American Association of Critical-Care Nurses (AACN) Certification Practice Test

What is a major characteristic of distributive shock?

1. Inadequate cardiac output

2. Excessive vasodilation and altered blood flow

3. Obstructed filling of ventricle

4. Decreased peripheral vascular resistance

The correct answer is: Excessive vasodilation and altered blood flow

Distributive shock is primarily characterized by excessive vasodilation and altered blood flow. This condition leads to a significant reduction in systemic vascular resistance, causing blood vessels to widen excessively. As a result, while the cardiac output may not be significantly impaired initially, the blood does not flow adequately to the tissues because it is not properly distributed. In distributive shock, such as septic shock or neurogenic shock, the body's normal compensatory mechanisms can be overwhelmed, leading to impaired oxygen delivery to tissues despite normal or even increased cardiac output. This characteristic of excessive vasodilation is critical, as it distinguishes distributive shock from other forms such as cardiogenic shock, where inadequate cardiac output is the primary concern, and obstructive shock, which involves physical obstruction to cardiac filling. In distributive shock, the blood vessels cannot appropriately constrict, creating a scenario where blood pooling occurs, and blood supply to vital organs becomes compromised. Therefore, recognizing this key feature helps in identifying and managing the condition effectively.