Anaphylaxis (Adult) CPG Notes Flashcards
(25 cards)
What are the 3 main care objectives for managing anaphylaxis?
- IM adrenaline with minimal delay
- Airway/perfusion support
- Hospital observation (≥ 4 hours)
What is the intended age group for this guideline?
Patients aged ≥ 16 years with anaphylaxis.
How is anaphylaxis defined?
A severe, potentially life-threatening systemic hypersensitivity reaction.
How quickly do symptoms usually begin?
Within 30 minutes, but may take up to 4 hours.
What is key to diagnosing anaphylaxis if there’s no known allergen exposure?
If ≥2 body systems are affected (e.g. respiratory + skin), accept anaphylaxis.
What are the 4 main systems affected in anaphylaxis and examples of symptoms?
- Respiratory: Distress, wheeze, stridor, cough, shortness of breath.
- Abdominal: Nausea, vomiting, diarrhoea, cramping.
- Skin: Hives, itching, flushing, angioedema (e.g. lips, tongue).
- Cardiovascular: Hypotension.
List common allergen categories.
- Insect stings (e.g. bees, wasps)
- Food (e.g. peanuts, shellfish, eggs)
- Medications (e.g. antibiotics, anaesthetics)
- Exercise-induced (young adults)
- Idiopathic (no known trigger).
Why is it important to be cautious in patients with asthma or food allergy?
They are at higher risk of fatal anaphylaxis, and anaphylaxis may be mistaken for asthma.
What types of non-allergic angioedema may resemble anaphylaxis?
ACE-inhibitor induced, hereditary angioedema, and bradykinin-mediated angioedema.
How is onset different from anaphylaxis?
It is slower, developing over several hours.
Name five risk factors for poor response or deterioration.
- Hx of severe anaphylaxis
- Hypotension (SBP < 90)
- IV allergen (e.g. contrast)
- Respiratory distress
- No response to IM adrenaline.
What is the preferred site of IM adrenaline injection?
Anterolateral mid-thigh.
Why do most anaphylaxis deaths occur?
Due to delayed adrenaline administration, not accidental overdose.
Can patients self-administer their autoinjector?
Yes. If symptoms improve, monitor and still transport to hospital.
When is an infusion indicated?
After 2 IM doses with ongoing hypotension or deterioration.
When is IV bolus adrenaline used?
Impending cardiac arrest or extremely poor perfusion.
How do you prepare an adrenaline infusion?
Dilute 3 mg adrenaline in 50 mL D5W or normal saline (in 50 mL syringe).
What is the infusion rate?
1 mL/hr = 1 mcg/min.
Should additional therapies delay adrenaline?
No, adrenaline must always take priority.
What are the secondary treatments for bronchospasm?
Salbutamol, ipratropium, and dexamethasone.
What is used if hypotension persists after 2 doses of adrenaline?
Normal saline IV, titrated to effect.
What if the patient is on beta blockers or has heart failure and doesn’t respond to adrenaline?
Give glucagon 1 mg IV/IM, may repeat once.
What if the patient has a pre-existing anaphylaxis plan?
Follow their plan if safe and appropriate.
What is the minimum observation period post-reaction?
4 hours (due to risk of biphasic reaction).
