The impact of first-aid dressing design on healing of porcine partial thickness wounds.

Literature describes that a well-maintained moist wound healing environment leads to faster healing by preventing scabbing and drying of the wound. A moist wound speeds healing by allowing for unimpeded movement of newly dividing epidermal cells in the wound. Contrary to what is described in literature and practiced by clinicians, first-aid dressings used at home by consumers advertise breathability and absorptivity as benefits. This manuscript examines the effects of dressing breathability and highly absorptive pads on healing and wound appearance in a porcine dermatome wound model, designed to mimic an abrasion injury. Partial thickness wounds were covered with an experimental silicone-polymer film dressing and various over-the-counter bandages for time frames ranging from 4 to 11 days. The progression of healing was quantified by histology and wound-size reduction measurements. The thickness and persistence of a scab or serocellular crust (SCC) over the injury was measured using both pixel density and optical coherence tomography to supplement visual observations, demonstrating new tools for quantification of SCC over wounds. The results of the experiments illustrate the impact of dressing features on the rate of wound reepithelialization and the formation of SCC. Both a low moisture vapor transmission rate (MVTR) and the absence of an absorptive layer were important in speeding wound healing. Surprisingly, use of a dressing with a low MVTR and a highly absorptive pad healed significantly more slowly than a comparative dressing with a low MVTR and no absorptive pad, even though both dressings had very little scab formation over the wound. This study shows that breathability and absorbency of dressings play independent roles in providing an optimal healing environment, and that these properties can vary widely among commercially available dressings.