The Past, Present, and Future of Deep-Tissue (Pressure) Injury

INTRODUCTION For the 35th anniversary of Advances in Skin & Wound Care, a variety of thought leaders have been invited to share their insight into a range of topics of current interest to the field. In this special installment of Practice Reflections, Dr Thomas P. Stewart shares his thoughts on the history of deep-tissue injury (DTI), Dr Joyce M. Black reflects on the current state of research in this area, and Drs Alderden and Yap provide a vision for the future of DTI management and prevention. DEEP-TISSUE INJURY: THE PAST Today, we find that literature searches will yield many articles published on the topic of DTI or deep-tissue pressure injury (DTPI).* Suppose the searcher is a clinical practitioner with limited knowledge of pressure injury (PI) or wound care. In this scenario, the search result may indicate to the recipient that DTIs have been investigated and well understood over an extended period. However, much of the seminal scientific and clinical work has been published in the last 15 to 20 years. Further, the search may also suggest that DTI differential diagnosis is readily executed in clinical practice. Unfortunately, there remains difficulty detecting DTI or proceeding with a differential diagnosis today. Although there are earlier references,1 Shea is often cited as the first reference to DTIs, in an article written in 1975 on the Classification of Pressure Sores.2 In this article, Shea described what we would now identify as a DTI: a “closed pressure sore.” In 1987, the International Association of Enterostomal Therapists published the Standards of Care for Pressure Sores.3 The standards included four stages of pressure sores based on the Shea classification system. The only mention of deep-tissue destruction was contained in the description of stage IV pressure sores. In 1988, Stewart and Magnano4 reported PIs at the subcutaneous tissue/muscle level without damage to the overlying skin, similar to Shea’s “closed pressure sore.” These PIs tended to occur during specific surgical procedures. Subsequently, the National Pressure Ulcer Advisory Panel (now National Pressure Injury Advisory Panel [NPIAP]) convened its first consensus conference in 1989.5 Subsequently, the NPIAP released the first iteration of the definitions and stages of pressure ulcers. However, complete understanding of DTI did not exist at this time; the only discussion of an unstageable ulcer was an ulcer with eschar. After the 1987 International Association of Enterostomal Therapists and 1989 NPIAP staging definitions, the Agency for Healthcare Policy Research guideline panel updated their staging definitions in 1992 and 1994.6,7 In 1998, the NPIAP again updated the staging definitions and added the term “purple” as a sign of stage 1 lesion in patients with darker skin tones.1,8 A few years later, in 2001, the NPIAP updated the staging definitions and included the following language: “Dark, purple or bruised areas, over bony prominences with intact skin may indicate deeper tissue damage. Pressure should be released and the area should be monitored carefully.”9 The 2001 update to the staging definitions was a landmark change for the study and understanding of DTIs. It was the result of the work from a task force formed within the NPIAP that was devoted to more fully understanding DTIs. The staging update was an indication that their work was already having an impact on clinical practice. Since the task force’s development, the ongoing efforts to enhance our understanding have been led by Dr Joyce Black. Further work from this taskforce has offered insight into DTI pathogenesis and influenced our awareness of the etiology and pathogenesis of PIs.10 THE PRESENT One of the largest hurdles to overcome in DTPI science has been changing the mindset of providers on the etiology of PIs. All of us were taught (and some are still taught) that PIs are attributable to pressure on the capillaries in the skin that leaves the skin ischemic, and it ulcerates. The work of Stekelenburg and colleagues11 in Eindhoven (a city named after the inventor of the electrocardiogram), The Netherlands, created the first biologic evidence that deep-tissue pressure ulcers are not from skin ischemia, but muscle cell death. Gefen et al12 in Israel have extended that work to confirm that the etiology of these wounds is not skin ischemia, but muscle ischemia and necrosis. This change in thought means that deep PIs do not progress through stages 1 to 4 in order but are stage 4 PIs at the onset because the damage is at the bone-muscle interface. As you can imagine, the debate continues, extending now into topics such as “Do all PIs start at the bone-muscle interface, and if so, how then does a stage 2 PI form?” The time from pressure to ulceration was somewhat elusive until the DTPI was identified. Some early work identified a temporal pattern of 48 hours from the pressure event until the skin turned maroon or purple and another 24 hours until the epidermis blistered off, leaving a dark open wound bed.13 Black and Berke14 presented a more recent review of cases and again confirmed this time frame. So, you might ask, what is the importance of the time frame? First, if the time frame is correct, then the actual location of the patient at the time pressure was applied to the skin can be determined. For example, if a woman had a stroke on Saturday and was lying on the floor until Sunday, then lying on the floor was the pressure event. So, when she was admitted to the hospital on Sunday, intact skin might be present. But by Monday, purple tissue is visible. Second, this temporal pattern is crucial to accurate root-cause analysis. Obviously, the hospital cannot be responsible for the patient while she is on the floor at home. But change the location to the OR, then the hospital is responsible for the patient. The case should be examined to see if the risk was identified and/or preventive care was provided before and during surgery. The reader can appreciate how this temporal progression of DTPI is important to both attorneys for patients and for hospitals. The timeline