gas gangrene

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gangrene

 [gang´grēn]
the death of body tissue, generally in considerable mass, usually associated with loss of vascular (nutritive) supply, and followed by bacterial invasion and putrefaction. Although it usually affects the extremities, gangrene sometimes may involve the internal organs. Symptoms depend on the site and include fever, pain, darkening of the skin, and an unpleasant odor. If the condition involves an internal organ, it is generally attended by pain and collapse. Treatment includes correcting the causes and is frequently successful with modern medications and surgery.
Types of Gangrene
. The three major types are moist, dry, and gas gangrene. Moist and dry gangrene result from loss of blood circulation due to various causes; gas gangrene occurs in wounds infected by anaerobic bacteria, among which are various species of Clostridium, which break down tissue by gas production and by toxins.

Moist gangrene is caused by sudden stoppage of blood, resulting from burning by heat or acid, severe freezing, physical accident that destroys the tissue, a tourniquet that has been left on too long, or a clot or other embolism. At first, tissue affected by moist gangrene has the color of a bad bruise, is swollen, and often blistered. The gangrene is likely to spread with great speed. Toxins are formed in the affected tissues and absorbed.

Dry gangrene occurs gradually and results from slow reduction of the blood flow in the arteries. There is no subsequent bacterial decomposition; the tissues become dry and shriveled. It occurs only in the extremities, and can occur with arteriosclerosis, in old age, or in advanced stages of diabetes mellitus. buerger's disease can also sometimes cause dry gangrene. Symptoms include gradual shrinking of the tissue, which becomes cold and lacking in pulse, and turns first brown and then black. Usually a line of demarcation is formed where the gangrene stops, owing to the fact that the tissue above this line continues to receive an adequate supply of blood.

Gas gangrene results from dirty lacerated wounds infected by anaerobic bacteria, especially species of Clostridium. It is an acute, severe, painful condition in which muscles and subcutaneous tissues become filled with gas and a serosanguineous exudate.
Internal Gangrene. In strangulated hernia, a loop of intestine is caught in the bulge and its blood supply is cut off; gangrene may occur in that section of tissue. In acute appendicitis, areas of gangrene may occur in the walls of the appendix with consequent rupture through a gangrenous area. In severe cases of cholecystitis, which is usually associated with gallstones, gangrene may develop where the stones compress the mucous membrane. Thrombosis of the mesenteric artery may result in gangrene. Gangrene can be a rare complication of lung abscess in pneumonia; a symptom is brown sputum with a foul smell.
Prevention. To prevent gangrene in an open wound, the wound should be kept as clean as possible. Special wound care is particularly important in patients with diabetes mellitus, malnutrition, and immunodeficiency. frostbite is especially dangerous, for the freezing impedes circulation, skin becomes tender and easily broken, and underlying cells are destroyed.
Fournier's gangrene an acute gangrenous infection of the scrotum, penis, or perineum following local trauma, operative procedures, an underlying urinary tract disease, or a distant acute inflammatory process. Called also Fournier's disease.
gas gangrene a condition often resulting from dirty, lacerated wounds in which the muscles and subcutaneous tissue become filled with gas and a serosanguineous exudate. It is due to species of Clostridium that break down tissue by gas production and by toxins.

gas gan·grene

gangrene occurring in a wound infected with various anaerobic spore-forming bacteria, especially Clostridium perfringens and C. novyi, which cause rapidly advancing crepitation of the surrounding tissues, due to gas liberated by bacterial fermentation, and constitutional toxic and septic symptoms including cytotoxic damage to kidney, liver, and other organs.

gas gangrene

n.
Gangrene occurring in a wound infected with anaerobic bacteria of the genus Clostridium, especially C. perfringens, characterized by the presence of gas in the affected tissue and rapid progression that can lead to shock and death if untreated.

