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Zorluk: KolayTrauma and Burns

A 45-year-old woman is brought to the emergency department after being thrown from a horse. She was wearing a helmet but landed forcefully on her back. Upon arrival, she is immobilized on a rigid backboard with a cervical collar. She is conscious and alert but reports an inability to move her legs and a lack of sensation below her chest. Vital signs reveal a blood pressure of 78/4278/42 mmHg, a heart rate of 5454/min, and a respiratory rate of 1616/min. Oxygen saturation is 98%98\% on room air. Physical examination demonstrates warm, flushed skin in the upper and lower extremities. Pulses are bounding. Which of the following is the most likely etiology of this patient's hemodynamic findings?

  1. Disruption of descending sympathetic pathwaysCevap
  2. B
    Acute hemorrhage into the retroperitoneal cavity
  3. C
    Accumulation of pressurized air in the pleural space
  4. D
    Rapid accumulation of blood in the pericardial sac
  5. E
    Systemic inflammatory response to an invasive pathogen

Cevap

Disruption of descending sympathetic pathways
This patient's presentation of hypotension, bradycardia, and warm extremities following significant spinal trauma (paraplegia, loss of sensation) is classic for neurogenic shock. Spinal cord injury above the level of T1-T4 can disrupt descending sympathetic pathways. This leads to a loss of sympathetic vascular tone, resulting in massive peripheral vasodilation (causing hypotension and warm, flushed skin). Furthermore, the loss of sympathetic innervation to the heart leaves parasympathetic (vagal) tone unopposed, preventing the expected compensatory tachycardia and instead causing bradycardia.

Adım Adım Çözüm

1
Analyze the patient's vital signs and physical examination findings.
The patient is hypotensive (78/4278/42 mmHg), bradycardic (5454/min), and has warm, flushed skin.
Identifying the specific pattern of hemodynamic derangement is essential to determine the type of shock.
2
Correlate the hemodynamic pattern with the mechanism of injury.
The patient suffered blunt spinal trauma resulting in paraplegia and sensory loss below the chest. The combination of acute spinal cord injury, hypotension, and bradycardia defines neurogenic shock.
Trauma patients frequently experience hypovolemic shock, but the presence of bradycardia and warm extremities points directly to a neurogenic etiology.
3
Identify the pathophysiologic mechanism of neurogenic shock.
Neurogenic shock occurs due to the interruption of autonomic descending sympathetic tracts in the spinal cord, leading to unopposed parasympathetic (vagal) tone.
Loss of sympathetic tone causes peripheral vasodilation (producing warm skin and hypotension) and prevents the expected compensatory tachycardia, resulting in bradycardia.

Anahtar Kavram

Neurogenic shock is characterized by hypotension, bradycardia, and warm extremities due to the loss of sympathetic vascular tone following a spinal cord injury.
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Trauma and Burns

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