Burn disease

Burn disease is a set of dysfunctions of various organs and systems that occur as a result of extensive burns. Burn disease has the following periods: burn shock, acute burn toxemia, the period of purulent-septic complications and convalescence.

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Acute toxemia

After burn shock has been relieved (usually 2-3 days after the injury), as a result of fluid resorption from the lesion, a large amount of toxic substances - tissue decay products and bacterial flora - accumulate in the vascular bed. In other words, a burn with necrotic tissue becomes a source of intoxication of the body. The bulk of toxic substances enter the blood during the first week, when the full picture of severe intoxication occurs. During this period, the volume of circulating plasma increases, and the number of circulating erythrocytes continues to decrease due to their destruction and suppression of bone marrow hematopoiesis. Anemia develops 4-6 days after the injury. Oxygen transport is significantly reduced due to anemia. Blood pressure fluctuates within normal values; moderate hypotension is observed in a small proportion of patients. Electrocardiographic examination reveals signs of myocardial hypoxia, and in elderly and weakened patients - circulatory failure. Due to the impairment of the ventilation function of the lungs, increasing dyspnea and increased carbon dioxide emissions, respiratory alkalosis often develops. Liver function is impaired. Kidney function is normalized, but the plasma flow and glomerular filtration rates remain low; renal osmoregulatory function insufficiency is revealed.

Burn disease is characterized by delirium, hallucinations, insomnia, and motor agitation often occurs. Patients are disoriented in time and space, try to get out of bed, and tear off bandages. The frequency of mental disorders is directly proportional to the severity of the burn injury: if intoxication delirium is rare with superficial burns, then with deep lesions exceeding 20% of the body surface, it occurs in 90% of victims. The occurrence of the most severe and protracted forms of delirium is facilitated by alcohol abuse before the injury.

Burn disease is often complicated by pneumonia. In this case, the condition of patients deteriorates sharply, body temperature rises, cough, shortness of breath, cyanosis appear. Moist rales are heard in the lungs. Bilateral pneumonia often leads to the development of respiratory failure, one of the most common causes of death. The combination of severe skin burns with inhalation trauma is considered especially unfavorable, when pneumonia develops early in all patients (2-4 days after the injury).

Ulcers of the gastrointestinal tract are a serious condition that often accompanies such a condition as burn disease. In this case, the appearance of vomit resembling "coffee grounds" or dark tarry feces indicates acute or existing bleeding from ulcers or erosions of the gastrointestinal tract. Much less often, they are accompanied by perforation of the stomach or intestines. The general serious condition of the victim levels out the symptoms of "acute abdomen", as a result of which this complication is often recognized too late.

In case of extensive burns, toxic myocarditis and hepatitis often occur. This is evidenced by an increase in the level of transaminases and bilirubin in the blood serum. Protein breakdown and nitrogen excretion in the urine increase, and there are pronounced disorders of the water-electrolyte balance.

During this period, appetite is reduced, intestinal motor function is impaired, inhibition or motor agitation with signs of intoxication delirium, visual and auditory hallucinations, and sleep disturbances are possible. The degree of intoxication depends on the nature of tissue damage. The period of toxemia is most severe in the presence of wet necrosis with suppuration of burn wounds. In dry necrosis, intoxication is much less pronounced. The duration of this period of burn disease is 7-9 days.

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Period of purulent-septic complications

This period of burn disease follows acute toxemia, but it is often difficult to draw a line between them. It usually begins 10-12 days after the burn and coincides with wound suppuration and the beginning of the rejection of non-viable tissues. This period is also observed in extensive IIIA degree burns in the case of severe wound suppuration. The duration of this period is either until the burn wounds heal or are closed with autografts, or until the death of the victim.

