Which of the following symptoms is NOT associated with late-stage anaphylaxis?

In the context of late-stage anaphylaxis, hyperventilation is not a typical symptom. Late-stage anaphylaxis, often referred to as symptomatic anaphylaxis, is marked by severe cardiovascular and respiratory distress.

Common symptoms in this stage may include tachycardia, which is an increased heart rate often due to the body's response to histamine release and a compensatory reaction to hypotension (low blood pressure). Hypotension itself occurs as a result of vasodilation and increased vascular permeability caused by anaphylactic mediators. Bradycardia is less common but can occasionally occur in response to severe hypotension, where the heart rate decreases as a physiological response to the compromised state of the body.

Hyperventilation, however, is generally associated with anxiety or respiratory distress from other causes, rather than indicative of late-stage anaphylaxis. As the condition progresses, individuals typically exhibit signs of respiratory failure and may not exhibit hyperventilation but rather signs of respiratory distress, such as wheezing or difficulty breathing. Therefore, identifying hyperventilation as a symptom NOT associated with late-stage anaphylaxis is accurate.