|
|
 |
U. S.
Department of Labor
Occupational Safety and Health
Administration
Directorate of Science, Technology and
Medicine
Office of Science and Technology
Assessment
|
|
Suspension Trauma/Orthostatic
Intolerance
|
| Safety and Health Information
Bulletins |
|
|
| SHIB 03-24-2004 |
| This
Safety and Health Information Bulletin is not a standard
or regulation, and it creates no new legal obligations.
The Bulletin is advisory in nature, informational in
content, and is intended to assist employers in
providing a safe and healthful workplace. The
Occupational Safety and Health Act requires employers to
comply with hazard-specific safety and health standards.
In addition, pursuant to Section 5(a)(1), the General
Duty Clause of the OSHAct, employers must provide their
employees with a workplace free from recognized hazards
likely to cause death or serious physical harm.
Employers can be cited for violating the General Duty
Clause if there is a recognized hazard and they do not
take reasonable steps to prevent or abate the hazard.
However, failure to implement any recommendations in
this bulletin, is not, in itself, a violation of the
General Duty Clause. Citations can only be based on
standards, regulations, and the General Duty Clause.
|
Purpose
 This Safety and Health Information
Bulletin provides employees and employers with important
information about the hazards of orthostatic intolerance and
suspension trauma when using fall arrest systems. This
bulletin:
 | describes the signs and symptoms of orthostatic
intolerance;
| discusses how orthostatic intolerance can occur while
workers are suspended following a fall; and
| outlines recommendations for preventing orthostatic
intolerance, as well as recommendations for worker training
and rescue. | | | Background
Orthostatic intolerance may be defined as "the
development of symptoms such as light-headedness,
palpitations, tremulousness, poor concentration, fatigue,
nausea, dizziness, headache, sweating, weakness and
occasionally fainting during upright standing" [1,2].
While in a sedentary position, blood can accumulate in the
veins, which is commonly called "venous pooling," and cause
orthostatic intolerance [3].
Orthostatic intolerance also can occur when an individual
moves suddenly after being sedentary for a long time. For
example, a person may experience orthostatic intolerance when
they stand up quickly after sitting still for a long time.
A well-known example of orthostatic intolerance is
that of a soldier who faints while standing at attention for
long period of time. The moment the soldier loses
consciousness, he or she collapses into a horizontal position.
With the legs, heart, and brain on the same level, blood is
returned to the heart. Assuming no injuries are caused during
the collapse, the individual will quickly regain consciousness
and recovery is likely to be rapid.
Venous pooling
typically occurs in the legs due to the force of gravity and a
lack of movement. Some venous pooling occurs naturally when a
person is standing. In the veins, blood normally is moved back
to the heart through one-way valves using the normal muscular
action associated with limb movement. If the legs are
immobile, then these "muscle pumps" do not operate
effectively, and blood can accumulate. Since veins can expand,
a large volume of blood may accumulate in the veins.
 An accumulation of blood in the legs
reduces the amount of blood in circulation. The body reacts to
this reduction by speeding up the heart rate and in an attempt
to maintain sufficient blood flow to the brain. If the blood
supply is significantly reduced, this reaction will not be
effective. The body will abruptly slow the heart rate and
blood pressure will diminish in the arteries. During severe
venous pooling, the reduction in quantity and/or quality
(oxygen content) of blood flowing to the brain causes
fainting. This reduction also can have an effect on other
vital organs, such as the kidneys [3].
The kidneys are very sensitive to blood oxygen, and renal
failure can occur with excessive venous pooling. If these
conditions continue, they potentially may be fatal [3].
Description of Hazard
Orthostatic intolerance may be
experienced by workers using fall arrest systems. Following a
fall, a worker may remain suspended in a harness. The
sustained immobility may lead to a state of unconsciousness.
Depending on the length of time the suspended worker is
unconscious/immobile and the level of venous pooling, the
resulting orthostatic intolerance may lead to death. While not
common, such fatalities often are referred to as "harness-induced pathology" or "suspension trauma."
| Signs & symptoms that may be observed in
an individual who is approaching orthostatic
intolerance:
|
| Faintness |
Nausea |
| Breathlessness |
Dizziness |
| Sweating |
Unusually Low Heart
Rate |
| Paleness |
Unusually Low Blood
Pressure |
| Hot Flashes |
"Greying" or Loss of
Vision |
| Increased Heart Rate |
|
References:
Seddon, Paul. Harness Suspension: review and evaluation
of existing information. Health and Safety Executive.
Research Report 451/2002. 104 pp.
Sheehan, Alan.
Suspension Trauma. Training
handout. |
| Factors that can affect the degree of risk of
suspension trauma:
|
| Inability to move legs |
Hypothermia |
| Pain |
Shock |
| Injuries during fall |
Cardiovascular
disease |
| Fatigue |
Respiratory disease |
| Dehydration |
Blood loss |
References:
Seddon, Paul. Harness Suspension: review and evaluation
of existing information. Health and Safety Executive.
Research Report 451/2002. 104 pp.
Sheehan, Alan.
Suspension Trauma. Training
handout. |
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. 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 [3,5].
Unless the worker is rescued promptly using established safe
procedures, venous pooling and orthostatic intolerance could
result in serious or fatal injury, as the brain, kidneys, and
other organs are deprived of oxygen [3].
The amount of time spent in this position, with the
legs below the heart, affects the manner in which the worker
should be rescued [3].
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 [3,5].
Rescue procedures must take this into account. Recommended
rescue procedures are outlined below in the Conclusions and Recommendations
section.
Conclusions and Recommendations
Prolonged suspension from fall
arrest systems can cause orthostatic intolerance, which, in
turn, can result in serious physical injury, or potentially,
death. Research indicates that suspension in a fall arrest
device can result in unconsciousness, followed by death, in
less than 30 minutes [4].
To reduce the risk associated with prolonged suspension in
fall arrest systems, 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.
| Be aware that some authorities advise against moving the
rescued workers to a horizontal position too quickly.
| | | | | | Training
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 a 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. | | | | | 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.
 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
resuscitation1
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. | | | | | References
- Robertson, David. Orthostatic Intolerance. Vanderbilt
University, Nashville, Tennessee.
- New York Medical College. Orthostatic Intolerance.
Vahalla, New York.
- Seddon, Paul. Harness Suspension: Review and evaluation
of existing information. Health and Safety Executive.
Research Report 451/2002. 104 pp.
- Sheehan, Alan. Suspension Trauma. Training handout.
- Weems, Bill and Bishop, Phil. Will Your Safety Harness
Kill You? Occupational Health & Safety. 72(3): 86-88,
90, March, 2003.
1National
Association of Emergency Medical Technicians (NAEMT). Provider
Textbook section in: PHTLS Basic and Advanced Prehospital
Trauma Life Support Fifth Edition St. Louis, MO: Mosby; 2003:
Section 1. Summary available at: http://phtls.org/datafiles/
PHTLS%205ed%20Compendium.pdf | |
Back to Top 
http://www.osha.gov/index.html
