Orthostatic Intolerance
Prevent Prolonged Suspension in Fall Protection Devices

When it comes to fall protection, comprehensive systems in industrial and commercial settings must go further than providing safety harnesses. Yes, they will arrest a fall, but that’s only half the battle. When someone is hanging from an arrest system, they have to be removed as soon as possible, usually within a matter of minutes.

“When a worker falls wearing a harness, the thigh straps can act like tourniquets, effectively cutting off any circulation of blood between the legs and the rest of the body,” said Michael C. Wright, PE, CSP, CPE, president of Safety Through Engineering, Inc., a manufacturer of fall protection systems. “When the person is rescued and the straps are removed, the trapped blood surges back into the body, which may flood the brain and cause a stroke.”

Prolonged suspension from fall arrest systems can cause orthostatic intolerance, which, in turn, can result in serious physical injury, or potentially, death. OSHA says, research indicates that suspension in a fall arrest device can result in unconsciousness, followed by death, in less than 30 minutes. Some say the time to respond is much shorter.

“Studies have shown that a suspended worker can experience orthostatic intolerance after being suspended for only 10 minutes,” said Wright.

Unconscious/immobile workers suspended in their harness will not be able to move their legs and will not fall into a horizontal position, as they would if they fainted while standing. During the static upright position, venous pooling is likely to occur and cause orthostatic intolerance, especially if the suspended worker is left in place for some time.

Safety Through Engineering’s Wright says his company has been looking at suspension trauma for about eight years and at rescue in general for 17 years.

“What is curious about this is that we have talked to medical doctors who specialize in trauma, and they say, ‘It’s out of our field.’ We ask how this could be out of their field, and they typically say suspension trauma is not car accident trauma or almost drowning trauma or burn trauma. You’ve got trauma that is basically caused by gravity, and it is totally different from the types of traumatic injuries they are trained for. This is an important distinction we have discovered; suspension trauma is a type of trauma that EMS providers typically are not trained for.”

When a worker falls, he or she can do certain things to help stave off the onset of this condition. For example, certain leg movements can help reduce thigh strap pressure, relieve the tourniquet effect and help circulate blood. Also, some types of fall protection harnesses come with straps into which workers can place their feet or legs to lift themselves up a little bit and relieve the tourniquet effect. These measures only work if the fallen worker is conscious and doesn’t have any injuries, such as broken arms or legs that render him or her physically incapable of employing these measures.

Venous pooling and orthostatic intolerance can be exacerbated by other circumstances related to the fall. For example, shock or the experience of the event that caused the fall, other injuries, the fit/positioning of the harness, the environmental conditions, and the worker’s psychological state all may increase the onset and severity of the pooling and orthostatic intolerance.

Unless the worker is rescued promptly using established, safe procedures, serious or fatal injury may result, as the brain, kidneys, and other organs are deprived of oxygen.

The amount of time spent in this position, with the legs below the heart, affects the manner in which the worker should be rescued. Moving the worker quickly into a horizontal position — a natural reaction — is likely to cause a large volume of deoxygenated blood to move to the heart, if the worker had been suspended for an extended period. The heart may be unable to cope with the abrupt increase in blood flow, causing cardiac arrest. Rescue procedures must take this into account.

Prevent Prolonged Suspension

To reduce the risk associated with prolonged suspension in fall arrest systems, OSHA says employers should implement plans to prevent prolonged suspension in fall protection devices.

The plan should include procedures for: preventing prolonged suspension, identifying orthostatic intolerance signs and symptoms, and performing rescue and treatment as quickly as possible.

OSHA recommends the following general practices/considerations:
• Rescue suspended workers as quickly as possible;
• Be aware that suspended workers are at risk of orthostatic intolerance and suspension trauma;
• Be aware of signs and symptoms of orthostatic intolerance;
• Be aware that orthostatic intolerance is potentially life threatening. Suspended workers with head injuries or who are unconscious are particularly at risk;
• Be aware of factors that can increase the risk of suspension trauma; and

• Be aware that some authorities advise against moving the rescued workers to a horizontal position too quickly.

Training

“Training is an often overlooked but essential element when it comes to purchasing fall protection equipment,” said Wright.

OSHA requires employers to train workers to use fall arrest systems and other personal protective equipment correctly while performing their jobs, in accordance with standards 29 CFR 1910.132 (Personal Protective Equipment) 29 CFR 1915.159 (Personal Fall Arrest Systems) and 29 CFR 1926.503 (Training Requirements for Fall Protection).

Workers who wear fall arrest devices while working, and those who may perform rescue activities, should also be trained in:

• How to ascertain whether their personal protective equipment is properly fitted and worn, so that it performs as intended;

• How orthostatic intolerance/suspension trauma may occur;

• The factors that may increase worker’s risk;

• How to recognize the signs and symptoms identified in this bulletin; and

• The appropriate rescue procedures and methods to diminish risk while suspended.

Wright asks the following: “How can I rescue somebody if I don’t have a plan, don’t have the equipment, haven’t gone through drills, and don’t know CPR or first aid? If you go through an industry site or a construction site, you hardly ever see anyone go through a rescue drill. And very seldom do you see an actual rescue plan in place before the people even arrive.

“These people are rescued by their buddies, who are untrained and unpracticed in rescue. Everyone is running around trying to think of something to do while in the meantime their buddy is suspended and blood is pooling in his legs. He may be starting to panic. There are so many things that could go wrong unless you plan for rescue and hold exercises to ensure everyone knows what their roles are in one of these situations.”

The best practice is to have everyone on a jobsite trained in how to rescue a suspended worker and to have in place any equipment necessary for that rescue before a fall occurs.

“It can take one to two hours to install high angle rescue equipment. If someone is suspended, then one better have that equipment already installed before that person goes up at heights. People don’t always think that through ahead of time. The challenge that exists is that people look at fall protection equipment as the sole solution. Gravity still exits.”

Rescue Procedures

Under 29 CFR 1926.502 (d) (Fall Protection Systems Criteria and Practices), OSHA requires that employers provide for “prompt rescue of employees in the event of a fall or shall assure that employees are able to rescue themselves.” This should include identifying rescue procedures that address the potential for orthostatic intolerance and suspension trauma. Rescue procedures also should address how the rescued worker will be handled to avoid any post-rescue injuries. n>

Rescue procedures should include the following contingency based actions:

• If self-rescue is impossible, or if rescue cannot be performed promptly, the worker should be trained to “pump” his/her legs frequently to activate the muscles and reduce the risk of venous pooling. Footholds can be used to alleviate pressure, delay symptoms, and provide support for “muscle pumping.”

• Continuous monitoring of the suspended worker for signs and symptoms of orthostatic intolerance and suspension trauma.

• Ensuring that a worker receives standard trauma resuscitation once rescued. Some authorities recommend that the patient be transported with the upper body raised.

• If the worker is unconscious, keeping the worker’s air passages open and obtain first aid.

• Monitoring the worker after rescue, and ensuring that the worker is evaluated by a health-care professional. The worker should be hospitalized when appropriate. Possible delayed effects, such as kidney failure, which is not unusual in these cases, are difficult to assess on the scene. FSM