Frostbites

Frostbites are open tissue injuries caused by local exposure to low temperatures. The effect of low temperatures on the entire body is called supercooling. Human tissues are very resistant to cold (with the exception of general overcooling), the outcomes depend not only on the temperature, duration of exposure to cold, but also on the qualification of rendering assistance to the victim. Only with a local decrease in temperature below 25 degrees does irreversible damage to nerves and blood vessels develop in the form of vasculitis and thrombus formation with trophic tissue disorder. Therefore, with frostbites, the main principles are timeliness and correctness of first aid and subsequent treatment. It must be remembered that the rapid restoration of blood flow can give the reversibility of the evolved process.

[1]

Clinic of the pre-active period

The clinic and complaints are of the same type for any degree of frostbite. Disturb pain, loss of sensitivity, movements, feelings of support.

On examination: the limb is pale, with a marble tint. With palpation, it is cold to the touch, dense to "woody", the loss of tactile sensitivity and impaired function are determined.

[2], [3], [4]

Clinic of the reactive period

Depends on the degree of frostbite and the ability of tissues to regenerate, which is largely determined by the correctness of care in the pre-active period. Completely determine the degree of frostbite is possible only by the end of the second week.

• 1 degree of frostbite. After thawing, during the first day, there are: dilating pain, moderate swelling, manifestations of cold dermatitis (skin tension due to edema, cyanosis, cyanotic skin), from the second day: increased skin sensitivity (hyperesthesia), tingling sensation, crawling (paresthesia ), the skin turns red, there is a feeling of support.

Edema and pain disappear by the 5th-7th day, there is a profuse exfoliation of the skin. Recovery comes on the 7-10th day. Long-term hyperpigmentation of the skin, chilliness, increased sensitivity to cold. Vessels remain labile, prone to angiopathy.

• 2 degree of frostbite. The pain is considerable, the feeling of bursting and heaviness is troubling. On the 2nd-3rd day, bubbles with serous contents (in the form of jelly) are formed. Edema of tissues is considerable, it seizes vast areas. By the end of the week, the bubbles are being opened. Epithelialization of the surface goes islets 2-3 weeks. Scars are not formed. Persistent hyperpigmentation of the skin, increased sensitivity to cold persists for years. Changes in the vessels are persistent, marked propensity to angiospasm, up to the development of obliterating endarteritis. Sometimes Bénya's disease is formed - persistent, symmetrical infiltrated foci of cyanotic color appear on the nose, cheeks, ear shells, fingers of the hands.
• 3 degree of frostbite. The pain is constant, sharp, it gives all over the limbs. Long-term loss of tactile sensitivity is noted. The swelling of the extremity is pronounced, with the squeezing of the vessels, which determines a decrease in pulsation in the peripheral arteries.

On the second day, bubbles with jelly-like hemorrhagic contents form. On the 3-5th day they are opened. At this time, preliminary differential probes can be carried out to determine the depth of frostbite. In contrast to the 2 degrees of frostbite, the third: tingling with a needle (Billroth's method), imposing alcohol applications (Mikulich's method) are painless. With thermometry of the skin, there is a persistent drop in temperature, which is not typical for the second degree of frostbite.

By the end of the week, edema decreases, and zones of delimitation appear that are clearly expressed (demarcation) with the formation of a dense scab of black color. Under it granulation develops, epithelialization comes from the edges, very slowly. Healing occurs with the formation of the scar.

• 4 degree of frostbite. The pain is sharp, on all limbs, but tactile sensitivity is absent. Edema is huge, on the entire limb, with the squeezing of blood vessels and nerve trunks. Bubbles may not be, or they are formed with hemorrhagic contents, but quickly open. Fingers and distal areas within a week turn black, the nails are rejected} their desiccation (mummification) takes place. By the end of the second week, the demarcation line clearly delimits the frostbite zone. If the segment is not removed operatively, then in 3-4 weeks its natural rejection takes place along the demarcation line. After this, a very slow granulation of the surface and epithelization from the edges (sometimes years), with the formation of a rough scar. Kul't in these cases is not adaptable. Moreover, often causalgia develop (burning, phantom pain in the stump) due to clavate deformation of the nerves. Perhaps the only way out of this situation is to carry out an early amputation within the healthy tissues with the formation of a supporting stump.

[5], [6], [7]

Classification of frostbites

According to the peculiarities of the appearance of frostbites, they are divided into 3 types:

• from prolonged exposure to cold, even at temperatures above "0" degrees, the so-called trench stop in peacetime develops among fishermen and timber merchants, etc .;
• from: the effect of temperature below "0" degrees in cases of local tissue freezing;
• from contact with a cooled object (for example, if you lick a frozen piece of metal).

In depth, 4 degrees of frostbite are formed:

1. Only the epidermis of the skin is affected.
2. The lesion deepens to the basal layer.
3. The whole thickness of the skin and subcutaneous tissue are affected.
4. Bones and soft tissues are affected.

Due to the high regenerative ability of tissues to recover after exposure to cold, as well as the opportunities for care and quality of treatment, the final decision on the depth of frostbite can be taken only 2 weeks after injury

Three periods are distinguished in the course of the process.

• Doreactive - from the moment of freezing to thawing of the limb segment.
• Reactive - from the moment of thawing to the restoration of skin.
• The period of reconvalescence - until the full recovery of work capacity or access to disability.

[8], [9], [10]

Complications of frostbites

• Accession of infection with development: purulent dermatitis, streptophiloderma, moist gangrene, sepsis, etc.
• Development of complications from the veins: thrombophlebitis, phlebitis, phlebothrombosis, up to the development of trophic ulcers.
• Formation: atrophy of muscles, arthritis, contracture changes in joints with stiffness, up to ankylosis.
• Development of Raynaud's disease and obliterating endarteritis due to damage to nerve trunks and arteries.
• Education cold: neurovascular, neurodermatitis, limb dermatitis.
• Involving limbs in the process of lymphatic vessels: lymphadenitis, lymphangitis, lymphodema, etc.

[11], [12]