CLINICAL FOCUS Exudate assessment and management Patricia Davies Patricia Davies is Senior Lecturer and Pathway Leader in Tissue Viability, Birmingham City University Email: [email protected] xudate is the fluid that seeps out of a wound. It is thought that the chronic wound is stuck in-between It is similar to the fluid that, when the skin is the inflammatory and proliferative stage of healing, the Eintact, would usually bathe the cells within the delicate balance in favour of the MMPs breaking down tissue dermis, providing nutrients to the cells. The waste products for too long. The presence of MMPs prevents new tissue produced by the cells are transported into the venous and from being created (Schultz, 2007). Some products indicate lymphatic circulation. When there is an injury involving the that they are able to reduce the level of MMPs at the wound tissues of the dermis, or below it, this fluid is able to leak bed to correct this balance; however, further research is out to the surface; fluid production is usually increased, due required to demonstrate the effectiveness of this clinically, in to the action of the inflammatory stage of wound healing relation to wound healing rates (Smeets et al, 2008). (World Union of Wound Healing Societies, 2007). Exudate is composed mainly of water, with electrolytes, Exudate – what needs nutrients and waste products, together with substances to be considered? directed to the wound by chemicals released on injury, Exudate assessment is an important element of the wound such as white blood cells, inflammatory mediators, growth assessment process. factors and enzymes, such as proteases (World Union of Wound Healing Societies, 2007; Romanelli et al, 2010). Effect of exudate on the patient Exudate can be beneficial to wound healing, especially Exudate is known to be problematic to patients when it in an acute wound, as it can be used to create a is not managed well. Strikethrough of exudate through moist environment, which has been demonstrated to the dressings or bandages is visually offensive, gives rise to enhance the rate of granulation tissue and epithelialisation odour and causes leakage of fluid onto furniture, bedding compared with a wound dried out in air (Alvarez et al, and clothing (Rich and McLachlan, 2003; Jones et al, 2008). 1983; Dyson et al, 1988; Thomas, 2010b). Patients with such symptoms admit to isolating themselves, The components of exudate, such as matrix and have been found to suffer from increased rates of metalloproteases (MMPs), can contribute to the breakdown depression and anxiety (Jones et al, 2008; Palfreyman, 2008). of dead and devitalised tissue, while other components, This needs to be borne in mind when dealing with known as growth factors and cytokines, contribute to frequency of dressing changes. Dressings and bandages building new tissue. MMPs participate in the clearing of should be changed before exudate strikes through to the dead tissue, then growth factors and cytokines enable the outer side, or leaks from beneath the dressing. The reason reforming of new tissue. for this is twofold: first, for patient comfort (physically and mentally), and second, to reduce the risk infection from bacteria gaining access through the wet material. Abstract An intact dry dressing prevents bacterial ingress; once Good wound management must involve an holistic approach to care; the dressing becomes sodden, bacteria have a route into without considering the whole person, appropriate management might not the dressing, through the material and thus to the wound be as good as it could be. In a time of austerity, it is important that money (Thomas, 2010b). If the skin surrounding the wound is spent appropriately on the correct wound-management technologies. becomes wet with exudate, this can cause excoriation of Exudate assessment and management are a vital part of wound the area (Benbow and Stevens, 2010), which can cause management. In this article, the focus will be on exploring the nature of pain and discomfort. exudate and tools available to evaluate exudate. Finally, suggestions will be made on the management of exudate. Colour of exudate Exudate is usually clear or straw-coloured fluid; however, in KEY WOrDs certain circumstances, this colour may be changed and still Exudate w Management w Assessment w Colour viewed as ‘normal’. The colour of exudate can relate to the tissue type present at the wound bed. An example would be if there were necrotic or sloughy tissue at the wound S18 WoundCare,September2012 CLINICAL FOCUS Figure 1. Macerated skin Figure 2. Excoriated skin bed, the exudate colour could be brown or dark green, to thickness of exudate reflect the tissue’s colour, which is breaking down. If using Exudate varies in its composition; it can be watery, or thicker a silver dressing, the exudate may be blue or grey in colour in nature (World Union of Wound Healing Societies, 2007). (World Union of Wound Healing Societies, 2007). The variation in thickness or viscosity is