What is anaphylaxis
Life threatening severe type 1 allergic reaction
- IgE responds inappropriately to allergen causing release of histamine and other substances
How does it present
80% present rash + angiooedema but 20% don’t
Sudden onset rapid progression of Sx Skin / mucosal change - Erythema - patchy or generalised red rash - Urticaria (Hives) - Flushing - Itch - Angio-oedema - similar to urticaria but swelling of deeper tissue e.g. eyes / mouth but sometimes airway Upper airway oedema and bronchospasm - common in asthmatics Abdo pain N+V Indicative of anaphylaxis = airway / breathing compromise - Stridor - Wheeze - Tachycardia - SOB - Collapse - Hypotension
How do you treat
ABCDE
- O2, IV access, fluid bolus etc
- 500ml adult saline
- 20 ml / kg child saline
Call 2222 - consider anaesthetist if think airway compromised
Remove trigger
If breathing normal = lie flat and raise head
If breathing compromised = sit up and monitor
Adrenaline IM anterolateral aspect of mid thigh
Repeat every 5 minutes even if detioerrate
Hydrocortisone IV
Chloroamphetamine IV
Can give salbutamol if wheezing
Doses adrenaline
1 in 1000
>12 = 0.5ml
6-12 = 0.3ml
<6 = 0.15ml
Doses hydrocortisone
200mg >12
100mg >6-12
50 mg >6 months-6
25mg <6 months
Doses chloroamphetamine
10mg >12
5mg 6months-12
2.5mg <6months
What may be needed
Intubation
What can be taken after to prove anaphylaxis
Serum typrtase
What must you do after an episode of anaphylaxis
Observe patient for 6-12 hours incase biphasic reaction occurs
Observe 24 hours if severe reaction, severe asthma, allergen trigger still present, previous Hx of biphasic reaction
Teach about epipen
Refer to allergic clinic
What does of adrenaline in rests
1 in 10,000 10ml IV
Cardiac arrest
OK
Common drugs causing anaphylaxis
Anaesthetic
Muscle relaxant
Ax
NSAID / aspirin
If bee sting has caused reaction what is important to do
Remove
What are the Ddx to consider of anaphylaxis
Asthma - Use Adrenaline first as will treat both - Use inhaler / nebuliser Septic shock - Hypotension with purpuric rash - Sepsis 6 Other - Vasovagal - Panic attack - Idiopathic urticaria
If patient states struggling to breath and hoarse voice / closing up
IM adrenaline ASAP
If hypotensive
Lie flat and raise legs
