Last
week’s entry discussed general keys to preventing environmental cold injuries
by having an emergency action plan in place, having appropriately trained
personnel available, learning to layer correctly to minimize heat loss and
knowing who may be most
susceptible. Specific
injuries or conditions may require specific prevention steps, but proper recognition and initial first aid are also important. I will focus primarily on hypothermia and frostbite since they happen most often, but there
are other conditions to be aware of. Recognizing
the signs and symptoms an athlete shows when presenting with an injury such
as frostbite or hypothermia is critical.
Taking the appropriate steps to minimize the severity of the injury and getting
appropriate treatment are also important.
HYPOTHERMIA:
Hypothermia,
defined as a core temperature of 95o F or lower, affects a variety
of body systems, getting more severe as the core temperature continues to
drop. Sometimes hypothermia is referred
to as accidental hypothermia in the literature to differentiate it from the
therapeutically induced hypothermia utilized by medical professionals. The severity of injury is described as mild,
moderate, and severe and each stage presents with specific signs and
symptoms. The ability to recognize these
signs and symptoms can help you understand the severity of hypothermia without
assessing core temperature. Assessing
core temperature requires the use a specifically designed thermometer and most typical clinical thermometers are inaccurate at temperatures below 95oF. Seeking immediately medical treatment for
someone suffering from hypothermia is critical, especially as the condition
becomes progressively worse.
Signs
and symptoms of mild hypothermia include a core temperature between 98.6oF
and 95oF, vigorous shivering, lethargy, loss of fine motor control
among others. As the patient progresses
to mild hypothermia the core temperature is between 90oF and 94oF,
respirations and pulse slow, cyanosis (blue hue to skin) is present and
shivering ceases. As the patient reaches
severe hypothermia the core temperature is below 90oF and may even
be comatose. The complete list of signs
and symptoms are available by clicking the “Cheat Sheet” link at the bottom of
this post. I have simply tried to
highlight some of the signs and symptoms here.
Athletes
most likely to suffer from hypothermia are those who experience prolonged
exposure to cold, wet, or windy conditions, or some combinations of these. This means those soccer and football games in
the late fall could put your athlete at risk if not properly prepared. The easiest way to prevent hypothermia is to
properly layer under (and over) the uniform to maintain warmth and to stay
properly hydrated. Most athletes do not
remember to drink when it is cold since the thirst mechanism is not as obvious.
If you
believe someone may be suffering from mild hypothermia it is important to
remove them from the weather conditions and remove any wet clothing. Using blankets to warm them is also
appropriate. Providing warm food and
fluids are also acceptable. Do not rub
hands and fingers to warm them as this could cause further tissue damage if
frostbite is also present. Immediate referral and transport to a hospital is important for anyone suffering from hypothermia, no matter the stage.
FROSTBITE:
Frostbite is the
actual freezing of body tissues and often happens to the face and extremities. Frostbite
can happen in cold, dry conditions while wet conditions can exacerbate the
condition and is a result of the body shunting blood to the core to keep vital
organs warm. Coming into contact with
cold objects (such as a lacrosse stick) can also result in frostbite. The stages are frostnip (precursor to
frostbite), mild frostbite and severe frostbite.
Frostnip
is freezing of the most superficial layers of the skin as a result of cold,
windy conditions or coming in contact with a cold object (typically
metal). Mild frostbite results in freezing of the skin and subcutaneous tissues, while severe frostbite is
freezing of the skin, subcutaneous tissues and other tissues below that
including muscle and bone. Signs and
symptoms include “waxy,” pale skin initially and can progress to a mottled
skin, edema and/or transient numbness and tingling. See “Cheat Sheet” for a complete list.
If you
believe someone may be suffering from frostbite it is important to know that
you should not rub the injury to warm it, it causes further tissue damage. If blisters are present, do not break them
open as it increases the risk of infection.
Finally, if you decide to re-warm (slowly) the extremity make sure there
will not be an opportunity for the tissues to refreeze making the tissue damage
more severe. While frostnip may not require further referral, mild and severe frostbite are likely to need immediate referral for further medical treatment.
CHILBLAINS/PERNIO:
Chilblains
(pernio) results from extended exposure (1 – 5 hours) to cold, wet
conditions and most often affects the hands and feet. Can occur in similar conditions as trench
foot, but is typically a more superficial and less severe injury. Signs and symptoms often include red or
cyanotic skin, numbness and tingling, swelling and tenderness among others (see
“Cheat Sheet”).
If you
believe someone is suffering from chilblains remove the wet and constrictive
clothing. As with frostbite do not rub
skin or break open any blisters that may be present. The patient should also be non-weight
bearing if it is the lower extremity that is affected. Immediate referral may be necessary depending on the severity of the condition.
IMMERSION
(TRENCH) FOOT:
Immersion
(trench) foot is similar to chilblains, in that it occurs
with prolonged exposure to cold and wet.
Exposure typically ranges from 12 hours to 4 days and often results from
wearing continually wet boots and socks.
Signs and symptoms include cyanotic skin, numbness and tingling, or skin
fissures and macerations.
RAYNAUD’S
SYNDROME:
Raynaud’s
syndrome (or phenomenon) is the result of constriction of blood
vessels in the fingers (most often) that leads to a white, pale
appearance. Raynaud’s is aggravated by
cold conditions. Often times, avoidance
of cold conditions is recommended for managing this poorly understood condition.
COLD
URTICARIA:
Cold urticaria is an
allergy to cold temperatures. Exposure
to cold will cause redness, itching, and hives on the exposed skin. Avoidance of cold conditions is recommended
for people with this condition.
REFERENCES:
Baumhakel,
M. & Bohm, M. (2010). Recent achievements in the management of Raynaud’s
phenomenon. Vascular Health and Risk Management, 6: 207 – 214.
Available at: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2856576/pdf/vhrm-6-207.pdf
Biem,
J., Koehncke, N., Classen, D., & Dosman, J. (2003). A the bedside: Management of hypothermia and frostbite. Canadian
Medical Association Journal, 168(3):
305 – 311. Available at: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC140473/pdf/20030204s00018p305.pdf
Cappaert,
T.A., Stone, J.A.,Castellani, J.W., Krause, B.A., Smith, D. & Stephens,
B.A. (2008). National Athletic Trainers’
Association position statement:
Environmental cold injuries. Journal of Athletic Training, 43(6): 640 – 658.
Available at: http://www.nata.org/sites/default/files/EnvironmentalColdInjuries.pdf
Castellani, J.W., Young, A.J., Ducharme, M.B., Giesbrecht, G.G., Glickman, E., and Sallis, R.E. (2006). Prevention of cold injuries during
exercise. Medicine and Science in Sports and Exercise, 38 (11):
2012 – 2029. Available at: http://journals.lww.com/acsm-msse/Fulltext/2006/11000/Prevention_of_Cold_Injuries_during_Exercise.19.aspx#
Submitted by Heather L. Clemons, MS, MBA, ATC
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