Gangrene is a condition that arises when a considerable mass of body tissue dies (necrosis) . This may occur after an injury or infection, or in people suffering from any chronic health problem affecting blood circulation. Gangrene is primarily caused due to reduced blood supply to the affected tissues that leads to cell death. Diseases like diabetes and long-term smoking increases the risk of gangrene. It can affect any part of the body but typically starts in the toes, feet, fingers and hands (the extremities).
Types of gangrene:
Dry gangrene: Dry gangrene begins at the distal part of the limb due to ischemia (restricted supply of blood), and often appears in the toes and feet of elderly patients due to arteriosclerosis and thus, it is also known as senile gangrene. Dry gangrene is generally seen due to arterial occlusion. As there is limited putrefaction and bacteria fail to survive, dry gangrene spreads slowly until it reaches the point where the blood supply is adequate to keep tissue viable. The affected part is dry, shrunken and dark reddish-black, like mummified flesh.
Wet gangrene: Wet gangrene occurs in moist tissues and organs such as the mouth, bowel, lungs, cervix, and vulva. Bed sores occurring on body parts such as the sacrum, buttocks, and heels are also classified as wet gangrene infections. Wet gangrene is characterized by numerous bacteria and generally has a poor prognosis (compared to dry gangrene) due to septicaemia. In wet gangrene, the tissue is infected by microorganisms like Clostridium perfringens or Bacillus fusiformis that causes the tissues to swell and emit a foetid smell. Wet gangrene usually develops rapidly due to blockage of venous (mainly) and/or arterial blood flow. The affected part is saturated with stagnant blood,that promotes rapid growth of bacteria.
Gas gangrene: Gas gangrene is a bacterial infection that produce gas within tissues. It is the most severe form of gangrene usually caused by Clostridium perfringens bacteria. Infection spreads rapidly as the gases produced by bacteria expand and infiltrate healthy tissues in the vicinity.Gas gangrene is generally treated as a medical emergency as it quickly spreads to the surrounding tissues.
Dry gangrene which is the most common type of gangrene, usually manifests in the following form.
• Firstly, the affected part turns red
• Then it becomes cold, pale and numb (though some people might experience pain).
• Furthermore, the body part may begin to change colour from red to brown to black without treatment. The dead tissue may shrivel up and fall away from the surrounding healthy tissue.
Wet gangrene progresses much faster than dry gangrene. Its symptoms include:
• Swelling and redness of the affected body part
• Pain which can often be severe
• Foul-smelling discharge of pus from a sore in skin
• Affected area will change colour from red to brown to black
The symptoms of Gas gangrene are as follows:
• Feeling of heaviness followed by severe pain
• In most cases of gas gangrene, pressing skin near the affected area will produce a crackling sound caused by a build-up of gas; producing the feeling of crushing fine tinfoil.
Gangrene is caused when a body part loses its blood supply due to an injury or an underlying disease. The conditions most commonly responsible for causing gangrene are as follows:
- Blood vessel disease such as arteriosclerosis causing hardening of the arteries, in arms or legs
- Suppressed immune system (for example, from HIV or chemotherapy)
- Due to infection or ischemia, such as by the bacteria Clostridium perfringens or by thrombosis (a blocked blood vessel).
Clinical tests can be carried out to confirm the diagnosis of gangrene. These include:
- Blood tests – An increase or decrease in the number of white blood cells can indicate infection.
- Tissue culture – A small sample of fluid (or tissue) from the affected area can be tested for bacteria. This test is called a Gram stain. Bacteria are stained with a dye and examined under a microscope. The test is also useful for determining the most effective type of antibiotic to treat the infection.
- Blood culture – A sample of infected blood is removed and placed in a warm environment to encourage the growth of bacteria.
- Imaging tests – A range of imaging tests, such as X-rays, MRI scans (where radio waves are used to produce an image of the inside of your body) or a computerized tomography (CT) scan can be used to confirm the presence and spread of gangrene. These tests can also be used to study blood vessels in order to identify the blockages.
- Surgery – Surgical examination may be necessary to confirm the diagnosis of gas gangrene.
Although Gangrene can be managed by its symptomatic treatment, yet it is also necessary to diagnose and treat the underlying cause. The symptomatic treatment is as follows:
Infection: Serious infections are usually treated with antibiotics.
Debridement: Debridement is the surgical removal of the dead tissue that results from gangrene.
Vascular surgery: Vascular surgeries can be used to restore the blood flow either by Angioplasty or Bypass surgery.
- Angioplasty – Where a tiny balloon is placed into a narrow, or blocked, artery and is inflated to open up the vessel. A small metal tube, known as a stent, may also be inserted into the artery to prevent it from getting closed.
- Bypass surgery – Where the surgeon redirects the flow of blood and bypasses the blockage by connecting (grafting) one of the veins to a healthy part of an artery.
Hyperbaric oxygen therapy: An alternative treatment for some forms of gangrene is hyperbaric oxygen therapy. As part of the therapy, a specially designed chamber that also contains a plastic hood filled with pure oxygen, is filled with pressurized air. The plastic hood is then placed over the damaged body part.
There are a number of self care techniques for the patients who are at risk of developing Gangrene. The most common methods used are as follows:
- Check feet daily for problems such as numbness, discoloration, breaks in the skin, pain, or swelling. • Avoid walking barefoot outside and wearing shoes without socks.
- Avoid walking barefoot outside and wearing shoes without socks.
- Wash your feet daily.
- Avoid using hot water bottles, electric blankets, foot spas, and sitting too close to the fire. These may burn the feet. Burnt tissue is vulnerable to gangrene.
- Avoid wearing sandals, flip-flops, slip-ons, shoes with a pointed toe, or heels higher than an inch. Shoes with round or square toes, and laces or fasteners, provide the best support and protection for feet. Always break into new shoes gradually.