Anaphylaxis
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Anaphylaxis: Causes, Symptoms, and Treatment
Understanding Anaphylaxis
An Exaggerated Immune Response to Allergens
Anaphylaxis is a severe immune reaction triggered by specific allergens, which can include:
- Bee Stings
- Peanuts
- Sesame Seeds
- Latex
It may affect individuals with known allergies or those encountering an unknown allergen for the first time. Anaphylaxis develops rapidly and can lead to life-threatening airway blockages, including bronchospasm and wheezing. It often presents with facial rashes, facial swelling, bronchoconstriction, and low blood pressure, and in some cases, it progresses swiftly to cardiac arrest. Individuals with pre-existing asthma face a higher risk of fatal anaphylactic reactions.
Treatment Essentials
Swift Action and Key Medications
The primary medication for anaphylaxis treatment is adrenaline, which acts by:
- Reversing Peripheral Vasodilation
- Reducing Oedema
- Dilating Bronchial Airways
- Enhancing Myocardial Contraction
- Suppressing Histamine Release and Inflammatory Mediators
Adrenaline is most effective when administered promptly, potentially preventing cardiac arrest. Common symptoms of anaphylaxis include a generalized rash, itching, swollen lips, tongue, and eyes, along with breathlessness, wheezing, fainting, abdominal pains, nausea, and vomiting. Signs may include reduced peak expiratory flow, hypoxaemia, and hypertension.
Immediate Steps
Managing Anaphylaxis
To address anaphylaxis:
- Remove the Trigger: If possible, eliminate the source of the allergen, such as a bee sting.
- Administer IM Adrenaline: Give adrenaline promptly at the appropriate dose based on the patient's age to prevent cardiorespiratory arrest. Repeat every five minutes until improvement is observed.
- Position the Patient: Lay the patient flat with elevated legs to ensure sufficient oxygen flow.
- Establish IV Access: Set up intravenous access and adjust IV fluids according to blood pressure levels.
- Follow ALS Guidelines: Adhere to standard Advanced Life Support (ALS) protocols for patients with cardiac arrest.
- Consider IM Adrenaline: In cases where IV or intramuscular access is not possible, administer IM adrenaline if a recent cardiorespiratory arrest has occurred.
- Treat Bronchospasm: Manage bronchospasm similarly to asthma treatment.
- Antihistamine Administration: Administer an antihistamine at an appropriate dose for the patient's age to counter the effects of histamine release during anaphylaxis.
- For Severe Cases: In severe or life-threatening situations, provide hydrocortisone at the appropriate dose to reduce the immune response.