PATIENT INFO - GANGRENE

Causes

Gangrene is the death of tissue in part of the body. Gangrene happens when a body part loses its blood supply. This may happen from injury, an infection, or other causes. You have a higher risk for gangrene if you have:

• A serious injury
• Blood vessel disease (such as arteriosclerosis, also called hardening of the arteries, in your arms or legs)
• Diabetes
• Suppressed immune system (for example, from HIV or chemotherapy)
• Surgery

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Symptoms

The symptoms depend on the location and cause of the gangrene. If the skin is involved, or the gangrene is close to the skin, the symptoms may include:

• Discoloration (blue or black if skin is affected; red or bronze if the affected area is beneath the skin)
• Foul-smelling discharge
• Loss of feeling in the area (which may happen after severe pain in the area)

If the affected area is inside the body, the symptoms may include:

• Confusion
• Fever
• Gas in tissues beneath the skin
• General ill feeling
• Low blood pressure
• Persistent or severe pain

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Types of gangrene

• Dry gangrene – Dry gangrene is characterized by dry and shriveled skin ranging in color from brown to purplish-blue to black. Usually, dry gangrene develops slowly. It occurs most commonly in people who have a blood vessel disease, such as atherosclerosis.
• Wet gangrene – Gangrene is referred to as "wet" if there's a bacterial infection in the affected tissue. Swelling, blistering and a wet appearance are common features of wet gangrene. It can develop after a severe burn, frostbite or injury. It often occurs in people with diabetes who unknowingly injure a toe or foot. Wet gangrene needs to be treated immediately because it spreads quickly and can be fatal.
• Gas gangrene – Gas gangrene typically affects deep muscle tissue. If you have gas gangrene, the surface of your skin may initially appear normal. As the condition progresses, your skin may become pale and then evolve to a gray or purplish-red color. A bubbly appearance to your skin may become apparent, and the affected skin may make a crackling sound when you press on it because of the gas within the tissue. Gas gangrene is usually caused by infection with the bacterium Clostridium perfringens, which develops in an injury or surgical wound that's depleted of blood supply. The bacterial infection produces toxins that release gas — hence the name "gas" gangrene — and cause tissue death. Like wet gangrene, gas gangrene can become life-threatening.
• Internal gangrene – Gangrene affecting one or more of your organs, most commonly your intestines, gallbladder or appendix, is called internal gangrene. This type of gangrene occurs when blood flow to an internal organ is blocked — for example, when your intestines bulge through a weakened area of muscle in your abdomen (hernia) and become twisted. Internal gangrene often causes a fever and severe pain. Left untreated, internal gangrene can be fatal.
• Fournier's gangrene – Fournier's gangrene is an uncommon type of gangrene that involves the genital organs. Men are more often affected, but women can develop this type of gangrene as well. Fournier's gangrene usually arises due to an infection in the genital area or urinary tract and causes genital pain, tenderness, redness and swelling.
• Progressive bacterial synergistic gangrene (Meleney's gangrene) – This rare type of gangrene typically occurs after an operation, with painful skin lesions developing one to two weeks after surgery.

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Tests for Gangrene

The doctor may diagnose gangrene from a physical examination. In addition, the following tests and procedures may be used to diagnose gangrene:

• Arteriogram (special x-ray to see any blockages in the blood vessels) to help plan treatment for blood vessel disease
• Blood tests (white blood cell [WBC] count may be high)
• CT scan to examine internal organs
• Culture of the tissue or fluid from wounds to identify bacterial infection
• Examining tissue under the microscope to look for cell death
• Surgery to find and remove dead tissue
• X-rays

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Treatment

Gangrene requires urgent evaluation and treatment. In general, dead tissue should be removed to allow healing of the surrounding living tissue and prevent further infection. Depending on the area that has the gangrene, the person's overall condition, and the cause of the gangrene, treatment may include:

• Amputating the body part that has gangrene
• An emergency operation to find and remove dead tissue
• An operation to improve blood supply to the area
• Antibiotics
• Repeated operations to remove dead tissue (debridement)
• Treatment in the intensive care unit (for severely ill patients)

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Call your doctor immediately if:

• A wound does not heal or there are frequent sores in an area
• An area of your skin turns blue or black
• There is foul-smelling discharge from any wound on your body
• You have persistent, unexplained pain in an area
• You have persistent, unexplained fever

Several factors increase your risk of developing gangrene. These include:

• Age – Gangrene occurs far more often in older people.
• Diabetes – If you have diabetes, your body doesn't produce enough of the hormone insulin (which helps your cells take up blood sugar) or is resistant to the effects of insulin. High blood sugar levels can eventually damage blood vessels, interrupting blood flow to a part of your body.
• Blood vessel disease – Hardened and narrowed arteries (atherosclerosis) and blood clots also can block blood flow to an area of your body.
• Severe injury or surgery – Any process that causes trauma to your skin and underlying tissue, including an injury or frostbite, increases your risk of developing gangrene, especially if you have an underlying condition that affects blood flow to the injured area.
• Obesity – Obesity often accompanies diabetes and vascular disease, but the stress of extra weight alone can also compress arteries, leading to reduced blood flow and increasing your risk of infection and poor wound healing.
• Immunosuppression – If you have an infection with the human immunodeficiency virus (HIV) or if you're undergoing chemotherapy or radiation therapy, your body's ability to fight off an infection is impaired.
• Medications– In rare instances, the anticoagulant drug warfarin (Coumadin) has been known to cause gangrene — especially in combination with heparin therapy.

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Prevention

Gangrene may be prevented if it is treated before the tissue damage is irreversible. Wounds should be treated properly and watched carefully for signs of infection (such as spreading redness, swelling, or drainage) or failure to heal.

People with diabetes or blood vessel disease should routinely examine their feet for any signs of injury, infection, or change in skin color and seek care as needed.

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