GF15: Neuro Neurogenic and Spinal Shock Flashcards
What is Neurogenic Shock?
- Autonomic dysregulation following a SCI (typically with injury above T6) or TBI
- This type of shock leads to the inability of the sympathetic nervous system to stimulate nerve impulses,
- With the inaction of the SNS, it leaves only the PNS to affect the body’s symptoms
- This imbalance between the SNS/PNS causes hemodynamic problems.
- This leads to a decrease in tissue perfusion where the cells that make up our organs and tissue don’t receive enough oxygen. Hence, signs and symptoms of shock occur
What is the patho of neurogenic shock?
Spinal injury >T6 → Loss of sympathetic tone → venous and arterial dilation → decreased venous return → decreased stroke volume → decreased CO → Decreased cellular O2 supply → impaired perfusion → impaired cellular metablosim
What are the three critical VS alterations that are caused by neurogenic shock?
- Hypotension
- Bradycardia
- Poikilothermic (inability to control body temp)
How does neurogenic shock cause hypotension?
- The SNS is responsible for vasoconstriction. As the SNS is disabled in neurogenic shock, the vascular system relaxes and dilates.
- This dilation slows down blood flow to the point where there is not enough internal pressure to provide for appropriate circulation return
- Due to the damage/location of injury, the SNS cannot respond to the low BP w/ factors to raise it back up as it normally would
How is the hypotension of neurogenic shock treated?
- IV fluids (0.9% NS), rate determined by case
- Vasopressors to assist w/ vasoconstriction
Why do we need to be careful with fluids admin when treating neurogenic shock?
- Hypovolemia in the case of neurogenic shock is not due to loss of volume, but vasodilation.
- As the situation is resolved and normal SNS vasoconstriction resumes, we must be careful to not cause fluid overload
How does neurogenic shock cause bradycardia?
The SNS cannot send signals to the heart to speed up and fight the hypotension of neurogenic shock. Only PNS messages of “rest and digest” are able to be received, so the heart rate slows accordingly
How is bradycardia treated in neurogenic shock?
With the administration of atropine, which will speed up the heart
Why is the body unable to control temperature in neurogenic shock?
Signals from the hypothalamus are disrupted, thus temp regulation cannot occur
How can hypothermia result from neurogenic shock?
- Low blood pressure does not provide enough pressure to return blood adequately to the heart
- As a result, blood pumps out to the extremities, but does not return
- This results in warm, dry limbs and a cooler core due to poor circulation
What is hypothermia risk managed?
- Rewarming devices for hypothermia
- Warm fluids
Why does poor tissue perfusion result from neurogenic shock?
- Due to extremely low HR, BP and circulation, blood is not passing through the lungs to oxygenate and get to the body’s tissue
- This ultimately impair cellular metabolism (ischemia)
- Death can occur if neurogenic shock is not identified and treated early
How soon after injury can neurogenic shock manifest and how long can it last?
- w/in 30 mins
- up to 6 wks
What are the main nursing interventions for neurogenic shock?
- Manage patient’s ABCS (Airway, Breathing, Circulation & Spine)
- Keep spine immobilized (don’t want to cause any more damage and decrease perfusion to the spine)
- Intubation and mechanical ventilation (if required due to injury)
- Maintain MAP of 85-90 to maintain perfusion
Besides Bradycardia, hypovolemia and temperature dysregulation, what are two other major concerns to monitor and address as needed?
- Urinary function
- DVT prevention
