Anaphalyaxis Flashcards
What is anaphalyaxis
Life threatening generalised or systemic hypersensitivity reaction
What does exposure to an allergen cause
Ige mediated mast cell degranulatiomn
What is the onset of anaphalyaxis
Sudden
What are the life threatening signs and symptoms of anaphalyaxis
Airway: hoarse voice, swelling of tongue
Breathing: increased respiratory rate, wheeze and cyanosis
Circulation: hypotension, tachycardia or myocardial infarction
Neurological: confusion, loss of consciousness
Skin mucosa changes: erythema, urticaria and angioedema
What are the allergens that can cause anaphalyaxis
Drugs: antibiotics, anaesthesia agents Foods: nuts, shellfish, milk, fish Latex Insect stings Idiopathic
What occurs during ana anaphalyaxis
- Antigen is introduced to the body
- Antigen bidns to specific IGE
- Antigen/ige complex cross links on FCR1 receptor on mast cells
- Mast cells release mediators of histamine, prostaglandins, tryptase, leukotrienes, PAF
What is the management of anaphalyaxis
ABCDE approach
IM adrenalin
What does adrenaline cause in the body
- Vasoconstriction
- This increases vascular resistance
- BP increases and coronary artery perfusion
- Reduced vascular permeabilirt and reduced agioedema
- Bronchodilation
- Decrease in inflammatory mediator release
With adrenaline what other things can we give
High flow oxygen
Bronchodilator therapy
Fluids
To prevent a biphasic reaction of anaphalyaxis what caan we give
Corticosteroids: iv hydrocortisone
Antihistamine: chlorpheniramine
How do we differentiate anaphalyaxis i,e what investigations can we carry out
Look at tryptase in the blood
When do we look at tryptrase
- As soon as possible
2. 2 hours after start of symptoms
What pattern would tryptase show in anaphalyaxis
Increase and then decline
Is normal and remains normal- not everyone releases tryptase
What tryptase pattern would suggest mastocytosis
Increase at reaction but doesnt return to normal
What is the amount of adrenaline given for adults over 30kg
0.5mg
