Planning and Fast Action Prevents Suspension Trauma
Since fall protection systems were mandated for work in elevated settings, countless lives have been saved and even more injuries have been prevented. Equipment such as fall protection harnesses and lanyards keep the worker from striking the surface below the work area and absorb much of the energy of the fall itself.
But fall protection equipment is only part of the equation. The other part involves removing the suspended worker safely. Once a harness has performed its role, two situations remain that can endanger workers. The first is failing to remove the worker properly and causing injuries to the workers who try to perform the rescue.
A more insidious danger involves what’s known as suspension trauma. A worker suspended in a fall protection harness begins to experience physiological responses that, according to an OSHA technical bulletin, could be fatal in just 30 minutes.
What is suspension trauma?
Also known as orthostatic intolerance and harness hang syndrome, suspension trauma is the physiological result of a human body that is confined in an upright position without movement. As the worker hangs in the harness, unable to move, the leg muscles become relaxed, allowing the veins in the leg to expand (vasodilation is the medical term for this process). In turn, that causes the worker’s blood to begin pooling in the legs, instead of making the normal return trip to the heart and lungs.
The pooling of blood means that less is available to deliver oxygen from the lungs to the brain and other organs. Without that supply of oxygen, the cells in the leg become desperate to produce energy and begin a process called anaerobic respiration. Sugar in the blood begins to break down into lactic acid, which builds up in the blood and can have life-threatening effects after a rescue (more on that later).
Suspension trauma symptoms
While some symptoms of suspension trauma have been known to happen quickly, most usually occur after a worker has been hanging for at least 20 minutes. The worker may sweat, experience shortness of breath, become nauseous, and feel numbness in the legs. His skin may become cold and clammy, and his pulse will speed up. As symptoms progress, vision may become blurry and “grey out.” The worker will feel lightheaded, and then increasingly dizzy and hot.
Without movement, the worker will eventually faint (what’s known as the central ischemic response), leading to a sudden drop in blood pressure and further reducing the life-sustaining supply of oxygen to the brain.
Once a suspended worker becomes unconscious, he needs to be rescued within five minutes, or brain damage is likely to begin. After ten minutes of unconsciousness, significant brain damage and organ failure are likely, and the worker may suffocate and die.
If workers are suspended in the harness and haven’t suffered any injuries, they can slow the onset of suspension trauma by using their leg muscles. If they’re hanging next to a wall or other surface, they can push their legs against that surface every few seconds. By moving their legs, they help the body pump blood back to the heart and lungs.
However, this process can be fatiguing, and as the worker becomes weaker, the efforts will be less effective. Some people recommend that the worker pedal an imaginary bicycle, but once the worker no longer has the energy to sustain that motion, he’s likely to faint.
After a rescue
Once a worker has been rescued and removed from the harness, the danger doesn’t end. As the worker’s blood circulation resumes, the lactic acid that developed in the legs will travel throughout the body, where it can quickly overwhelm the liver and the kidneys. In extreme cases, the lactic acid can trigger heart failure. Never allow a worker to lay down or stand upright immediately after a rescue, because that can allow the lactic acid to rapidly flow to the heart and other organs.
To prevent this, place the rescued worker in a “W” position, sitting upright on the ground with legs bent so that their knees line up with the bottom of their chin. Keep their feet flat on the ground. The worker should remain in this position for at least 30 minutes and even longer if symptoms are slow to subside. The “W” position slows the flow of the pooled blood back into the body, giving it time to filter the lactic acid out and return to normal chemical balances.
Prevention is key
As with many aspects of workplace safety, prevention and training is the key to reducing the potential damage of suspension trauma. Workers should be trained in proper single-rope rescue approaches, particularly the single rope pickoff method. To ensure that workers can perform these rescues properly, it’s important to practice them regularly.
A set of trauma straps should be attached to the fall protection harness, and workers should be trained in their use. These straps allow workers to stand up in the fall harness, reducing pressure on the legs and maintaining circulation longer. Another technique to teach workers for situations when someone can’t be rescued immediately is to use a loop of rigging tape or other equipment to raise the worker’s legs to a sitting position.
Most of all, on any site on which fall protection is being used, the safety plan must include a rescue plan that calls for keeping rescue equipment on hand, training workers in its use, and notifying local first responders about proper rescue procedures in the event a worker falls.