dependent upon The colour of exudate needs to be considered, so you the amount of wound fluid being produced by the patient, are to be able to make a judgement of what is normal and and the amount of white cells and bacteria present within appropriate for your patient at that specific point in time. the wound (Blackwell, 1997). White cells and bacteria, when This needs to be considered in conjunction with other present in large amounts within the wound, act in a similar signs of inflammation or infection. way to gravy granules, thickening up the exudate. It is important that the colour of the exudate is noted Pus is a form of thick exudate and is one of the classic at every dressing change, to ensure subsequent assessments signs of infection (Cutting et al, 2005). Thick exudate have relevant information with which to compare. can be associated with an infected wound; however, just WoundCare,MarchSeptember20112012 S19 CLINICAL FOCUS box 1. What exudate colours tell us Colour now Colour previously Indication Action Straw-coloured or clear Straw-coloured or Normal exudate colour Continue as planned clear Blood-stained or rust- Straw-coloured or Patient may have injured the Ask the patient if they had injured the area; if coloured clear site to take back to haemostasis so, assess if it needs extra protection. stagem or the wound could be If the patient had not had an injury to the area, demonstrating a sign of infection consider if other signs of infection are present*. If other signs of infection are present, treat as advised by local wound-care formulary Straw-coloured or clear Blood-stained or Now normal exudate colour Continue as planned rust-coloured Brown, dark green or No exudate or If necrotic or sloughy tissue Continue as planned grey brown, dark green is present at wound bed, this or grey could be normal, as the body is breaking down the necrotic or sloughy tissue Fluorescent green Straw-coloured or Could indicate the bacteria Check if other signs of infection are present; if clear Pseudomonas aeruginosa is not, continue as planned. Due to the colour the present bacteria displays, this is one of the few bacteria we are able to see visual evidence of. However, being present does not necessarily indicate the wound is infected; it could be colonised (bacte- ria in lower numbers than infected rate), which is normal. If other signs of infection are present*, continue as advised by local wound care formulary Purulent green, milky or Straw-coloured or Could indicate presence of Check if other signs of infection present*; If cloudy clear infection other signs of infection are present, treat by taking a wound swab or fluid sample for culture and sensitivity; systemic antibiotics to be pre- scribed and antimicrobial dressing to be used, as advised by local wound care formulary *Note: in patients with diabetes, signs of infection such as inflammation response can be negligible or absent. because the exudate is not thick does not mean that a bags are being used to collect the fluid; however, when wound is not infected. Clinically, several patients have been using dressings, it can be more difficult. For example, observed to be producing thin exudate, draining from a the amount of exudate absorbed by different dressings in pinhead-sized sinus, in cases of chronic osteomyelitis (bone different ways does not allow direct comparison between inflammation/infection). dressings (Thomas, 2010a). There are several suggested methods of assessing exudate level, but none as yet has Amount of exudate been identified as the best method. This is an area that The amount of exudate can vary depending on the requires further research to determine which is the most wound’s aetiology; for example, venous leg ulcers and clinically relevant. burns can produce large amounts of exudate when Falanga (2000) proposed a method of scoring for exudate, compared with arterial ulcers (Rolstad and Ovington, as part of a staging system for wound bed preparation 2007). Wound fluid amounts can also vary due to stage (Box 2). The scoring system gives some guidance on the of wound healing. In the inflammatory phase of wound degree of exudate in relation to the dressing changes. healing and early proliferative phase of wound healing, However, since this scoring system was devised, new exudate production is usually higher, due to the cellular products on the market, such as super absorbents, may activity taking place. In the later stage of the proliferative affect the frequency of dressing changes needed. phase, the amount of fluid produced usually drops (White The extent of control is also dependent on interpretation. and Cutting, 2006). The amount of exudate may also relate For example, if a patient with a very exudative wound is to the size of the wound, larger wounds producing more being dressed with a wound dressing designed to stay in exudate than smaller ones, in the main (World Union of place for 24 hours, exudate is controlled if the dressing Wound Healing Societies, 2007).