Frostbite

FROSTBITE (congelatio), damage to tissues caused by the effect of low temperature. The damage resulting from F. can vary in intensity and depends, on one hand, on the surrounding low temperature, the duration of its effect, and accompanying atmospheric phenomena, and on the other hand, on the condition in which a person finds himself at the moment of F. Cold, humid air with wind at a temperature not particularly low can lead to F. if it acts for a prolonged time. This is especially facilitated by tight footwear and poor, insufficiently protective clothing. As for the condition of the body, all other things being equal, a sleeping person is more susceptible to F. than one who is awake or in motion. Recently experienced illnesses, inadequate nutrition, fatigue, long marches, and old age favor F. Good blood supply provides the best and most reliable protection against F. Therefore, peripheral parts of the body—fingers of the hands and feet, hand and foot, nose, auricles, scrotum—are more often subject to F. The combination of the listed factors in their interaction ultimately results in three degrees of F. The first degree of F. is characterized by superficial inflammation of the skin, which first becomes pale, wrinkled, and loses sensitivity to a greater or lesser degree. After some time, these phenomena subside; the skin on the frostbitten area turns red (congelatio erythematosa), becomes hot, and swelling of the skin and subcutaneous tissue appears, which manifests as swelling of the affected tissues; to this is added a feeling of itching, burning, or tingling. Pain can sometimes be very severe, especially if the frostbitten area is warmed up quickly. The basis of these phenomena is vasospasm, causing anemia, followed by paralysis of the vessels, expressed as hyperemia. The redness of the skin in F. differs from the redness that occurs after burns by its more violet hue. After a few days, the inflammatory redness and swelling disappear, usually leaving no aftereffects. At the same time, the epidermis begins to peel off in flakes or pieces, and the skin returns to its normal appearance. In F. of the second degree, blisters (congelatio bullosa) form on the skin, sometimes filled with a light and transparent fluid if the blisters arise from reactive inflammation of the skin, or more often with a cloudy, bloody-serous fluid, which occurs when, as a result of F., there is a deep circulatory disturbance in the skin, bordering on its necrosis. In F. of the second degree, the affected skin takes on a dark red, even bluish color. The resulting loss of sensitivity can last for several days, and in such cases the prognosis for reptitutio ad integrum is questionable. It is not always possible to distinguish F. of the second degree from F. of the third degree, since in most cases with the formation of blisters, spreading gangrene develops. In this respect, the effect of F. on tissues differs from the effect of burns, in which strong heating of a part directly leads to necrosis having clear boundaries and not spreading further. In F., on the contrary, cold, acting on tissues, first brings them to freezing; after thawing, it becomes clear that the circulatory disturbance due to complete stasis in the vessels has a much greater extent than it seemed at first, and at the same time the area of necrosis is larger. F. of the third degree is characterized, in addition to blisters, by the formation of eschars. Frostbitten tissues are completely insensitive, colored a dark blue-red, immobile, and brittle; small members break off with careless handling, like glass. Sometimes at the first examination, the area of spread of F. of the third degree seems larger than it actually is: after some time, in more proximal areas, blood circulation is restored, and distal parts, most often the fingers of the extremities, become necrotic. But such a course usually constitutes an exception. In most cases, the impaired blood circulation due to complete thrombosis of the vessels is not restored, and tissues affected by F. of the third degree undergo necrosis (congelatio necroticans). The resulting gangrene can be dry or wet depending on how dehydrated the necrotic tissues are, and in connection with this—whether infection has occurred or not. In dry gangrene, the necrotic parts mummify and separate after the formation of a demarcation line. At the same time, the intact skin around the demarcation line has a brighter color due to reactive inflammation. An added infection leads to wet gangrene, which has a tendency to spread. Changes in tissues in F. come down to a violation of the biochemical properties of the cell: at a certain temperature (below 0°) the cellular fluid freezes, and the cell dies. The vessels undergo the greatest changes: their spasm initially