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How Safe is a Safety Harness?

You are dispatched to a priority 2 fall at UNR. Dispatch informs you that there is a building under construction and the patient fell from a third floor and is hanging from a safety harness. You arrive to find a construction worker hanging from a support beam by his safety harness approximately 25 feet above the ground. You are able to talk to the man and he says that he isn’t hurt but his legs are starting to “go to sleep”. The jobsite foreman informs you that he fell approximately 6 minutes ago and that he fell about 5 feet until his harness stopped him. RFD arrives within moments but is unable to reach him with their equipment. They call for a ladder truck to respond to the scene. You are fairly certain that this will be an AMA since there doesn’t seem to be any injuries. While awaiting the RFD ladder truck someone yells out “I think he’s unconscious!” You look up to see the man hanging lifeless in his harness. His coworkers are yelling to him but he doesn’t respond. You are helpless, awaiting the arrival of the ladder truck. The ladder truck arrives within minutes and sets up to rescue the man but it takes 4 minutes before they reach him. They carry down a lifeless patient to you and your partner. Your initial assessment reveals a man in his early 30’s that is unconscious and unresponsive. He is pulseless and apneic. You immediately start CPR and move into the ambulance. You do the usual treatments and procedures in route to Renown but to no avail. You hand the patient off to the physician at Renown and he is pronounced dead several minutes later.

What happened? Why did this young and seemingly healthy man die from such a short fall? Suspension trauma is a rare but we should be aware of the dangers associated with safety harness use. Death or injury secondary to the use of a safety harness is called, “suspension trauma.” The cause of death or syncope from suspension trauma is “orthostatic intolerance.” Orthostatic intolerance can be caused by several things. A common cause of orthostatic intolerance is standing with the knees locked for long periods of time. When the knees are locked there is not much need for the leg muscles to remain tight so they relax. This allows blood to pool in the legs and thus resulting in hypotension and syncope. When this occurs, the person will quickly become supine and blood is returned to the heart and the symptoms are resolved.

There are several types of safety harnesses out there but most of them support the majority of the person’s weight with leg straps. When a person falls and is suspended by the harness, the body is usually in an upright position with the legs hanging below. The legs become relaxed and the harness impedes venous return to the inferior vena cava. This results in a large amount of blood pooling in the lower extremities which lowers the amount of circulating blood to a potentially lethal level and also creates a relative “compartment syndrome.” When a person’s blood pressure falls, creating an unconscious state it would normally result in a supine position. When hanging in a harness, this doesn’t happen. Instead, the body is suspended upright with no way to correct the situation. There have been many documented cases of death from suspension trauma however not all of them occur while the person is still suspended. There is another potentially lethal situation here called “post rescue death.” Because of the relative “compartment syndrome” the blood in the person’s legs is deoxygenated and may also be contaminated with very high levels of sodium and potassium. If the person is brought to the ground and immediately moved to a supine position, the rush of “bad” blood from the legs can cause cardiac arrest.

So what does this mean for us? Well if you are the lucky one that gets this call there are a few things you can do. If the person is still conscious but hanging in a harness you can instruct them to pump their legs up and down or ride an imaginary bike which will cause the muscles to contract and squeeze the blood out of their legs. If the person is unconscious they need to be rescued quickly (probably by fire). According to OSHA 29 CFR 1926.502 employers are required to provide for “prompt rescue of employees in the event of a fall or shall assure that employees are able to rescue themselves.” This may be by calling 911 or the employer may have a “Fall Rescue Team.” If this is the case, work with the team as they probably know more about harness safety and rescue than we do. After the initial rescue the patient needs to be handled very carefully. If they still have a pulse, some experts advise not moving the patient to a supine position immediately to deter a rush of “bad blood” into the central circulation. However other experts advise that if the patient is hypotensive, the brain may not be perfused requiring the need for positioning in trendelenburg. You may elect to transport with the head up and the patients legs hanging over the sides of the gurney if you feel it is appropriate. If the person doesn’t have a pulse or at any time during the rescue develops cardiac arrest they should be promptly placed in a supine position and CPR initiated. Regardless of how the person presents to you after rescue, transport is necessary to rule out damage to the heart, kidneys, lungs and brain as even in the absence of symptoms, damage could occur.

Eric Bridges EMT-P

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