Slough and biofilm: removal of barriers to wound healing by desloughing

Abstract

The presence of non-viable tissue in a chronic wound presents a barrier against effective wound healing, hence removal facilitates healing and reduces areas where microorganisms can attach and form biofilms, effectively reducing the risk of infection. Wound debridement is a necessary process in those wounds that have evidence of cellular debris and non-viable tissue. As slough is a form of non-viable tissue we hypothesise that it will support the attachment and development of biofilms. Biofilms are entities that have serious implications in raising the risk of infection and delaying wound healing. In those wounds that contain only slough, high-risk debridement methods are not considered necessary for its removal. The use of mechanical techniques for removing the slough is regarded as posing a much lower risk to the patient and the wound bed. The process of removing slough from a wound is referred to as 'desloughing'. We propose that mechanical desloughing is a low-risk method of debridement to aid the specific removal of slough. Slough in a wound is a recurrent issue for a large majority of patients. Consequently, desloughing should not be deemed a one-off process but an on-going procedure referred to as 'maintenance desloughing'. Maintenance desloughing will help to achieve and maintain a healthy wound bed and aid the removal of wound biofilms, facilitating wound healing.

Autolysis: mechanisms of action in the removal of devitalised tissue

“…Although clinical observations describe several types of devitalised tissue (Table 2) (Percival and Suleman, 2015). It is clear, however, that there can be significant variability in the properties of non-viable tissues between patients (European Wound Management Association, 2004).…”

“…It is clear, however, that there can be significant variability in the properties of non-viable tissues between patients (European Wound Management Association, 2004). However, despite this variability, general characteristics of necrotic tissue and slough have recently been proposed (Percival and Suleman, 2015). Necrotic tissue is a hard, dry tissue that is generally black/brown in colour and is firmly attached to the underlying viable tissue (Figure 1).…”

“…Table 2 itemises the similarities and differences between the three main types of devitalised tissue. Dry, black and hard necrotic tissue, eschar and necrotic tissue appears to be made up of a fibrous mass of extracellular matrix components (e.g., fibronectin, collagen, elastin fibres) (Percival and Suleman, 2015;Thomas et al, 1999), dried skin and granulation tissue (Black et al, 2010). Percival & Suleman (2015) Wound slough is very different from necrotic tissue/eschar.…”

“…It is generally pale yellow or yellow/brown in colour (Figure 3). It is a soft tissue and is generally more loosely attached to the underlying tissue when compared with the strength of attachment of necrotic tissue (Percival and Suleman, 2015). Slough is composed of white blood cells, bacteria and foreign material, and dead tissue.…”

Wound bed preparation: A novel approach using HydroTherapy

“… Prevent practitioners from assessing the extent and size of the wound, which is particularly problematic when staging pressure ulcer damage (Weir, 2007)  Increase odour and exudate (Vowden and Vowden, 2011) Devitalised tissue is known to provide an environment in which microorganisms can attach and form biofilms, which as a consequence results in wound infection (Percival and Suleman, 2015). Ultimately this may lead to a more serious deep tissue infection that can be life threatening (Leaper et al, 2015).…”