Distributive shock is characterized by which mechanism?

• A. Hypovolemic Shock
• B. Obstructive Shock
• C. Distributive Shock
• D. Neurogenic Shock

Answer: (C)

Distributive shock is driven by widespread vasodilation with maldistribution of blood flow. When the vessels dilate broadly, systemic vascular resistance falls and blood pools in the venous system, so venous return to the heart drops and tissue perfusion suffers despite the total blood volume being normal or even high. This mechanism explains why perfusion is impaired even though the overall blood volume may not be reduced. Causes include sepsis, anaphylaxis, and neurogenic injury, which all promote excessive vasodilation.

In contrast, hypovolemic shock comes from actual loss of circulating blood volume, and obstructive shock from a physical blockage to cardiac filling or outflow. Neurogenic shock is a form of distributive shock caused by loss of sympathetic tone, leading to vasodilation.