What Is Dry Gangrene?

Gangrene (gangrene) refers to the black, dark green and other special morphological changes after tissue necrosis due to secondary infection of spoilage bacteria and other factors. Necrotic tissue is decomposed by spoilage bacteria to produce hydrogen sulfide, which combines with iron decomposed from hemoglobin to form iron sulfide, which makes the necrotic tissue black.

Basic Information

Causes of gangrene and common diseases

1. dry gangrene

It is mostly found in the extremities, such as atherosclerosis, thromboangiitis obliterans, and frostbite.

2. wet gangrene

Wet gangrene mostly occurs in the internal organs (intestines, uterus, lungs, etc.) communicating with the outside world, and can also be seen in the limbs (with congestion and edema). Common wet gangrene include gangrene appendicitis, intestinal gangrene, pulmonary gangrene, and postpartum gangrene endometritis.

3. Gas Gangrene

It is a special type of wet gangrene, which is mainly seen in severe open wounds of deep muscles and combined with anaerobic infections such as perfringens. When the bacteria decompose the necrotic tissue, a large amount of gas is generated, so that the necrotic tissue contains a large number of air bubbles, and there is a "twisting" sound. Gas gangrene lesions develop rapidly, the symptoms of poisoning are obvious, and the consequences are serious, requiring urgent treatment.

Differential diagnosis of gangrene

Dry gangrene

Most arteries are blocked and venous return is unobstructed, so there is less water in the necrotic tissue. In addition, the water on the surface of the body is easy to evaporate, which causes the diseased part to dry and shrink, dark brown, and there is a clear dividing line with surrounding healthy tissue. Because necrotic tissue is relatively dry, spoilage bacteria infections are generally mild.

2. wet gangrene

Because the necrotic tissue contains more water, the spoilage bacteria are severely infected, and the area is obviously swollen, showing dark green or dirty black. The spoilage bacteria decomposes the protein, produces indole, skatole, etc., and causes malodor. Due to the rapid development of lesions and diffuse inflammation, there is no clear dividing line between necrotic tissue and healthy tissue. At the same time, after the toxic products and bacterial toxins produced by tissue necrosis are absorbed, they can cause symptoms of systemic poisoning and even cause toxic shock and death. Common wet gangrene include gangrene appendicitis, intestinal gangrene, pulmonary gangrene, and postpartum gangrene endometritis.

3. Gas gangrene

It is caused by the invasion of traumatic wounds by gas gangrene bacillus, which develops rapidly and has serious consequences, and may or may not produce gas. The incubation period is 6 hours to 6 days. The clinical symptoms are severe pain like swelling and fissure. The wound begins to be red and swollen, and the skin is pale and tense. Then the wound turned purple-black, blisters with dark red liquid appeared, and foul liquid could flow out. The muscles in the wound were dark red and swollen, and lost elasticity. The knife cut did not shrink or bleed. Systemic symptoms, including toxemia, appear later. Aerobic gangrene is a severe acute specific infection caused by the anaerobic bacterium Clostridium. Pathogens mainly grow and multiply in the wound, and the tissues in the wound are necrotic and rotten, producing an anaerobic environment, which is more conducive to bacterial reproduction and makes the disease worse.

Gangrene check

Grade 0: No open lesions, apparently insufficient blood supply.

Grade I: Superficial ulcer. Can be caused by blisters or other injuries, or spontaneously.

Grade II: ulcers deep into tendons, ligaments, bones and joints.

Grade III: Deep ulcer infection with osteomyelitis and abscess sinus formation.

Grade IV: Gangrene with toe and / or part of the foot.

Level : full foot gangrene.

Gangrene treatment principles

The principle of treatment of gas gangrene is to remove inanimate muscle tissue as soon as possible, and the lesions are widely and incisionally opened; the wound is opened; the oxidant is rinsed and wet applied to change its anaerobic environment.