Neurogenic Shock in Spinal Trauma
Neurogenic shock is a distributive circulatory collapse that can follow acute spinal cord injury (SCI). It results from interruption of descending sympathetic pathways with loss of vasomotor tone and relative unopposed parasympathetic activity.
Although less common than haemorrhagic shock in trauma, neurogenic shock is clinically important because it requires different haemodynamic management, can coexist with hypovolaemia, and often accompanies high cervical or upper thoracic cord lesions with respiratory compromise.
UK guidance on initial assessment, immobilisation and transfer is given in NICE NG41; Resuscitation Council UK provides practical guidance on haemodynamic support in traumatic and post‑resuscitation scenarios.
Pathophysiology
- Interruption of sympathetic outflow (classically at or above T6, often with high cervical or upper thoracic injuries) causes loss of systemic vasoconstrictor tone.
- Consequences include systemic vasodilation, pooling in venous capacitance beds, reduced preload, hypotension and often relative or absolute bradycardia from unopposed vagal tone.
- Cardiac contractility is usually preserved unless there is coexisting hypovolaemia, myocardial injury or profound vagal influence.
- Autonomic dysregulation also causes impaired thermoregulation (risk of hypothermia) and altered sweat responses.
When to suspect neurogenic shock
- Recent traumatic spinal cord injury, particularly high cervical or upper thoracic lesions.
- Hypotension with relative or absolute bradycardia (heart rate often < 60 bpm) and warm, well‑perfused peripheries rather than cold, clammy skin.