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GENERAL PURPOSE: To review newly published pressure injury (PI)literature.LEARNING OBJECTIVES/OUTCOMES:After participating in this educational activity, the participant will1. Describe the pathophysiologic mechanisms that contribute to the development and progression of PI. 2. Explain the implications for patients with chronic medical conditions predisposing them to PI development. 3. Identify evidence- based strategies for the prevention and management of PI.
Clinicians are constantly challenged to stay current with the literature. This challenge is especially true in the field of pressure injuries (PIs), where relevant articles may appear in diverse journals, including those dedicated to nursing, geriatrics, or solely to wounds. This is now the authors’ sixth year in reviewing and commenting on this highly diverse PI literature for Advances in Skin & Wound Care. As with past years, the authors have reviewed every abstract identified through a PubMed search using the terms “pressure ulcer,” “pressure injury,” or “decubitus ulcer” and limited to 2024. More than 650 new articles were identified. From these abstracts, ~30 articles were selected for a more in-depth review and discussion of their contributions to the field of PIs. Based on these discussions, 6 articles were selected for inclusion based on the authors’ opinion of the articles’ perceived interest, importance, and/or innovation. These should not be considered the 6 “best” articles from the past year, and they were deliberately selected to cover a range of topics. Articles that the authors co-authored were excluded. In past years, articles that were published in Advances in Skin & Wound Care were not included. However, given the ongoing importance of articles published in this journal, these have no longer been excluded. Articles not published in English were omitted.
The year 2024 has been notable for the number of impactful articles, which made selecting 6 articles particularly challenging. Among the articles that were not selected were 2 that focused on an important source of information for many patients and caregivers, YouTube. Limitations on the quality of much of this information were highlighted. The critical role of long-term care staffing was once again demonstrated by Chen and Grabowski with their analysis demonstrating lower PI rates in nursing homes that had achieved Institutional Special Needs Plan maturity, a care model promoting care coordination often through a dedicated nurse practitioner. The scientific process required in developing PI quality measures was illustrated by Zhou et al in their article focusing on intraoperative care for cancer patients. Finally, Kottner and El Genedy-Kalyoncu noted the extensive ongoing interest in the international PI clinical practice guidelines, which have been cited >2000 times in the literature, achieving status as among the top 1% in articles cited.
Considering broader trends in the PI literature, the continued growth in the number of articles employing artificial intelligence (AI) and the use of natural language processing should be noted. Among topics covered in this literature are enhanced risk prediction, identification of PIs from electronic health record notes, and even the demonstration of an AI mattress. This update has covered AI extensively in past years and does not feature any of these articles this year. The relative dearth of high-quality clinical trials remains an issue. Although these are the articles that could have the greatest impact on practice, there just were not many that warrant highlighting, often due to questionable methods or small sample sizes. Finally, as the COVID-19 pandemic seems to fade from memory, PI articles dealing with the infection and its sequela are also becoming less frequent.
For this current article, the authors describe 6 PI articles published in 2024. Among the topics covered are an analysis of slough, the potential role of zinc in PI development, the etiology of skin failure, and the implications of PIs in people with spinal cord injury and other long-term neurological conditions. For each article, the authors first provide the reference. They next summarize the key findings from the article. Finally, a commentary is offered on what this article adds to the literature.
SELECTED LITERATURE
Article 1
Townsend EC, Cheong JZA, Radzietza M, Fritz B, Malone M, Bjarnsholt T, Ousey K, Swanson T, Schultz G, Gibson ALF, Kalan LR. What is slough? Defining the proteomic and microbial composition of slough and its implications for wound healing. Wound Repair Regen 2024;32:783-98.
In this pilot study, Townsend and colleagues evaluated the proteomic and microbiologic components of slough obtained from wounds of various etiologies and examined whether these components may predict the wound trajectory over the ensuing 3 months. The study was performed at 2 hospitals located in the United States and Australia; however, complete data were available only from the United States. Eligible subjects were 18 years or older with a chronic nonhealing wound. Swabs were obtained from the wound center and edge. Bacterial bioburden was assessed by both quantitative bacterial cultures and quantitative polymerase chain reaction of the 16S ribosomal RNA gene. The wound bed was subsequently washed with soap and water before sharp debridement to collect samples for electron microscopy, fluorescence, and proteomics. The participants from the United States also had a clinical assessment using the Bates-Jensen Wound Assessment Tool. Ten participants from the United States and 13 from Australia were enrolled in the study. The US study participants had a mean age of 66 years, 40% were male, and the mean wound age was 2.4 years. At the 3-month follow-up visit, 3 wounds were healed, 4 were ongoing, and 3 had deteriorated. The proteomic analysis revealed that slough is enriched for proteins involved in skin barrier formation, wound healing, regulation of blood clotting, as well as various immune functions, including responding to bacteria, acute inflammatory response, immune effector cell responses, and humoral immunity. Wound slough is polymicrobial with corynebacterium, pseudomonas, and Staphylococcus most abundant. The bioburden of slough was high, with 8 of the 10 subjects having >10 colony-forming units per milliliter. Despite this amount being considered a standard for infection, only 1 of the 8 had a clinically apparent infection. In addition, microbes were not consistently detected in slough samples when evaluated via laser and electron microscopy, suggesting lower sensitivity for these approaches. Forty-eight proteins were differently abundant in healing versus deteriorating wounds. Healing wounds were enriched by proteins involved in skin barrier formation, wound healing, and blood clot formation. In contrast, the deteriorating wounds were characterized by proteins involved in a chronic inflammatory response. The proteomic and microbial composition of slough, when combined with the Bates-Jensen Wound Score, could distinguish between wounds that went on to heal or deteriorate; the proteomics data had the strongest correlation to wound healing. Deteriorating wounds had a higher Bates-Jensen score, a greater abundance of anaerobic bacteria, and proteins involved in the immune response. The authors emphasize how clinical proteomic and microbiome data may be integrated to predict wound healing outcomes. An important limitation of this study, though, is the small sample size, and further study is required to expand knowledge on the use of slough as a biomarker to identify the healing trajectory of chronic wounds.
