What is Harness Hang Syndrome?

Harness suspension trauma victims can die rapidly due to lack of blood supply to the brain. Stale, non-circulating blood may also form clots in their legs while other organs could also suffer due to low oxygen levels and electrolyte imbalance.

Safety professionals, rescuers and paramedics must understand suspension trauma - also referred to as orthostatic shock while suspended and mechanical asphyxia - which is also known as suspension trauma or mechanical asphyxia.

Symptoms

Suspension trauma can happen to anyone suspended in an extended suspension in a harness, and in extreme cases this may even lead to death. Our bodies were never intended to stay immobile vertically for long, so when movement ceases, blood pools in lower legs, cardiac output falls, and cerebral perfusion decreases [1].

Suspension trauma causes presyncopal symptoms including lightheadedness, dizziness, vision changes and numbness of extremities - often within three minutes after initial fall - which progress into unconsciousness and ultimately death. While altitude illnesses typically affect mountaineers and ice climbers only, suspension trauma has also been seen among speleologists, paragliders and industrial climbers.

Rescuers should be trained in the appropriate procedure for rescuing victims of suspension trauma and plan their rope access or climbing job with this in mind, taking into account potential consequences from falls and the possibility of becoming suspended motionlessly in a harness harness harness harness when planning any job. Anyone who falls while suspended in their harness should be immediately rescued or repositioned with knees raised, with the goal of elevating out within 10 minutes after falling.

Diagnosis

Suspension trauma or harness hang syndrome is the result of natural physiological responses to immobile vertical positions, in particular fall protection systems with leg straps exerting pressure on thighs to restrict blood flow to legs and brain, which in turn lower oxygen levels leading to low consciousness levels or loss. Without prompt rescue efforts this condition may even become fatal within minutes if left unattended and not moved upon quickly enough.

When workers use personal protective equipment (PPE) systems to arrest a fall, they remain suspended motionless in a vertical position for long periods. Their PPE's design often forces them into this immobile state until they are finally able to stand. At this point, victims often experience pre-syncopal symptoms like lightheadedness, dizziness, cold sweats, vision changes and nausea before finally being able to stand.

Vertical suspension of a harness causes blood to pool in the lower extremities, decreases cardiac output and causes cerebral perfusion to decline, leading to uncontrolled syncopal episodes and even eventual death. Slamming forces from terminal impact forces may transform nylon leg loop straps into tourniquets directly over the femoral vein located just beneath the skin at its "pulse point," placing recreational and occupational climbers, novice rock climbers, construction workers and anyone who wears harnesses for work at risk of serious injury or even death.

Treatment

Under normal conditions, acidosis from anaerobic metabolism reduces vascular resistance and allows an increase in blood flow with concurrent increases in oxygen provision and waste product removal. When an individual is motionless and suspended in a harness, their increased blood flow sequesters in peripheral regions containing highly acidotic venous blood - this may decrease cerebral perfusion resulting in syncope, suspension shock or even rhabdomyolysis with potential fatal consequences.

Suspension trauma or harness hang syndrome (HHS) occurs when anyone who is suspended in a harness without movement - for instance mountain climbing and caving are activities where HHS could occur. Although its frequency remains unknown, HHS could contribute significantly to deaths during rope-secured work activities.

Priority one should be to free the person as quickly as possible from being suspended, using standard Advanced Trauma Life Support (ATLS) treatments upon reaching them. In particular, airway obstruction caused by unconscious hanging should be reversed while lifting legs is done so they lie more horizontally on the hammock. There has been no indication of harm incurred from immediately placing patient back down after rescue.

Prevention

Human bodies are designed to support our brains through oxygenating our lungs, loading it with nutrition (including glucose), and pumping it throughout our bodies. The heart is especially essential in transporting blood around, especially to the brain and other organs. When people remain suspended in harness for extended periods, they risk suffering suspension trauma or orthostatic intolerance.

Weighty individuals put undue strain on their shoulders and abdomens, compressing veins and impairing circulation - which in turn results in reduced oxygen supply to their brain, organs and spinal cord which may eventually prove fatal.

Suspension trauma may not be common, but all workers must remain mindful of its threat. Prevention strategies include providing regular training on fall protection systems and developing emergency rescue plans; additionally employers should equip workers with trauma relief straps.

It is strongly suggested that anyone who falls from their harness be rescued within 10 minutes, first by positioning themselves to raise their knees as high as possible and, if this cannot be accomplished, by calling an ambulance. In addition, all people using harnesses should consider adopting an automatic self-descent system for safe descents.