Re: [FIREFLYR] Rescuers reach BASE jumper in tree near
The correct name is Suspension Shock Syndrome aka Suspension Trauma. The correct definition of what it is exactly is as follows:
Anecdotal evidence suggests that an immobilized person suspended in a harness will begin to deteriorate after as little as four minutes leading to coma and possibly death.
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 affect on persons suspended in a harness with a dorsal/shoulder 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, which are capable of considerable expansion and, therefore, have considerable capacity. The excess of blood in the veins is known as venous pooling.
Pressure from the harness straps on veins and arteries could also be a contributory factor to this retention of blood in the venous system, which reduces the circulating blood volume available to the heart. Thus, the circulatory system is disturbed. This can lead to critical reduction of blood to the brain and the symptoms described above.
Other organs critically dependent on a good blood supply, such as kidneys, can also suffer serious damage, with fatal consequences.
The movement of a person with venous pooling (e.g. in a rescue) into a horizontal position can cause a massive flow in venous blood to the heart, which cannot cope, and this can cause potentially fatal cardiac abnormalities.
In several clinical trials where the 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. Others managed for longer before reporting symptoms.
It seems that steps can be taken to minimize the risk of experiencing the condition. Frequent ‘pumping’ of the legs, preferably against a firm surface, will activate the muscles and should reduce the risk of venous pooling. Harness leg loops should be well padded and as wide as possible to spread the load and reduce any restrictions.
Hope this can help to shed some light on the topic.