Frostbite (frostbite)
Causes and symptoms of frostbite (frostbite)
What is frostbite (frostbite)?
Under the influence of low temperatures and with prolonged exposure to the open air, local cooling of the body (frostbite) or general cooling (freezing) is likely. High humidity and strong winds contribute to frostbite and freezing. In addition to unfavorable climatic factors, the likelihood of frostbite increases with vascular diseases, smoking and drinking alcoholic beverages, inappropriate clothing and footwear with environmental conditions.
Causes of frostbite (frostbite)
When frostbite under the influence of low temperatures, the skin and tissues located deeper are affected. Exposure to cold does not in itself cause frostbite. Tissue death occurs due to impaired blood circulation. Spasm and paresis of blood vessels, a decrease in the rate of blood circulation, stagnation of blood cells and the formation of blood clots are the main causes of necrosis. Over time, the endothelial layer increases in the walls of the vessels, which is saturated with plasma, areas of necrotic tissue are formed, connective tissue appears, and obliteration of the vascular wall occurs.
Therefore, frostbite necrosis develops gradually and captures the reactive phase. The cause of obliterating diseases and tissue nutritional disorders are changes that occur in the vascular wall.
Frostbite (frostbite) symptoms
In 95% of cases, the limbs suffer from frostbite, since under the influence of low temperatures in them, first of all, blood circulation is disturbed. During the course of the disease, a latent period (pre-reactive) and reactive are distinguished. The first lasts several hours or a day and covers the time elapsed from the onset of the first symptoms of frostbite to the stage of warming the body and restoring the normal functioning of the circulatory system. This period is also called the period of hypothermia.
The next period, which begins from the moment of warming the affected organ and restoring blood flow, is divided into early and late. The early one covers 12 hours and is manifested by impaired microcirculation, changes in the vascular wall, increased blood clotting and thrombosis. In the late period, areas of necrotic tissue appear, and infection is attached. The characteristic symptoms of frostbite at this stage are: intoxication, a decrease in hemoglobin in the blood, a decrease in body temperature.
Depending on the depth of tissue damage, four degrees of frostbite are distinguished. In the first and second degree, frostbite affects superficially located tissues, in the third and fourth degrees, the process of necrosis goes to tissues located deeper.
The first degree of frostbite is characterized by impaired blood circulation. At this stage, tissue necrosis does not develop, and recovery occurs on the fifth or seventh day.
In the second degree of frostbite, the growth layer of the skin remains intact. All changes occur only in the surface layer, the destroyed cells of which are restored after a couple of weeks.
In the third degree of frostbite, necrosis covers all layers of the skin. The affected skin areas are not restored. Over time, the scab is rejected, granulation tissue forms in its place, and then a scar, the appearance of which can be prevented by a skin transplant made at the stage of granulation tissue formation.
The fourth degree of frostbite is characterized by necrosis of the skin and tissues located deeper. The pathological process affects bones and joints. Gangrene of the extremities (dry or wet) appears, localized in most cases on the feet or hands.
When examining a patient for successful treatment, it is important not only to identify the symptoms of frostbite by listening to the complaints of the victim, but also to clarify the conditions that caused them. In a conversation with the patient, an anamnesis is collected, various factors are established: temperature and humidity, the presence of wind, time spent in low temperatures, the nature of first aid and its volume.
Symptoms of frostbite, characteristic of the latent period of the disease, are the appearance of paresthesia in the affected areas, numbness, and sometimes pain. In the area of frostbite, pallor of the skin is noted, in some cases - cyanosis. The skin is cold, insensitive or numb. Loss of sensation may be the first symptom of severe frostbite. It is impossible to establish the exact extent of the disease at this stage.
As the frostbite areas get warmer, their blood supply is restored and the reactive period begins. Symptoms of frostbite at this stage are tingling and burning, the skin begins to itch, pain appears or intensifies, and the damaged area becomes warm to the touch. If frostbite affects the deep layers of the skin, then the pain does not intensify. During the reactive period, the skin becomes red or cyanotic (with severe frostbite), the tissues swell. Severe edema indicates deep frostbite.
The degree of frostbite and the nature of its distribution are established, as a rule, after a few days.
Under the influence of alternating periods of cooling and warming of the extremities and in special environmental conditions (temperature 0-10 ° C Celsius and high air humidity), a certain type of local frostbite can develop - "trench foot". Cooling lasts for several days, and the first symptoms of frostbite appear several days after the cessation of exposure to low temperatures.
The disease begins to manifest itself with aching pain in the lower extremities, burning sensation, numbness. Edema appears, the skin of the foot is pale and cold, its sensitivity is lost. Later, the skin becomes covered with blisters with hemorrhagic contents, at their bottom there are areas of necrotic tissue, symptoms of intoxication join: increased body temperature and heart rate, weakness. Sepsis is a common complication of the disease.
Frostbite treatment
The nature and volume of first aid depend on the degree of frostbite, the presence or absence of general hypothermia of the body, concomitant diseases. First aid comes down to stopping cooling, warming the limbs, restoring impaired blood circulation, and preventing infection. The measures that should be taken first of all when providing assistance to the victim include the delivery of the patient to a warm place, the release of frozen parts of the body from cold clothes, and a call to the doctor.
At the first degree of frostbite, the frozen skin is warmed with warm hands, a light massage is done, rubbed with a cloth made of wool, and a bandage of cotton and gauze is applied.
From the second to the fourth degree, the frozen areas of the skin warm quickly, rubbing is not carried out. The bandage is made of heat-insulating materials. The limbs are fixed. The patient is given hot drinks, food, a little alcohol, a tablet of acetylsalicylic acid, an analgin tablet, no-spa (80 mg), a papaverine tablet. The affected areas of the skin should not be rubbed with snow, it is not recommended to warm the limbs near an open fire, use heat sources uncontrollably, rub oils, fat, and alcohol into the skin if deep layers of the skin are affected.
With a mild degree of frostbite, you can warm the victim in a bath with a water temperature of 24 degrees Celsius, gradually increasing it to normal body temperature.
In case of moderate and severe frostbite, the patient must be urgently hospitalized.
Medical care is aimed at restoring impaired blood circulation, local treatment of lesions, prevention of infection, treatment of already infected skin areas. For the treatment of frostbite, conservative and surgical methods are used.
Infusion therapy is used as a conservative method of treating frostbite. In the late reactive period, detoxification drugs, blood substitutes, immunological drugs, and parenteral nutrition are prescribed. They use bacteriophages, carry out antibiotic therapy, and use chemical antiseptics.
Surgical treatment of frostbite is reduced to the removal of necrotic skin areas and transplantation to the site of the defect of its own tissues.
Local treatment consists of changing the antiseptic dressings. The fourth degree of treatment for frostbite, as a rule, is not complete without surgery. Conservative therapy is performed before the operation.
Article author: Mochalov Pavel Alexandrovich | d. m. n. therapist
Education: Moscow Medical Institute. IM Sechenov, specialty - "General Medicine" in 1991, in 1993 "Occupational Diseases", in 1996 "Therapy".
