Types of gangrene
The form determines both the speed of development and treatment tactics. Dry gangrene occurs when the arteries are gradually blocked: the tissues dehydrate, darken, and mummify, the border with living tissues is usually clear, and the general condition suffers little. Wet gangrene develops when there is a sudden interruption of blood flow or the addition of an infection: tissues swell, disintegrate, foul-smelling discharge appears, and poisoning of the body with decay products quickly increases. Gas gangrene is caused by special bacteria that live without oxygen and is one of the most severe surgical infections.
- Dry - slow, with tissue mummification
- Wet - quick, with swelling and decay
- Gas - with the formation of gas bubbles in the tissues
- Internal - for thrombosis of intestinal vessels and strangulated hernia
- Fournier's gangrene - lesion of the perineum
Causes and risk factors
The main reason is impaired blood flow. In people over fifty years of age, this is most often atherosclerosis of the arteries of the legs, especially due to smoking and high cholesterol. The second key group is people with diabetes: their blood vessels and nerves are simultaneously affected, which is why a minor injury goes unnoticed and turns into an ulcer. A sudden blockage of an artery by a thrombus or embolus causes acute ischemia, which without treatment turns into gangrene within hours. Other causes are deep burns and frostbite, severe injuries, prolonged compression, deep tissue infections.
- Atherosclerosis of the arteries of the lower extremities
- Diabetes mellitus and diabetic foot
- Smoking
- Thrombosis and embolism of arteries
- Frostbite and burns
- Trauma and long-term compression
- Deep soft tissue infections
How to recognize in time
Long before blackening, warning signs appear that are worth paying attention to. With a chronic lack of blood flow, this is pain in the calves when walking, which goes away with rest, chilliness and pallor of the foot, hair loss on the lower legs, thickened nails, slow healing of abrasions. With an acute disturbance of blood flow, the leg suddenly becomes cold, pale, then marbled, severe pain and numbness appear, and the pulse disappears. People with diabetes may have no pain at all due to nerve damage, so they need to have their feet examined daily.
- Pain in the calves when walking, which goes away with rest
- Cold pale foot, weak pulse
- Long-lasting wounds and cracks
- Numbness and tingling in the foot
- Change in skin color: pallor, bluishness, blackness
- Unpleasant odor from the wound
Survey
The surgeon's examination determines the shape, depth and boundaries of the lesion. To assess blood flow, Doppler ultrasound of the arteries is performed; when planning to restore patency, angiography or computed tomography of the vessels is performed. Be sure to check blood glucose and glycated hemoglobin, since newly diagnosed or poorly controlled diabetes is common. Blood tests show the severity of inflammation and kidney function. The discharge from the wound is sent for culture to determine sensitivity to antibiotics, and if bone damage is suspected, for radiography or MRI.
- Examination by a surgeon and assessment of the pulse in the feet
- Dopplerography of the arteries of the lower extremities
- Blood glucose and glycated hemoglobin
- Complete blood count, C-reactive protein, creatinine
- Culture of discharge with sensitivity determination
- X-ray or MRI if osteomyelitis is suspected
Treatment and prevention
Treatment is inpatient and complex. In case of wet and gas forms, the operation is performed urgently: all dead tissue is removed, the lesion is widely opened and drained, and antibiotics are prescribed intravenously. At the same time, they are trying to restore blood flow - using shunting or intravascular methods; This is the main condition for healing. Amputation is performed when it is impossible to save a limb, trying to make it as low as possible. Prevention is especially important in diabetes: daily foot inspection, comfortable shoes, careful nail care, smoking cessation and sugar control.
- Emergency surgical treatment for wet forms
- IV antibiotics based on culture results
- Restoring blood flow: bypass or stenting
- Removal of dead tissue, dressings
- Amputation when it is impossible to save a limb
- Glucose control and smoking cessation
- Daily foot examination for diabetes
