Anaphylaxis Managment

Question 1

How does anaphylaxis occur?

Answer 1

Antigen enters body, TH2 cells release cytokines that trigger release of IGE antibodies which present antigen to mast cells. Mast cells become sensitised to antigen.
On 2nd exposure the mast cells degranulate releasing excessive levels of inflammatory mediators.
Histamine- vasodilator
Heparin
Prostaglandin- bronchoconstrictor

Question 2

How to manage anaphylaxis?

Answer 2

1- ABCDE
2- Look for sudden onset of airway, breathing or circulation problems
3- look for skin changes
4- Remove the trigger if possible
5- Administer IM adrenaline
6- Establish airway, give high flow oxygen. Obs
7- If no response repeat IM adrenaline after 5 mins. Consider IV fluid bolus
8- if no improvement in breathing or circulation problems after 2 doses of IM adrenaline follow refractory anaphylaxis algorithm.

Question 3

What are the doses for IM adrenaline?

Answer 3

Adult- 500 mcg at 1mg/ml concentration (1:1000)
Child aged 6-12- 300mcg
Child 6months to 6 years- 150mcg
Child <6months- 100mcg

Question 4

Discuss IV fluid?

Answer 4

Use crystalloid
Adult- 500-1000ml
Child- 10ml/kg

Question 5

Further treatment in anaphylaxis?

Answer 5

Consider nebulised salbutamol for bronchospasms

Question 6

Describe management of refractory anaphylaxis?

Answer 6

Establish peripheral IV or IO access
Give rapid IV fluid bolus
Give IM adrenaline every 5 mins
Give high flow oxygen titrated to 94-98%
Monitor obs