Management of Shear, Pressure and Microclimate by Foam Dressings

Introduction:

It is widely recognised that pressure ulcers are caused by a number of factors including pressure, shear and microclimate.¹ The aim of this study was to assess four foam dressings* for pressure and shear redistribution, and skin surface microclimate control.

Methods:

Pressure and shear forces were measured when a standard weight was applied to a pressure sensitive mat. A dressing was then applied between the mat and the weight, and the effect of this on the pressure and shear forces measured. Six replicates were conducted for each dressing.

To measure microclimate, dressings were applied to a high humidity-containing chamber (~90%RH), and the change in chamber humidity measured over eight hours at a constant temperature.

 

Results:

When weight was applied directly to the pressure mat, the average pressure recorded was 55mmHg, and the average pressure gradient (shear) was 21mmHg/cm. With Dressing A, the average pressure reduced by 52%, and pressure gradient (shear) by 46%. The other dressings reduced the pressure by 32% (B), 33% (C) and 22% (D), and average pressure gradient (shear) by 35% (B), 28% (C) and 31% (D).

Microclimate test results showed Dressing A had reduced the humidity to 58%RH, Dressing B to 75%RH and Dressings C and D to 83%RH.  

Conclusions:

This study showed that all of the dressings reduced pressure and shear forces, but not all dressings are able to do this to the same extent. Dressing A maintained a much lower humidity in the microclimate test chamber; indicating that this dressing generated a more favorable microclimate by removing excessive moisture, while not completely drying out the environment.