Gangrene refers to the death of the tissue in any particular area of the body caused by the loss of blood supply. Though gangrene can occur in any part of the body, it normally affects toes, fingers, feet and hands. Infections, vascular disease, diabetes, injury and weakened immunity are some of the causes of gangrene.
Types of gangrene
Dry gangrene: Dry gangrene involves lack of blood supply due to cell death and necrosis. This condition is not associated with infection and develops gradually over a period of time. Patients with diabetes, atherosclerosis and other blood vessel diseases are most likely to develop dry gangrene. Those suffering from injuries, burns, frostbite and any other arterial trauma are also prone to dry gangrene.
Symptoms of dry gangrene
Wet gangrene: Bacterial infection, loss of blood supply due to swollen tissues and gas production are some of the causes of wet gangrene. Wet gangrene spreads very quickly and in no time turns into sepsis. It restricts the white blood cells from reaching affected area, allowing the bacteria to feed on the surrounding muscles. Hence wet gangrene is a medical emergency and requires immediate treatment.
There are few variations to wet gangrene and one of them is gas gangrene. The bacterial organism called Clostridium perfringens causes gas gangrene. The bacteria present in the site releases toxins and produces gas bubbles in the dead tissues affecting not only the local site, but adjoining tissues and muscles. Though gangrene normally occurs on external parts of the body like hands, toes and legs, it can also attack internal organs like gallbladder, intestines and appendix. This condition is called internal gangrene. Internal organs may develop hernia, get strangulated and as a result do not receive sufficient blood supply causing gangrene.
Fournier gangrene is the gangrene that occurs in the male genital area due to an infection or urinary tract infection. Red skin, swelling, tenderness associated with pain are some of the symptoms of Fournier gangrene.
Necrotizing fasciitis is a type of wet gangrene that is caused by bacterial infection, affecting the deep layers of skin. It progresses rapidly and starts eating up the flesh in the body.
Symptoms of wet gangrene
Causes of gangrene
The first and the primary cause of gangrene is complete loss or insufficient supply of blood to the tissue. When there is no blood supply, the required oxygen does not reach the cells allowing them to decay and die. Bacterial infections, trauma, damaged blood vessels, and blood vessel disease like atherosclerosis are some of the causes that restrict the blood supply leading to gangrene. Surgery wounds, frost bites, severe burns are typical breeding sites for bacteria causing infection and gangrene.
Doctor will conduct a thorough physical examination and look for the symptoms like discoloration, pus, shrinking of skin, odor to determine the type of gangrene. If it is a wet gangrene, further tests like blood test, blood culture and tissue cultures are carried on to find out about the white blood cell count and the kind of bacteria causing the issue. This helps the doctors to decide on the right course of antibiotics. Imaging studies like X-ray, MRI and CT scan are done to determine the spread of gangrene.
Treatment approach varies depending upon the type of gangrene. However, whatever be the type of gangrene; it should be brought to the notice of the medical practitioner at the earliest to prevent it from spreading. In case of dry gangrene, firstly, doctor will remove the dead tissues from the affected area surgically. Next, he will try to correct the destroyed blood vessels to smoothen the blood flow. Patient will be administered antibiotics to curtail the spread and will also be given some anti blood clotting drugs.
Wet gangrene is a medical emergency and once diagnosed, treatment should start as quickly as possible. Debridement procedure is normally adopted to treat wet gangrene. Debridement refers to the removal of dead and decaying tissues from the affected site. Antibiotics are administered to control the infection and pain killers are given to relieve the patient from pain. In worst cases surgeon may have to amputate, where the affected limb will be separated from the body to prevent further deterioration. Gas gangrene is a deadly disease. Though it is treated in the same way as mentioned above, it necessitates swift action when compared to all other gangrenes. The infection can spread and enter the blood stream very quickly causing organ failures.
There is also an alternate therapy called hyperbaric oxygen therapy that is gaining momentum to treat gas gangrene. This process involves exposing the patient to 100% oxygen at inflated pressure for 90 to 120 minutes, three times a day for 2 days. Then the frequency will be brought down as per the patient's requirements. This therapy stimulates the cell growth, enhances the white blood cell count thereby regulating the infection and increasing the blood flow to areas affected by the arterial blocks.
Dry gangrene is easily treatable provided there is no infection associated with it. Chances of recurrence are higher in diabetes patients. The outlook for wet gangrene is poor and patients with severe infection and sepsis may also lose their life, if treatment is not initiated in time. It requires an aggressive treatment and patients with wet gangrene may end up with amputation.
