Cath Lab Digest

P ressure ulcers are all-too-often an outcome of acute and chronic illness. They occur across the continuum of care and their prevalence among patients in acute care ranges from 3.5% to 29.5%.^1,2

Determining prevalence can be useful for benchmarking over time. Serial prevalence audits can serve as a pressure ulcer outcomes-management tool, reflecting the way changes in practice affect pressure ulcer prevention and treatment. One way to impact the prevention and treatment of pressure ulcers is through allocation of resources, specifically implementation of support surfaces.

Literature Review

The role of mechanical forces on the development of pressure ulcers has long been recognized. Many investigators^3-7 have measured the relative contribution of shear and pressure in diminishing blood flow. Considerable investigation has concluded that a relationship exists between external pressure loading and tissue damage. Shear also has been identified as a major mechanical force that causes tissue damage; specifically, an inverse relationship exists between pressure and shear. As the amount of shear increases, the amount of pressure required to cause pressure ulcers is reduced.

Utilizing support surfaces is one way to impact the prevention and treatment of pressure ulcers.⁸ The Agency for Health Care Policy and Research (AHCPR) guidelines recommend that patients at risk for the development of pressure ulcers should be placed on pressure-reducing support surfaces.⁹ One acute care facility used serial prevalence audits to determine the effect of a new support surface protocol on the number of nosocomial pressure ulcers.¹⁰

When evaluating the efficacy of a support surface, measuring its ability to relieve direct downward pressure and shear pressure is important. The pressure-relieving capability of a support surface added to a multiple of its ability to relieve shear yields a measurement of the major mechanical forces that are known to cause pressure ulcers. This relationship between pressure and shear has been referred to as the "isolibrium factor".¹¹

In 1999, a new technology became available in the support surface market with the introduction of ISOFLEX® (Gaymar Industries, Inc, Orchard Park, NY). The pressure and shear management technology consists of a grid-like matrix of vertical columns constructed of an elastomer material. A column design manages pressure by redistributing a patient's weight; thereby, optimizing low tissue interface pressures. Additionally, this support surface has the ability to reduce shearing forces in the supine and Fowler positions.

Purpose

A study was conducted to compare prevalence rates, the number of patients with hospital-acquired pressure ulcers, and the total number of facility-acquired pressure ulcers before and after a hospital-wide change in support surfaces. The goal was to determine if a change in support surface technology would impact the occurrence of facility-acquired pressure ulcers. Implementing the new pressure and shear management support surface was the only change in practice in the period of time between the first and second prevalence audits.

Methods

Subjects and setting. The study facility is a 243-bed acute care medical center in rural northeastern Pennsylvania. All individuals hospitalized on five medical-surgical units and two intensive care units on each of the study days were eligible to participate. One hundred, nine (109) inpatients (two African American and 107 Caucasian patients) participated in the first audit in June 1999, and 128 (one African American and 127 Caucasian patients) inpatients participated in the second audit in October 2000.