Testing the Durability of Dressings in a Simulated Wound System

Background: Dressings used to manage exuding wounds are exposed to both fluids and mechanical forces, e.g. during dressing changes, and hence their mechanical durability is important, so that they do not disintegrate upon removal from the wound. We aimed to develop a new laboratory methodology, which enables direct comparisons of the durability of dressings, accounting for clinical protocols.

Methods: A computer-controlled phantom of an active exuding sacral wound has been developed to facilitate standardised experiments where dressings are exposed to exudate-like fluids under mechanical, thermodynamic and clinical use conditions which closely replicate real-world settings. We compared the post-use mechanical performances of two dressing types: high-density dressings (HDDs) with isotropic fiber arrangement versus low-density dressings (LDDs) with anisotropic arrangement. We applied the products onto the phantom and loaded them with exudate substitutes delivered at pre-defined volumes and rates. Tensile tests were then used to determine the strain energy density (SED) levels required to induce failure of the dressing materials.

Results: Our experiments revealed that the HDDs were able to withstand ~5-times greater SED levels before material failure occurred, compared to the LDDs. The design of the HDDs further facilitated larger dressing deformations, ~4-times more than those that were tolerable by the LDDs.

Conclusion: It is crucial that used dressings maintain mechanical strength and structural integrity, to endure pull-out forces that occur as they are removed from a wound. Our present methodology allows standardised testing of dressings in all clinically-relevant scenarios.