In neurogenic shock, which parameters are expected to decrease?

In neurogenic shock, the fundamental issue revolves around the loss of sympathetic nervous system tone, which leads to widespread vasodilation. This condition is typically a result of spinal cord injury or significant disruption to the autonomic nervous system.

As a result of this vasodilation, systemic vascular resistance significantly decreases. The drop in vascular resistance contributes to a decrease in blood pressure, as there is less pressure exerted per unit area within the blood vessels due to the decreased resistance to blood flow.

Additionally, heart rate also tends to decline during neurogenic shock. This could be due to the unopposed vagal activity that occurs when the sympathetic pathways are disrupted—leading to bradycardia (slower heart rate). The body's compensatory mechanisms, which usually increase heart rate to counteract hypotension, are impaired, resulting in an overall drop in heart rate.

When considering these physiological responses, it becomes clear that neurogenic shock is characterized by decreased heart rate, decreased systemic vascular resistance, and decreased blood pressure. This triad of decreased parameters is crucial for understanding and managing neurogenic shock in critical care situations.