User:Huyha63/Gangrene

User:Huyha63/Gangrene

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Dry gangrene[edit]
Dry gangrene is a form of coagulative necrosis that develops in ischemic tissue, where the blood supply is inadequate to keep tissue viable. It is not a disease itself, but a symptom of other diseases.[10] Dry gangrene is often due to peripheral artery disease, but can be due to acute limb ischemia. The limited oxygen in the ischemic limb limits putrefaction and bacteria fail to survive. The affected part is dry, shrunken, and dark reddish-black. The line of separation usually brings about complete separation, with eventual falling off of the gangrenous tissue if it is not removed surgically, a process called autoamputation.

Dry gangrene is the end result of chronic ischemia without infection. If ischemia is detected early, when  ischemic wounds rather than gangrene are present, the process can be treated by revascularization (via vascular bypass or angioplasty).[11] However, once gangrene has developed, the affected tissues are not salvageable.[12] Because dry gangrene is not accompanied by infection, it is not as emergent as gas gangrene or wet gangrene, both of which have a risk of sepsis. Over time, dry gangrene may develop into wet gangrene if an infection develops in the dead tissues.[13]

Diabetes mellitus is a risk factor for peripheral vascular disease, thus for dry gangrene, but also a risk factor for wet gangrene, particularly in patients with poorly controlled blood sugar levels, as elevated serum glucose creates a favorable environment for bacterial infection.[14]

Treatment[edit]
Surgical removal of all dead tissue is the mainstay of treatment for gangrene. Often, gangrene is associated with underlying infection, thus the gangrenous tissue must be debrided to hinder the spread of the associated infection. The extent of surgical debridement needed depends on the extent of the gangrene, and may be limited to the removal of a finger, toe, or ear, but in severe cases may involve a limb amputation.

Dead tissue alone does not require debridement, and in some cases, such as dry gangrene, the affected part falls off (autoamputates), making surgical removal unnecessary. It should be noted however that waiting for autoamputation may cause health complications and that surgical amputations increases quality of life.

As infection is often associated with gangrene, antibiotics are often a critical component of its treatment. The life-threatening nature of gangrene requires treatment with intravenous antibiotics in an inpatient setting.

After the gangrene is treated with debridement and antibiotics, the underlying cause can be treated. In the case of gangrene due to critical limb ischemia, revascularization can be performed to treat the underlying peripheral artery disease.

Ischemic disease of the legs is the most common reason for amputations. In about a quarter of these cases, the other side requires amputation in the next three years.[20]

In 2005, an estimated 1.6 million individuals in the United States were living with the loss of a limb caused by either trauma, cancer, or vascular disease; these estimates are expected to more than double to 3.6 million such individuals by 2050.[21] Antibiotics alone are not effective because they may not penetrate infected tissues sufficiently.[22] Hyperbaric oxygen therapy treatment is used to treat gas gangrene. It increases pressure and oxygen content to allow blood to carry more oxygen to inhibit anaerobic organism growth and reproduction.[23] A regenerative medicine therapy was developed by Dr. Peter DeMarco to treat diabetic gangrene to avoid amputations.[citation needed] Growth factors, hormones, and skin grafts have also been used to accelerate healing for gangrene and other chronic wounds.[citation needed]

Angioplasty should be considered if severe blockage in lower leg vessels (tibial and peroneal artery) leads to gangrene.[24]