(LR-017) An in vitro Study Investigating the Impact of Perspiration on the Coefficient of Friction Between Multilayered Wound Dressings and a Skin Substitute

Jordan Fisk, Masters – Convatec

Introduction: A high coefficient of friction (COF) between dressings and skin can increase soft tissue exposure to shear forces, raising the risk of pressure injuries. Many dressings used for pressure injury prevention (PIP) include an adhesive silicone skin-contact layer that transfers frictional forces inward, potentially counteracting their PIP effect. This study compared COFs of two multilayer dressings, one with a silicone skin-contact layer and one with a Hydrofiber skin-contact layer, in an in vitro model which accounted for perspiration.

Methods: COFs were measured using a sled test based on ASTM D1894-14. Dragon skin was cast at 3.5 mm. Dressings were applied to a 63.5x63.5 mm sled weighing 200 g, with an additional 3 kg for silicone dressings due to their high COFs. Simulated perspiration used a water/sodium/calcium ions solution, sprayed at 0.3 g increments. Sled speed was 150 mm/min.

Results: At 5% and 10% dressing saturation, Hydrofiber COFs were 0.52 ± 0.05 and 0.28 ± 0.03 (static), and 0.47 ± 0.05 and 0.25 ± 0.02 (kinetic), showing no statistically significant changes as moisture levels increased. Regardless of dressing saturation level the COF values were significantly higher for silicone, at a 100% dressing saturation the COF values were 2.07 ± 0.20 (static) and 1.47 ± 0.17 (kinetic).

Discussion: A novel multilayer dressing with Hydrofiber skin-contact layer* demonstrated lower COFs compared to silicone, reducing tissue shear exposure. Even in low-sweat areas, natural moisture accumulation could further minimise Hydrofiber COFs, making this beneficial for direct skin contact in a PIP dressing.