Standardized Support Surface Testing: A New Model

Introduction and Purpose: Supports surfaces are used for pressure redistribution in the prevention and management of pressure ulcers. Currently, standardized test methods are being developed in order for clinicians to compare and contrast the standard functionality of differing support surfaces.

Immersion, a physical concept relating to support surfaces defined by the Support Standards Initiative (S3I), was chosen as the test standard. Immersion is important in caring for patients at risk or with pressure ulcers. By immersing or sinking a patient into a therapeutic support surface, there is an increase in contact area and therefore an inverse relationship to pressure resulting in lower contact pressures.

Methodology: The S3I has developed the Mattress Immersion Test Methodology to determine the depth of penetration or sinking into a support surface.

The immersion of a 50^th percentile male mannequin was measured on both air support surfaces and air-fluidized support surfaces, after being set per manufacturer’s operating instructions.  Immersion testing was accomplished and measured by lowering the mannequin onto the support surface and comparing the support surface vertical reference points before and after loading. To calculate immersion the post loading measurement was subtracted from the initial loading measurement.

Findings: The test was validated between two test labs prior to use. The immersion test completed on the air and air-fluidized product showed repeatability factor after 3 trials with a standard deviation of ±0.02 and a 95% Confidence Interval.  The average percent of immersion per mattress was 79% on air and 62% on air-fluidized. The average inches of immersion per mattress was 5.71 inches on air and 4.31inches on air-fluidized.

Conclusion: Although this study has provided evidence that immersion into air may be deeper, the clinical significance of these findings will require additional research. This includes clinical outcomes studies that should be related to the immersion testing.