Diagnosis

Tests used to help make a diagnosis of gangrene include:

  • Blood tests. An abnormally elevated white blood cell count often indicates the presence of an infection. Your doctor might also perform blood tests to look for the presence of certain bacteria or other germs.
  • Imaging tests. An X-ray, a computerized tomography (CT) scan or a magnetic resonance imaging (MRI) scan can be used to view interior body structures, such as your internal organs, blood vessels or bones, and assess the extent to which gangrene has spread. These types of tests can also help your doctor see any gas that is present under your skin.

    An arteriogram is an imaging test used to visualize your arteries. During this test, dye is injected into your bloodstream and X-ray pictures are taken to determine how well blood is flowing through your arteries. An arteriogram can help your doctor find out whether any of your arteries are blocked.

  • Surgery. Surgery may be performed to determine the extent to which gangrene has spread within your body.
  • Fluid or tissue culture. A culture of the fluid from a blister on your skin may be examined for the bacterium Clostridium perfringens, a common cause of gas gangrene, or your doctor may look at a tissue sample under a microscope for signs of cell death.

Treatment

Tissue that has been damaged by gangrene can't be saved, but steps can be taken to prevent gangrene from progressing. Depending on the severity of your gangrene, your doctor could choose one or more of these treatment options.

Surgery

Your doctor may perform a surgical procedure to remove dead tissue, which helps stop gangrene from spreading and allows healthy tissue to heal. If possible, your doctor may repair damaged or diseased blood vessels in order to increase blood flow to the affected area. Occasionally, more than one surgery may be required to remove all dead or infected tissue.

If reconstructive surgery is needed, your doctor might use a skin graft to repair damage to your skin caused by gangrene. During a skin graft, your doctor removes healthy skin from another part of your body — usually a place hidden by your clothing — and carefully spreads it over an affected area. The healthy skin may be held in place by a dressing or by a couple of small stitches. A skin graft can be done only if an adequate blood supply has been restored to the damaged skin.

In severe cases of gangrene, an affected body part, such as a toe, finger or limb, may need to be surgically removed (amputated). In some cases, you may later be fitted with an artificial limb (prosthesis).

Antibiotics

Antibiotics that are given through a vein (intravenous), or those that are taken orally, may be used to treat gangrene that has become infected.

If you have to have surgery to remove dead tissue, your doctor will probably prescribe certain antibiotics until no further surgery is needed and your infection is cleared. Your doctor might also prescribe antibiotics to be taken while you complete hyperbaric oxygen therapy.

Hyperbaric oxygen therapy

In addition to antibiotics and surgery, hyperbaric oxygen therapy also may be used to treat gangrene. Under increased pressure and increased oxygen content, your blood is able to carry greater amounts of oxygen. Blood rich in oxygen slows the growth of bacteria that thrive in the absence of oxygen and helps infected wounds heal more easily.

In this type of therapy, you'll be situated in a special chamber, which usually consists of a padded table that slides into a clear plastic tube. The chamber is pressurized with pure oxygen, and the pressure inside the chamber will slowly rise to about 2.5 times normal atmospheric pressure. Hyperbaric oxygen therapy for gas gangrene generally lasts about 90 minutes. You may need two to three treatments daily.

Other treatments for gangrene may include supportive care, including fluids, nutrients and pain medication to relieve your discomfort.

Outlook

Generally, people who have dry gangrene have the best chance of a full recovery because dry gangrene doesn't involve a bacterial infection and spreads more slowly than do the other types of gangrene. However, when gangrene caused by an infection is recognized and treated quickly, the odds of recovery are good.

Preparing for your appointment

Call your doctor right away if you have symptoms of gangrene. Depending on the severity of your symptoms, you may be told to go to the emergency room or to call 911 or your local emergency number for medical help.

If you have time before you leave home or on the way to the hospital, use the information below to get ready for your medical evaluation.

What you can do

  • Write down any symptoms you're experiencing, and for how long. It will help your doctor to have as many details as possible about when your symptoms first appeared and how they may have worsened or spread over time.
  • Write down any recent injury or trauma to your skin, including cuts, bites, injections, surgery or possible frostbite. If you have recently used injectable recreational drugs, this is critical information to share with your doctor.
  • Write down your key medical information, including any other conditions with which you've been diagnosed. Also write down all medications, vitamins or supplements that you're taking.
  • Take a family member or friend along. Gangrene is a medical emergency. Take someone with you to help you remember all of the information your doctor provides and who can stay with you if you need immediate treatment.
  • Write down questions to ask your doctor.

For gangrene, some basic questions to ask your doctor include:

  • What's the most likely cause of my symptoms or condition?
  • What kinds of tests do I need?
  • Do I need to be hospitalized?
  • What treatments do I need?
  • How soon do you expect my symptoms will improve with treatment?
  • Will I have a full recovery? If so, how long will recovery take?
  • Am I at risk of long-term complications?

Don't hesitate to ask your doctor if you have any additional questions.

What to expect from your doctor

Your doctor is likely to ask you a number of questions to help determine the next steps in making your diagnosis and starting care. Your doctor may ask:

  • What are your symptoms?
  • When did you first begin experiencing symptoms?
  • How painful is the affected area?
  • Do your symptoms seem to be spreading or getting worse?
  • Have you had any recent injuries or trauma to your skin, such as cuts, wounds, bites or surgery?
  • Have you recently had any prolonged exposure to extreme cold that made your skin change color or turn numb?
  • Do you use injectable drugs, including recreational drugs?
  • Have you been diagnosed with any other medical conditions?
  • What medications are you taking or have you recently taken, including prescription drugs, over-the-counter medications, herbs and supplements?
July 13, 2017
References
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  8. Ogle JW et al., eds. Infections: Bacterial and spirochetal. In: Current Diagnosis & Treatment Pediatrics. 23rd ed. New York, NY: McGraw-Hill; 2016. http://accessmedicine.mhmedical.com. Accessed March 13, 2017.
  9. Mechem CC, et al. Hyperbaric oxygen therapy. http://www.uptodate.com/home. Accessed March 27, 2017.