hypothermia+and+cold+injuries

clinical home > environmental toc =Hypothermia = = abnormally low //core// temperature - < 35 degrees C Do not classify hypothermia on the basis of core temperature alone. Oesophageal temperature measurement is more accurate than rectal temperature measurement. Bother are probably more accurate than tympanic membrane temperature.

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Mechanisms of heat loss
Radiation (when the body is warmer than the surrounding environment) Conduction (through contact with a colder object) Convection (through contact with a colder fluid, heat loss increases as the speed of the fluid (e.g. wind) increases) Evaporation Respiration (exhaled air is warm)

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Recognition
If a group member is shivering they should be managed as though they have hypothermia. All other group members should be considered to be at risk.
 * The "umbles" are characteristic of early hypothermia**: mumbles, grumbles, fumbles and stumbles - these all related to a decline in brain function but can be detected without any special equipment.

Treatment

 * Treatment should be based on the casualty's condition rather than their temperature. **

The presence of trauma or other significant co-mordibity is an indication for active rewarming, when this is possible, even in grade I hypothermia.
 * **Grade** || **Consciousness** || **Cardiovascular stability** || **Treatment** ||
 * I || Yes & shivers || Yes || Passive ||
 * II || Impaired& does not shiver || Dysrhythmias (initially AF) || Active ||
 * III - V || Impaired || No || Active ||

If a casualty is to be treated with **passive rewarming**: • Provide shelter for them. • Remove wet clothing a replace with dry clothing. • Provide fluid and carbohydrates (warm if possible). • They may then be able to self evacuate and the exertion involved will help to maintain core temperature - they must be closely observed at all times for any evidence of hyppothermia returning.

'Strategies for treating Hypothermia'- presentation for stage 4 oral assessment wilderness medicine & hypothermia.pptx Presentation: hypothermia presentation.ppt

[|Alaskan cold injury guideliens]

[|Hypothermia]

Although ECGs will rarely be available in the wilderness setting it is worth knowing about the ECG findings in hypothermia since it not an uncommon presentation to EDs. media type="custom" key="25565006"

Preventing cold casualties (US Army): chppm_ldr.ppt



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=Cold injuries =

Frostnip
Intense vasoconstruction in exposed skin (nose, ears, cheeks - especially in skiers). Affected area looks pale and waxy and may feel numb. Treated by rewarming gently - not rubbing.

Trenchfoot
This is a non-freezing injury most often found in limbs - especially if inactive - that are immersed for a long tim ein cold water or mud.

Trenchfoot can cause chronic problems with pain.

Frostbite
Freezing injury of the cells - usually in the peripheries: especially the digits. Can clinically be classified as superficial (in which case any blister fluid will be clear) or deep (blood stained blister fluid).

If the feet/toes have been affected the tissues must not be rewarmed before the casualty is evacuated if they will have to walk. Once the tissues have rewarme they will probably be too swollen and painful to walk on. <span style="font-family: Georgia,serif;">Rewarming should also be avoided if there is a risk of refreezing; repeated freezing and thawing causes additional damage.

<span style="font-family: Georgia,serif;">Rubbing and the application of direct heat should be avoided as they are likley to worsen tissue injury. The best way to rewarm is in a circulating warm water at 40-42 degrees C. Pain is common on rewarming: provide analgesia. The blisters should be managed as thermal burns: sterile dressings, avoid aspiration of the blisters if possible, treat as a tetanus-prone wound. Smoking, because it causes vasoconstriction, should be avoided.

<span style="font-family: Georgia,serif;">Early surgery is best avoided as more tissue may survive than looks likely at first. Isotope bone scanning may help identify early how much tissue will survive.

<span style="font-family: Verdana,Geneva,sans-serif;">Recommended books
<span style="font-family: Georgia,serif;">Hypothermia, frostbite and other cold injuries