Suspension trauma

Suspension trauma, also known as orthostatic shock while suspended, harness hang syndrome (HHS), suspension syndrome, or orthostatic intolerance, is an effect which occurs when the human body is held upright without any movement for a period of time. If the person is strapped into a harness or tied to an upright object they will eventually suffer the central ischaemic response (also known as syncope or fainting). Fainting while remaining vertical increases the risk of death from cerebral hypoxia. Since there is no evidence that these effects are specifically due to trauma, or caused by the harness itself, climbing medicine authorities have argued against the terminology of suspension trauma or harness hang syndrome and instead termed this simply "suspension syndrome". People at risk of suspension syndrome include people using industrial harnesses (fall arrest systems, abseiling systems, confined space systems), people using harnesses for sporting purposes (caving, climbing, parachuting, etc.), stunt performers, circus performers, and occupations that require the use of harnesses and suspension systems in general. In the UK the term "suspension trauma" has been replaced by "syncope" or "pre-syncope" as "trauma" suggests that there has been a physical injury that has resulted in the fallen person becoming unconscious. In the circumstances where a person has fallen into suspension on a rope/lanyard and has become unconscious, it is thought that the unconscious state "syncope" is due to a combination of orthostasis or motionless vertical suspension, with "pre-syncope" being the state before the person becomes unconscious where the fallen person may experience symptoms such as light-headedness; nausea; sensations of flushing; tingling or numbness of the arms or legs; anxiety; visual disturbance; or faintness. HSE Research Report RR708 2009 1 Introduction page 5 paragraphs 1 and 3 refers.