Special Report: The Use of Technology for Improved Pressure Ulcer Prevention

  Pressure ulcer prevention, an important quality care measure, is often a challenge regardless of facility type. Prevalence rates vary among different healthcare settings but are reported to be between 3% and 30%. Regulatory oversight as well as significant legal liability awards contributes to current demand to reduce prevalence through implementation of evidence-based practices associated with detection and prevention of pressure ulcers.   A pressure ulcer is defined by the National Pressure Ulcer Advisory Panel¹ as a localized injury to the skin and/or underlying tissue, usually over a bony prominence, as a result of pressure or pressure in combination with shear and/or friction. This definition is a direct result of work conducted by the 2001 NPUAP Task Force. This task force was initiated to examine current practice, including the pressure ulcer staging system, and to establish a mechanism for the recognition of deep tissue injury under intact skin. Specifically, this task force acknowledged the current staging system as limited – there was no way to know what was happening under intact skin. In fact, Richard Bennett, Task Force Co-chair, noted that definitions of pressure damage were more clinical than empirical. Furthermore, although the 2007 definitions also include a definition for suspected deep tissue injury, the definition remains clinical and mostly subjective. Also, this definition, along with the definition of Stage I, is not helpful to clinicians who practice culturally competent care and the need to eliminate the current disparity where people of color have a greater chance of developing pressure ulcers.

  Pressure ulcers often are discussed within the context of poor quality of care or failure to care. Although the identification of persons at risk for pressure ulcers in concert with a comprehensive skin assessment for the detection of pressure damage are all essential components of clinical protocols, one must recognize the lack of objective assessment tools. Could the lack of objective information be a major contributor to continued pressure ulcer prevalence? Could an objective assessment tool reduce the prevalence of pressure ulcers regardless of skin color or pigment?

The Promise of Ultrasound

  To accurately identify and define deep tissue injury under intact skin for improved prevention and outcomes, a tool that allows for visualization of the skin and underlying tissues is required. Can ultrasound be the solution? Will the use of ultrasound reduce or eliminate clinical dependence on the less accurate measures of identifying skin changes associated with pressure ulcer development and better detect pressure-related deep tissue injury? Similar to other indications, soft tissue ultrasound may illustrate tissue changes associated with pressure-related deep tissue injury, especially over bony prominences.

  Ultrasound (ultrasonography) works by utilizing the echoes of sound waves to create images of soft tissue anatomy. A probe transmits sound waves into the body. When these sound waves “hit” a boundary between acoustically different tissues (ie, fluid, soft tissue), a proportion of the energy, dependent upon the degree of acoustic mismatch, is reflected back (echoes). The ultrasound machine then calculates the distance and intensity of these reflections and displays a two-dimensional image, incorporating the reflection intensities and distances the sound wave has traveled. High-frequency ultrasound (20 MHZ) will provide high-resolution images of the skin and underlying soft tissue and because the images are related to tissue density (not pigment), the clinician’s assessment ability is enhanced significantly.

  Interpretation involves identifying visual differences associated with the reflective pattern. It is important to remember that tissue reflects sound and fluid absorbs sound. In other words, when the ultrasound wave encounters a dense object such as bone, most of the sound is bounced back up to the probe and little is allowed to pass through the tissue. This is seen as a bright reflection and is known as hyperechoic or echogenic. In contrast, fluid (eg, edema) is seen as a dark area and is known as hypoechoic and nonechoic. Therefore, tissue injury can be described as a loss of the expected reflective pattern and hypoechoic or anechoic areas in the subdermal (subcutaneous), dermal, and/or subepidermal tissues.

Literature Review

  Although ultrasound is widely used as a safe and cost-effective technique for non-invasive visualization of specific human anatomy, its use for skin assessment is just now available. Quintavalle et al² (2006) supports its clinical value in the use of 20 MHz ultrasound; they reported a 79.3% rate of the presence of edema in the subdermal tissues on participants before clinical signs were apparent. Moreover, Zulkowski³ (2007) found a greater than 90% rate of abnormal ultrasound images (heels) on study participants upon admission to a long-term care facility. Both of these research studies strongly suggest that clinicians should consider high-frequency ultrasound as an improved method for identifying and implementing good pressure ulcer preventive care.

Case Studies

  Figures 1 through 4 are from two different individuals but both show abnormal ultrasound images captured on admission and, when nurses intervened with preventive protocols, improvement over time. Both individuals were determined to be “low risk”(per Braden scale scores) and skin was intact with no signs of breakdown – ie, nursing assessment documents stipulated “low-risk Braden score/no signs of breakdown.” Nurses intervened with preventive protocols.   The availability of ultrasound to detect early subdermal compromise can be useful in determining patients at risk and appropriate treatment, as well as establish onset of symptoms to offset culpability of neglect/poor care in our litigious society.

Conclusion

  As technology such as ultrasound is incorporated into assessment protocols, clinicians will improve their ability to assess and manage threats to skin integrity that may not be readily apparent in overt skin changes. Proving the cost-effectiveness of such practices will further the cause of prevention and save time, effort, and suffering.

Sound Advice is made possible through the support of Longport, Inc, Glen Mills, Pa. This article was not subject to the Ostomy Wound Management peer-review process.

1. Dyson M, Lyder C. Wound management: physical modalities. In: The Prevention and Treatment of Pressure Ulcers. St. Louis, Mo: Mosby;2001:177-193

2. Georgia Tech Research News. Skin deep: imaging technologies may detect pressure ulcers and deep-tissue injuries that healthcare workers may miss. Research Horizons Magazine. 2006. Available at: http://gtresearchnews.gatech.edu/newsrelease/skin-deep.htm.

3. Quintavalle PR, Lyder, CH, Mertz PJ, Phillips-Jones C, Dyson M. Use of high-resolution, high-frequency diagnostic ultrasound to investigate the pathogenesis of pressure ulcer development. Adv Skin Wound Care. 2006;19(9):498-506.