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Dealing With
Frostbite
 One
of the most common winter injuries most people will worry about is frostbite.
Fortunately,
thanks to public education
and other preventative measures,
this once common
injury has
become relatively rare.
In fact, frostbite has become so uncommon that
nowadays, many doctors will never treat a case during their careers.
Despite
its rarity however, frostbite is one injury where prevention really is better
than cure, so for any travellers or holiday makers intending to spend some time
in a cold environment, it is important to know how to prevent,
recognize and quickly treat a frostbite injury.
How Frostbite Works
Frostbite is literally the freezing
and subsequent death of bodily tissues
due to prolonged exposure to cold temperatures. It occurs when the body's
mechanisms for keeping warm are unable to cope with the conditions. When exposed
to low temperatures (-12° C, or about 10° F), ice crystals form in the tissue
cells; at lower temperatures, or longer exposures, the tissues literally freeze
and the cells die.
Peripheral areas such as the hands, feet, cheeks and
ears are the first to be affected. The body tries to compensate for the cold by
sending extra warm blood to these areas, but as the exposure continues and the
entire body begins to cool, the body diverts warm blood away from the peripheral
areas, basically sacrificing them in order to warm and protect the vital organs
and brain.
Hands, feet, noses, ears and other extremities are thus most likely to be
affected by frostbite.
How To Get Frostbite
The most obvious cause of
frostbite is prolonged exposure to cold temperatures. Windy weather exacerbates
the risk of frostbite, as high winds
increases the rate of heat loss from skin.
Next to the weather however, the biggest cause of
frostbite is some degree of carelessness, whether it be wearing the wrong
clothes or staying out longer than is wise.
People taking certain
kinds of medications (eg, beta-blockers, which decrease the flow of blood to the skin) are particularly
susceptible, as are those suffering from poor circulation or diseases which
affect the blood vessels, such as peripheral vascular disease, diabetes
and peripheral neuropathy. A prior cold injury is a particularly
important risk factor, as each time an area is frostbitten, the circulation to
that area is reduced. Smoking and drinking, both of which affect blood
circulation, increase the risk of succumbing to frostbite, as does wearing
tight, sweaty or inadequate clothing.
How To Recognize Frostbite
Below minus 10°C, any tissue that feels numb for
more than a few minutes may become frostbitten. The first symptoms
are an aching, throbbing or "pins and needles" sensation, quickly followed by
numbness. The tissue is commonly described as feeling like a "block of wood, or
ice".
Frostbite, like burns, comes
in degrees depending on how much damage has been done to the tissues. Mild,
first degree frostbite leaves the skin a yellowish-gray colour, often
leathery to the touch; fingers and toes would have difficulty bending.
Second and third degree
frostbite reduces the affected areas to a hard, white coloured, obviously
frozen state; fingers and toes are very difficult to move.
Very severe, fourth
degree frostbite (pictured right) will show up as blistered, blackened, dead
tissue and severe damage to deep internal tissues such as tendons, muscles,
nerves, and bone.
The first three degrees of frostbite affect only the
superficial layers of the skin and if quickly treated, are reversible; the only
long-term damage would be increased chance of another cold injury. The deep,
permanent damage of fourth degree frostbite often means that the affect tissue
is unrecoverable and has to be amputated.
The danger for most people is that
frostbite is often difficult to notice; the routine numbness of feet or
hands that many habitually endure without ill effects during winter sports is
almost indistinguishable from the early symptoms of frostbite. The quickest
method to check for frostbite is to flex the fingers and toes, stamp the feet or
any other method to try and return some sensation. If the flesh still feels
numb, the safest course is to assume frostbite and take action.
How To Treat Frostbite
-
If you suspect frostbite, whether
mild or severe, immediately remove any constricting jewelry and wet
clothing. Seek warm shelter and medical care as soon as possible.
The first few hours can be
critical, and aggressive treatment can make a big difference in the
patient's outcome.
-
If the frostbite is mild (an ear
tip, fingertips), you may wish to treat it yourself; if normal feeling and
color still does not return however, or if ANY other symptoms (fever,
malaise, discoloration) develop, seek emergency medical help medical
immediately.
-
If the frostbite is severe,
emergency medical care must be sought IMMEDIATELY. If at all
possible, the victim should be moved to a safe, warm place. Moving the
victim can be a concern as the pressure and abrasions on affected areas may
further damage the tissue; as a general rule however, it is safer and more
effective to move a victim to a safe, warm place for treatment rather than
to attempt treatment in a camp. To protect the affected areas while
transporting the victim, wrap them in sterile dressings, being especially
careful to separate the fingers and toes.
