Anaphylactic Shock

Question 1

What type of hypersensitivity reaction is this?

Answer 1

Type I IgE mediated

Question 2

What type of shock does it cause?

Why does it cause angio-oedema?

Answer 2

Distributive shock due to vasodilation

Capillary leakage

Question 3

Causes:

What foods could cause this?

What bug stings could cause it?

What material could cause it?

Answer 3

Peanuts and tree nuts
Eggs
Fish 
Shellfish 
Strawberries 

Bee and wasp stings

Latex

Question 4

S+S:

Circulation - 3 signs?

Airway:

• They get SOB and cyanosis!
• Why do they get stridor?
• Why do they get wheezing?

Answer 4

Low BP
High HR
Loss of consciousness

Due to laryngeal oedema

Due to bronchospasm

Question 5

S+S:

Angio-oedema - where does this happen? - 3

What happens to the skin? - 4

What GI symptoms do they have? - 2

How long after exposure does it begin?

Answer 5

Eyes
Lips
Hands
Feet

Itch
Sweating
Erythema
Urticaria

D&V
Abdo pain

Seconds or minutes but may be hours

Question 6

Diagnosis:

There are one of 3 criteria.

(1) What is needed on top of skin/mucosa symptoms to diagnose it as anaphylaxis?
(2) What is needed on top of exposure to a likely allergen to diagnose it as anaphylaxis?
(3) What is needed on top of exposure to a known allergen to diagnose it as anaphylaxis?

Answer 6

Skin/mucosa + Cardiac/resp compromise

Exposure + >2 organ systems affected (e.g. skin/mucosa, GI, cardiac, resp)

Exposure + hypotension

Question 7

Management:

Step 1:

• What needs to be done to protect airway?
• What needs to be given alongside this?

Step 2:
- The source should be removed. What could be done to improve circulation?

Step 3:

• What drug needs to be given ASAP?
• Dose?
• Route?
• Where is it given?
• How often should it be repeated if there is still cardiorespiratory compromise?
• What is the dose for children <6 yrs?
• What is the dose for children between 6-12 yrs?

Answer 7

Raise feet

Intubation + oxygen

Adrenaline 0.5 mg (500 μg) IM (0.5 ml 1:1000)
Middle of the anterolateral thigh

Every 5 mins

<6 yrs = 150 μg (0.15 mg)

6-12 yrs = 300 μg (0.3 mg)

Question 8

Management:

Step 4 - IV access secured and fluids are given according to BP:

• Why may chlorphenamine 10 mg IV be given?
• Why may hydrocortisone 200 mg IV be given?

Step 5:
- If there is continued wheeze, it should be treated as you would treat asthma. How would this be treated? - 3

Answer 8

C - Reduces itch and hives

H - Reduces prolonged or biphasic reactions

Salbutamol
Ipratropium
Magnesium Sulphate

Question 9

Discharge:

Patients are warned about a biphasic reaction. What is this?

What are they given just in case?

Where should they be referred to, to identify the allergen?

Answer 9

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. The second reaction can be less severe, equal to or more severe than the first reaction.

Self-injected adrenaline - Epipen

Allergy clinic - skin prick testing