Neurogenic shock: Clinical sciences

Neurogenic shock is a serious condition associated with the loss of vascular sympathetic tone and a subsequent unopposed parasympathetic response usually from an injury to the spinal cord.

When blood vessels lose sympathetic stimulation, they vasodilate leading to a sudden drop in blood pressure from a sharp decrease in peripheral vascular resistance.

Classically, patients present with hypotension, bradycardia, and temperature dysregulation. Bradycardia in neurogenic shock is the result of the unopposed parasympathetic nervous system in the absence of the sympathetic stimulation. This is a unique characteristic of neurogenic shock that differentiates it from other types of shock.

The most common cause of neurogenic shock is blunt traumatic injury to the spinal cord above the level of T6. Other less common causes include Guillain-Barré syndrome, spinal anesthesia, and transverse myelitis. One important thing you should keep in mind is that neurogenic shock is not the same as spinal shock. Spinal shock refers to flaccidity of muscles and a loss of reflexes after a spinal cord injury.

Alright, let’s dive into how we can diagnose and treat a patient with neurogenic shock! When you encounter a patient with signs and symptoms suggestive of neurogenic shock, you should first perform an ABCDE assessment then immediately begin acute management.

Start by stabilizing the patient’s airway, breathing, and circulation. This means that you may need to intubate the patient, obtain IV access, and administer fluids before continuing with your assessment. In addition, spinal cord stabilization is crucial in cases of neurogenic shock with suspected spinal cord injury to prevent further damage.

Make sure to continuously monitor the patient’s vital signs and hemodynamic status. You can consider placing an arterial line, which will allow for more accurate monitoring of the patient’s blood pressure and mean arterial pressure, or MAP.

Now that you have stabilized your patient, let’s focus on obtaining more information! Your next step is to perform a focused history and physical examination including an evaluation of your patient’s level of consciousness using the Glasgow Coma Scale, or GCS.

This will assess your patient’s eye opening, verbal, and motor response. Keep in mind that a normal GCS is 15, which is the maximum score. Any score below 15 is considered abnormal, and a GCS of 3 indicates an unconscious comatose state.

History might reveal a recent traumatic spinal cord injury, neurosurgery, spinal anesthesia, or underlying neurodegenerative disorder such as transverse myelitis or Guillain-Barré syndrome.

On physical examination, you can expect to find hypotension, bradycardia, and some patients may have an altered mental status with a GCS less than 15 as we talked about before.

Additionally, you might find flushed warm skin, as well as sensory and motor deficits distal to the affected spinal cord level. If the patient suffered a traumatic injury, they might have midline tenderness along the spine.

If you see these findings, especially hypotension and bradycardia, you should suspect neurogenic shock right away. Then, your next step is to order a CT scan of the head and spine to evaluate for any injuries.