Suspension syncope / trauma (toxic shock)

Anecdotal evidence suggests that an immobilised person suspended in a harness will begin to deteriorate after as little as four minutes — leading to coma and possibly death.

The symptoms

Suspension trauma is a condition in which a person suspended in a harness can experience:

Pallor, cold sweats, nausea
Ringing in the ears, blurred vision, dizziness
Feeling faint, loss of consciousness, and eventual death

The condition appears only to have a serious effect on persons suspended in a harness with a dorsal attachment without moving — for example, when unconscious.

Muscular action in moving the limbs normally assists the return against gravity of blood in the veins back to the heart. If the legs are completely immobile, these 'muscle pumps' do not operate and an excess of blood accumulates in the veins — venous pooling.

Pressure from harness straps on veins and arteries could also be a contributory factor. The reduction of circulating blood volume disturbs the circulatory system, leading to critical reduction of blood to the brain.

The danger during rescue

Moving a person with venous pooling into a horizontal position can cause a massive flow of venous blood to the heart, which cannot cope — potentially causing fatal cardiac abnormalities.

In several clinical trials where test subjects were told not to move, most experienced many of the symptoms of suspension trauma — some including loss of consciousness — in just a few minutes.

Risk reduction

Steps that can minimise the risk:

Frequent 'pumping' of the legs, preferably against a firm surface, activates the muscles and reduces venous pooling.
Harness leg loops should be well-padded and as wide as possible to spread the load and reduce restrictions.
The use of a work seat might be advisable if work in one position is to be sustained for an extended period.

Work seats

Your instructor will demonstrate a variety of work seats currently in use.

During the rescue

It would be advisable for the casualty to be sat-up with the knees elevated slightly. This can be achieved by suspending the casualty from the sternal attachment point and, if possible, positioning the harness leg loops under the knees — elevating them and avoiding a rapid return of venous blood to the heart.

The eventual movement of the casualty to the horizontal should be carried out over an extended period of around 20–30 minutes. Medical advice should always be sought.