The purulent process in wounds is accompanied by a severe systemic inflammatory reaction and sepsis. The duration of the febrile state is on average 2-3 weeks, but in case of complications it can be 2-3 months. After the burn scab is rejected, the body temperature usually decreases by 1-1.5 °C. The general condition of patients remains severe, they complain of constant pain in the burn sites, poor sleep, loss of appetite, irritability, capriciousness, and often tearfulness. Anemia increases, the causes of which include the destruction of red blood cells, inhibition of erythropoiesis, infectious complications, bleeding from granulating wounds, ulcers, and erosions of the gastrointestinal tract. With severe burns, neutrophilia develops with a predominant increase in the number of band neutrophils (up to 30%) and the appearance of their young forms. Eosinopenia and lymphopenia are considered an unfavorable sign. The number of leukocytes decreases slightly after the rejection of non-viable tissues. In severe patients, toxic granularity of leukocytes is detected. There is a constant loss of tissue and serum proteins, reaching 80 g / day and more. Progressive hypoproteinemia is a prognostically unfavorable sign. Hypoalbuminemia and an increase in the number of globulin fractions reflect the activity of wound infection and indicate a violation of the processes of protein synthesis and resynthesis. Direct confirmation of sepsis is the growth of microorganisms when blood is seeded on nutrient media.

In the sepsis stage, infectious complications are very diverse: pneumonia, bronchitis, phlegmon, abscesses, arthritis may develop. Digestive disorders are common, especially gastrointestinal paresis. Burn disease is complicated by the formation of acute (stress) Curling ulcers, which are often accompanied by bleeding and perforation into the abdominal cavity.

With the development of severe sepsis, the condition of the burnt person significantly worsens: consciousness is confused, orientation in the surrounding environment is impaired, the skin becomes jaundiced, hemorrhages and petechial rash are common. Burn disease is characterized by the formation of metastatic abscesses in the subcutaneous fat, muscles, and internal organs. The fever is hectic, poorly responds to drug therapy and is accompanied by chills and profuse sweating.

In sepsis, persistent hypochromic anemia, hypoproteinemia, pronounced leukocytosis, increased concentrations of residual nitrogen and bilirubin in the blood serum quickly develop. Erythrocytes, leukocytes, cylinders, and protein are found in the urine. High leukocytosis and a shift in the leukocyte formula to the left before the appearance of myelocytes indicate the activity of an infectious-toxic factor with preserved reactivity of the body, while eosinopenia and lymphocytopenia are considered unfavorable signs.

If the lost skin is not restored surgically within 1.5-2 months, burn disease progresses to exhaustion, which is caused by pronounced dystrophic changes in the internal organs, profound metabolic disorders, and a sharp suppression of the body's defenses. Patients develop bedsores, various complications from the cardiovascular, respiratory, excretory, and nervous systems. Weight loss reaches 25-30%. In burn exhaustion, reparative processes in wounds are sharply slowed down or absent. Granulations are pale, glassy, with a gray coating and a large amount of purulent discharge. Hematomas and secondary necrosis spreading to areas of healthy skin are often visible in the wounds. Putrefactive anaerobic microflora, Proteus spp., Pseudomonas aeruginosa are sown from the wounds.

Extensive purulent wounds are the cause of constant intoxication, hypoproteinemia and fever. Patients develop unresponsiveness, their immunity decreases, and exhaustion progresses. The resulting bedsores reach large sizes. Burn disease is often accompanied by the development of purulent arthritis, muscle atrophy, joint stiffness, and contractures. The course of exhaustion is complicated by damage to internal organs with the development of severe sepsis, which becomes the immediate cause of death.

The duration of the period of purulent-septic complications is determined by the duration of the existence of burn wounds. If the lost skin is successfully restored surgically, the patient begins to recover slowly but surely: fever gradually passes, sleep and appetite improve, anemia and hypoproteinemia disappear, and the functions of internal organs are normalized. Patients quickly gain weight, become more active, which indicates the beginning of the last period of burn disease.

Convalescence

The duration of the period is 1-1.5 months. However, not all those who had burn disease can be considered healthy people in the future: some suffer from chronic kidney diseases (pyelonephritis, nephrolithiasis), while others show signs of myocardial dystrophy. The most numerous group of convalescents requires reconstructive and restorative treatment of cicatricial contractures and deformations that have arisen at the site of deep burns, so the convalescence period for this category of victims is increased.