A Transparent Sacral Dressing to Mitigate Tissue Strain

Introduction: Pressure injuries form on load bearing surfaces on the buttocks, sacrum, and heals of immobile patients. Silicone-based multilayer dressings are available to aid in protecting the skin and possibly underlying tissues from the mechanical strains; which are believed to cause the injury. A new sacral dressing, which is also transparent, may provide protection while enabling assessment with the dressing in place. The new transparent dressing and 3 other opaque dressings were tested in a lab for their ability to mitigate lateral strains in a tissue-like gel model.

Methods: A custom digital image correlation apparatus was constructed with a digital camera and Raspberry PI single-board computer. A gelatin and glycerol-based gel was mixed with blue beads and cast into a square mold; the solidified gel served as a tissue model. The gel was subjected to incremental lateral stress with or without a dressing (n = 3). The strain on the tissue model was measured by a combination of ImageJ and Python. The maximum displacement for each replicate was chosen as the basis of comparison. A one-way ANOVA followed by Tukey’s Honest Significant Difference (HSD, alpha = 0.05).

Results: There was an ~7-fold reduction between the control and dressings (p = 1 x 109), and Tukey’s HSD determined that the differences only existed between the treatments and control (p = 0.001) and not among the dressings (minimum p = 0.6084).

Discussion: The sacral dressings provided substantial protection of the model tissue. Statistically, the dressings appear to be substantially equivalent in their ability to protect against lateral strain.