You are carrying out work at height. You have put all of the safety controls in place and are using all the necessary equipment for the job. Even so, the unthinkable happens and you trip and fall off the edge. Immediately your fall arrest equipment takes effect and you are saved from a fall which most certainly would have ended in injury or possibly even worse.
However, be aware that you are still in danger and the need for an immediate rescue needs to be taken. Why?
What is Suspension Trauma (Syncope) or Orthostatic Shock?
Suspension trauma occurs when the human body is held in an upright position without any movement for a period of time in a fall arrest body harness.
Do all harness induce Suspension Trauma?
Harnesses used by rock climbers, abseilers and arborists (normally front attached) enable the user to be suspended for longer periods as their design applies little pressure to the femoral vein in the legs (the main vessel that returns blood from the legs to the heart). They also place the user in a more horizontal position which assists with gravitational pull. Provided they remain active they are able to be suspended for much longer periods without any problems.
However, rear attached harnesses used for fall arrest are made to stop a fall and are not designed for prolonged suspension. The leg straps, which form part of the design, place direct pressure on the femoral vein and nerve. If suspension continues the person will eventually faint and if they remain in this position for an extended period they can be deprived of oxygen and even risk death. The diagram to the right outlines the cycle of events.
How long before Suspension Trauma occurs?
Suspension trauma can occur in as little as 5 minutes so it is vital that rescue is actioned as soon as possible.
What are the signs of Suspension Trauma?
Similar to shock, the symptoms of suspension trauma are faintness, tingling or numbness of the arms or legs, breathlessness, sweating, nausea, dizziness, low blood pressure, unconsciousness.
What can be done before rescue to try and relieve Suspension Trauma?
Easier said than done, but try to keep the worker calm. Ensure that professional help has been alerted and is on its way. If the harness they are wearing has an emergency leg strap designed to alleviate pressure, commence using it as a “stand up” device at once. If it is only for single leg use make sure they alternate legs. If there is no strap try to elevate the legs into a sitting position.
(Reference HSE 2009 Guidance on first aid measures for suspension trauma)
What is the treatment once rescue has occurred?
Download the current recommended guidelines (Section 9.1.5 – Harness Suspension Trauma Management) as set out by the AUSTRALIAN RESUSCITATION COUNCIL on what to do after you rescue a person who has been suspended in a fall arrest harness.
If you are in a situation where you or a fellow worker is suspended in a fall arrest harness remember that time plays a vital part in overall safety. Call an ambulance and if possible and safe to do so, organise immediate rescue.