The skin is the largest organ in the human body. It is readily exposed to different kinds of damages and injuries. When the skin and its surrounding tissues are unable to redistribute external pressure and mechanical forces, pressure ulcers may be formed. Pressure ulcers pose a significant health and economic concern internationally, across both acute and long-term care settings. Pressure ulcers impact approximately 2.5 million people a year in the United States and an equivalent number in the European Union. In long-term and critical care settings, up to 25% of elderly and immobile patients develop pressure ulcers. Approximately 60,000 U.S. patients die per year due to infection and other complications from pressure ulcers.
Most pressure ulcers occur over bony prominences, where there is less tissue for compression and the pressure gradient within the vascular network is altered. Pressure ulcers are categorized in one of four stages, ranging from the earliest stage currently recognized, in which the skin remains intact but may appear red over a bony prominence (Stage 1), to the last stage, in which tissue is broken and bone, tendon or muscle is exposed (Stage 4). Detecting pressure ulcers before the skin breaks and treating them to avoid progression to later stages is a goal of policy makers and care providers in major economies. Most pressure ulcers are preventable, and if identified before the first stage of ulceration, deterioration of the underlying tissue can be halted.
Of the four main stages of pressure ulcers, the earliest stage currently recognized (Stage 1) is the least expensive to treat at an average of $2,000 per ulcer, but is also the hardest to detect. In many cases, injuries on the epidermis layer are not present or apparent when the underlying subcutaneous tissue has become necrotic. As a result, it is common that a clinician's first diagnosis of a pressure ulcer in a patient occurs at late stages of the ulcer development—at which time the average cost of treatment is $43,000 per Stage 3 ulcer, or $129,000 per Stage 4 ulcer. If clinicians could identify and diagnose pressure ulcers at earlier stages of ulcer development, the healing process would be considerably shortened and the treatment costs would be significantly lower.
To treat pressure ulcers in a timely and effective manner, clinicians need to be able to identify, with precision, the ulceration area. However, the current standard to detect pressure ulcers is by visual inspection, which is subjective, unreliable, untimely, and lacks specificity.