Assessment of the uptake of simulated viscous exudate by adhesive foam dressings

Wound management products have been widely tested with solutions such as water and Solution A in order to understand their absorption characteristics. These solutions however are not always representative of the wound environment where the presentation of wound exudate can vary greatly in volume, colour and viscosity.  Exudate can be much more viscous than these solutions in its properties, especially where infection is present.  The study was therefore conducted with the aim of understanding the differences in exudate absorption with increasing viscosity, and to understand applicability of dressings to different wound environments.

In this study, Solution A was thickened using increased percentage volumes of xanthan gum in order to simulate three tiers of exudate viscosity in order to cover a broad range of wound environments.

Each dressing underwent a series of testing on a WRAP¹ wound model in order to analyse their ability to handle various levels of exudate thickness. The volume of fluid taken up by the dressing was recorded as a percentage of fluid fed into the simulated wound bed.

Dressings presented significant differences in absorption behaviour between the range of fluids. Fluid of a lower viscosity was handled in a much more efficacious manner than that of increased viscosity. The absorption characteristics observed demonstrate a difficulty in the area of thick exudate and therefore dressing selection becomes of increasing importance. Foam dressings with larger open space in the wound contact layer demonstrated greater efficacy in viscous exudate uptake, with foams with larger volumes of adhesive failing to absorb much larger percentages of the fluid supplied.