TYK156
Which of the following is usually the EARLIEST detected sign of anaphylaxis in anesthetized patients?
a) Urticarial rash
b) Bronchospasm
c) Hypotension
d) Tongue edema
e) Elevated tryptase
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Which of the following is usually the EARLIEST detected sign of anaphylaxis in anesthetized patients?
a) Urticarial rash
b) Bronchospasm
c) Hypotension
d) Tongue edema
e) Elevated tryptase
Answer c.
Anaphylaxis is a potentially life-threatening allergic reaction, most commonly mediated by IgE (although anaphylactoid reactions are not IgEmediated). In awake patients, any combination of the above signs may be present, and hypotension is usually a late finding. However, under general anesthesia (and surgical drapes), urticaria may not be present and may not be observed if present, bronchospasm may or may not be present (especially in the setting of bronchodilatory effects of inhalational agents), and edema/swelling is difficult to differentiate from normal perioperative third-spacing. Thus, often the first sign of a reaction is hypotension or circulatory collapse; conversely, any unexplained hypotension should be investigated as a potential case of anaphylaxis until proven otherwise.