The incidence of neurogenic shock in patients with isolated spinal cord injury in the emergency department.

BACKGROUND: Spinal cord injury (SCI) is recognised to cause hypotension and bradycardia (neurogenic shock). Previous studies have shown that the incidence of this in the emergency department (ED) may be low. However these studies are relatively small and have included a mix of blunt and penetrating injuries with measurements taken over different time frames. The aim was to use a large database to determine the incidence of neurogenic shock in patients with isolated spinal cord injuries.
METHODS: The Trauma Audit and Research Network (TARN) collects data on patients attending participating hospitals in England and Wales. The database between 1989 and 2003 was searched for patients aged over 16 who had sustained an isolated spinal cord injury. The heart rate (HR) and systolic blood pressure (SBP) on arrival at the ED were determined as was the number and percentage of patients who had both a SBP<100mm Hg and a HR<80 beats per minute (BPM) (the classic appearance of neurogenic shock).
RESULTS: Four hundred and ninety patients had sustained an isolated spinal cord injury (SCI) with no other injury with an abbreviated injury scale (AIS) of greater than 2. The incidence of neurogenic shock in cervical cord injuries was 19.3% (95% CI 14.8-23.7%). The incidence in thoracic and lumbar cord injuries was 7% (3-11.1%) and 3% (0-8.85%).
CONCLUSIONS: Fewer than 20% of patients with a cervical cord injury have the classical appearance of neurogenic shock when they arrive in the emergency department. It is uncommon in patients with lower cord injuries. The heart rate and blood pressure changes in patients with a SCI may develop over time and we hypothesise that patients arrive in the ED before neurogenic shock has become manifest.