A decrease in blood pressure may indicate:

A decrease in blood pressure may indicate:

• A. Loss of blood or its fluid components
• B. Loss of vascular tone and sufficient arterial constriction to maintain the necessary pressure even without any actual fluid or blood loss
• C. A cardiac pumping problem
• D. An increase in blood volume

Answer: (A)

A drop in blood pressure most directly signals a loss of circulating blood or its fluid components. When volume falls, venous return to the heart decreases, which lowers stroke volume and cardiac output, causing arterial pressure to drop. This is what happens with hemorrhage or dehydration and other fluid losses. While problems with the heart’s pumping or with widespread vasodilation can also reduce blood pressure, the most immediate and common cause you’d identify in EMS is a reduction in circulating blood or fluids. Increasing blood volume would raise blood pressure, not lower it.

A drop in blood pressure most directly signals a loss of circulating blood or its fluid components. When volume falls, venous return to the heart decreases, which lowers stroke volume and cardiac output, causing arterial pressure to drop. This is what happens with hemorrhage or dehydration and other fluid losses. While problems with the heart’s pumping or with widespread vasodilation can also reduce blood pressure, the most immediate and common cause you’d identify in EMS is a reduction in circulating blood or fluids. Increasing blood volume would raise blood pressure, not lower it.