Buerger's disease (thromboangitis obliterans) is characterized by inflammation of the blood vessels in the legs. This leads to restricted blood flow. Over time it can lead to gangrene. Buerger's disease is usually noticed in men in the age group of 20 - 40 years. This condition has been strongly associated with smoking. Heavy smokers, especially those who have started at a young age are at higher risk.
What may begin as reduced blood supply to the limbs may later affect blood vessels in other parts of the body. There is decay in the tissues of the feet due to lack of blood. The limbs may turn white or blue as in the case of persons affected by Raynaud's disease. There may be numbness or tingling sensation in the limbs. There may be enlarged red surface veins. It is essential to treat Buerger's Disease promptly lest it lead to infection of the legs and gangrene. Patients suffering from Buerger's Disease must quit smoking.
Cold burn or Frostbite occurs when the skin is in touch with an extremely cold body. Extreme cold can cause damage to the skin and underlying tissues. For example, if there is a prolonged contact of the skin with moderately cold body like snow or very cold bodies like dry ice, liquid helium or liquid nitrogen for a brief period, cold burns or ice burns will occur. Here heat is transferred from the skin and organs to the cold body that is in contact. In other kinds of burns, the body that causes the burn is hotter and heat is transferred to the skin or the organ.
Symptoms of frostbite include pins and needles sensation and then numbness in the area. Initially there may be throbbing or aching. The affected part seems to become insensate. In severe frostbite, when the tissue starts to freeze, the skin at that area may appear white and numb. In areas affected by frost burn, abnormal accumulation of blood takes place. In addition to accumulation of body fluids, a blood clot may form thereby preventing blood circulation around the area resulting in tissue decay. Mottled and violaceous tissue is noticed. Normal functioning of the body is disturbed because of cooling of the internal organs, which will lead to a critical condition called hypothermia. Cooling of the brain or heart is very dangerous.
If hypothermia is noticed, treating it should be the priority. Blisters are noticed when there is very severe frostbite. Blisters are the result of expansion of the surrounding layers of the skin and the release of serous fluid or plasma.
The accumulated plasma in the blister is intended to prevent further damage and also to help in the healing process. To avoid infection from the blister, it is important that it is not punctured as it would expose the raw skin for further infection. The serous fluid will be reabsorbed by the skin usually after 24 hours if there is no infection.
Severe frostbite may also damage tendons, muscles, nerves and bones. Gangrene is inevitable in the case of very severe frostbite. Frostbite may affect any part of the body.
The most vulnerable parts are hands, feet, nose and ears. Recovery may be significant when the skin and underlying body tissues are injured and it may be permanent if there is injury to the blood vessels. If gangrene follows, the affected part may have to be amputated. When warming up of the affected part begins, the patient will experience intense pain. There will be tingling or burning sensation in the affected area also.
People taking beta-blockers that decrease blood flow to the skin and those who suffer Peripheral Vascular Disease are at risk when exposed to cold for a prolonged period. Any person who is exposed to extreme cold for a long period is susceptible to frostbite. Diabetes, peripheral neuropathy or Raynaud's phenomenon are some conditions that may have increased risk of cold burns. Smoking and windy weather when the rate of heat loss from the skin is more will hinder the healing process. Cold burns at the work place are common. People who work in factories where they may come in contact with metal surfaces that are at extremely cold temperatures are prone to cold burns. When the skin is moist, they may receive almost instantaneous cold burns.
Prevention of freeze burns
Extreme cold, wet clothes, high winds and poor circulation are some of the factors that can contribute to freeze burns. Tight boots or clothing and conditions like cramped positions, some medications, smoking or alcohol can cause frostbite. Wearing appropriate clothing in winter when the temperature goes below normal and will help. Winter clothes like mittens, layered clothing that is wind-proof and water resistant gives good protection.
First Aid for cold burns
It is essential that the ice burn treatment is correctly done as soon as possible.
Frostnip is the least severe form of cold injury that occurs after the distal extremities are exposed to prolonged period of cold but non-freezing temperatures. Vasoconstriction is felt. Frostnip is a precursor to frostbite and does not involve the same levels of tissue destruction. The affected area appears pale.
Immersion foot is a condition where there is severe tissue injury due to prolonged and persistent exposure to wet conditions, cold or hot. It results in tissue edema and inflammation. This is often seen in homeless persons who are exposed to the elements. The extremities appear swollen and erythematous (skin turning red often manifested in patches). Bad odor is often noticed as also tissue sloughing.
Bibliography / Reference
Collection of Pages - Last revised Date: August 23, 2017