Which finding is a sign of Cushing's triad?

Which finding is a sign of Cushing's triad?

• A. Heart rate decreases from 75 to 55 beats/minute
• B. Kussmaul respirations
• C. Temperature over 100.4° F (38° C)
• D. Heart rate increases from 90 to 110 beats/minute

Answer: (A)

Cushing's triad is a late sign of rising intracranial pressure and includes a rise in systolic blood pressure with a wide pulse pressure, bradycardia, and irregular respirations. The drop in heart rate from 75 to 55 beats per minute is bradycardia, which fits this triad. The other signs point to different processes: Kussmaul respirations suggest metabolic acidosis, fever indicates infection or inflammation, and an increased heart rate would not reflect the bradycardia characteristic of Cushing's triad. Mechanistically, as ICP increases, cerebral perfusion pressure drops; the body raises systemic BP to compensate, and baroreceptors respond with a slower heart rate, while brainstem involvement causes irregular breathing.

Cushing's triad is a late sign of rising intracranial pressure and includes a rise in systolic blood pressure with a wide pulse pressure, bradycardia, and irregular respirations. The drop in heart rate from 75 to 55 beats per minute is bradycardia, which fits this triad. The other signs point to different processes: Kussmaul respirations suggest metabolic acidosis, fever indicates infection or inflammation, and an increased heart rate would not reflect the bradycardia characteristic of Cushing's triad. Mechanistically, as ICP increases, cerebral perfusion pressure drops; the body raises systemic BP to compensate, and baroreceptors respond with a slower heart rate, while brainstem involvement causes irregular breathing.