Anaphylaxis Flashcards
What is anaphylaxis?
life-threatening, systemic, hypersensitivity reaction characterised by sudden onset of life-threatening airway and/or breathing and/or circulation problems (with or without skin changes) after exposure to a trigger (allergen)
What are resp features of anaphylaxis?
- Shortness of breath
- Stridor
- Wheezing
What are the circulation features of anaphylaxis?
- Pale and clammy
2. Hypotension
What are the skin/mucosal features of anaphylaxis?
- Flushing
- Urticaria
- Angio-oedema
What are common triggers?
foods, drugs, chemicals
What are RF for anaphylaxis?
Hx of Atopy
What is the patho of anaphylaxis?
- Systemic mast-degranulation
2. Leads vessel dilation, increase vessel permeability, bronchospasm
What investigations are done for anaphylaxis?
- Medical emergency, treat as soon as possible!
- A-E (with reassessment)
- If uncertain elevated serum tryptase and plasma histamine
What is the acute management of anaphylaxis?
- Help!
- Lie flat
- IM adrenaline
What is the acute management of anaphylaxis with equipment?
- High-flow oxygen (15 L/min via non-rebreathe mask)
- Monitoring (pulse oximetry, ECG, BP)
- IV fluid challenge
- IM or slow IV Chlorphenamine and Hydrocortisone
What are the aftercare management of anaphylaxis?
- Observe
- safety net
- EpiPen
- refer to allergy services
What are possible complications of anaphylaxis?
- Death
- MI
- Reccurence
What is acute management?
- CALL FOR HELP
- Remove trigger e.g. antibiotic
- Lie patient flat and elevate legs if possible
- Adrenaline: one 500 microgram dose of 1:1000 intramuscular adrenaline (for adults
- Reassess the airway – any immediate response? Still patent and unobstructed?
What would u give to give fluids?
Ask your nurse colleague to place two wide-bore 18G cannula in each arm and then reassess
What is the most common anaphylaxis?
Immunologic anaphylaxis
What is the process of immunological anaphylaxis?
- first time an allergen enters the system it interacts with the B cells and create IgE antibodies in response to the allergen
- IgE docks onto mast cells
- second time that the allergen enters the system it can immediately bind to the mast cells docked with the specific IgE antibodies and activates cytokines to produce WBCs and also release histamines.
What does histamine do?
- dilate blood vessels
- cause leaky blood vessels
- bronchospasm
What does the dilated blood vessels mean?
drop in BP and lose function of circulatory system
What does the leaky blood vessels cause?
fluid leaves the extracellular space, which causes swelling.
What is non-immunological anaphylaxis?
- similar but has a slightly different pathophysiology
2. instead of mast cells being stimulated by IgE, the allergen specifically targets the receptors on the mast cells
If unsure what do you give and emergency?
IM ADENALINE
