preventing progression makes adrenaline uniquely effective as anaphylaxis treatment.
When to Use Adrenaline Auto-Injectors
Recognising the signs of anaphylaxis is crucial for knowing when to use adrenaline devices. The ASCIA action plan for anaphylaxis provides clear guidelines for adrenaline use. Signs that indicate the need for immediate adrenaline administration include:
Mild to Moderate Allergic Reaction Signs:
Swelling of lips, face, or eyes
Hives or welts on the skin
Tingling or itching in the mouth
Abdominal pain, vomiting, or diarrhoea
Severe Allergic Reaction (Anaphylaxis) Signs:
Breathing is difficult or there is wheeziness or persistent coughing
Swelling of the tongue or throat, or tightness in the throat
Difficulty talking or a hoarse voice
Loss of consciousness or collapse
Pale and floppy (in young children)
Step-by-Step Instructions for Using an Epinephrine Epipen
When faced with an anaphylaxis emergency, follow these steps to use the adrenaline device:
Before Administration:
Confirm the person is experiencing signs of anaphylaxis
Call 000 for emergency medical assistance immediately
Help the person lie flat or sit if breathing is difficult
Locate their prescribed adrenaline auto-injector if available
Administering the Injection:
Remove the adrenaline injector from its protective case
Check the device has not expired (expired adrenaline devices may still be used in emergencies if no alternative is available)
Remove the safety cap from the auto-injector
Hold the device firmly with the orange/black tip pointing downward
Place the tip against the outer thigh, perpendicular to the leg
Push down hard until you hear a click, indicating the auto-injector works and has activated
Hold firmly in place for 10 seconds to ensure the full dose of epinephrine is delivered
Remove the device and massage the injection site
Important Safety Notes:
You can inject through clothing if necessary
Use the adrenaline auto-injector on the outer thigh only
Never inject into hands, feet, or buttocks
Be aware of needle stick injury risks when handling used devices
After Giving the Adrenaline Device
Following epinephrine administration, several important steps must be taken:
Immediate Actions:
Keep the person lying down unless breathing is difficult, in which case help them sit upright
Stay with the person and monitor their condition closely
Be prepared to give a second dose if symptoms return or worsen
Prepare for possible resuscitation if the person becomes unconscious
Medical Follow-up: All people who receive emergency treatment for anaphylaxis must be transported to a hospital or emergency department for monitoring and further treatment. Even if symptoms improve after the first dose of adrenaline, medical evaluation is essential because:
Symptoms may return (biphasic reaction)
A second dose may be needed
Other treatments might be required
Medical supervision is needed for several hours
Second Dose Considerations
In some situations where adrenaline may be given, a second dose might be necessary. If symptoms persist or worsen after 5-15 minutes following the first injection, another adrenaline auto-injector should be used if available. People at high risk of anaphylaxis often carry two devices specifically for this reason.
The dose of epinephrine may need to be repeated, and this decision should ideally be made in consultation with emergency medical services or medical professionals. However, if breathing difficulties persist or the person’s condition deteriorates, do not hesitate to use another adrenaline device.
Storage, Handling, and Expiry of Adrenaline Devices
Proper storage of adrenaline auto-injectors is crucial for their effectiveness. These devices should be:
Stored at room temperature (not refrigerated or frozen)
Kept away from direct sunlight and heat
Protected from physical damage
Checked regularly for expiry dates
Replaced before expiry dates
People who carry an adrenaline autoinjector should always have their device readily accessible. Workplace first aid kits may include adrenaline devices, but these are typically intended for general use rather than individual prescription use. Any adrenaline device available should be checked for expiry and proper storage conditions.
Common Misconceptions and Important Considerations When Using An Epipen
Several important points often cause confusion regarding adrenaline auto-injector use:
Prescription vs Emergency Use: While adrenaline auto-injectors require prescription for personal use, they may be administered by trained first aiders in emergency situations. The treatment for anaphylaxis takes priority over prescription requirements when someone’s life is at risk.
Side Effects of Adrenaline: Some people worry about side effects of adrenaline, such as rapid heart rate, anxiety, or trembling. These effects are temporary and far less dangerous than untreated anaphylaxis. The correct dose of adrenaline in auto-injectors is designed to be safe for emergency use.
Asthma Considerations: People with asthma face increased risk of severe anaphylaxis, particularly if their asthma is poorly controlled. However, having asthma does not prevent the use of adrenaline. In fact, adrenaline can help improve breathing in people experiencing anaphylaxis with respiratory symptoms.
FAQs
Do food allergy reactions progress differently than other anaphylaxis triggers?
Food allergies typically cause anaphylaxis within 30 minutes of consumption, with most severe reactions occurring within the first 15 minutes. Unlike insect sting reactions that may develop over hours, food-triggered anaphylaxis often progresses rapidly from mild symptoms to life-threatening collapse.
What should be done with the used adrenaline auto-injector when emergency services arrive?
After use, place the adrenaline auto-injector in a container with the time of administration clearly marked on the side. This container should be handed to emergency services personnel on arrival. The used device provides important information about the type and timing of treatment given.
What happens if you accidentally inject adrenaline when someone doesn't have anaphylaxis?
Accidental adrenaline injection in healthy individuals causes temporary side effects like rapid heart rate, anxiety, and tremors lasting 15-30 minutes. These effects resolve without treatment and cause no permanent harm. The risk of unnecessary injection is far lower than the risk of death from untreated anaphylaxis.
