The Royal Marsden Hospital Manual of Clinical Nursing Procedures - Lisa Dougherty [636]
Figure 15.4 The maturation phase of wound healing.
Reproduced by kind permission of Wayne Naylor.
Methods of wound assessment
In order to provide a method of wound assessment and a simple way of selecting appropriate dressings, an international group of wound care experts developed a concept using ‘TIME’ (tissue, infection/inflammation, moisture balance and edge advancement) as an acronym to identify the key barriers to healing (Dowsett and Ayello 2004, Werdin et al. 2008) (see Table 15.2).
Table 15.2 TIME principles for wound bed preparation
Wound bed preparation
Wound bed preparation (WBP) focuses on controlling and optimizing the wound environment for healing (Falanga 2000). It provides a means of bringing together a cohesive plan of both patient and wound care (Ayello et al. 2004, Vowden and Vowden 2002).
Tissue factors affecting wound healing
The rate of wound healing varies depending on the general health of the individual, the location of the wound, the degree of damage and the treatment applied. It is necessary when treating a wound to appraise all potential detrimental factors and minimize them, where possible, in order to provide the optimum systemic, local and external conditions for healing.
Factors that may delay healing include disease (including malignancy), poor nutritional state and infection. Other influences involve the local microenvironment of the wound, including temperature, pH, humidity, air gas composition, oxygen tension, blood supply and inflammation (Storch and Rice 2005). Whether this influence is positive or negative may depend on the stage of wound healing that has been reached. Other important considerations are external variables such as continuing trauma, possibly caused by treatment or the presence of foreign bodies. Factors known to affect wound healing are listed in Table 15.1.
Achieving a well-vascularized wound bed
Improving the blood flow to the wound bed will increase the availability of nutrients, oxygen, active cells and growth factors within the wound environment (Collier 2002). This may be achieved through the use of compression therapy, topical negative pressure therapy or wound management products that exert an osmotic pull on the wound bed, increasing capillary growth, for example Vacutex (Collier 2002).
Debridement of devitalized tissue
Surgical debridement is the most effective method of removing necrotic tissue (Wolcott et al. 2009). It is performed by a surgeon and usually involves excision of extensive or deep areas of necrosis, usually to the point of bleeding viable tissue to ‘kickstart’ healing (Hampton and Collins 2004). While this option is very effective, it carries the risks associated with general anaesthesia. An alternative method of rapid debridement is ‘sharp’ debridement, which may be utilized for the removal of loose, devitalized, superficial tissue only (Vowden and Vowden 1999). Sharp debridement can be performed at the patient’s bedside by an experienced healthcare professional with relevant training (Poston 1996). However, this can be a dangerous practice in inexperienced hands and is controversial (Fairbairn et al. 2002). Potentially, ligaments may be severed as they can have the appearance of sloughy tissue or vascular damage could occur (Hampton and Collins 2004). It is also acknowledged that informed patient consent is required as this is an invasive procedure with potential risks and complications (Fairbairn et al. 2002).
Autolytic debridement is recommended as a less invasive technique which utilizes the body’s natural debriding mechanism. This effect is enhanced in a moist wound environment, which can be achieved through the use of hydrogel dressings or semi-occlusive dressings that maintain moisture at the wound surface. Many dressings are designed for this purpose and break down necrotic tissue naturally (Hampton and Collins 2004, Hess 2005) (Table 15.3).
Table 15.3 Dressing groups. Please refer to manufacturer