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Flashcards in Cardiac arrest in anaphylaxis Deck (12):


Food triggers commonest in young patients
Drug triggers commonest in elderly patients

Food-Nuts are commonest cause
Drugs-Muscle relaxants, Abx, NSAIDS and aspirin are commonest

Risk of death increased in asthmatics

Fatal food reactions 30-35mins
Fatal insect stings cause collapse from shock 10-15mins
Fatal IV injections within 5mins


Criteria for anaphylaxis

Sudden onset and rapid progression

Life threatening airway, breathing and circulation

Skin and mucosal changes (flushing, urticara and angioedema)

Supportive but not mandatory: exposure to known allergen


Supportive criteria

Skin and mucosal changes alone not a sign of anaphylaxis

Skin and mucosal changes can be subtle or absent in 20%

GI symptoms include abdo pain, vomiting and incontinence.


Life threatening Airway, Breathing and Circulation

Airway problems:
- Airway swelling e.g. throat/tongue swelling (Pharyngeal/laryngeal oedema)
-Hoarse voice

- Wheeze
- Tiredness
- Confusion caused by hypoxia
- Cyanosis
- Resp arrest

- Signs of shock
- Tachyc
- Hypotension
- Reduced consciousness
- Arrest


Skin and mucosal changes

Present in 80% of anaphylactic
Can be subtle and dramatic
Angioedema-swelling of deeper tissues, eyelids, lips and sometimes in the mouth and throat.


Life threatening conditions differentials

- Life threatening asthma
- Septic shock


Non life threatening

Panic attack
Breath holding episode in child
Urticaria or angioedema


Sit patients up
Lying flat with leg elevation can helpful

Remove trigger for reactions

Give highest oxygen concentration

Adrenaline is the most important drug. Alpha receptor agonist-reverses peripheral vasodilation and reduces oedema.

Its beta receptor dilates the bronchial airways, increases the force of myocardial contraction

Suppresses histamine and leukotriene release

IM route is best 0.5mg (0.5ml of 1:1000=0.5mg=500mcg)
Inject at anterolateral side of thigh

IV adrenaline using 50mcg boluses-if repeated doses needed 10mls syringe of 1:10,000 contrains 100mcg per ml. A dose of 50mcg is 0.5ml

Give rapid IV fluid challenge 500-1000ml. Hartmanns or saline is best fluid to give.

Antihistamine are second line treatment for anaphylaxis (H1-antihistamine)
Give chlorphenamine 10mg IM or IV slowly.
Give hydrocortisone 200mg IM or IV slowly


Page 134 see algorithm

Page 134 see algorithm


If asthma like features alone
Airway obstruction:
- Angioedema
- Swelling of tongue and lips
- Hoarseness
-Oropharyngeal swelling

Consider early tracheal intubation

Treat as asthma alone
- Salbutamol IV or inhaled
- Ipratropium inhaled
- Aminophylline IV
- Magnesium IV
(Vasodilator can cause hot flushes and hypotension)

Adrenaline first line vasopressor
Others include (Noradrenaline, vasopressin, matraminol and glucagon)

Glucagon good in anaphylaxis for pts on beta blocker

In arrest use steroids, antihistamines and large volumes of IV fluids.


Page 134 onwards

Page 134 onwards


Anaphylaxis treatment

Oxygen, 0.5 mg IM adrenaline, fluids, bronchodilators. Antihistamines and hydrocortisone are second line drugs.

Delivering intravenous adrenaline has potential disastrous effects in the hands of those who do not use it in their routine practice and should be avoided. The wrong dose of adrenaline at the wrong rate can cause serious harm to the patient. IM adrenaline has a much greater safety margin.

Mr Jobbs is at risk of airway compromise. Early treatment with adrenaline and consulting expert help for airway management is vital.