Anaesthetic Emergencies Acute Anaphylaxis Dr T E Allan Palmer FRCA FANZCA MD

Presentation  Primary indicators –Unexplained hypotension –Bronchospasm –Angioedema  More likely to be anaphylaxis if: –More than one feature –Erythema, rash or urticaria –Severe reaction

Immediate Management  Remove trigger agent –Stop injection or infusion of drug –Remove triggering materials  Remember latex allergy  Chlorhexidine –Summon assistance  Anaesthetist if in building, MET otherwise

First Aid  100% Oxygen  Secure airway –Beware LMA.  Stomach inflation  Subglottic Oedema  Volume Expansion –Fluid that doesn’t release histamine –Hartmans initially –4% Albumen

Definitive Management CVS  IV adrenaline –1:10,000 1ml increments. Typically 5+ml  Need more if patient on beta blocker  Repeat as needed –Fast flowing IV –Adrenaline infusion if reaction persists  1mg adrenaline in 50ml 3-60mls per hour  May need triple dose  CPR as needed

Definitive Management RS  Bronchospasm –Systemic adrenaline first choice –Nebulised salbutamol –Steroids  1gm (ie 10amps hydrocortisone)  1gm methylprednisolone

Monitoring  ECG in all cases –Acute myocardial infarction common if history IHD  Blood pressure –NIBP may read low due to low cardiac output –Arterial line if in situ  Hourly urine output  CVP

Ongoing Management  HDU or ICU monitoring  Ongoing adrenaline if needed  Supportive care –Safe airway –Oxygenation –Cardiovascular support

Investigation  Takes second place to treatment  Mast Cell tryptase –1 to 4hrs after reaction and 6 weeks later –Cross match tube. Call lab as has to be spun down and frozen  History –Detailed timeline of all events  Subsequent skin testing

Think About!  Chlorhexidine allergy –Skin prep, shower soap, central lines lignocaine gel!  Latex allergy –Particularly repeat exposures

Questions  What is wrong with subcutaneous or IM adrenaline?  Why not use haemaccel if the blood pressure is low?  First monitor to show any changes?