What type of shock is associated with decreased heart rate and blood pressure due to loss of sympathetic tone?

• A. Cardiogenic shock
• B. Neurogenic shock
• C. Septic shock
• D. Hypovolemic shock

Answer: (B)

Neurogenic shock is characterized by a loss of sympathetic tone, which leads to vasodilation and results in decreased peripheral vascular resistance. This condition often arises from spinal cord injuries or severe central nervous system injuries, leading to the disruption of sympathetic nervous system output. As a result, blood vessels dilate, causing hypotension, and there may be a concurrent bradycardia (decreased heart rate) due to unopposed parasympathetic activity.

In contrast, cardiogenic shock is primarily due to the heart's inability to pump effectively, resulting in decreased cardiac output and potential tachycardia as a compensatory mechanism. Septic shock involves a systemic inflammatory response that can also lead to vasodilation, but it typically presents with tachycardia and febrile responses due to infection. Hypovolemic shock occurs due to a significant loss of blood volume, leading to increased heart rate in an attempt to maintain cardiac output despite low volume.

Thus, the defining characteristics of neurogenic shock—such as low blood pressure and a decreased heart rate from a loss of sympathetic tone—distinguish it from the other types of shock.