Anaphylaxis

Definition

Usually defined as severe multi-system allergic reaction.

Key features include one or several of:

1) Airway swelling: visible or audible as stridor

2) Bronchospasm: causing wheeze

3) Hypotension: collapse, dizziness, confusion

Treatment

Initial management targeted to life-saving measures

Cease any infusions of drugs, contrast, colloids

1) Epinephrine: always IM initially (see below)

    -IM 0.3-0.5mg Q5-15min 

    -Epi infusion if slow response 

    -try Glucagon if on B-blocker

2) IV access and NS bolus

3) secure airway early if threatened

Secondary management (largely symptom control)

4) Nebulised B-agonist for wheeze

5) Antihistamines (H1 & H2)

    -only once haemodyn stable 

6) Corticosteroid

Epinephrine

(1:1,000; 1mg = 1mL)

• IM (lateral thigh) = 0.3-0.5mg Q5-15min

(Peds = 10 mcg/kg/dose)

SEVERE: consider infusion, iv push is hazardous

IV: 5-15 mcg/min

(Peds = 0.05-1 mcg/kg/min)

NB: Cardiac Arrest adult dose: 1mg of 1:10,000 IVP

Glucagon

consider if not responsive to Epi, esp if on B-blocker

1-5mg iv over 5min

then infusion, start at 5mcg/min & titrate to BP

(Peds = 0.02-0.1 mg/kg stat, max. 1mg)

Source

2/6/06 DONALDSON (adapted from Tintinalli)

Brown SGA, Mullins RJ and Gold MS, Anaphylaxis: diagnosis and management, MJA 2006; 185: 283–289

Ewan PW, ABC of allergies – Anaphylaxis, BMJ 1998; 316: 1442-1445

Simons FER, Gu X, Simons KJ, Epinephrine absorption in adults: Intramuscular versus subcutaneous injection, J Allergy Clin Immunol 2001;108:871-3

Lieberman P et al, The diagnosis and management of anaphyalxis: An updated practice parameter, J Allergy Clin Immunol 2005;115;3:S483-S523

Sheikh A, Shehata YA, Brown SGA, Simons FER. Adrenaline (epinephrine) for the treatment of anaphylaxis with and without shock.Cochrane Database of Systematic Reviews2008, Issue 4. Art. No.: CD006312. DOI:10.1002/14651858.CD006312.pub2.