Gas gangrene (clostridial myonecrosis) is a life-threatening infection of muscle tissue caused mainly by the anaerobic bacteria Clostridium perfringens and several other species of clostridia.

• Gas gangrene can develop after certain types of surgery or injuries.
• Blisters with gas bubbles form near the infected area, and the heartbeat and breathing become rapid.
• Symptoms suggest the diagnosis, and imaging tests or culture of a sample taken from infected tissue is usually done.
• Treatment involves high doses of antibiotics and surgical removal of dead or infected tissue.

Gas gangrene is a fast-spreading clostridial infection of muscle tissue that, if untreated, quickly leads to death. The bacteria produce gas that becomes trapped in the infected tissue. Several thousand cases occur in the United States every year. Gas gangrene usually develops after injuries or surgery. High-risk injuries include wounds that

• Are deep and severe
• Involve muscle
• Are contaminated with dirt, decaying vegetable matter, or the person's stool
• Contain crushed or dead tissue

High-risk surgery includes operations on the colon or gallbladder.

Gas gangrene can occur when there is no injury or surgery—usually in people with colon cancer. People with open fractures and frostbite are also susceptible to gas gangrene. Gas gangrene may develop when a contaminated needle is used to inject an illegal drug into a muscle.

Symptoms

Gas gangrene causes severe pain in the infected area. Initially, the area is swollen and pale but eventually turns red, then bronze, and finally blackish green. Large blisters often form. Gas bubbles may be visible within the blister or may be felt under the skin, usually after the infection progresses. Fluids draining from the wound smell rotten (putrid).

People quickly become sweaty and very anxious. They may vomit. Heart rate and breathing often become rapid. In some people, the skin turns yellow, indicating jaundice. These effects are caused by toxins produced by the bacteria. Typically, people remain alert until late in the illness, when dangerously low blood pressure (shock) and coma develop. Kidney failure and death rapidly follow.

Without treatment, death occurs within 48 hours. Even with treatment, about one of eight people with an infected limb and about two of three people with infection in the torso die.

Diagnosis

The initial diagnosis is based on symptoms and results of a physical examination. X-rays are taken to check for gas bubbles in muscle tissue, or computed tomography (CT) or magnetic resonance imaging (MRI) is done to check for signs of muscle involvement. These findings support the diagnosis. However, gas bubbles may also occur in other anaerobic infections.

Fluids from the wound are examined under a microscope to check for clostridia, and cultures are done to confirm their presence. However, not all people with clostridia have gas gangrene. Confirmation of the diagnosis may require exploratory surgery or removal of a tissue sample for examination under a microscope (biopsy) to check for characteristic changes in muscle.

Prevention and Treatment

Doctors do the following to prevent gas gangrene:

• Clean wounds thoroughly
• Remove foreign objects and dead tissue from wounds
• Give antibiotics intravenously before, during, and after abdominal surgery to prevent infection

No vaccine can prevent clostridial infection.

If gas gangrene is suspected, treatment must begin immediately. High doses of antibiotics, typically penicillin and clindamycinSome Trade Names
CLEOCIN
, are given, and all dead and infected tissue is removed surgically. About one of five people with gas gangrene in a limb requires amputation. Treatment in a high-pressure oxygen (hyperbaric oxygen) chamber is of uncertain value, and such chambers are not always readily available.

Last full review/revision September 2008 by Matthew E. Levison, MD