Perioperative anaphylaxis
Perioperative anaphylaxis is anaphylaxis during anesthesia and surgery, most often caused by neuromuscular blocking agents, antibiotics, latex, or chlorhexidine, and is dangerous because skin signs are hidden under drapes so cardiovascular collapse may be the first clue. Management is immediate intramuscular or intravenous epinephrine, and later tryptase and skin testing identify the culprit for future avoidance.
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What this article covers
- Overview
Definition: perioperative anaphylaxis is anaphylaxis occurring during the perioperative period, triggered by drugs or materials used in anesthesia and surgery.
- Epidemiology
A recognized cause of anesthetic morbidity and mortality, with incidence varying by agent and region.
- Risk factors
Prior perioperative reaction or known drug allergy.
- Pathophysiology
IgE-mediated anaphylaxis: drug- or material-specific IgE triggers mast cell degranulation (typical for neuromuscular blocking agents, beta-lactams, latex, chlorhexidine).
- Clinical features
Cardiovascular collapse: sudden, often profound hypotension and tachycardia, frequently the first sign.
- Differential diagnosis
Other causes of intraoperative hypotension: hemorrhage, anesthetic overdose, vasodilation, or vagal reaction, without the bronchospasm, urticaria, or tryptase rise of anaphylaxis.
- Diagnosis
Recognize clinically during the event, then confirm with tryptase and identify the culprit by later skin testing: the diagnostic basis is acute anaphylaxis (cardiovascular collapse, bronchospasm…
- Management
First, halt the suspected trigger and treat as anaphylaxis immediately: Epinephrine 0.3 to 0.5 mg IM, repeated every 5 to 15 minutes as needed.
- Complications
Death or hypoxic-ischemic injury: from delayed recognition under anesthesia.
- Prognosis
Good with immediate treatment: prompt epinephrine and fluids usually reverse the reaction.
- Prevention
Identify the culprit after any reaction with acute tryptase and delayed skin testing performed 4 to 6 weeks later, and document it prominently.
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Related articles
- Anaphylaxis
Anaphylaxis is an acute, potentially fatal systemic hypersensitivity reaction from massive mast cell and basophil mediator release, presenting within minutes as skin, respiratory, cardiovascular, and gastrointestinal involvement after allergen exposure. It is a clinical, treat-first diagnosis, and intramuscular epinephrine is the immediate life-saving therapy.
- Urticaria
Urticaria is transient, pruritic, edematous wheals from mast cell histamine release, classified by duration into acute (under 6 weeks) and chronic (6 weeks or longer, usually spontaneous/idiopathic). Diagnosis is clinical with minimal testing, and treatment is stepwise second-generation H1 antihistamines up-titrated as needed, adding omalizumab for refractory chronic disease.