Anaphylaxis

Question 1

Common identified causes of anaphylaxis:

Answer 1

food (e.g. nuts) - the most common cause in children
drugs
venom (e.g. wasp sting)

Question 2

Clinical features of anaphylaxis ?

Answer 2

sudden onset and rapid progression of symptoms

Airway and/or Breathing and/or Circulation problems

Airway problems may include:
swelling of the throat and tongue →hoarse voice and stridor

Breathing problems may include:
respiratory wheeze
dyspnoea

Circulation problems may include:
hypotension
tachycardia

This means that if there are no ABC problems then the patient is technically not having anaphylaxis

Question 3

Where is adrenaline administered in anaphylaxis ?

Answer 3

anterolateral aspect of the middle third of the thigh

Question 4

Adrenaline dose in adult and child >12 years

Answer 4

500 micrograms (0.5ml 1 in 1,000)

Question 5

Adrenaline dose in 6- 12 years

Answer 5

300 micrograms (0.3ml 1 in 1,000)

Question 6

What is refractory anaphylaxis ?

Answer 6

defined as respiratory and/or cardiovascular problems persist despite 2 doses of IM adrenaline

IV fluids should be given for shock
expert help should be sought for consideration of an IV adrenaline infusion

Question 7

Management following stabilisation

Answer 7

persisting skin symptoms (urticaria and/or angioedema) - non-sedating oral antihistamines, in preference to chlorphenamine

Question 8

To establish whether a patient had a true episode of anaphylaxis

Answer 8

Serum tryptase levels are sometimes taken in such patients as they remain elevated for up to 12 hours following an acute episode of anaphylaxis

Question 9

Why should a a risk-stratified approach to discharge be taken?

Answer 9

biphasic reactions can occur in up to 20% of patients

Question 10

risk-stratified approach to discharge for fast track

Answer 10

Discharged after 2 hours of symptom resolution

good response to a single dose of adrenaline

complete resolution of symptoms

has been given an adrenaline auto-injector and trained how to use it

adequate supervision following discharge

Question 11

risk-stratified approach to discharge of minimum 6 hours stay after symptom resolution due to ?

Answer 11

2 doses of IM adrenaline needed, or
previous biphasic reaction

Question 12

risk-stratified approach to discharge of minimum 12 hours stay after symptom resolution due to ?

Answer 12

severe reaction requiring > 2 doses of IM adrenaline

patient has severe asthma

possibility of an ongoing reaction (e.g. slow-release medication)

patient presents late at night

patient in areas where access to emergency access care may be difficult

observation for at 12 hours following symptom resolution