Biofilms and Wound Care: Important Terms to Know
by the WoundSource Editors
Aerobic microorganisms: Organisms thriving in an oxygen-rich environment.
Anaerobic microorganisms: Organisms thriving in an oxygen-depleted environment.
Bioburden: Normally defined as the number of bacteria living on a surface that has not been sterilized. The term is most often used in the context of bioburden testing, also known as microbial limit testing, which is a quality control test performed on medical devices and pharmaceutical products.
Biocide: An agent that kills microorganisms.
Biofilm: A complex microbial community containing self- and surface-attached microorganisms that are embedded in an extracellular polymeric substance or EPS.
Clean technique: Meticulous hand washing or sanitizing that is utilized while preparing a clean field; the equipment including gloves, instruments, and dressings can be from multiuse or bulk packaging and not sterile for each use or application; the term non-sterile does not mean that it was not ever sterile, but that the package is multiuse and with appropriate technique can be used.
Debridement: Removal of devitalized or necrotic material and debris from a wound.
- Autolytic debridement: A selective process by which endogenous phagocytic cells and proteolytic enzymes break down necrotic tissue, occurring in varying degrees in the presence of a moist wound healing environment and dependent on the patient's having a functioning immune system.
- Biological debridement: Application of sterile, medical grade larvae (maggots) into the wound bed that remove any devitalized tissue, disinfect the wound bed, and thus promote wound healing. Also referred to as maggot debridement.
- Conservative sharp debridement: Performed outside the operating room; not as aggressive a procedure to make a wound acute; the removal of clearly identifiable, devitalized tissue to above the level of viable tissue by using sharp instruments, including but not limited to scalpels, scissors, or curettes.
- Enzymatic debridement: Achieved with the use of exogenous proteolytic enzymes that work directly on the devitalized tissue or indirectly by dissolving the collagen that attaches the devitalized tissue to the wound bed and have little or no effect on healthy tissue.
- Mechanical debridement: The non-selective removal or separation of necrotic tissues from the wound bed by using a using a physical method.
- Serial debridement: Repeat debridement with a goal of preventing biofilm reformation.
- Sharp debridement: Performed in the operating room; the most efficient debridement method to convert a chronic wound to an acute wound.
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Devitalized tissue: May include necrotic tissues, foreign debris, and bacteria, which are removed from the wound bed.
- Eschar: Thick, leathery, necrotic tissue located on the surface of a wound that is often tan, gray, brown, or black.
- Non-viable tissue: The general term for tissue that has died and has therefore lost its usual physical properties and biological activity. Also called devitalized tissue or necrotic tissue.
- Necrotic: (See above) Tissue that is no longer viable. Can manifest as either slough or eschar.
- Slough: A stringy or fibrinous mass that may or may not be firmly attached to surrounding tissue. Composed of serum and matrix proteins. Ranges in color from white to yellow or green (because of varying levels of bacterial colonization) to brown (hemoglobin is present). May become thicker and harder to remove the longer it is present.
Extracellular polymeric substance: A primarily polysaccharide protective matrix synthesized and secreted by the microorganisms that attaches biofilm firmly to a living or non-living surface. This protective covering does not allow the body's immune system to recognize the presence of the microorganism; therefore, the bacteria evade an immune response, avoid detection by standard diagnostic techniques, and avoid destruction by standard treatments and therapies.
Microcolony: Mixed microbial colonies within biofilm that utilize their collective strengths and abilities to further the survival of the group; this gives significant protective advantages.
PSI: Pounds per square inch; 4-15 psi is the safe range of pounds per square inch of pressure for delivery of wound cleansing agents that will remove necrotic material or debris and at the same time protect fragile granulation tissue.
Sterile technique: Meticulous hand washing or sanitizing is utilized while preparing or maintaining a sterile field. The procedure should emphasize that all equipment, including gloves, instruments, and dressing, is and remains sterile.
Wound bed preparation: Systematic approach to wound management by identifying and removing barriers to healing including cleansing and debridement of the wound bed.
The views and opinions expressed in this blog are solely those of the author, and do not represent the views of WoundSource, Kestrel Health Information, Inc., its affiliates, or subsidiary companies.