Wound Bed Preparation: The Science Behind the Removal of Barriers to Healing

Stuart Enoch, MBBS, MRCSEd, MRCS (Eng), Keith Harding, MB ChB, MRCGP, FRCS

Disclosures

Wounds. 2003;15(7) 

In This Article

Infection and Wound Bed Preparation

Effective wound bed preparation depends on the management of microbial balance as well as the treatment of infection. The concept of wound bed preparation recognizes that a patient with a chronic wound may display all the classic signs of infection but that infection could equally be clinically less obvious. The reasons for this lie in the immunological response to chronic wound infection.

The continual presence of a bacterial infection stimulates the host immune defenses leading to the chronic production of inflammatory mediators, such as prostaglandin E2 and thromboxane. Neutrophils continue to migrate into the wound, releasing cytotoxic enzymes and free oxygen radicals.[106] Thrombosis and vasoconstrictive metabolites cause wound hypoxia, leading to enhanced bacterial proliferation and continued tissue damage. With prolonged bacterial presence in chronic wounds, the bacteria change their pattern of behavior and alter their phenotype and their immune expression. All these factors help them to evade detection by the body's immune system, thus making it difficult to be negated by the host defenses. This development of "immune tolerance" can create the spurious impression of no infection[74] and may prevent the eradication of microorganisms from the wound.

Wound bed preparation transforms the way infection is viewed and treated because it recognizes that wound healing may be delayed by bacteria, even in the absence of classic signs of infection. Instead, subtle secondary signs of infection, such as lack of healthy granulation tissue, change in color of the wound bed, and friable granulation tissue, could be present. A common feature of locally infected wounds will be failure to heal and progressive deterioration. Wound bed preparation expands our existing view and recognizes that critical colonization as well as infection may need to be addressed so that healing can be optimized.

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