-
 If immediate professional medical
care is not available, re-warming first aid may be given. Do note that this
is only to be attempted if emergency medical care is unavailable. DO NOT
thaw out a frostbitten area if it cannot be kept thawed. Refreezing may
make tissue damage even worse.
The most
effective method is to immerse the frostbitten area in a saucepan of "hand
hot" water; 39-42°C or 104°F to 108°F is optimal. If you have no
thermometer, heat the water until it is hot to the touch, or about as hot as
your elbow can stand. Immerse the affected area for periods of 20 minutes,
keeping the water circulating to aid the warming process.
DO
NOT use direct dry heat (such as a radiator, campfire, heating pad, or
hair dryer) to thaw the frostbitten areas. Direct heat can burn the tissues
that are already damaged.
-
As much as possible, DO NOT
knock, rub or massage the frozen tissue, as this will exacerbate the damage.
If there are blisters, do not disturb them.
-
If a hot water container is not
available, warm the affected parts in a warm sleeping bag (or on the
abdomen, groin or armpits) for several hours. Above 5500m, oxygen should be
given if it is available. Also, give warm drinks to the victim in order to
replace lost fluids.
-
Severe burning pain, swelling and
color changes will occur during warming. Painkillers can be taken, provided
they do not interfere with any complicating conditions (hypothermia,
dehydration, fever, etc). Warming is complete when the skin is soft, pink or
red, warm to the touch and sensation returns. Once the affected areas are
thawed, gently dab away all traces of moisture and loosely wrap in warm, dry
cloth or bandages.
-
As a
measure of last resort, the affect areas may be surgically removed.
This is more commonly done for the fingers and toes. When opting for
surgery, be sure to discuss your options with the surgeon, as the manner in
which the tissue is amputated may affect subsequent sensitivity of the
resulting digit.
Surgery is not a decision to be made lightly,
especially as it may take weeks or months before a clear demarcation line
between the good tissue and the dead becomes clear. Be sure you are
comfortable with the decision as sometimes a physician or insurance company
may try to rush the decision. After surgery, there are still weeks of
therapy and then years of becoming used to "the new you," both physically
and mentally.
-
During recovery:
-
DO
NOT smoke or drink alcoholic beverages, as both can interfere with
blood circulation.
-
Physical therapy is important in regaining full and prompt use of
the affected limbs. Sessions with a qualified therapist, or approved
exercises at home, are important features of rehabilitation.
-
Warm water
whirlpools are also a great way to warm up before each exercise
session, as well as helping restore circulation to the affected areas.
-
You
may also choose to undergo HBO treatment, in which the patient is
placed in a special highly oxygenated chamber to saturate the body
(including areas with compromised blood supply) with oxygen. Though
somewhat controversial, HBO treatment is said to promote faster
recovery, fewer complications, less tissue loss, better closures of the
amputation sites and decreased cold sensitivity.
How
To Prevent Frostbite
-
The
primary defence against frostbite is to get out of the cold.
If
caught in a severe snowstorm, find shelter early or increase physical
activity to maintain body warmth.
-
Follow
weather forecasts.
Keep
track of the temperature, especially in unfamiliar terrain: many
miniature portable thermometers are available, so clip one on your sack
or outer jacket zipper tab.
-
Wear wind-proof, water-resistant
clothing in cold temperatures.
Avoid tight-fitting
clothing, particularly on hands and feet.
-
Avoid
perspiration by using adequately ventilated and/or
many-layered
clothing. For example, wear
two pairs of socks (cotton next to skin, then wool); a scarf and a hat
that cover the ears to avoid substantial heat loss through the scalp;
and mittens, not gloves (they keep your hands warmer).
-
Cover head, neck, and
face in windy conditions.
-
Keep hands and feet dry;
keep toenails and fingernails trimmed.
-
Increase
fluid and caloric intake in cold weather.
-
Do
not wash hands, face, or feet frequently under extreme cold conditions,
as weather-beaten skin is more resistant to frostbite.
-
Avoid
alcohol and tobacco.
Alcohol dilates your blood vessels, increasing the rate at which you
lose heat. Nicotine constricts your blood vessels and causes premature
cooling of your extremities.
-
Keep
tetanus immunization status current.
-
In remote areas, use a
buddy system to help prevent cold injury. Have a system for rapid
evacuation, if needed.
-
At
high altitudes, individuals should moderate their activity to minimize
the work of breathing and associated heat loss through the respiratory
tree. Use of supplemental oxygen has been found to reduce the incidence
of frostbite among mountain climbers.
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