Anaphylaxis

Question 1

What is anaphylaxis?

Answer 1

• Systemic type I (IgE mediated) life-threatening hypersensitivity reaction
• Immediately get help, call MET 2222
• Remove allergen

Question 2

What are common causes of anaphylaxis?

Answer 2

• Drugs → abx, gelofusine, N-acetylcysteine, IV contrast
• Foods → nuts, strawberries, eggs, shellfish
• Animals → wasp/bee stings
• Latex

Question 3

What is the immediate (ABC) management of anaphylaxis?

Answer 3

• Secure airway
• Adrenaline 0.5mg IM (0.5ml of 1:1000) → may be repeated at 5min intervals
• Attach 15L/min O₂ via non-rebreathe mask
• If wheeze, give salbutamol 5mg nebs
• Secure IV access (2 large-bore IV cannulae)
• IV fluids 500-1000ml 0.9% saline/Hartmann’s STAT fluid challenge initially, may need up to 4-8L fluids, titrate to BP
• Hydrocortisone 200mg IV
• Chlophenamine 10mg IV
• Apply 3-lead cardiac monitoring

Question 4

What is further short-term management of anaphylaxis?

Answer 4

• If the pt not improving rapidly, seek anaesthetic/ICU input
• Admit for obs (at least 6hrs post-adrenaline bc biphasic rxns can occur)
• Continue prednisolone 30-40mg OD PO (3-5d course)
• Continue chlorphenamine 4mg QDS PO if itching
• Monitor ECG
• Further IV fluids if required
• Document event + allergy
• Consider taking mast cell tryptase to confirm anaphylaxis (must be done ASAP)

Question 5

What is the longer-term management of anaphylaxis?

Answer 5

• Educate patient
• Teach about self-injected adrenaline (epipen)
• Medic alert bracelet
• Refer to allergy clinic +/- skin prick tests to identify allergens if unknown
• Clinical incident form if given allergic antibiotic