Early Identification of Deep Tissue Pressure Injury (DTPI) in Patients with Darker Skin Tones Utilizing Photography and Long-Wave Infrared Thermography (LWIT)

Abstract

Introduction & Purpose
Skin assessment is a key element in deep tissue pressure injury (DTPI) prevention and documentation to determine visual and tactile changes in skin properties. In patients with darker skin tones, DTPIs can be difficult to detect early and definitively since erythema, purple, and maroon hues often present subtly or as hyperpigmentation, a sign associated with many other discolored skin conditions. Studies confirm that patients with darker skin are more likely to develop higher stage pressure injuries than those with lighter skin. Subsequently, DTPI in patients with darker skin tones leads to higher rates of mortality than lighter skin tones, likely due to delayed interventions.

Method
Based on the premise that DTPIs can be preceded by tissue that differs in temperature, warmer or cooler, than adjacent tissue, patients with darker skin tones were assessed utilizing an FDA-approved photographic and thermographic imaging device, clinically reliable to capture thermal anomalies on localized sites that had experienced pressure. The device captured images in a standardized manner, perpendicular to the site at 18 inches. The visual and thermographic image pair simultaneously appeared on the computer for immediate analysis.

Results
In this case series, all three patients showed little to no visual signs of any skin abnormalities or discoloration on localized pressure sites, namely the sacrococcygeal region and heel. Upon analyzing the thermographic images, the localized pressure sites in this case series revealed significantly warmer or cooler areas compared to adjacent tissue. Localized warm areas were quantified greater than or equal to 1.2 °C, clinically significant for inflammation. Similarly, localized cool areas were less than 1.2 °C, clinically significant for hypoperfusion.

Conclusion
Use of photography and LWIT imaging is effective for detecting early signs and symptoms of DTPI prior to skin discoloration in patients with darkly pigmented skin, which may promote improved quality of care and reduced mortality rates.