Anaphylaxis

Question 1

What is anaphylaxis?

Answer 1

A type I, IgE mediated life-threatening hypersensitivity reaction

Question 2

What is the pathophysiology of anaphylaxis?

Answer 2

Release of histamine and other agents by mast cells and basophils due to IgE mediated reaction involving a specific antigen -> capillary leak and swelling

Question 3

What allegens can cause anaphylaxis?

Answer 3

• Drugs - penicillin, contrast media, antisera
• Latex
• Stings - wasps, bees, hornets
• Eggs
• Fish
• Peanuts
• Strawberries, Citrus fruits
• Semen

Question 4

What are symptoms of anaphylaxis?

Answer 4

• Itching
• Sweating
• Diarrhoea
• Vomiting
• Urticaria/Erythema
• Swelling

Question 5

What are signs of anaphylaxis?

Answer 5

• Oedema
• Erythema/Urticaria
• Wheeze
• Laryngeal obstruction
• Cyanosis
• Tachycardia
• Hypotension

Question 6

How would you approach intially managing someone with suspected anaphlaxis?

Answer 6

ABCDE

• A - Secure airway
• B - Attach 15L/min O2, Give adrenaline IM (0.5mg), Consider salbutamol neb
• C - IV access, Fluids, Hydrocortisone (200mg), Chlorphenamine (10mg)

Admit for observation

Question 7

What flow rate would you set oxygen at when treating someone with anaphylaxis?

Answer 7

15L/min

Question 8

What dose of adrenaline woul dyou give someone who was experiencing anaphylaxis?

Answer 8

0.5mg (0.5ml of 1:1000)

Question 9

How would you administer adrenaline in anaphylaxis?

Answer 9

Intramuscular injection

Question 10

What IV access would you want to establish in someone experiencing anaphylaxis?

Answer 10

2 large-bore IV cannulae

Question 11

How often would you repeat adrenaline injections in someone with anaphylaxis?

Answer 11

Every 5 mins, as guided by BP, HR, RR etc.

STOP AS SOON AS RESULT OBTAINED

Question 12

What dose of hydrocortisone would you administer in someone with anaphylaxis?

Answer 12

200 mg

Question 13

How would you administer hydrocortisone?

Answer 13

IV

Question 14

What dose of chlorphenamine would you administer in someone with anaphylaxis?

Answer 14

10 mg

Question 15

How would you administer chlorphenamine?

Answer 15

IV

Question 16

What dose of nebulised salbutamol would you consider giving somoene with anaphylaxis?

Answer 16

5mg

Question 17

What volume of saline woul dyou consider giving someone in anaphylactic shock?

Answer 17

500 ml over 15 mins initially, but may need 1L if hypotensive

Question 18

What is the general approach to fluid administration in someone in anaphylactic shock?

Answer 18

Give as fast as needed and titrate to BP - may need up to 4-8L

Question 19

Once initially managed, what short term management measures would you take to manage someone with anaphylaxis?

Answer 19

• Admit for obervation
• Continue prednisolone 30-40 mg for 3-5 days
• Continue chlorphenamine 4mg/6h PO - if itching
• Monitor ECG
• Further fluids
• Consider serum tryptase (1-6h after suspected anaphylaxis)

Question 20

What would you consider as part of longer term management in someone with anaphylaxis?

Answer 20

• Medic alert bracelet
• Educate on self injection
• Refer to allergy clinic +/- skin prick testing to identify allergens
• Clinical incident form if allergic to antibiotic

Question 21

In terms of short term management, what dose and rate of chlorphenamine would you continue somoene on until itching subsided?

Answer 21

4mg/6h

Question 22

How long would you continue someone on prednisolone as part of short term management of anaphylactic shock?

Answer 22

3-5 days

Question 23

What dose of prednisolone woul dyou consider giving somoene as part of short term management of anaphylaxis?

Answer 23

30-40mg

Question 24

What disease processes can mimic anaphylaxis?

Answer 24

• Carcinoid
• Phaeochromocytoma
• Systemic mastocytosis
• Hereditary angioedema

Question 25

What would you do immediately once you recognised someone was having an anaphylactic reaciton?

Answer 25

Call 2222