Anaphylaxis During the Perioperative Period

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Anaphylaxis During the Perioperative Period

• 2004/11/30 presented by R1 ???

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Definition

• Anaphylaxis
• IgE-mediated hypersensitivity reaction
  involving mast cells and basophils
• Anaphylactoid reaction
• 1. direct nonimmune-mediated release of
  mediators from mast cells and basophils
• 2. direct complement activation

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Anaphylaxis

• Rapid in onset
• Early cutaneous signs are often unrecognized
• The first recognized signs cardiovascular
  collapse and bronchospasm

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Latex

• High-risk groups
• 1.Health-care workers or other occupational
  exposure
• 2.Multiple surgical procedures
• 3.Atopic patients
• 4.Fruit allergy

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Colloids

• Prior drug allergy and male
• Gelatins(0.34) and dextrans(0.27) more likely
  than albumin(0.1) and hetastarch(0.06)

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Pathophysiology

• Multiple organ systems are affected
• Initial exposure to antigen ? IgE production and
  bind to mast cells and basophils
• Reexposure ? release of mediators from mast cells
  and basophils

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Diagnosis

• History
• Physical examination
• Serologic and skin tests

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Serum Tryptase

• Mast cell protease
• Can be measured 30 min after the first signs of
  anaphylaxis
• Half-life 2 hrs, then decrease over time
• Does not differentiate anaphylactic from
  anaphylactoid reaction
• Histamine not measured due to half-life of a few
  minutes

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In vitro tests

• Radioallergosorbent test (RAST)
• RIA
• Basophil histamine release

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Skin Test

• Prick and intradermal test
• 4-6 weeks after the anaphylactic episode
• Small risk of anaphylaxis induced
• Should be performed in a setting with adequate
  resuscitative equipment

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Management(1)

• Withdraw the offending drug
• Interrupt the effects of the performed mediators
• Prevent more mediator release

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Management(2)

• Discontinuation of anesthetics and drugs
• Airway support with 100 oxygen
• IV crystalloid (2-4 L) replacement
• Epinephrine 5-10µg IV bolus for hypotension, and
  0.1-0.5mg IV for cardiovascular collapse

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Management(3)

• Antihistamine diphenhydramine 0.5-1 mg/kg
• Corticosteroids 1-5 mg/kg hydrocortisone
• Bronchodilators
• Delayed extubation airway swelling and
  inflammation may continue for 24 hrs

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Prevention

• Careful history regarding adverse drug reactions
  and allergies
• Premedication with antihistamines and
  corticosteroids for allergic patients less
  benefit
• Desensitization

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Risk Factors

• Gender female male31
• Age children undergoing many operations, such as
  spina bifida for latex
• Atopy
• History of drug allergy

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Investigation Strategy Prior to Anesthesia

• Patients presenting a documented allergy to
  anesthetic drugs
• Unexplained reaction during a previous general
  anesthesia list of all injected substances
• Patients allege an allergy to local anesthetics
  challenge test
• High risk group for latex

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Emergency Surgery

• Based on patient history
• Unexplained reaction during previous general
  anesthesia ?regional block or no muscle relaxant
  use
• Allergy to local anesthetics ? general anesthesia
  or challenge test
• Known allergy to a muscle relaxant ? avoid such
  drugs

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References

• Anesth Analg 2003971381-95
• European Journal of Anaesthesiology
  200219240-262
• Br J Anaesth 200187549-58
• Drug Safety 200124(11)843-853

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Thanks for Your Attention!!