Neurogenic shock

What is Neurogenic Shock?

Neurogenic shock is an emergency condition, wherein, the nervous system fails or malfunctions after a severe trauma, neurological insult, or spinal cord injury. It occurs when the sympathetic nervous system fails to adequately stimuate arteriole constriction, resulting in pooling of blood in the vascular compartment and a subsequent drop in blood pressure and circulation.

Specifically, neurogenic shock is associated with two Shocked states: Hypotensive and Hypertonic. Hypotensive shock is caused by the failure of the sympathetic nervous system, resulting in a drop of the systolic blood pressure below 90 mmHg with signs of poor tissue perfusion. Hypertonic shock is also due to a sympathetic nervous system malfunction, but results in an increased vascular resistance, leading to increased afterload that results in increased cardiac work and decreased cardiac output.

Signs and Symptoms of Neurogenic Shock

The clinical features of neurogenic shock can be categorised into four stages:

• Stage 1 : The patient presents with intense vasodilation, a sudden drop in blood pressure, and an increased heart rate secondary to both the catecholamine and spinal cord releasing hormone release.
• Stage 2 : Tachycardia, tachypnea, sweating and pallor caused by pooling of the blood in peripheral vessels.
• Stage 3 : Loss of consciousness, mental confusion, agitation, and hypotonia.
• Stage 4 :Metabolic acidosis due to hypoperfusion caused by decreased cardiac output.

Treatment for Neurogenic Shock

Treatment for neurogenic shock will aim at restoring blood pressure aswell as the other signs and symptoms. The mainstays of therapy includes the following.

• Fluid therapy to improve perfusion and increase blood volume.
• Administration of vasopressors, such as norepinephrine, to increase peripheral vascular resistance, increasing cardiac output.
• Intubation, mechanical ventilation, and administration of anesthetic agents to improve oxygenation and pulmonary functions.
• Administration of corticosteroids to reduce inflammation.

Conclusion

Neurogenic shock is a rare but life-threatening condition that requires urgent medical intervention to restore blood pressure and other signs and symptoms. Treatment options includes fluid therapy, administration of vasopressors and corticosteroids, intubation and mechanical ventilation.