Archive for the ‘Frostbite’ Category

New! From The Wilderness Medicine Newsletter

February 10, 2012

For decades the Wilderness Medicine Newsletter has provided up-to-date information to pre-hospital and definitive care providers. Since becoming an on-line journal, the readership of the WMN has become international. Now the WMN has it’s own web site: www.wildernessmedicinenewsletter.com

Subscribers pay the same $15 a year subscription rate but have access to more than 165 articles from back issues as well as current issues. You can search the site either by category, or by key words making the Wilderness Medicine Newsletter site a much more useful reference for everything from reviewing splinting to the prevention and treatment of tropical diseases.

Check it out!

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Book Review:

March 22, 2007

Hypothermia, Frostbite, and other Cold Injuries
Prevention, Survival, Rescue, and Treatment

By Gordon Giesbrecth, Ph.D., and James A. Wilkerson, M.D.

The book is published by The Mountaineers Books
They describe themselves as “Outdoor books by the experts” and in this case it is certainly true. The authors of this text are recognized experts in the field of cold-related injuries.

The authors have done an excellent job of describing and reviewing the various cold-related injuries. The text is up-to-date, comprehensive, well written, and applicable. This is a very useful body of knowledge for both the outdoor enthusiast as well as mountain rescue personnel. The authors have taken the time to provide information on the fundamentals of thermoregulation and clothing design as well as the recognition and management of cold-related injuries. I had the opportunity and honor of writing the chapter on non-freezing cold injuries.

If you enjoy the outdoors, or if you are a provider wilderness emergency medicine and rescue, this is a must read book. I think you will enjoy it.

This blog is powered by the Wilderness Medicine Newsletter, now celebrating 20 years of publication. The WMN is published and distributed online six times each year by TMC Books, and subscriptions cost as little as $10 per year. To find out more, or to subscribe online, click here.

Cold-Related Injuries #6 – Raynaud’s Disease

December 8, 2006

Raynaud’s Disease:

This is also a non-freezing cold injury. 
It is a hypersensitivity reaction to cold exposure.
It is more of a nuisance than a limb-threatening injury.
This condition has been caused by chronic cold exposure and, for some unknown reason, the peripheral circulation has now developed an exaggerated response to the cold which now occurs at warmer temperatures, i.e., not as cold as it used to have to be.  The peripheral circulation in the hands and/or feet will now overreact and vasoconstrict or close down too much.
So, the response is too early and too much.
Upon rewarming, there is also an exaggerated response: the skin will turn red, and painful.  The extremity may also throb with pain during the rewarming process.
Once rewarmed the tissues should return to normal.

Treatment of Raynaud’s:

Avoid and limit cold exposure.
Keep the affected areas well-insulated, warm, and dry.
Avoid nicotine, caffeine, alcohol, and over-the-counter decongestants.
Drugs:  may try calcium channel blockers for their vasodilatory effects.
 Eg:  Nifedine XL 30 – 90mg po qd, or diltiazem 30 – 120mg po qid.
“Pavlovian” response trials, also known as Murray’s Method (for Dr. Murray Hamlet),  a technique to re-educate the nerves affecting the vasculature.

Rehabbing Raynaud’s or Murray’s Method:

Equipment: 2 – 4 Styrofoam coolers, 2 for hands + 2 for feet.
Warm water.
Warm inside & cool, <32°F (0°C) outside.
Fill the Styrofoam coolers with warm water, 105°F – 110°F, one set inside and one set outside.
Start inside, dressed lightly so that you are comfortable, and sit with your hands or feet in the warm water for about 5 mintues; then, get up and go outside.  Stay lightly dressed, and put your hands or feet in the warm water outside, for 5 – 10 minutes. 
For this to work your body has to be able to cool off while your hands and feet stay warm.  This is the re-education process.
You have to repeat this process about 50 times.  It seems to be most effective when you do this about 5 times a day, every other day.

Click on the images below to see full size.

raynauds-2-for-blog.gif   raynauds-1-for-blog.gif

For more detailed information on Raynaud’s Disease see the Jan/Feb 2005 issue of the Wilderness Medicine Newsletter, Non-Freezing Cold Injuries.  Click on this link to learn more about or subscribe to the Wilderness Medicine Newsletter.

