Glossary of Terms

Abscess

A circumscribed collection of pus that forms in tissue as a result of acute or chronic localized infection. It is associated with tissue destruction and frequently swelling.

Abrasion

Circumscribed removal of the superficial layers of skin.

Bacteremia

The presences of viable bacteria in the circulating blood.

Cellulitis

Inflammation of cellular or connective tissue. Inflammation may be diminished or absent in immunosuppressed individuals.

Clean Dressing

Dressing that is not sterile but is free of environmental contaminants such as water damage, dust, pest and rodent contaminants, and gross soiling.

Clean Wound

Wound free of purulent drainage, devitalized tissue or dirt.

Contaminated

Containing bacteria, other microorganisms or foreign material. The term usually refers to bacterial contamination and, in this context, is synonymous with colonized. Wounds with bacterial counts of 10 organisms per gram of tissue or less are generally considered contaminated; those with higher counts are generally considered infected.

Culture (Bacterial)

Removal of bacteria from a wound for the purpose of placing them in a growth medium in the laboratory to propagate to the point where they can be identified and tested for sensitivity to various antibiotics. Swab cultures are generally inadequate for this purpose.

Dead Space

A cavity remaining in a wound.

Debridement

Removal of devitalized tissue and foreign matter from a wound. Various methods may be used for this purpose.

Dehiscence

Separation of the layers of a surgical wound.

Denude

Loss of epidermis.

Dressing

The material applied to a wound for the protection of the wound and absorption of drainage.

Edema

Presence of abnormally large amounts of fluid in the interstitial space.

Epibole

Edges or top layers of epidermis have rolled down to cover lower edges of epidermis, including basement membrane, so that the epithelial cells cannot migrate from wound edges; also described as closed wound edges.

Epithelialization

The stage of tissue healing in which the epithelial cells migrate (move) across the surface of a wound.

Erythema

Redness of the skin

Eschar

Thick, leathery, necrotic, devitalized tissue.

Excoriation

Linear scratches on the skin.

Exudate

Any fluid that has been extruded from a tissue or its capillaries, more specifically because of injury or inflammation. It is characteristically high in protein and white blood cells.

Fascia

A sheet or band of fibrous tissue that lies deep below the skin or encloses muscles and various organs of the body.

Friction

Mechanical force exerted when ski is dragged across a coarse surface such as bed linens.

Full-Thickness Tissue Loss

Loss of tissue below the dermis level, involving subcutaneous and possibly other tissue layers, to include loss of fascia, tendons, muscles, bone or other underlying structures, full-thickness wounds heal by formation of granulation tissue, contraction, and epitheliazation.

Granulation Tissue

The pink/red, moist tissue that contains new blood vessels, collagen, fibroblasts and inflammatory cells which fills an open, previously deep wound when it starts to heal.

Healing

A dynamic process in which anatomical and functional integrity is restored. This process may be monitored and measured. For wounds of the skin, it involves repair of the dermis (granulation tissue formulation) and epidermis (epitheliazation). Healed wounds represent a spectrum of repair; they can be ideally healed (tissue regeneration), minimally healed (temporary return of anatomical continuity) or acceptably healed (sustained functional and anatomical result). The acceptably healed wound is the ultimate outcome of wound healing but not necessarily the appropriate outcome for all patients.

Induration

Abnormal firmness of tissue with a definite margin.

Infection

Overgrowth of microorganisms capable of tissue destruction and invasion, accompanied by local and/or systemic symptoms.

Irrigation

Cleansing by a stream of fluid, preferably saline.

Ischemia

Deficiency of blood supply to a tissue, often leading to tissue necrosis.

Macerate

To soften by wetting or soaking. In (a healing) context, it refers to degenerative changes and disintegration of skin when it has been kept too moist.

Moisture

In the context of this document, moisture refers to skin moisture that may increase the risk of pressure ulcer development and impair healing of existing ulcers. Primary sources of skin moisture include perspiration, urine, feces, drainage from wounds of fistulas.

Necrotic Tissue

Tissue that has died and has, therefore, lost its usual physical properties and biological activity. Also called “devitalized tissue.”

Osteomyelitis

Inflammation of the bone marrow and adjacent bone, often due to infection.

Pressure (Interface)

Force per unit area that acts perpendicularly between the body and the support surface. This parameter is affected by the stiffness of the support surface, the composition of the body tissue and the geometry of the body being supported.

Pressure Reduction

Reduction of interface pressure, not necessarily below the level required to close capillaries (i.e. capillary-closing pressure).

Pressure Relief

Reduction of interface pressure below capillary-closing pressure.