North Carolina EMT State Practice Exam

What type of shock is caused by mechanical obstruction of the cardiac muscle?

1. Distributive shock

2. Obstructive shock

3. Hypovolemic shock

4. Cardiogenic shock

The correct answer is: Obstructive shock

Obstructive shock occurs when there is a mechanical obstruction that impedes the heart's ability to pump effectively. This can be caused by various conditions such as cardiac tamponade, tension pneumothorax, or massive pulmonary embolism. In these scenarios, something external or internal exerts pressure on the heart or major vessels, limiting the volume of blood returning to the heart or being pumped out, thus compromising circulation and leading to shock. In contrast, distributive shock is characterized by widespread vascular dilation, often due to severe infections (septic shock) or anaphylaxis, resulting in inadequate blood flow despite a normal or increased blood volume. Hypovolemic shock is due to a significant loss of blood or fluids, while cardiogenic shock is a result of the heart's failure to pump effectively due to intrinsic cardiac issues, such as myocardial infarction. Each type of shock is fundamentally different in its cause and mechanism, making it critical to recognize obstructive shock as specifically related to mechanical obstruction of the heart's function.