Gas gangrene

Definition

Gas gangrene is a potentially deadly form of tissue death (gangrene).

See also: Necrotizing subcutaneous infection

Alternative Names

Tissue infection - Clostridial; Gangrene - gas; Myonecrosis; Clostridial infection of tissues

Causes, incidence, and risk factors

Gas gangrene is rare in the United States. The condition is most often caused by a bacteria called Clostridium perfringens. However, it also can be caused by Group A streptococcus. Staphylococcus aureus and Vibrio vulnificus can cause similar infections.

Clostridium is present in most environments. As the bacteria grow, they can produce gas in body tissues and produce many different toxins that can damage tissues. Under low-oxygen (anaerobic) conditions, Clostridium produces toxins that cause tissue death and related symptoms.

Gas gangrene generally occurs at the site of trauma or a recent surgical wound. The onset of gas gangrene is sudden and dramatic. About 1 in 5 cases occur without an irritating event. Patients who develop this disease in this manner often have underlying blood vessel disease (atherosclerosis or hardening of the arteries), diabetes, or colon cancer.

Clostridium bacteria produce many different toxins, four of which (alpha, beta, epsilon, iota) can cause potentially deadly syndromes. The toxins cause damage to tissues, blood cells, and blood vessels.

Symptoms

The site of infection becomes inflamed with a pale to brownish-red and very painful tissue swelling. If you press on the swollen tissue with your fingers, you may feel gas as a crackly sensation. The edges of the infected area expand so quickly that changes can be seen over a few minutes. The involved tissue may be completely destroyed.

Symptoms include:

• Air under the skin (subcutaneous emphysema)
• Blisters filled with brown-red fluid
• Drainage from the tissues, foul-smelling brown-red or bloody fluid (serosanguineous discharge)
• Increased heart rate (tachycardia)
• Moderate to high fever
• Moderate to severe pain around a skin injury
• Pale skin color, later becoming dusky and changing to dark red or purple
• Progressive swelling around a skin injury
• Sweating
• Vesicle formation, combining into large blisters
• Yellow color to the skin (jaundice)

Note: Symptoms usually begin suddenly and quickly worsen.

If the condition is not treated, the person can develop shock with decreased blood pressure (hypotension), kidney failure, coma, and finally death.

Signs and tests

The person may be in shock. A health care professional might feel air in the tissues (crepitus).

• Anaerobic tissue and fluid cultures may reveal Clostridium species.
• Blood culture may grow the bacteria causing the infection.
• Gram stain of fluid from the infected area may show gram-positive rods (Clostridium species) or other bacterial types.
• X-ray, CT scan, or MRI of the area may show gas in the tissues.

Treatment

The person will need to have surgery quickly to remove dead, damaged, and infected tissue (debridement). Surgical removal (amputation) of an arm or leg may be needed to control the spread of infection. Often this must occur before all diagnostic test results are available.

Patients should get antibiotics, preferably penicillin-type with clindamycin. Initially, patients receive antibiotics through a vein (intravenously). Some people may need analgesics to control pain. Doctors have tried hyperbaric oxygen for this condition, with varying degrees of success.

Expectations (prognosis)

Gas gangrene is progressive and often fatal.

Complications

• Coma
• Delirium
• Disfiguring or disabling permanent tissue damage
• Jaundice with liver damage
• Kidney failure
• Shock
• Spread of infection through the body (sepsis)
• Stupor

Calling your health care provider

This is an emergency condition requiring immediate medical attention.

Call your heath care provider if you have signs of infection around a skin wound. Go to the emergency room or call the local emergency number (such as 911), if you have symptoms of gas gangrene.

Prevention

Clean any skin injury thoroughly. Watch for signs of infection (such as redness, pain, drainage, or swelling around a wound), and consult your health care provider promptly if these occur.

References

Bartlett JG. Clostridial infections. In: Goldman L, Ausiello D, eds. Cecil Medicine. 23rd ed. Philadelphia, Pa: Saunders Elsevier; 2007:chap 319.