Neurogenic Shock


Neurogenic shock occurs when an acute spinal cord injury above the level of T6 disrupts the autonomic system, preventing tachycardia and peripheral vasoconstriction.

PATHOPHYSIOLOGY:

  1. Loss of sympathetic fxn causes unopposed vagal tone
  2. Etiologies

 

SYMPTOMS/EXAM

DIAGNOSIS

  1. Symptoms
  2. PE
  3. Diagnostic testing

TREATMENT

  1. ABCs, IV, O2, monitor
  2. Goals:
  3. IV fluids
  4. If bradycardia:
  5. Pressor support:
  6. Steroid protocol
  7. Keep warm; monitor core temp

Disposition

  1. Admit
  Receptor Activity    
Agent a1 b1 b2 DA  
Effects
Indication
Phenylephrine
40-180 mcg/min
+++ 0 0 0 SVR ↑↑
CO ↔/↑
Sepsis,
Neurogenic shock
(Levophed)
Norepinephrine
1-30 mcg/min
+++ ++ 0 0 SVR ↑↑
CO ↔↓↑
Sepsis
Epinephrine +++ +++ ++ 0 CO ↑↑
SVR ↓ (L)
SVR ↔/↑ (H)
Anaphylaxis,
ACLS,
Sepsis
Dopamine (mcg/kg/min)
Low-dose (0.5-2) 0 + 0 ++ CO ↑
SVR ↑↓
Sepsis,
Cardiogenic shock
Mid-dose(5-10) + ++ 0 ++ CO ↑
High-dose(10-20) ++ ++ 0 ++ SVR ↑↑
Doubutamine
2.5-20 mcg/kg/min
0/+ +++ ++ 0 CO ↑
SVR ↓
Cardiogenic shock
Isoproterenol
2-10 mcg/min
0 +++ +++ 0 CO ↑
SVR ↓
Cardiogenic shock w/
bradycardia
Vasopressin
(Adjunct)
0.01-0.04 U/min
        V2 receptors Vasoconstriction
Augments catecholamine