Understanding Obstructive and Neurogenic Shock

Neurogenic shock is defined as a loss of sympathetic stimulation, resulting in parasympathetic stimulation. The body experiences a massive vasodilation and the body is unable to compensate for the drop in cardiac output.


What causes Neurogenic Shock?

  • Brain Injury
  • Spinal Cord injury (cervical injury or high thoracic spinal injury)
  • Spinal Anesthesia

Neurogenic Shock Assessment

Sympathetic nervous system loss means the body loses the “fight or flight” response and the parasympathetic nervous system’s “rest and digest” system is unopposed.

  • Bradycardia instead of tachycardia
  • Bradypnea rather than tachypnea
  • Hypotension
  • Skin warm, dry, and flushed
  • Full pulses
  • Priapism


Neurogenic Shock Interventions

  • Airway, Breathing, and Circulation to prevent secondary cord injury
  • Fluid resuscitation
    • Mean Arterial Pressure (MAP) above 60-70 mmHg
    • Central Venous Pressure (CVP) 8-12 mmHg
    • Urine output 0.5mL/kg per hour or 30-60 mL per hour
    • Normal serum lactate levels
    • SvO2 65-75%
    • Systolic Blood Pressure above 90 mmHg
  • Administer vasopressors (phenylephrine)
  • Administer atropine for bradycardia
  • Routine administration of high-dose corticosteroids no longer recommended

What is Obstructive Shock?

Obstructive shock is defined as inadequate cardiac output and tissue perfusion due to resistance to ventricular filling.

What causes Obstructive Shock

  • Pulmonary embolism
  • Pericardial tamponade
  • Tension pneumothorax

Obstructive Shock Interventions

  • Determine the cause of hypovolemia and fix the problem
  • Pulmonary Embolism
    • Intravenous anticoagulation and thrombolytics
  • Pericardial tamponade
    • Immediate pericardiocentesis and subsequent surgical repair
  • Tension pneumothorax
    • Immediate needle thoracotomy and chest tube placement