gas gangrene

necrosis accompanied by gas bubbles in soft tissue after surgery or trauma. It is caused by anaerobic organisms, such as various species of Clostridium, particularly C. perfringens. Symptoms include pain, swelling, and tenderness of the wound area; moderate fever; tachycardia; and hypotension. The skin around the wound becomes necrotic and ruptures, revealing necrotic muscle. A characteristic finding is toxic delirium. Spontaneous gas gangrene is most often caused by the spread of C. septicum from the GI tract of colon cancer patients. Because of its aerotolerant nature, C. septicum can infect normal tissues. If untreated, gas gangrene is rapidly fatal. Prompt treatment, including excision of gangrenous tissue and IV administration of penicillin G, saves 80% of patients. The disease is prevented by proper wound care. Also called anaerobic myositis.
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Gas gangrene due to Clostridium perfringens

gangrene

Pathology Tissue death, often due to loss of adequate blood supply, which is most common in the distal lower extremities or internal organs–eg, the large intestine; the gangrene type is a function of the environment or host
Gangrene types
Dry gangrene A condition caused by chronic occlusion that slowly progresses to severe tissue atrophy and mummification, often associated with peripheral vascular disease, eg DM, atherosclerosis
Gas gangrene A condition most common in open or dirty wounds infected by gas-producing gram-positive anaerobes, eg Clostridium perfringens, C histolytica, C septicum, C novyi, and C fallax which release histolytic enzymes, eg collagenase, fibrinolysin, hyaluronidase, and lecithinase
Wet gangrene A condition caused by relatively acute vascular occlusion, eg burns, freezing, crush injuries, and thromboembolism, resulting in liquefactive necrosis, causing bleb and bullae formation with violaceous discoloration

gas gan·grene

(gas gang'grēn)
Gangrene occurring in a wound that is infected with various anaerobic spore-forming bacteria, especially Clostridium perfringens and C. novyi, which cause crepitation of the surrounding tissues, due to gas liberated by bacterial fermentation, and constitutional septic symptoms.

gas gangrene

The effect of deep muscle infection with the dangerous anaerobic, gas-producing organism Clostridium welchii or Clostridium oedematiens . There is extensive tissue death, gas production and severe general upset. Energetic surgery may be necessary to preserve life.

gangrene

the death of body tissue, generally in considerable mass, usually associated with loss of vascular (nutritive) supply, and followed by bacterial invasion and putrefaction. Although it usually affects the extremities, gangrene sometimes may involve the internal organs. Signs depend on the site and include fever, pain, darkening of the skin, and an unpleasant odor. If the condition involves an internal organ, it is generally attended by pain and collapse.

dry gangrene
occurs gradually and results from slow reduction of the blood flow in the arteries. There is no subsequent bacterial decomposition; the tissues become dry and shriveled. It occurs only in the extremities, and usually because of gradual diminution of the blood supply. Signs include gradual shrinking of the tissue, which becomes cold and lacking in pulse, and turns first brown and then black. Usually a line of demarcation is formed where the gangrene stops, owing to the fact that the tissue above this line continues to receive an adequate supply of blood.
gas gangrene
results from dirty lacerated wounds infected by anaerobic bacteria, especially species of Clostridium. It is an acute, severe, painful condition in which muscles and subcutaneous tissues become filled with gas and a serosanguineous exudate.
internal gangrene
in strangulated hernia, a loop of intestine is caught in the bulge and its blood supply is cut off; gangrene may occur in that section of tissue. Thrombosis of the mesenteric artery may result in gangrene of a section of intestine. Gangrene can be a rare complication of lung abscess in pneumonia.
moist gangrene
caused by sudden stoppage of blood, resulting from burning by heat or acid, severe freezing, physical accident that destroys the tissue, a tourniquet that has been left on too long, or a clot or another embolism. At first, tissue affected by moist gangrene has the color of a bad bruise, smells atrociously, is swollen, and often blistered. The gangrene is likely to spread with great speed. Toxins are formed in the affected tissues and absorbed.
segmental gangrene
gangrene of a section of an organ, e.g. of part of an elephant's ear, as a result of sectional compromising of blood supply.