leads to ischemia, which can later turn into stasis with cessation of blood circulation; thrombosis of the vessels is the main cause of gangrene in F. Red blood cells of blood that has frozen and then thawed undergo disintegration with the dissolution of Hb. The blood takes on a bright red color—lacquer color. Impaired nutrition causes paresthesias of sensory nerves, rigidity of muscles. If the person affected by F. does not notice the first symptoms in the form of tingling, burning in the skin and does not take necessary protective measures, cold continues to act further and causes the above-mentioned disturbances in tissues. This especially often happens with people who are tired or in a state of intoxication. In peacetime, F. most often affects the homeless, vagrants, people forced by their profession to remain for long periods in cold air in humid wind; sometimes—athletes, among them often skiers. In the latter, F. of all degrees of the auricles, nose, fingers of the extremities, scrotum is observed. In many cases, F. was noted even when the external temperature did not drop below 3-4° above zero. In wartime, F. is especially often observed among soldiers tired from long marches, weakened due to experienced illnesses, inadequate nutrition, and difficult trench life. Forced to remain for long periods in wet trenches, in soaked footwear, which is often not removed for many days, these people very often become subject to F., mainly of the lower extremities. Such cases were observed in previous wars; there were many of them in the last imperialist war. F. of the extremities in these cases is actually a secondary process, owing its origin not to the direct, tissue-killing effect of strong and prolonged cold, but to disturbances in the nutrition of the vessels and nerves of the extremities. This disease, correctly called dystrophic necrosis of the extremities, can with full right be classified as a troop disease, since under similar conditions it was observed in many armies in previous wars. The condition of the vasomotors undoubtedly plays a role in this. To this same group of diseases caused by cold should be attributed trophic disorders with the presence of ulcers, usually on the lower extremities, vascular disorders on the basis of chilblains with thickening of the skin, anesthesias, observed among workers in refrigerators (Nikiforov). As an extreme rarity, cases of F. in medical practice from the application of ice in inflammatory processes are observed. Cold, applied for therapeutic purposes, requires certain precautions: it is necessary to place a towel or napkin under the ice pack, to remove the ice from time to time, and by no means to keep it constantly for a long time in one place. Non-compliance with this can lead to deep freezing of tissues with necrosis. Measures for the prevention of F. consist in eliminating the harmful factors mentioned above. Here, along with general body care, sufficiently spacious footwear, warm gloves, care to change wet clothing and footwear, muscle movements in the cold are of great importance. Smearing the skin of open parts of the body in frosty weather with fatty substances—vaseline, goose fat, etc., which is practiced for example by athletes, is expedient and makes sense in that the fatty substance as a poor conductor of heat reduces heat loss from the skin in the open air. Mild cases of F. require no treatment. One should only avoid too rapid warming of the frostbitten part. The very common practice of rubbing with snow, leading to gradual active hyperemia of tissues, should be recognized as rational; it should only be done in a cold room. The treatment of F. of the second and third degrees pursues a dual purpose—to improve the blood supply of the affected tissues and to prevent the occurrence of infection. The first is achieved by vertical elevation of frostbitten extremities, the use of dry-air, as well as warm water baths. Dry aseptic dressings, compresses from dehydrating fluids (alcohol) are the best protection against infection.

Under the influence of the dehydrating action of alcohol, the process of mummification of dead tissues proceeds more rapidly. Light therapy in the form of blue light and mountain sun acts well in frostbite, as well as in chilblains. In some cases, ulcers remaining after the rejection of dead tissues are susceptible to the action of sol-lux and diathermy. The general principle of treatment is possible conservatism. Amputation or exarticulation should be undertaken only when the demarcation line of necrosis is clearly defined, and only vital indications, such as threatening general infection or inevitable intoxication from dead tissues, force one to resort to primary amputation or exarticulation. Wet gangrene gives cause for this much more often than dry gangrene.