Anaphylaxis Flashcards
What is anaphylaxis?
Anaphylaxis may be defined as a severe, life-threatening, generalised or systemic hypersensitivity reaction.
What are common identified causes of anaphylaxis?
Common identified causes include food (e.g. nuts), drugs, and venom (e.g. wasp sting).
Food is the most common cause in children.
What are the features of anaphylaxis according to the Resus Council UK?
The features include sudden onset and rapid progression of symptoms, and problems with Airway, Breathing, and Circulation.
What are airway problems in anaphylaxis?
Airway problems may include swelling of the throat and tongue, leading to a hoarse voice and stridor.
What are breathing problems in anaphylaxis?
Breathing problems may include respiratory wheeze and dyspnoea.
What are circulation problems in anaphylaxis?
Circulation problems may include hypotension and tachycardia.
What percentage of patients experience skin and mucosal changes in anaphylaxis?
Around 80-90% of patients also have skin and mucosal changes, such as generalised pruritus and a widespread erythematous or urticarial rash.
What is the first-line management for anaphylaxis?
Intramuscular adrenaline is by far the most important drug in anaphylaxis and should be given as soon as possible.
What was removed from the Resuscitation Council guidelines in 2021?
IV hydrocortisone was removed from the guidelines due to a poor evidence base.
What are the recommended doses for adrenaline in anaphylaxis?
The doses are:
- < 6 months: 100 - 150 micrograms (0.1 - 0.15 ml 1 in 1,000)
- 6 months - 6 years: 150 micrograms (0.15 ml 1 in 1,000)
- 6-12 years: 300 micrograms (0.3ml 1 in 1,000)
- Adult and child > 12 years: 500 micrograms (0.5ml 1 in 1,000).
How often can adrenaline be repeated in anaphylaxis?
Adrenaline can be repeated every 5 minutes if necessary.
Where is the best site for IM injection of adrenaline?
The best site for IM injection is the anterolateral aspect of the middle third of the thigh.
What defines refractory anaphylaxis?
Refractory anaphylaxis is defined as respiratory and/or cardiovascular problems persisting despite 2 doses of IM adrenaline.
What should be given for shock in refractory anaphylaxis?
IV fluids should be given for shock.
What should be done following stabilisation of anaphylaxis?
Non-sedating oral antihistamines may be given, especially in patients with persisting skin symptoms.
What is the purpose of serum tryptase levels in anaphylaxis?
Serum tryptase levels are sometimes taken as they remain elevated for up to 12 hours following an acute episode of anaphylaxis.
What should all patients with a new diagnosis of anaphylaxis do?
All patients should be referred to a specialist allergy clinic.
What should be prescribed to patients with a new diagnosis of anaphylaxis?
Patients should be prescribed 2 adrenaline auto-injectors and training on how to use them.
What is the risk-stratified approach to discharge recommended by the Resus Council UK?
The approach includes fast-track discharge after 2 hours of symptom resolution if there is a good response to a single dose of adrenaline and complete resolution of symptoms.
What are the criteria for minimum 6 hours observation after symptom resolution?
Criteria include needing 2 doses of IM adrenaline, previous biphasic reaction, or severe reaction requiring > 2 doses of IM adrenaline.
What are the criteria for minimum 12 hours observation after symptom resolution?
Criteria include severe reaction requiring > 2 doses of IM adrenaline, severe asthma, possibility of ongoing reaction, or presenting late at night.
Anaphylaxis 2021 guidelines
Refractory anaphylaxis
