Exudate management made easy
09/02/10 | Complex wounds, Service development and delivery, Wellbeing and concordance, Wound bed preparation | M Romanelli, K Vowden, D Weir
This document builds on the principles presented in the document Wound exudate and the role of dressings, and focuses on how a rigorous approach to exudate management can improve patient quality of life, promote healing and enhance healthcare effectiveness.
Exudate production by open wounds is essential for moist wound healing. However, when wounds produce insufficient or too much exudate, and/or the composition of the exudate is harmful, a wide range of problems can occur that ultimately delay healing, distress patients and consume considerable healthcare resources. This document builds on the principles presented in the document Wound exudate and the role of dressings, and focuses on how a rigorous approach to exudate management can improve patient quality of life, promote healing and enhance healthcare effectiveness.
WHAT IS EXUDATE?
Exudate can be defined as fluid leaking from a wound. It plays a central role in healing.
Exudate is mainly water, but also contains electrolytes, nutrients, proteins, inflammatory mediators, protein digesting enzymes (eg matrix metalloproteinases (MMPs)), growth factors and waste products, as well as various types of cells (eg neutrophils, macrophages and platelets). Although wound exudate frequently contains micro-organisms, their presence does not necessarily mean that the wound is infected. Exudate is usually clear, pale amber and of watery consistency. In general, it is odourless, although some dressings produce a characteristic odour that may be mistaken as coming from exudate.
Wound exudate should be evaluated in the context of the wound tissue type being treated. For example, exudate produced by a necrotic wound as a result of autolytic or enzymatic debridement would characteristically be opaque and tan, grey or even green (if the wound contains certain bacteria). This exudate may also present with a foul odour.
WHAT DOES EXUDATE DO?
In healing wounds, exudate supports healing and a moist wound environment. The main role of exudate is in facilitating the diffusion of vital healing factors (eg growth and immune factors) and the migration of cells across the wound bed5. It also promotes cell proliferation, provides nutrients for cell metabolism, and aids autolysis of necrotic or damaged tissue.
WHAT AFFECTS RATE OF EXUDATE PRODUCTION?
As healing occurs, the amount of exudate produced usually decreases. It is important to recognise that the volume of exudate is related to the surface area of the wound, and therefore large wounds such as burns, venous leg ulcers and skin donor sites often produce higher volumes of exudate.
Although a moist wound environment is necessary for optimal wound healing, over- or under-production of exudate may adversely affect healing.
Any factor that increases capillary leakage or predisposes to the development of tissue oedema (eg inflammation, bacterial contamination or limb dependency) may boost exudate production. Low exudate production may indicate a systemic problem, eg dehydration, hypovolaemic shock, microangiopathy, or may be a feature of ischaemic ulcers.
When too much or too little exudate is produced, it is essential that the healthcare professional accurately determines and evaluates the factors contributing to the problem. Only then can effective management strategies be introduced.