Emergency Medical Technician (EMT) Intermediate Practice Exam

Obstructive shock occurs when the:

1. Heart is physically restricted from pumping adequately

2. Blood volume is reduced

3. Blood vessels are dilated

4. Heart rate is excessively elevated

The correct answer is: Heart is physically restricted from pumping adequately

Obstructive shock occurs when there is a physical obstruction that prevents the heart from effectively pumping blood. This can happen in situations such as tension pneumothorax, cardiac tamponade, or massive pulmonary embolism. In these conditions, the heart is mechanically hindered, which leads to a reduction in the amount of blood that can be circulated to the body's tissues. In contrast, other forms of shock involve different mechanisms. For instance, a reduction in blood volume typically characterizes hypovolemic shock, where significant fluid loss leads to decreased perfusion. Dilation of blood vessels can cause distributive shock, resulting from conditions such as sepsis or anaphylaxis, where the circulation volume is sufficient, but the blood vessels are too expansive, leading to inadequate blood pressure. Lastly, an excessively elevated heart rate can be seen in various types of shock but does not define obstructive shock directly. Each of these mechanisms plays a role in different kinds of shock but does not apply to the obstruction of blood flow specific to obstructive shock.