This blog is powered by the Wilderness Medicine Newsletter, now celebrating 20 years of publication. The WMN is published and distributed online six times each year by TMC Books, and subscriptions cost as little as $10 per year. To find out more, or to subscribe online, click here.

Cold-Related Injuries #5 – Trenchfoot/Immersion Foot

December 6, 2006

TRENCHFOOT/IMMERSION FOOT

A non-freezing cold injury that is caused by continual dampness and cold of the hands or feet.
The wet and cold causes vasoconstriction of the peripheral circulation in the hands or feet reducing blood flow, causing ischemia. 
The skin can survive with reduced circulation for about 6 hours; after that it will die from ischemia. 
The resulting injury is severe, painful, and lifelong.

Cause: 
Vasoconstriction deprives hands or feet of adequate blood supply for too long.

Symptoms:
While wet and cold: 
The extremities are cold, wet, numb, and macerated (wrinkled from being waterlogged).  
With rewarming: 
The extremities become red, swollen, painful; may lead to gangrene or nerve damage.

Treatment:  TREAT THE WHOLE PATIENT
Remove all wet clothing.
Get them dry & Keep them dry.
Reinsulate  & Rewarm.
Hydrate & Feed with sickly sweet drinks – warm liquid Jello is best because it has lots of calories.
Do not allow them to get cold and wet again.
NSAID’s;  eg. ibuprofen 800mg po tid, may be given with Tylenol for pain relief.
Evacuate.

PREVENTION:
Keep hands and feet dry.
Change socks regularly.
Sleep in dry socks at night.
Make sure foot gear is not too tight, impairing circulation.
Do not tolerate cold, numb, wet extremities – Do something!

For more detailed information of trench/immersion foot injuries see the Jan/Feb 2005 issue of the Wilderness Medicine Newsletter, Non-Freezing Cold Injuries.  Click on this link to learn more about or subscribe to the Wilderness Medicine Newsletter.

This blog is powered by the Wilderness Medicine Newsletter, now celebrating 20 years of publication. The WMN is published and distributed online six times each year by TMC Books, and subscriptions cost as little as $10 per year. To find out more, or to subscribe online, click here.

Cold-Related Injuries #4 – Frostbite

December 4, 2006

FROSTBITE:
Localized cooling and/or freezing of tissue caused by constriction of blood vessels and shunting of blood away from cold areas of the body. 

TYPES OF FROSTBITE:
SUPERFICIAL:   
1st degree or “frostnip:”  numb, soft, cold, pale.
– return to normal tissue with rewarming.
2nd degree:  numb, soft, cold, pale, waxy appearing.
– painful on thawing, with formation of clear fluid-filled or blood-filled bleb.

Treatment of superfical frostbite:
Field rewarm, using skin-to-skin contact.
Never massage, rub with snow, or use an external, dry, heat source.
If a bleb forms, protect & evacuate. 
– do not pop or deflate the blebs, leave intact if possible.
Beware of refreezing, which can happen quickly.
– refreezing causes much greater damage.
 
DEEP FROSTBITE: 
3rd degree:  numb, cold, white, and rock hard.

Treatment  of Deep Frostbite:   
DO NOT field rewarm.
 
Once thawed, the area is useless, and excruciatingly painful.
Remove frozen wet clothing, reinsulate to prevent further injury.
Keep dry, may walk on frozen feet if necessary to facilitate evacuation.
Evacuate for treatment.

PREVENTION – PREVENTION – PREVENTION:
Keep the whole body warm– if your feet are cold, put on a hat.
Eat & drink to maintain constant energy/heat production.
Dehydration contributes to the risk of frostbite.
Low blood sugar contributes to the risk of frostbite.
– you need fuel to burn, “logs on the fire.”
STAY DRY!  CARRY AND USE RAINGEAR– TOPS & BOTTOMS!
Pack extra socks, hats, mittens, and any other clothing that is likely to get wet.
Wear wool or pile (cotton is warm only as long as it is dry).
Once wet – cotton becomes the death cloth.
Avoid alcohol and tobacco.
Avoid tight clothing, boots, crampons.
Watch out for each other.
Rewarm cool or numb areas early – to prevent damage.

