Give high-dose oxygen via a mask, aiming for an oxygen saturation >94%
Give 0.01 mg/kg adrenaline up to 0.5 mg (0.5 mL of 1:1000 solution) IM into the upper lateral thigh
Attach patient to pulse oximetry and ECG monitoring, obtain large IV access
If no response, treat as critical anaphylaxis:
Ensure two large-bore IV lines
Repeat the dose of adrenaline 0.01 mg/kg up to 0.5 mg every 3-5 minutes
Alternatively place adrenaline 1mg (1mL of 1:1000) in 100mL of normal saline and administer IV at 60-120 mL/h (10-20 microgram/min) titrated to response
Give faster in cardiac arrest
Must be ECG monitor
Hypotension
Lay the patient supine and elevate the legs
Give adrenaline as above
Give normal saline bolus 20 mL/kg IV under pressure, repeat twice more as necessary
Give glucagon 1 mg IV repeated every 5 minutes for patients on a beta-blocker who are resistant to the above treatment
Beta blockers blunt the affect of adrenaline
Glucagon can also cause positive ionotropic and chronotropic effects on the heart and improves vasodilation; also stabilises mast cells
Give atropine 0.6 mg IV boluses if bradycardia unresponsive to adrenaline
Cardiac arrest
Give adrenaline 1 mg IV dose and repeat; can use larger doses of adrenaline 3-5 mg IV
Deliver rapid boluses up to 60 mL/kg of normal saline
Adjunctive agents
Laryngeal oedema
Give 1:1000 adrenaline 5 mg (5 mL) nebulised with oxygen
Call anaesthetist and prepare for surgical airway
Give hydrocortisone 200 mg IV or prednisone 50 mg PO
Give nebulised salbutamol 5 mg and repeat up to continuously as necessary
H1 and or H2 antihistamines following recovery from anaphylaxis
Cetirizine 10 mg PO or fexofenadine 180 mg plus rantidine 150 mg following recovery from the anaphylaxis