Hypothermia
“A decrease in the core body temperature to a level at which normal muscular and cerebral functions are
impaired."
Conditions Leading to Hypothermia
- Cold temperatures.
- Improper clothing and equipment.
- Wetness.
- Fatigue, exhaustion.
- Dehydration.
- Poor food intake.
- No knowledge of hypothermia.
- Alcohol intake - causes vasodilation leading to increased heat loss.
What are "Hypothermia" temperatures
- Below freezing
- 40 degrees - Ex. Shenandoahs, wind and rain
- 60 degrees - Ex. Rayanna and hurricane
- Any temperature less than 98.6 degrees can be linked to hypothermia (ex. hypothermia in the elderly in cold houses) or
- peripheral circulation problems such as trench foot and frostbite.
Signs and Symptoms
a. Watch for the "-Umbles" - stumbles, mumbles, fumbles, and grumbles which show changes in motor coordination
and levels of consciousness.
Mild Hypothermia - core temperature 98.6 - 96 degrees F.
- Shivering - not under voluntary control.
- Can't do complex motor functions (ice climbing or skiing) can still walk & talk.
- Vasoconstriction to periphery.
Moderate Hypothermia - core temperature 95 - 93 degrees F.
- Dazed consciousness.
- Loss of fine motor coordination - particularly in hands - can't zip up parka, due to restricted peripheral blood flow.
- Slurred speech.
- Violent shivering.
- Irrational behavior - Paradoxical Undressing - person starts to take off clothing, unaware s/he is cold.
- "I don't care attitude" - flattened affect.
Severe Hypothermia - core temperature 92 - 86 degrees and below (immediately life threatening.)
- Shivering occurs in waves, violent then pause, pauses get longer until shivering finally ceases - because the heat output.
- from burning glycogen in the muscles is not sufficient to counteract the continually dropping core temperature, the body shuts down on shivering to conserve glucose.
- Person falls to the ground, can't walk, curls up into a fetal position to conserve heat.
- Muscle rigidity develops - because peripheral blood flow is reduced and due to lactic acid and CO2 buildup in the muscles.
- Skin is pale.
- Pupils dilate.
- Pulse rate decreases.
- at 90 degrees the body tries to move into hibernation, shutting down all peripheral blood flow and reducing breathing rate and heart rate.
- at 86 degrees the body is in a state of "metabolic icebox." The person looks dead but is still alive.
Death from Hypothermia
- Breathing becomes erratic and very shallow.
- Semi-conscious.
- Cardiac arrythmias develop, any sudden shock may set off Ventricular Fibrillation.
- Heart stops, death.
Treating Hypothermia
Mild - Moderate Hypothermia
1. Reduce Heat Loss
- Additional layers of clothing.
- Dry clothing.
- Increased physical activity.
- Shelter.
2. Add Fuel & Fluids
It is essential to keep a hypothermic person adequately hydrated and fueled.
a. Food types
- Carbohydrates - 5 calories/gram - quickly released into blood stream for sudden brief heat surge - these are the best touse for quick energy intake especially for mild cases of hypothermia.
- Proteins - 5 calories/gram - slowly released - heat given off over a longer period.
- Fats - 9 calories/gram - slowly released but are good because they release heat over a long period, however, it takesmore energy to break fats down into glucose - also takes more water to break down fats leading to increased fluid loss.
b. Food intake
- Hot liquids - calories plus heat source.
- Sugars (kindling).
- GORP - has both carbohydrates (sticks) and protiens/fats (logs).
c. Things to avoid
- Alcohol - a vasodilator - increases peripheral heat loss.
- Caffeine - a diuretic - causes water loss increasing dehydration.
- Tobacco/nicotine - a vasoconstrictor, increases risk of frostbite.
3. Add Heat
- Fire or other external heat source.
- Body to body contact. Get into a sleeping back, in dry clothing with a normothermic person in lightweight dry clothing.
Severe Hypothermia
1. Reduce Heat Loss
Hypothermia Wrap: The idea is to provide a shell of total insulation for the patient. No matter how cold, patients can still internally rewarm themselves much more efficiently than any external rewarming. Make sure the patient is dry, and has a polypropylene layer to minimize sweating on the skin. The person must be protected from any moisture in the environment. Use multiple sleeping bags, wool blankets, wool clothing, Ensolite pads to create a minimum of 4" of insulation all the way around the patient, especially between the patient and the ground. Include an aluminum "space" blanket to help prevent radiant heat loss, and wrap the entire ensemble in plastic to protect from wind and water. If someone is truly hypothermic, don't put him/her naked in a sleeping bag with another person.
2. Add Fuel & Fluids
Warm Sugar Water - for people in severe hypothermia, the stomach has shut down and will not digest solid food but can absorb water and sugars. Give a dilute mixture of warm water with sugar every 15 minutes. Dilute Jello™ works best since it is part sugar and part protein. This will be absorbed directly into the blood stream providing the necessary calories to allow the person to rewarm themselves. One box of Jello = 500 Kilocalories of heat energy. Do not give full strength Jello even in liquid form, it is too concentrated and will not be absorbed.
Urination - people will have to urinate from cold diuresis. Vasoconstriction creates greater volume pressure in the blood stream. The kidneys pull off excess fluid to reduce the pressure. A full bladder results in body heat being used to keep urine warm rather than vital organs. Once the person has urinated, it precious body heat will be used to maintain the temperature of vital organs. So in the end urinating will help conserve heat. You will need to help the person urinate. Open up the Hypothermia Wrap enough to do this and then cover them back up. You will need to keep them hydrated with the dilute Jello solution described above.
3. Add Heat
Heat can be applied to transfer heat to major arteries - at the neck for the carotid, at the armpits for the brachial, at the groin for the femoral, at the palms of the hands for the arterial arch.
Chemical heat packs such as the Heat Wave™ provides 110 degrees F for 6-10 hours.
Hot water bottles, warm rocks, towels, compresse.
For a severely hypothermic person, rescue breathing can increase oxygen and provide internal heat.
Source:
http://www.princeton.edu/~oa/safety/hypocold.shtml
