This review considers exudate from the perspectives of its nature, composition, assessment and the range of management strategies available.
The management of wound exudate requires the clinician to have an understanding of what it is, why it is present and how to monitor and assess it accurately.
Wound exudate was described by the Swiss physician Paracelsus (c1491-1541) as nature’s balsam .
It is derived from serum through the inflammatory/extravasation process.
Acute wound exudate contains molecules and cells that are vital to support the healing process.
It has a high protein content (although lower than that found in serum), with a specific gravity greater than 1.020.
This type of exudate has justifiably been termed ‘a wounding agent in its own right’ because it has the capacity to degrade growth factors and peri-wound skin and predispose to inflammation .
In order to develop an effective management approach, the clinician must be able to accurately assess and understand the implications of the composition and quantity of exudate present in the wound.
In the chronic wound, exudate contains proteolytic enzymes and other components not seen in acute wounds .Its composition includes electrolytes, glucose, cytokines, leukocytes, metalloproteinases, macrophages and micro-organisms .In the first 48 to 72 hours after wounding, platelets and fibrin may be present, but this reduces as bleeding diminishes. As fluid passes through the inflamed vessel walls (extravasation) it may be seen that wound exudate is in essence modified serum and will therefore contain similar solutes.Exudate management is relevant to patient quality-of-life issues as it is often associated with leakage and malodour.
It impacts on health economics because failure to control exudate production will lead to increased management costs and patient morbidity.
To achieve these goals a detailed knowledge of dressing materials and their performance is required.