Which hemodynamic change is most indicative of rupture of an abdominal aortic aneurysm?

• A. Hypertension
• B. Tachycardia
• C. Hypotension
• D. Normal blood pressure

Answer: (C)

When an abdominal aortic aneurysm ruptures, internal bleeding rapidly reduces circulating blood volume, which lowers venous return to the heart and decreases cardiac output. The result is a fall in arterial pressure, i.e., hypotension. This drop in blood pressure is the most direct and concerning indicator of rupture.

Tachycardia can occur as a compensatory response to blood loss, but it isn’t as specific to rupture and can happen in many conditions. Hypertension would be unlikely with active hemorrhage, and normal blood pressure would suggest there isn’t significant blood loss.