Anaphylaxis Flashcards
ABCDE
Airway, Breathing, Circulation, Disability, Exposure approach.
Early treatment with _ is the treatment of choice for patients having an anaphylactic reaction.
intramuscular adrenaline
Possible triggers for anaphylactic reaction:
Stings (wasp, bee) Nuts (peanut, almond) Food (milk, fish, banana) Antibiotics (penicillin, cephalosporin) Anaesthetic drugs (Suxamethonium) Other drugs Contrast media (iodinated) Other (latex, hair dye)
Suxamethonium
Short term anaesthetic
Cephalosporin
Antibiotic
Fatal food reactions cause respiratory arrest typically after_
30–35 minutes;
insect stings cause collapse from shock after _
10–15 minutes
deaths caused by intravenous medication occur most commonly within_
five minutes
Anaphylaxis is likely when all of the following 3 criteria are met:
Sudden onset and rapid progression of symptoms
Life-threatening Airway and/or Breathing and/or Circulation problems
Skin and/or mucosal changes (flushing, urticaria, angioedema)
Anaphylaxis Airway problems:
Airway swelling, e.g., throat and tongue swelling (pharyngeal/laryngeal oedema). The patient has difficulty in breathing and swallowing and feels that the throat is closing up.
Hoarse voice.
Stridor – this is a high-pitched inspiratory noise caused by upper airway obstruction
Anaphylaxis Breathing problems:
Shortness of breath – increased respiratory rate.
Wheeze.
Patient becoming tired.
Confusion caused by hypoxia.
Cyanosis (appears blue) – this is usually a late sign.
Respiratory arrest.
Anaphylaxis Circulation problems:
Signs of shock – pale, clammy.
Increased pulse rate (tachycardia).
Low blood pressure (hypotension) – feeling faint (dizziness), collapse.
Decreased conscious level or loss of consciousness.
Anaphylaxis can cause myocardial ischaemia and electrocardiograph (ECG) changes.
Cardiac arrest.
Non life-threatening conditions mistaken for Anaphylaxis (these usually respond to simple measures):
Faint (vasovagal episode).
Panic attack.
Breath-holding episode in child.
Idiopathic (non-allergic) urticaria or angioedema.
Patients with Airway and Breathing problems may prefer to sit up_
as this will make breathing easier.
Lying flat with or without leg elevation is helpful for patients with_
a low blood pressure (Circulation problem).
If the patient feels faint,_ - this can cause cardiac arrest.
do not sit or stand them up
Patients who are breathing and unconscious should be placed _
on their side (recovery position).
Pregnant patients should lie on_
their left side to prevent caval compression
Adrenaline IM dose adults
– adults 0.5 mg IM (= 500 micrograms = 0.5 mL of 1:1000) adrenaline
Adrenaline IM dose children
> 12 years: 500 micrograms IM (0.5 mL) i.e. same as adult dose
300 micrograms (0.3 mL) if child is small or prepubertal
6 – 12 years: 300 micrograms IM (0.3 mL)
6 months – 6 years: 150 micrograms IM (0.15 mL)
< 6 months: 150 micrograms IM (0.15 mL)
In patients with a spontaneous circulation, intravenous adrenaline _
can cause life-threatening hypertension, tachycardia, arrhythmias, and myocardial ischaemia.
Initially, give the highest concentration of oxygen possible using a mask with an oxygen reservoir. Ensure high flow oxygen (usually greater than 10 litres min-1) to _
prevent collapse of the reservoir during inspiration
Antihistamines are a second line treatment for an anaphylactic reaction.
_
Inject chlorphenamine slowly intravenously or intramuscularly.
The dose of chlorphenamine depends on age:
> 12 years and adults: 10 mg IM or IV slowly
6 – 12 years: 5 mg IM or IV slowly
6 months – 6 years: 2.5 mg IM or IV slowly
<6 months: 250 micrograms/kg IM or IV slowly
Undertake the usual investigations appropriate for a medical emergency, e.g., _
lead ECG, chest X-ray, urea and electrolytes, arterial blood gases etc.
The specific test to help confirm a diagnosis of an anaphylactic reaction is _
measurement of mast cell tryptase.
Tryptase sampling:
Three timed samples:
Initial sample as soon as feasible after resuscitation has started
Second sample at 1-2 hours after the start of symptoms
Third sample either at 24 hours or in convalescence) - this provides baseline tryptase levels
A biphasic reaction is a_
two phase anaphylactic event. This means that after anaphylaxis is treated and the symptoms go away, they return without you being re-exposed to the allergen.
Standard UK needle gauges and lengths
Brown 26G 10 mm
Orange 25G 16 mm or 25 mm
Blue 23G 25 mm
Green 21G 38 mm
Stridor
a high-pitched, wheezing sound caused by disrupted airflow
AVPU - assess the alertness
A - Alert
V - Voice
P - Pain
U - Unresponsive
