Frostbite- What you need to know (Part 2)


Frosbite Prevention

Frostbite and related cold injuries can generally be prevented with planning prior to exposure to the cold. Ensuring adequate tissue perfusion and minimizing heat loss are the main components of
frostbite prevention.

Measures to reduce the risk of frostbite include:
■ Maintaining adequate hydration and nutrition
■ Minimizing restriction in blood flow by avoiding immobility or constrictive clothing or footwear
■ Avoiding environmental conditions below -15°C, even with low wind speeds
■ Dressing appropriately; wear a warm hat and heavy warm mittens (preferred over gloves), increase insulation by layering clothes appropriately, choose synthetic fabrics, fleece, silk or wool blends,
and avoid cotton as it retains moisture
■ Avoiding perspiration or wet extremities (keep hands and feet dry)
■ Avoiding drugs or alcohol as they may impair awareness of changing physical and environmental conditions.
■ Using chemical hand and foot warmers (these must not be placed directly against the skin or constrict blood flow in any way)
■ Recognizing frostnip or superficial frostbite before it progresses: an extremity at risk of frostbite (e.g., numb, poor dexterity, pale colour) should be warmed in the axilla or on the abdomen
■ Minimizing duration of exposure to cold
■ Using caution while exercising; it can increase core and peripheral temperatures and perfusion, but
can also lead to exhaustion and collapse
■ Note: applying emollients on the skin is not preventive and may even increase risk of frostbite

Nonpharmacologic Therapy
Until emergency medical care is available, the following First aid measures can be undertaken
■ Move the patient to a warm location as soon as possible; unless absolutely necessary, the person
should not walk on frostbitten toes or feet
■ Do not thaw the area if there is any risk of refreezing, which can worsen tissue damage
■ Remove jewellery or constrictive clothing from the affected area
■ Do not rub the area (even to dry it), as friction can increase tissue damage
■ Remove wet clothing once the patient is in a warm environment
Institute passive rewarming (warm environment, blankets, tucking affected area into the axilla,
groin or against the abdomen) until active rewarming can be started; if active rewarming cannot be
undertaken, allow passive thawing to occur
Institute rapid active rewarming as soon as possible by immersing in warm water (40-42°C; comfortably warm bath for 15-30 minutes until the skin feels soft and pliable and appears red.

After re warming, elevate the affected area to minimize edema
Fingers and toes may be separated by dry sterile dressings/gauze
Ensure the patient is adequately hydrated

If blisters develop, leave them intact to decrease risk of infection, unless they are restricting range of motion.
If blisters rupture, cover with clean dry gauze until emergency medical care is available.
Patients should not smoke, as nicotine may cause vasoconstriction and reduce blood flow.
Frostnip responds quickly to rewarming with no sequelae.f4lP°l Chilblains are treated conservatively with warmth, elevation of the area and application of soothing moisturizers.l4! Trench foot is treated by
rewarming the skin, elevating the area and wrapping the patient in loose, soft material to maintain constant warmth.

Frostbite Pharmacologic Therapy

Frostbitten areas may become very painful during the rewarming process. Adequate pain relief should be provided. NSAIDs (e.g., ibuprofen, naproxen sodium) are recommended; by decreasing production
of prostaglandins and thromboxanes (which can cause vasoconstriction and therefore worsen dermal ischemia), they may prevent further tissue damage in addition to relieving pain

Some guidelines recommend the routine use of ibuprofen at a dose of 12 mg/kg/day divided BID for its prostaglandin inhibitory effects (even in the absence of pain) Acetaminophen can be used to relieve pain for
patients unable to take NSAIDs In serious frostbite, opioid analgesics may be required for pain not responding adequately to nonprescription analgesics.

Limited observational evidence shows aloe vera may improve frostbite outcomes by reducing prostaglandin and thromboxane formation in more serious frostbite where blisters have formed.

Although it does not penetrate far into tissue and may be beneficial only for superficial areas, some guidelines recommend aloe vera gel be applied to thawed tissue at each dressing change or every 6 hours despite the limited evidence, as the risks associated with its use are low.

A systematic review showed there is inconclusive evidence regarding whether aloe vera gel or dressings improve healing in acute or
chronic wounds.

Frostbite injuries are not particularly prone to infection, and use of systemic antibiotics for infection prophylaxis is controversial; however, they are sometimes used in cases of significant tissue loss.
Although evidence is not available regarding effectiveness, some sources recommend topical antibiotics be applied in cases where blisters have been debrided or have ruptured, as the area may be at a higher risk of infection.
Frostbite injuries that include blisters are prone to tetanus and therefore tetanus prophylaxis is indicated.

Other therapies aimed at increasing tissue perfusion (with varying amounts of evidence to support their use) may be considered in some patients admitted to hospital. These may include low-molecular- weight dextran, thrombolytics, vasodilators and pentoxifylline.

Other measures that may improve healing include hydrotherapy and hyperbaric oxygen.

Baby it’s cold outside

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