Sun14November1246PM 19

A 24-year-old man is admitted to the Emergency department following a high velocity road traffic accident. He has sustained injuries to his head, neck and chest. With an admission GCS of 9 he has been intubated sedated and ventilated prior to an urgent CT scan.

The patient has surgical emphysema in the neck with bruising and tyre marks on the left side of the chest. A left-sided chest drain has been inserted and connected to an underwater drain. The water in the tubing is swinging which is draining small volumes of blood. His peripheries are warm.

The following measured parameters are available:

Oxygen saturation 98%

Blood pressure 60/40 mmHg

Pulse rate 30 beats per minute

Temperature 34.4°C

Haemoglobin 12 g/dL

White cell count 12 ×109/L

ECG Sinus rhythm and ST segment depression V5 and V6 and inversion

Which of the following is the most likely cause this clinical picture?

(Please select 1 option)

Obstructive shock Incorrect answer selected

Neurogenic shock This is the correct answer

Septicaemic shock

Haemorrhagic shock

Cardiogenic shock

Explanation

This patient is likely to have suffered cervical spinal cord injury following his road traffic accident. This is characterised by the loss of spinal and autonomic reflexes below the level of the lesion. There is associated flaccid paralysis, areflexia and sensory disturbances below the damaged spinal cord.

The autonomic supply to the heart is from the sympathetic ganglia at the level T1-T4; injury above this level results in unopposed parasympathetic activity and profound bradycardia. The peripheries are characteristically warm with peripheral dilatation from impaired sympathetic innervation. This results in the loss of control of temperature and heat loss.

All the other causes of shock are associated with a tachycardia. The chest drain tube fluid level is swinging and oxygen saturation normal, which makes a tension pneumothorax on that side unlikely. Myocardial contusions can give rise to non-specific ST segment changes and myocardial damage leading to cardiogenic shock. Pericardial tamponade may cause cardiogenic shock following chest trauma and may need to be excluded.

Whilst a normal haemoglobin at this stage does not exclude concealed bleeding, a 24-year-old would normally be able to compensate for mild to moderate degrees of blood volume loss by developing a tachycardia and increasing his systemic vascular resistance.

Answer Statistics

1

28%

2

50%

3

1%

4

11%

5

12%

Times answered: 269