There is more detailed information in the Jan/Feb 2004 – When Jack Frost Bites and in the Nov/Dec 2004 – Frozen Mythbusters, issues of the Wilderness Medicine Newsletter.  To subscribe to the newsletter click on this link, Wilderness Medicine Newsletter.

This blog is powered by the Wilderness Medicine Newsletter, now celebrating 20 years of publication. The WMN is published and distributed online six times each year by TMC Books, and subscriptions cost as little as $10 per year. To find out more, or to subscribe online, click here.

Cold-Related Injuries #3

November 30, 2006

FUEL AND WATER REQUIREMENTS TO STAY WARM

How much food/fuel and water do we need on a daily basis, not only live, but to be able to maximize our performance?  Dehydration may not rapidly lead to death but, it will definitely decrease and impair normal physical and mental abilities.  So, to be at our best we have to stay well hydrated and well fed – fuel to burn.

NUTRITIONAL REQUIREMENTS = average of 2500 CALORIES/DAY

Carbohydrate = 4cal/gram 60%
    (200 – 400 grams/day = 1200 -1600 cal/day)
Fat   = 9cal/gram  10%
    (20 – 60 grams/days = 180 – 540 cal/day)
Protein = 4cal/gram  30%
    (30 – 55 grams/day  = 120 – 220 cal/day)

Number of calories required varies with activity:
Normal daily activity:  2000 – 2500 calories/day.
Winter outdoor sports:  3000 – 4000 calories/day
High altitude mountaineering:  4000 – 6000 calories/day.

HYDRATION REQUIREMENTS = average of 2 LITERS/DAY

Normal water losses per day:  
Insensible loss:   nl temp.    hot temp.     heavy exercise
Skin  =      350ml          350ml           350ml
Respiration  =      350ml          250ml           650ml
Sweating  =     100ml         1400ml         5000ml
Urination  =    1400ml         1200ml          500ml
Defecation  =      100ml         100ml           100ml
TOTALS        2300ml      3300ml        6600ml

Water requirements will vary with activity, sweat output, and altitude.
Exertional sweat loss is 1 – 3 liters/hour for up to 4 hours without replacement.
        (can lose up to 3 liters per hour for 4 hours = 12 liters or 3 gallons = 24 pounds)
Altitude has a very low vapor pressure = will lose 1 cup/hour via respirations.
            (or 24 cups/24 hours = 6 quarts or liters)                                                     
        
LIFE AT ALTITUDE:
O – 8000 feet  = normal elevations for humans to live within.
8000 – 14000 feet = upper limits of sustainable life.
14000 – 18000 feet (½ atmosphere) = high altitude, can visit.
18000 – 28000 feet very high altitude, constant negative deficit, the death zone.

More detailed information in the Jan/Feb 2004 issue of the Wilderness Medicine Newsletter.

This blog is powered by the Wilderness Medicine Newsletter, now celebrating 20 years of publication. The WMN is published and distributed online six times each year by TMC Books, and subscriptions cost as little as $10 per year. To find out more, or to subscribe online, click here.

Cold-Related Injuries #2

November 29, 2006

THE HUMAN ANIMAL

How do we stay warm? How do we produce heat? How do we regulate our core temperature?

Heat Regulatory Mechanism:
We “evolved” in the tropics and subtropics.
Therefore, we have a very sensitive and efficient heat regulatory mechanism.
We are naked, hairless, with sweat glands.
All warm-blooded animals use the evaporation of water to cool. 
Humans sweat; the evaporation of water off the skin cools the skin and blood.
Fur-covered mammals & birds pant, evaporating water out of the lungs thus cooling the pulmonary circulation.

Heat Production and Heat Loss

Heat Production: 
Basal metabolism, we burn glucose as a fuel to produce heat.
Metabolic activity set by thyroid, can be increased 5x’s.
Exercise – muscle activity.
Voluntary or involuntary = shivering, increases up to 10x’s.

Heat Conservation: 
Vasoconstriction in the skin.
Piloerection – hair stands on end.
Abolition of sweating.
           
