Which type of shock is caused by a pump problem due to mechanical obstruction of the heart muscle?

• A. Cardiogenic shock
• B. Obstructive shock
• C. Hypovolemic shock
• D. Distributive shock

Answer: (B)

Obstructive shock is when a mechanical obstruction hinders blood flow, creating a pump problem for the heart even if the heart muscle itself is capable of contracting. This type of shock happens when something physically blocks circulation, such as a tamponade around the heart, a tension pneumothorax that collapses venous return, or a large pulmonary embolism that blocks blood from leaving the right side of the heart. Because the obstruction prevents either filling or outflow, cardiac output drops and shock develops. This differs from cardiogenic shock, where the heart muscle itself is damaged and cannot pump effectively even without any external blockage. Hypovolemic shock comes from too little circulating blood volume, and distributive shock from widespread vasodilation and relative hypovolemia, not from a mechanical blockage to the heart’s flow. So the best match for a pump problem caused by a mechanical obstruction is obstructive shock.