Debridement is the process of removal of non-viable tissue (necrosis) and foreign material, e.g. sand, from a wound to expose healthy tissue.
A wound containing necrotic tissue cannot heal.
Necrotic tissue provides an ideal growth medium for bacteria.
There are five major techniques of debridement:
Autolytic debridement:
Supporting the body’s own immune system to dissolve and remove dead tissue. Under normal circumstances, the immune system carries out highly effective debridement. However, the body’s immune system can be inhibited in performing this task by substances such as proinflammatory factors, proteases, bacterial toxins and enzymes and similar which typically are present in the exudate and necrotic tissue on the surface of complicated wounds. If these substances can be effectively removed, however, the wound will be speedily and effectively cleaned by the body’s immune system which means it will undergo autolytic debridement.
Surgical debridement / Sharp debridement:
Surgically cutting away the necrotic tissue using a scalpel or a pair of scissors.
Chemical debridement / Enzymatic debridement:
Usually, the chemical debridement method makes use of enzymes but other compounds can also be used in order to dissolve dead tissue. The most commonly used enzyme is collagenase. This is only available as a pharmaceutical and duration of application (few hours) must be strictly adhered to as it can otherwise cause harm.
Biological debridement:
Also known as maggot therapy it consists of living larvae of Lucilia sericata (greenbottle fly) being applied directly onto the wound where the larvae will eat necrotic tissue and pathogenic bacteria.
Mechanical debridement:
A saline-moistened dressing is placed on a wound and allowed to dry. It will adhere to the surface underneath. When the dressing is removed, the tissue adheres to the dressing, thereby being pulled away from the wound. It does not distinguish between dead and living tissue and will therefore in addition to the dead tissue also remove new forming cells. Apart from being very painful, it is also delaying healing, as the generating new cells are not protected but being pulled off with the gauze.