Lifetime prevalence of anaphylaxis is 0.05% to 2%, most common triggers being food, stings, and iatrogenic causes.

Occurs in approximately 1 in 10,000 to 1 in 20,000 anesthetic procedures, and 1 in 6500 administrations of neuromuscular blocking agents (NMDAs). Causes 3% of anesthesia-related deaths.

Females outnumber males 3:1.

Hx of atrophy, prior anaphylaxis, and prior adverse reaction to anesthesia.

Significant risks of life-threatening CV collapse, airway compromise, and bronchospasm.

Most common causes are NMDAs (60%), latex (15%), and antibiotics (15%).

Increased risk of life-threatening reactions with beta blockers, ACEIs, asthma, and underlying cardiac disease.

Significant risks of life-threatening CV collapse, airway compromise, and bronchospasm.

Most common causes are NMDAs (60%), latex (15%), and antibiotics (15%).

Increased risk of life-threatening reactions with beta blockers, ACEIs, asthma, and underlying cardiac disease.

Hx of atrophy, prior anaphylaxis, and prior adverse reaction to anesthesia.

Timing: Most reactions occur around the time of induction or within 10 min of drug administration. May be difficult to distinguish from other drug reactions or mechanical problems.

Rapid progression: Time to cardiac or resp arrest is within 5 min for anesthetic reactions, compared to 30 min for food and 15 min for stings.

Diagnostic difficulty: Varied presentations, tachycardia or bradycardia, less than 50% have bronchospasm, cutaneous signs may be absent or occur later in severe reactions.

Biphasic response: May recur from 4-24 h later

Defined as a severe, life-threatening, generalized or systemic hypersensitivity reaction.

Classified as:

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  Allergic reactions, usually involving IgE.

  
  
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  Nonallergic reactions, previously called anaphylactoid.

  
  
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  Itching, burning hands, feet, mouth or genitals, abdominal pain, nausea, and a feeling of doom or tunnel vision may be reported by awake pts.

Most common initial features during anesthesia are pulselessness, desaturation, and difficult ventilation.

Allergic: IgE antibodies crosslink receptors on mast cells and basophils, causing degranulation, releasing many vasoactive substances, incl histamine, in an inflammatory cascade.

Usually requires prior exposure. However, can occur with NMDAs with first exposure, thought to be due to common quaternary amine in NMBAs and chemicals (e.g., found in cleaners and cosmetics). In Europe, linked with ingredient in cough syrup, pholcodine.

Can occur with any muscle relaxant, most commonly succinylcholine. Increasing reports with rocuronium; also reported with sugammadex.

Risk factors for latex allergy include meningomyelocele, as well as allergy to figs, papayas, or avocados. Increased in healthcare workers

Rarely due to opiates or local anesthetics (more likely intravascular injection or epinephrine)

Nonallergic: Related to drug dose and speed of injection. Usually less severe than IgE-mediated reactions.