gangrene
(gang'grēn‵ 
, gan'grēn‵ )
[Gr. gangraina, a corrosive sore]
Necrosis (death of tissue), usually resulting from deficient or absent blood supply.
SEE: illus.; necrosis.
Etiology: Gangrene is usually caused by obstruction of the blood supply to an organ or tissue, as from inflammation, injury, or degenerative changes such as arteriosclerosis. It is commonly a sequela of infections, frostbite, crushing injuries, or diseases such as diabetes mellitus and Raynaud disease. Emboli in large arteries in almost any part of the body can cause gangrene of the area distal to that point. The part that dies is known as a slough (for soft tissue) or a sequestrum (for bone). The dead matter must be removed before healing can take place.
Patient Care: The older or diabetic patient is assessed for arterial insufficiency related to decreases in the strength and elasticity of blood vessels. Capillary refill is also assessed. The presence and strength of distal pulses and the patient's normal response to light and deep palpation are checked. Symmetry, color, temperature, and quantitative and qualitative changes in fingernails or toenails, skin texture, and hair patterns are assessed. Any unusual areas of pigmentation indicating new skin lesions or scarring from past injury or ulceration are observed and documented, with descriptions of the extent and nature of gangrene that is present.
If prescribed, vasodilating and thrombolytic agents are administered, and the patient's response is evaluated. If surgical intervention is required, the patient's understand ing of the procedure, its desired effects, and possible complications are evaluated. Health care professionals collaborate with the surgeon to instruct and prepare the patient for surgery and the postoperative period. Postoperative care will depend on the procedure. If amputation is required, the patient must understand that the level of amputation depends on determining the presence of viable tissues to ensure healing and the requirements for fitting a prosthesis. The entire health care team must understand the patient's perception of the amputation in order to assist with resolution of grief and adjustment to a permanent change in body image. Physical and occupational therapists help the patient deal with changes in mobility and ability to perform activities of daily living. The multidisciplinary rehabilitation team involves the patient, nurse, physician, social worker, psychologist, prosthetist, and physical and occupational therapists. The patient's age and presence of other body system dysfunctions affect immediate and long-term responses to treatment. The at-risk patient should be taught preventive measures such as avoiding exposure to cold; keeping the extremities covered with gloves, clean, dry socks, and well-insulated footwear; and promptly treating any breaks in skin integrity.
diabetic g.Gangrene, esp. of the lower extremities, occurring in some diabetics as a result of vascular insufficiency, neuropathy, and infection.
dry g.Gangrene that results when the necrotic part has a progressive reduction in its blood supply but does not typically become infected. This occurs when arterial blood flow to a tissue is obstructed. The tissue gradually dries, the process continuing for weeks or months.
Dry gangrene causes pain in the early stages. The affected part is cold and black and begins to atrophy. The most distal parts (the fingers or toes) are generally affected first. Dry gangrene is often seen in arteriosclerosis associated with diabetes mellitus.
Patient care concerns for dry gangrene are similar to those of moist gangrene. Necrotic matter must be removed and circulation to the remaining tissues ensured before healing can occur. The older diabetic patient with microvascular and macrovascular disease may experience very little pain because of a reduction in feeling produced by peripheral neuropathy. The condition may come to light only upon inspection. For this reason, all patients with diabetes mellitus or peripheral vascular disease should avoid cigarette smoking, be taught proper foot inspection and care, and show their feet to their caregivers at every office and /or home visit.
The recommended plan of care may include amputation of gangrenous tissue or observation while the tissue sloughs on its own. The gangrenous limb should be kept clean and dry and protected as much as possible from trauma or infection. Psychological needs resulting from the loss of a body part may require a psychiatric nurse practitioner, a psychologist, or a spiritual counselor of the patient's choice.
embolic g.Gangrene arising after an embolic obstruction.
SEE: Fournier gangrene.
gas g.Gangrene in a wound infected by a gas-forming microorganism, the most common causative agent being Clostridium perfringens.
Gas gangrene is treated with débridement of the wound site, antibiotics, and clostridial antitoxin.
hospital g.Necrotizing fasciitis.
idiopathic g.Gangrene of unknown cause.
inflammatory g.Gangrene associated with acute infections and inflammation.
primary g.Gangrene developing in a part without previous inflammation.
secondary g.Gangrene developing after local inflammation.
symmetrical g.Gangrene on opposite sides of the body in corresponding parts, usually the result of vasomotor disturbances. It is characteristic of Raynaud disease and Buerger disease.
traumatic g.Tissue death caused by serious injuries, e.g., compartment syndrome or crush injury.
wet g.Gangrene that is wet as a result of tissue necrosis and bacterial infection. The condition is marked by serous exudation and rapid decomposition.
At first the affected part is hot and red; later it is cold and bluish, starting to slough. Moist gangrene spreads rapidly and carries a significant risk of local or systemic infection and occasionally death.
SYN: moist gangrene.