June 27, 2009

NATIONAL SCIENCE FOUNDATION, HPWREN

Members of the High Performance Wireless Research and Education Network (HPWREN) project at the University of California, San Diego practice the use of fall arrest systems and the simulated rescue of a fellow staff member.

Occupational Health and Safety

Quick rescue critical with fall arrest systems

PETER KENTER

correspondent

Sophisticated fall arrest equipment has clearly resulted in increased survival rates in worksite falling incidents, but surviving a fall is only half the battle.

Workers waiting for rescue can experience suspension trauma, known otherwise as orthostatic intolerance.

The mechanism of the syndrome is simple.

A person who is rendered immobile while suspended in a fall arrest harness can lose consciousness in as few as 10 minutes, as blood begins to pool in the lower extremities.

A person who faints will normally fall or be carried to a reclining position where blood flow can be restored.

Not so for the worker suspended in a fall arrest harness, who will probably remain motionless after fainting, risking death through oxygen deprivation to the brain.

“An effective rescue plan is critical here,” said Alex Tsen, product manager, fall protection—Americas, Honeywell Safety Products at North by Honeywell.

“If your rescue plan is to call 9-1-1, then you haven’t got a rescue plan at all.”

Tsen said that an effective rescue plan will minimize the time a worker is suspended, and provide appropriate treatment after the rescue has been accomplished.

While blood flow will already be minimized as a result of the suspended worker’s position, the position of fall arrest harness straps can also minimize circulation.

“Studies show that a person suspended after a fall can feel dizzy in as little as three minutes, experience loss of consciousness in as little as 10 minutes and die in as little as 20 minutes,” said Tsen.

Timely rescue is even more important for a worker who has suffered an injury during the fall, or who has pre-existing health conditions affecting the heart and blood pressure.

“During and after a rescue, it’s important that you not allow the victim to lie on the ground, as this can cause a heart attack and multiple organ failure when the deoxygenated blood comes flooding back to the heart,” he said.

“Keep the person in a kneeling position, then a sitting position for the first 30 minutes after the rescue.”

Tsen noted that paramedics who arrive on scene need to be informed that the worker may have suffered suspension trauma.

“What’s the first thing a paramedic usually does when they answer an emergency call?” asked Tsen.

“They lift the person to a horizontal stretcher, trolley or hospital cart, which is the wrong thing to do in the case of suspension trauma. They need to be informed about what might have happened before they arrived.”

A person, who is conscious while suspended in a harness, can also engage in potentially life-saving strategies.

“Relax, because panic can make your situation worse,” he said.

“Find something to kick against or lift your knees into a sitting position, if possible. This gets your legs above your hips and keeps the blood flowing. If you’re able, swing yourself upside down every few minutes.”

A specially designed trauma strap can also be used to buy a suspended worker some time while awaiting rescue.

It’s essentially a loop that allows the worker to stand on it while suspended.

“Even if you can’t move, then strain your leg muscles as hard as you can every five seconds, while breathing slowly and deeply,” said Tsen.

“Rescue is a priority, but the suspended person who is conscious can help to improve the potential outcome.”

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