Aims: Good exudate management needs to be maximised for both the wound and the patient to ensure wound healing can take place in a timely manner. The in vitro studies in this article evaluate a new Hydrofiber® cover dressing (HCD) for both its exudate management and biophysical properties (eg cellular adhesion and contouring to uneven wound surfaces).

Methods: These included measuring fluid absorption and retention, the conformability of dressings to a simulated wound surface, measurements of fluid lateral spread, dressing bioadhesion and interactions with wound fibroblasts that were set into a collagen gel matrix. Results: Although the majority of the foam dressings absorbed more fluid than the corresponding new HCD, when placed under pressure the ability to retain fluid was far greater with the HCD showing fluid retention in excess of 90%. Similar results were shown for the lateral spread of fluid. Not all the dressings showed complete conformability to the simulated wound surface due to the more 'rigid' structure of the foam dressings. The results for the bioadhesion and gel contraction studies showed the importance of combining absorption properties of foams with Hydrofiber® Technology by showing less bioadhesion (p<0.001) and being less detrimental to fibroblast contraction and viability (p<0.001). Conclusions: These studies highlight the need to choose the most appropriate wound dressing, which not only provides the best possible exudate management, but also subjects the wound to the least number of interventions that might interfere with the repair process.

Any breakdown of the protective function of the skin results in the formation of a wound, which not only provides a portal of entry for bacteria, but also creates an exit portal for wound exudate. The amount of exudate produced in any one wound may become a problem to both the patient and the clinician if it is not controlled.

In a healing wound, exudate is considered to be an aid to the healing process by maintaining a moist environment, promoting cell proliferation and providing essential cell nutrients, as well as stimulating autolysis (the removal of dead or damaged tissue)[1].

In chronic wounds, however, exudate is considered to be 'a corrosive biological fluid', due to the many harmful components (eg bacteria, enzymes) that are contained within it[2]. Consequently, it is important to manage exudate 'to maximise the benefits to the wound and the patient'[1]. If leakage is allowed to occur there is the potential for maceration and excoriation of the healthy periwound skin, which can lead to further breakdown of this tissue due to the corrosive nature of chronic wound exudate.

Recent studies have shown that the periwound skin area of ischaemic diabetic patients is often compromised[3,4]. It is important that an appropriate dressing is chosen which not only has the capacity to absorb exudate, but can also be retained within the dressing structure and not become laterally spread onto the surrounding skin.

Equally important is the ability of the dressing to conform to the wound surface, as this leaves no room for dead spaces between the wound and the dressing interface, reducing the possibility of increased bacterial proliferation[5,6].

Wound dressings should also be able to 'respond' to the wound environment, influencing the cellular environment of a healing wound through the maintenance of moisture balance[7].

Some wound care products can become attached to a wound or skin surface, and this can result in trauma to the wound upon removal of the dressing, which may disrupt the newly formed fragile re-epithelial tissue surrounding the wound. This can be painful for the patient. A previous study using an in vitro wound fibroblast cell adhesion model has shown that fibroblast adhesion can vary with dressing composition[8].