Experimental Simulation Study to Assess Pressure Distribution of Different Compression Applications Applied Over an...

Compression is integral to the management of edema and the prevention of venous leg ulcers (VLUs).

The aim of this study is to assess the sub-bandage pressure distribution under 3 compression applications as well as to assess the impact of an innovative primary wound dressing, applied under the compression products, on pressure distribution.

A series of controlled tests were performed using a simulated leg model (SLM). A pressure mapping sensor and system software was used to measure the interface pressure (IP) and pressure distribution created by the application of 3 different compression systems with and without the addition of an elastic longitudinal stockinette (fuzzy wale compression; FWC). These included: (1) 2-layer cohesive wrap; (2) 3-layer compression application; and (3) 4-layer compression application. The IP was pressure between the SLM and the innovative dressing over which the compression applications were applied. Seven different configurations were tested, including the compression applications alone and in combination with the FWC. In addition to the IP measurements, pressure mapping visualizations were captured with the pressure mapping sensor and system software. A custom MATLAB program was written for data analysis, differentiations in discrete high- and low-pressure locations across the compressed area, and graphing of the pressure readings.

The overall average pressure for each testing setup without FWC ranged from 34.65 ± 4.84 mm Hg for the 2L configuration to 63.92 ± 7.08 mm Hg for the 4L configuration. The addition of the FWC resulted in a 19% increase for the 2L, 9% increase for the 3L, and 7% increase for the 4L compression systems. Additionally, it was noted that the inclusion of FWC resulted in a significant change in pressures vertically oriented under the 2-, 3-, and 4-layer compression applications of 34.52 ± 9.06 mm Hg, 99.21 ± 29.81 mm Hg, and 128.96 ± 22.97 mm Hg, respectively. The pressure distribution under the compression alone was observed to be largely uniform except for areas of overlap that produce horizontal bands of elevated pressures. The presence of the primary wound dressing did not have a significant impact on the IP measurements. The addition of FWC to all compression applications demonstrated a vertical distribution of compression along the sensor with alternating areas of little or no compression.

The unique alternating pressure distribution observed in the in vitro pressure testing with the use of FWC in a clinical setting has been observed to produce better edema management and wound edge migration that mirrors the vertical pressure distribution observed in the study. Additional in vitro and in vivo research to evaluate the biophysical impact of IP created by the use of a combination of primary wound dressings and compression applications with focus on the total pressure and the distribution across the surface of intact tissue and open wound bed is warranted.