Which statement about shock classifications is accurate?

• A. All shocks are due to decreased heart rate
• B. Hypovolemic and cardiogenic shocks are the same
• C. Obstructive shock accounts for increased venous return
• D. Septic shock is a type of distributive shock

Answer: (D)

Shock classifications organize conditions by the mechanism causing inadequate tissue perfusion. The major groups are: hypovolemic (low circulating volume), cardiogenic (pump failure), obstructive (mechanical obstruction to blood flow), and distributive (maldistribution of blood flow due to widespread vasodilation or inflammatory changes). Septic shock fits into distributive shock because infection triggers systemic vasodilation and increased capillary permeability, leading to blood pooling and relative hypovolemia even if the heart is producing adequate or high output initially.

The statement that all shocks stem from a decreased heart rate isn’t accurate; heart rate can be higher as compensation, and some shock types center on volume loss or pump failure rather than HR alone. Hypovolemic and cardiogenic shocks are distinct entities with different causes. Obstructive shock does not increase venous return; it actually reduces it through obstruction such as tamponade, massive PE, or tension pneumothorax.