Gas Gangrene – Symptoms & Causes

Gas Gangrene

Gas Gangrene Defiition: This is a spreading infective gangrene of the muscles characterized by collection of gas in the muscles and subcutaneous tissue.

As this condition is caused by Clostridium infection, it is also called ‘Clostridium myonecrosis’.

Gas Gangrene Etiology

Gas gangrene is caused by Clostridium perfringens which is the most common microorganism.

Various other organisms causing gas gangrene are Clostridium septicum, Clostridium redemptions, Clostridium histolyticum.

“Gas Gangrene Symptoms and Causes”

Gas Gangrene Predisposing Factors

• Contaminated, manured or cultivated soil, intestines are the sources.
  • Fecal flra commonly contains clostridial organisms enters the wound; in presence of calcium from blood clot or silica (silicic acid) of soil, it causes infection.
• It is common in crush wounds, following road traff accidents, after amputations, ischemic limb, gunshot wounds, war wounds.
  • Injury or ischemia or necrosis of the muscle due to trauma predisposes infection.
• Anaerobic environments in the wound-initial infection with aerobic organism utilizes existing oxygen in tissues creating anaerobic environment to cause clostridial sepsis.

“Gas Gangrene and Foul-Smelling Discharge”

Gas Gangrene Types

• Subcutaneous type: This is a crepitant infection involving necrotic tissue, but healthy muscles are not involved.
  • Cellulitis is characterized by foul smelling, seropurulent infection of a wound.
• Single muscles type: The infection is limited to one muscle.
• Group type: The gas gangrene is limited to one group of muscles.
• Massive type: The gas gangrene involved almost the whole muscle mass of one limb.
• Fulminating type: In this condition, the gas gangrene spreads very rapidly even beyond the limb and is often associated with intense toxemia with high fatal rate.

“Gas Gangrene and Clostridium Perfringens”

Gas Gangrene Clinical Features

• Presence of features of toxaemia, fever, tachycardia and pallor.
• Wound is under tension with foul-smelling discharge.
• Color of skin is khaki brown due to hemolysis.
• Crepitus can be felt.
• Jaundice can be present and oligouria signifies renal failure.
• Most commonly the site affcted are adductor region of lower limb and buttcks and subscapular region in upper limb.

Gas Gangrene Investigations

• X-ray shows gas in muscle plane or under the skin.
• Liver function tests, blood urea, serum creatinine, total count, PO2, PCO2
• CT scan of the part may be useful, especially in chest or abdominal wounds.
• Gram stain shows gram-positive bacilli.
• Robertson’s cooked meat media is used which causes meat to turn pink with sour smell and acid reaction.
• Clostridium welchii is grown in culture media containing 20% human serum in a plate.
  • Antitoxin is placed in onehalf of the bacteria grown plate sparing the other half.
  • Zone of opacity will be seen in that halfofthe plate where there is no antitoxin. In the other half part of the plate where there is antitoxin there is no opacity-Nagler reaction.

“Gas Gangrene and Traumatic Injuries”

Gas Gangrene Complications

• Septicemia, toxemia
• Renal failure, liver failure
• Circulatory failure, Disseminated intravascular coagulation, secondary infection.
• Death occurs in critically ill patients.

Gas Gangrene Treatment

• Injection benzyl penicillin 20 lacs 4 hourly + lnjection metronidazole 500 mg 8 hourly + lnjection aminoglycosides or third generation cephalosporins or metronidazole.
• Fresh blood transfusion.
• Polyvalent antiserum 25,000 units given intravenously after a test dose and repeated after 6 hours.
• Hyperbaric oxygen is very useful.
• Liberal incisions are given. All dead tissues are excised and debridement is done until healthy tissue bleeds.
• Rehydration and maintaining optimum urine output.
• Electrolyte management is done.

“Gas Gangrene Skin Discoloration”

• In severe cases, amputation has to be done as a life-saving procedure-stump should never be closed (Guillotine amputation).
• Often ventilator support is required.
• Once a ward or Operation theatre is used for a patient with gas gangrene, it should be fumigated for 24 – 48 hours properly to prevent the risk of spread of infection to other patients especially with open wounds.
• Hypotension in gas gangrene is treated with whole blood transfusion.