creates a clear picture of who was responsible for the patient at the time pressure was applied and whether PI prevention was possible. Newer data are starting to demonstrate that patients who are paralyzed have skin color changes faster than 48 hours and patients with obesity take longer than 48 hours for the purple/maroon skin color to change. Using the described time frame, the ability to claim a DTPI as “present on admission” (POA) should be clear. But it is not; most hospitals allow staff 24 hours to find POA skin problems. Some hospitals require a skin assessment within 4 hours of admission. I would encourage facilities to expand the admission time frame for the DTPI, recognizing that other conditions are considered POA and do not have to be immediately apparent, such as pneumonia and occult fractures. The CMS official guidelines for coding and reporting state that there is no required time frame as to when a provider must identify or document a condition to be POA. In some clinical situations, it may not be possible for a provider to make a definitive diagnosis for a period of time after admission. In some cases, it may be several days before the provider arrives at a definitive diagnosis. This does not mean that the condition was not POA. Further, the guideline states that conditions that develop during an ED visit can be considered POA.15 There remains a healthcare provider training gap on the recognition of DTPI, distinguishing it from other conditions that change the color of the skin (eg, COVID-19 skin manifestations and Trombley-Brennan terminal tissue injury), and recognizing how rapidly the injury can evolve. Treatment of DTPI should involve complete offloading of the area and the use of noncontact, low-frequency ultrasonic mist for treatment.16 IMAGINING THE FUTURE OF DTPI PREVENTION AND MANAGEMENT The future of tailoring care delivery for managing DTPI will be heavily dependent on wound care professionals’ ability to engage with technology and data. Prevention and management of DTPIs are transitioning from a one-size-fits-all approach in which current prevention and treatment strategies developed for the “average” patient will evolve into individualized approaches that will be most effective based on genetic, physiologic, environmental, and lifestyle factors.17 This precision medicine approach uses genetic and other molecular information alongside data generated from routine care (eg, electronic health records and technology-related data) to determine the best treatment approach for each individual. Predictive analytics, a component of precision medicine, helps to identify the right treatment at the right time while recognizing patterns and trends within data, thus enabling clinicians to make more informed decisions and preemptively alter future outcomes.18,19 There remains a persistent incidence of DTPIs, even though increased focus has been placed on prevention protocols.20 Despite these protocol advances, DTPIs remain associated with restricted mobility, immobility, impaired sensation, and reduced tissue tolerance,21,22 and the impact of these factors has been difficult to observe and track, thus limiting our assessments related to prevention. Recent advances in technology have enabled personalized monitoring of patient mobility and movement patterns and subsequently the amount of time tissue is offloaded, thus allowing clinicians to predict more accurately the required prevention strategies. Both researchers and clinicians benefit from objective real-time monitoring. For example, pressure-mapping technology quantifies pressure placed on different areas in different positions to determine more accurate risk of potential tissue breakdown and/or DTPI formation. Another example is patient monitoring systems that not only track movement, but also document said movement in real time23–25 and cue staff for patient repositioning needs.26,27 These two examples demonstrate that technology can produce data useful for both research and clinical care. There is a significant burden on today’s healthcare system, given the increased acuity of patients admitted to hospitals and the growing geriatric population, along with the increasing rates of obesity, diabetes, and cardiovascular disease—and this will continue to grow.28 These changes in patient populations alongside the call to provide more community-based healthcare29 are another example of how technology can advance care delivery related to DTPIs. In fact, the recently developed model of care known as “Wound Center Without Walls” is a care delivery approach using telemedicine to untether DTPI and wound care from a physical location (such as a wound clinic) while continuing to provide comprehensive care across the healthcare spectrum.30 As the name suggests, DTPIs start deep within the tissue and usually do not become visibly apparent until about 24 to 72 hours after the event that caused the tissue damage; this type of remote monitoring gives clinicians a just-in-time ability to change clinical tactics if required. Further, if one could monitor remotely, this could lead to a clearer understanding of DTPI etiology and eventually positively impact prevention strategies.31 Technology will advance our data collection capabilities, although it will require behavioral change in nursing care and interprofessional practice. Much like how the entire healthcare industry relies on data to analyze every situation, environment, and illness, collecting high-quality and accurate data is critical for successful prevention and treatment of DTPIs. Patients facing a DTPI deserve a suitable approach to care, and using a data- and technology-informed approach will provide improved outcomes. CONCLUSION Even though DTPIs have been identified for decades, they are slow to be identified in real time. Further, DTPI remains a frequent source of litigation in part because of the extent of the wound, once evolved. Because impaired mobility and sensation are the most common risk factors, early mobilization and frequent movement in bed are crucial preventive measures. Available technology for prevention will have a positive cost-benefit ratio.