Gangrene

WHAT YOU SHOULD KNOW

Gangrene is the medical term for the death of a patch of tissue. It can occur in the skin, the muscles, or even the internal organs. Symptoms usually start suddenly, then get steadily worse. The problem is most commonly found in the arms and legs.

Causes

The death of tissue that defines gangrene begins when a section of the body loses its blood supply. It's often the result of a serious accident in which an arm or leg is crushed. Less commonly, it follows an internal blockage, such as a clogged or obstructed artery. There are two major types of gangrene:

Dry gangrene . This variety is free of infection. It is usually brought on by a blood clot, frostbite, or poor circulation that causes the tissues to become dry and shriveled.

Wet gangrene (also called gas gangrene) . In this form of the disease, dead tissue becomes a breeding ground for bacteria—typically Clostridium , which thrives in the absence of oxygen—causing the area to become moist and foul-smelling.

Signs/Symptoms

Typically, the skin may look pale at first, then become red or bronze, and finally turn dark red or purple. Infection makes the skin warm and swollen. Inflammation at the site of the infection can become extremely painful as the tissue swells. Gas produced by the infecting bacteria may produce a crackly sensation when the swollen area is pressed. The margins of the infection expand so rapidly that changes are often noticeable within minutes. A foul-smelling brown-red or bloody discharge may drain from the afflicted tissues, which are completely destroyed.

Elsewhere in the body, the infection soon produces sweating, fever, and increased heart rate. Left untreated, the victim will develop a shock-like syndrome with decreased blood pressure, kidney failure, coma, and finally death.

Care

Because gangrene spreads rapidly, immediate treatment is essential. The goal is to prevent infection from spreading. Any dead tissue must be removed at once. Antibiotics are needed to keep bacteria from attacking surrounding tissues. Pain killers may be necessary; and the doctor will also attempt to treat the underlying cause, restoring the disrupted blood supply if possible. Hyperbaric oxygen therapy (pure oxygen under high pressure) may also be administered, but offers varying degrees of success.

Unfortunately, in severe cases, amputation of the infected body part or parts, usually part of an arm or leg, is necessary to prevent the gangrene from attacking the rest of the body.

Risks

Gangrene can be fatal if not treated immediately. The sooner treatment begins, the better the outcome. Amputation is a major risk. Additional complications as the infection spreads can include liver damage, kidney failure, shock, stupor, delirium, and coma.

WHAT YOU SHOULD KNOW

Seek Care Immediately If...

Signs of infection develop at any time around a skin wound. Warnings include pain, swelling, redness, and drainage of pus or blood. Be especially quick to get help if you also have a fever.

IF YOU'RE HEADING FOR THE HOSPITAL...

What to Expect While You're There

You may encounter the following procedures and equipment during your stay.

• Taking Vital Signs: These include your temperature, pulse, blood pressure, and respiration. A stethoscope is used to listen to your heart and lungs. Your blood pressure is taken with a cuff wrapped around your arm. These tests may be performed hourly.
• IV: A tube placed in your vein for giving liquids and medications such as antibiotics and pain killers. It will either be capped or have tubing connected to it.
• Wound Culture: This procedure is usually performed by a nurse, who inserts a swab or a syringe into the wound to collect a sample of the attacking bacteria. In a deep wound in which gangrene is suspected, this type of culture is known as an anaerobic culture , since it detects organisms, such as Clostridium , that cannot live in the presence of oxygen.
• Oxygen: Your body may need extra oxygen. It is given either by a mask or nasal prongs.
• CT Scan: Computerized axial tomography, also know as a CAT scan or CT scan, takes a picture of the area and shows the extent of the damage.
• MRI: This imaging procedure also helps to determine the extent of the problem. During the imaging, you'll need to lie on a narrow bed that slides into the scanner.
• Hyperbaric Chamber: This form of treatment provides oxygen at much higher than normal pressure, allowing it to penetrate deeper into the wound and help fight the infection. Some chambers accommodate one person; others hold as many as ten. In a single-person chamber, you lie on a narrow bed that slides into the chamber, much like an MRI scanner. In larger chambers, patients are given oxygen through a mask, hood, or tube connected to the wall.
• X-ray: This picture of the affected area shows whether there is any gas under the skin.
• Pulse Oximeter: This is a clip placed on your ear, finger, or toe and connected to a machine that measures the oxygen in your blood.
• Neuro Signs: To assess the status of your nervous system, the doctor will check your eyes, test your memory, and see how easily you can be awakened.
• Blood: Samples are usually taken for testing from a vein in the hand or the bend in the elbow. Because the oxygen content of your blood will also be evaluated, additional samples may be drawn from the wrist, elbow, or groin.

After You Leave

• Keep the site of the injury clean. Wash the area with warm, soapy water three to five times a day.
• Follow your doctor's instructions regarding changing bandages and dressings.
• Take your medications exactly as directed. Be sure to completely finish all antibiotics the doctor may have prescribed
• Rest in bed, stay warm, and limit your activity as much as possible for a few days.

Seek Care Immediately If...

• You notice further signs of infection, such as redness, pain, drainage, or swelling around the wound.
• You develop any aftereffects of hyperbaric oxygen therapy such as ringing in the ears, nausea, vomiting, sweating, twitching, visual changes, confusion, or apprehension.

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