Presentation on theme: "Anaphylaxis SHO presentation Tom Francis ICU Registrar."— Presentation transcript:
Anaphylaxis SHO presentation Tom Francis ICU Registrar
Anaphylaxis What is it Pathophysiology Common causes / precipitants Features / signs Treatment After-care / discharge
Anaphylactic shock Type 1 IgE mediated (usually) hypersensitivity reaction Chain Reaction Release of histamine and other cytokines from mast cells and basophills Causes contraction of bronchial smooth muscles, vasodilation of peripheral vasculature, capillary leak and cardiac muscle depression
ADRENALINE Mainstay of treatment is Adrenaline 0.5mg IM ADRENALINE
Recognition Airway – Airway oedema – larynx, lips, tongue, eyelids – Stridor is a sign of airway obstruction Breathing – Bronchial smooth muscle constriction – wheeze, respiratory distress, increased work of breathing Circulation – Relaxation of vascular smooth muscle – Vasodilation, hypotension and erythema – Increased capillary permeability leading to loss of fluid from circulation : hypotension, tissue swelling, urticaria and Angioedema
Promethazine (Phenergan) 25mg slow IV injection (can use IM) Sedating anti-histamine (H1) Prevents capillary leak and helps treat hypotension due to loss of intravascular fluid If persistant hypotension despite treatment with adrenaline can use ranitidine (H2) as second line. 50mg Ranitidine IV slowly
Hydrocortisone 200mg IV hydrocortisone Requires reconstituion with sterile water OF NO VALUE IN IMMEDIATE RESUSCITATION Is of value to prevent rebound anaphylaxis though onset of several hours, should be given to prevent further deterioration in severely affected patients
IV Fluids Vasodilation and increased vascular permeability 3 rd spacing of fluid into interstitial space DISTRIBUTIVE SHOCK 1 litre Crystalloid or colloid STAT once Adrenaline given IM 1 – 3 litres commonly required 50mg Ranitidine can help persitant low BP
Treatment ADRENALINE 0.5mg IM Airway (and supplemental Oxygen) – nebulised adrenaline 5mg (5 x 1/1000) – Consider intubation. Breathing – bronchospasm usually responds to adrenaline, can give nebulised salbutamol 5mg if wheeze persists. Treat as acute asthma Circulation – Raise legs / head down on bed if hypotension – Large bore IV access – 1 litre IVI stat – 50mg Ranitine IV if persistant
Where now? Pts who require treatment for anaphylaxis need to be discussed with ICU Rebound Anaphylaxis is a concern Tryptase levels to confirm diagnosis – <1 Hour, 8 hours, 24 hours
Discharge post anaphylaxis Oral antihistamine e.g loratadine 3/7 Oral Steroid 3/7 – Reduces risk of further reaction Refer for specific allergy diagnosis Epi-pen prescription – 300mcg Adrenaline
Further Mx… ACC form Refer to GP for Medic Alert bracelet Fill out an Alert/Adverse Reactions/Allergies form Complete CARM report if a medication allergy – (Centre for adverse reactions monitoring) – https://nzphvc-01.otago.ac.nz/carm/ https://nzphvc-01.otago.ac.nz/carm/ – Or easily found on google!
Further Mx Hydrocortisone 4mg/kg IV Q6H H1 antihistamine (loratadine / cetirizine) – Itch – Angioedema PO Ranitidine 1-2mg/kg (max 150mg) in sever reactions If require more than 1x dose Adrenaline require 24 hour admission
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