Necrosis
Causes and symptoms of necrosis, outcome and prevention
Causes of necrosis
Necrosis is an irreversible cessation of the vital activity of cells, tissues or organs in a living organism, caused by the influence of pathogenic microbes. The cause of necrosis can be tissue destruction by mechanical, thermal, chemical, infectious and toxic agents. This phenomenon occurs due to an allergic reaction, impaired innervation and blood circulation. The severity of necrosis depends on the general condition of the body and unfavorable local factors.
The development of necrosis is facilitated by the presence of pathogenic microorganisms, fungi, viruses. Also, cooling in the area where there is a violation of blood circulation has a negative effect, in such conditions vasospasm increases and blood circulation is even more disturbed. Excessive overheating affects the increase in metabolism and with a lack of blood circulation, necrotic processes appear.
Symptoms of necrosis
Numbness, lack of sensitivity is the very first symptom that should be a reason for visiting a doctor. Pallor of the skin is observed as a result of improper blood circulation, gradually the color of the skin becomes cyanotic, then black or dark green. If necrosis occurs in the lower extremities, then at first it is manifested by rapid fatigue when walking, a feeling of cold, convulsions, the appearance of lameness, after which non-healing trophic ulcers are formed, necrotizing over time.
Deterioration of the general condition of the body occurs from dysfunctions of the central nervous system, blood circulation, respiratory system, kidneys, liver. In this case, a decrease in immunity is observed due to the appearance of concomitant blood diseases and anemia. There is a metabolic disorder, exhaustion, hypovitaminosis and overwork.
Types of necrosis
Depending on what changes occur in the tissues, two forms of necrosis are distinguished:
Coagulative (dry) necrosis - occurs when tissue protein coagulates, thickens, dries up and turns into a curdled mass. This is the result of the cessation of blood flow and evaporation of moisture. The areas of tissue are dry, brittle, dark brown or gray-yellow in color with a clear demarcation line. At the site of the rejection of dead tissue, an ulcer occurs, a purulent process develops, an abscess is formed, and a fistula is formed upon opening. Dry necrosis is formed in the spleen, kidneys, umbilical cord stump in newborns.
· Colliquation (wet) necrosis - manifested by swelling, softening and liquefaction of dead tissues, the formation of a gray mass, the appearance of a putrid odor.
There are several types of necrosis:
· Heart attack - occurs as a result of a sudden cessation of blood supply in the focus of tissue or organ. The term ischemic necrosis means necrosis of a part of an internal organ - infarction of the brain, heart, intestines, lung, kidney, spleen. With a small infarction, autolytic fusion or resorption occurs and the tissue is completely restored. An unfavorable outcome of a heart attack is a violation of the vital functions of the tissue, complications or death.
Sequestration - a dead area of bone tissue is located in the sequestral cavity, separated from healthy tissue due to a purulent process (osteomyelitis).
· Gangrene - necrosis of the skin, mucous surfaces, muscles. Its development is preceded by tissue necrosis.
· Pressure ulcers - occur in immobilized people due to prolonged compression of tissues or damage to the skin. All this leads to the formation of deep, purulent ulcers.
Diagnosis of necrosis
Unfortunately, patients are often sent for an examination performed using an X-ray, but this method does not allow detecting pathology at the very beginning of its development. Necrosis on X-rays is noticeable, only in the second and third stages of the disease. Blood tests also do not provide effective results in investigating this problem. Modern devices for magnetic resonance imaging or computed tomography today make it possible to timely and accurately determine changes in tissue structure.
Outcome of necrosis
The outcome of necrosis is favorable if there is an enzymatic melting of the tissue, the germination of connective tissue into the remaining dead tissue, and a scar is formed. The zone of necrosis can become overgrown with connective tissue - a capsule is formed (encapsulation). Bone can also form in the area of dead tissue (ossification).
With an unfavorable outcome, purulent fusion occurs, complicated by bleeding, the spread of the focus - sepsis develops.
Fatal outcome is typical for ischemic strokes, myocardial infarction. Necrosis of the cortical layer of the kidneys, necrosis of the pancreas (pancreatic necrosis), etc. etc. - damage to vital organs is fatal.
Necrosis treatment
Treatment of any kind of necrosis will be successful if the disease is detected early. There are many methods of conservative, gentle and functional treatment, only a highly qualified specialist can determine which one is best suited for the most effective result.
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".