Heat Loss: 
Conduction: 
Transfer of heat from one solid object to another. 
0% – 40%  depending upon the type of solid material
Convection:  Transfer of heat from a solid object into the air or water. 
0% – 40% depending upon air penetration
Radiation:   Transfer of heat by infrared radiation. 
5% – 80% depending upon surrounding temperature
Evaporation:  Transfer of heat by the evaporation of water. 
0% – 90% depending upon vapor pressure & moisture

This blog is powered by the Wilderness Medicine Newsletter, now celebrating 20 years of publication. The WMN is published and distributed online six times each year by TMC Books, and subscriptions cost as little as $10 per year. To find out more, or to subscribe online, click here.

Cold-Related Injuries #1

November 27, 2006

FROSTBITE

We have just seen our first case of frostbite for this winter season.  An individual spent most of the night outside, barefoot, at about 20F.  They have a combination of superficial frostbite and immersion foot and may lose their toes– only time will tell.  Thus, we are inspired to produce several blogs that will deal with the recognition and management of Frostbite and the non-freezing cold injuires – Immersion Foot and Raynaud’s Disease. 

But first prevention:

WINTER WISDOM:  The Principles of Prevention of Hypothermia and Frostbite:
Know your personal limits and equipment.
Have proper-fitting clothing and boots.
Beware of tight-fitting boots or crampons.
Wear multiple layers, including socks.
Carry spare mittens and socks.
Control the rate of sweating.
Keep extremities WARM & DRY.
Keep the whole body warm, dry, well-fed, and well-hydrated.
Drink more than you think you need; do not rely on thirst to tell you to drink.
Carry and eat lots of carbohydrates; you burn glucose to stay warm.
React quickly to the very first signs of cold, numbness, or tissue changes.

This blog is powered by the Wilderness Medicine Newsletter, now celebrating 20 years of publication. The WMN is published and distributed online six times each year by TMC Books, and subscriptions cost as little as $10 per year. To find out more, or to subscribe online, click here.

High Altitude Illness

November 13, 2006

Post #1 of 6:

The most recent issue of the Wilderness Medicine Newsletter, Nov/Dec 2006, is dedicated to the recognition and management of high altitude illnesses. To follow is a series of postings regarding high altitude illnesses, recognition, and management.

What is High Altitude?
The scientific consensus for the definitions of altitude are:

High altitude: 1500 – 3500m (5000 – 11500ft)
Very High Altitude: 3500 – 5500m (11500 – 18000ft)
Extreme High Altitude: above 5500m (18000ft)
18,000′ (5500m) is ½ atmosphere

What are the RISKS of HIGH ALTITUDE MOUNTAINEERING?

As you go Higher it gets COLDER & DRYER, less and less OXYGEN, and more and more UV LIGHT that combing to CAUSE:

Dehydration (exhale 250cc of water per hour or 6 liters per day)
Hypothermia (may need up to 6000 calories per day)
Frostbite (dehydration contributes to the risk of frostbite)
Snow blindness (UV light concentration increases 4% every 1000′)
Severe sunburn (UV light concentration increases 4% every 1000′)
Acute Mountain Sickness (signs of lack of acclimatization)
High Altitude Pulmonary Edema (wet lungs)
High Altitude Cerebral Edema (wet brain)

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Myth#7

November 1, 2006

Frozen Mythbusters: Myth #7 of 13.
There are a variety of myths regarding human response to cold exposure.  These myths are explained and debunked by Dr. Murray Hamlet, DMV, Dr. Gordon Giesbrecht, PHD, and Frank Hubbell, DO.  After posting the thirteen myths, a complete article from the Wilderness Medicine Newsletter will be loaded for anyone interested in all the chilly little details.
Myth #7
            Frostbite is rarely associated with hypothermia.
            This myth is interesting because it flies in the face of common sense. If an individual has a lower than normal core temperature with decreased circulation to the skin, it is a set-up for frostbite. As they continue to cool off, circulation to the extremities becomes more and more impaired. So, the lower the core temperature, the greater the risk for severe frostbite.
           Busted – The lower the core temperature, the greater the risk for frostbite. When managing a hypothermia victim, be sure to use heat packs on their hands and feet, cover their head, and monitor their extremities for signs of frostbite.

This blog is powered by the Wilderness Medicine Newsletter, now celebrating 20 years of publication. The WMN is published and distributed online six times each year by TMC Books, and subscriptions cost as little as $10 per year. To find out more, or to subscribe online, click here.