What is Gas Gangrene?
This is a severe form of tissue death caused by the Clostridium species of bacteria.
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.

How is it caused?
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 also develop when a contaminated needle is used to inject an illegal drug into a muscle.

These bacteria under conditions of low oxygen produces toxins that cause tissue death or gangrene. This occurs at the site of a wound in a sudden manner causing brownish-red, extremely painful swelling. The affected wounds are usually severely crushed and dirty. Gas may be felt in the tissue like a crackling feeling when the swollen area is pressed. The affected area expands rapidly and the involved tissue becomes completely destroyed. The toxins produced by the bacteria in addition to causing tissue death also cause destruction of the red blood cells and blocking and leaking of the blood vessels.

What are the symptoms?
The symptoms include pain at the site of the injury, swelling, low grade fever, formation of blisters filled with reddish-brown fluid and seepage of fluid from the tissues. There may be sweating and anxiety. If untreated the individual develops a shock-like condition wherein his blood pressure falls, there may be kidney failure, coma and eventually death.

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).
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].

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.

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.

How is the condition diagnosed?
Shock may be evident by the general pallor, cold extremities, low blood pressure and a rapid heart rate. Air may be felt in the tissues. Yellow skin colour or jaundice because of excessive breakdown of blood cells may be present. A tissue or fluid culture may reveal the Clostridium species. An X-ray, CT scan or MRI of the affected part may show gas in the tissues.

What is the treatment?
Prompt surgical removal of dead, damaged and infected tissue is necessary. Amputation of a limb may be urgently required to control the spread of infection. Antibiotics are given to treat the infection and analgesics for the control of pain.

What are the complications?
Permanent tissue damage causing disfiguring or disability.
Kidney failure.
Spread of infection through out the body (septicaemia).
Coma.
Jaundice with liver damage.

 

  Gangrene that developed an infection with underlying deep space infection. "Milking" the wound produced purulent exudate from the abscess

  Foot infection with purulent discharge secondary to open ulceration in a diabetic foot