Comment
Slough is defined as “nonviable tissue of varying colour (eg, cream, yellow, grayish, or tan) that may be loose or firmly attached, slimy, stringy, or fibrinous.” Slough is believed to promote bacterial growth and biofilm promotion, while inhibiting granulation tissue formation and wound healing. The appearance of slough is familiar to clinicians, and typically, the only thought given is what manner of debridement should be employed to get rid of it. This lack of interest in slough is reflected in the literature. A recent search, including articles through 2020, identified only 3 scholarly articles on the effects or components of slough. Thus, this article by Townsend and colleagues represents the first detailed analysis of this common clinical problem. Despite the small number of patients examined, Townsend and colleagues show that slough is highly heterogeneous in its structure, protein composition, and microbial community. Bacterial counts are high and often above what is considered indicative of infection. More importantly, this composition of slough may be predictive of wound healing outcomes. These results are still preliminary. Yet based on these data, it is not hard to imagine a future in which slough samples are sent to the lab to obtain information that may inform treatments and prognosis. It may not be able to ignore slough much longer.
Article 2
Yokokawa H, Morita Y, Hamada I, Ohta Y, Fukui N, Makino N, Ohata E, Naito T. Demographic and clinical characteristics of patients with zinc deficiency: analysis of a nationwide Japanese medical claims database. Sci Rep 2024;14(1):2791.
This retrospective cross-sectional observational study analyzed demographic and clinical factors associated with zinc deficiency using a nationwide Japanese medical claims database of >38 million patients. Researchers examined data from the 13,100 patients with recorded serum zinc concentrations between January 1, 2019, and December 31, 2021, after excluding those below 20 years old and those prescribed zinc-containing medications. Patient data from the time of the zinc determination were collected, including sex, age, weight, inpatient or outpatient status, and laboratory parameters. Serum zinc levels were classified as deficient (<60 μg/dL), marginally deficient (60 to 79 μg/dL), or normal (≥80 μg/dL). Select comorbidities from the previous 60 days, including PIs, were identified using ICD-10 codes and analyzed for their association with zinc levels.
The study population was nearly evenly divided between males (48.6%) and females (51.4%), with an average age of 69 years. The mean serum zinc concentration was 65.9 μg/dL, with 34.8% classified as zinc deficient, 45.5% as marginally deficient, and 19.7% as normal. Zinc deficiency was more prevalent among older adults, particularly males. Two hundred sixty-five patients (2.0%) had a PI, and of these, 160 (60.4%) had zinc deficiency. Adjusting for age and gender, having a PI was significantly associated with the presence of zinc deficiency, with an odds ratio of 2.4 (95% CI: 1.9, 3.1). Among the 28 other comorbidities examined, only the presence of aspiration pneumonitis was more strongly associated with zinc deficiency. with OR=3.0 (95% CI: 2.4, 3.6). Sarcopenia, COVID-19 infection, and chronic kidney disease, as well as the use of certain medications, including spironolactone, furosemide, thyroid hormones, systemic antibacterials, and corticosteroids, also had associations with zinc deficiency. Limitations noted by the Yokokawa et al include selection bias as it is unknown why zinc levels were measured, possible intake of zinc-containing medications, and that the cross-sectional study design prevents the establishment of any causal relations. Nevertheless, they concluded that zinc deficiency is common in patients with PI and suggest that evaluating serum zinc levels in at-risk populations may support early detection and intervention.
Comment
Those who have been managing patients with PIs for many years may remember a time when nearly every patient with a PI received zinc and, often, vitamin C supplementation. This practice, however, fell out of favor in the early 2000s as animal studies and clinical trials failed to show benefits from zinc and potential harms were noted. Systematic reviews from that time emphasized the lack of benefit, which subsequent guidelines continue to support. The current Japanese study is noteworthy for its large sample size and the strong association noted between zinc deficiency and having a PI. Moreover, these results are supported by another large study from 2024 that reached similar conclusions. This second study used Mendelian randomization in a European sample to examine causal associations between 13 micronutrients and PI. Only zinc deficiency demonstrated a significant association. (Mendelian randomization involves 2 separate large samples; in one sample, genetic markers of low zinc levels are identified; these gene-predicted zinc levels are then examined in a second sample for an association with PIs.) Collectively, these 2 articles could suggest a reexamination of the role of zinc deficiency in PIs. However, they both have methodological concerns. In addition, plasma zinc levels may not accurately reflect tissue stores, and these levels are impacted by the presence of systemic inflammation. As much as 25% of the US population may consume inadequate zinc, emphasizing that further research on the role of zinc in the development and treatment of PIs is clearly warranted. Only then might it be appropriate to say "zinc is back."
Article 3
Kopp MA, Finkenstaedt FW, Schweizerhof O, Grittner U, Martus P, Watzlawick R, Brienza D, Failli Vieri, Chen Y, DeVivo MJ, Schwab JM. Hospital-acquired pressure ulcers and long-term motor score recovery in patients with acute cervical spinal cord injury. JAMA Netw Open 2024;7:e2444983.
This multicenter cohort study examined the impact of PIs on long-term neurological and functional outcomes following acute traumatic spinal cord injury (SCI). Data from 1282 patients with cervical SCI [American Spinal Injury Association Impairment Scale (AIS) grades A, B, or C] from 20 SCI centers within the SCI Model Systems (SCIMS) Database were analyzed. Patients were enrolled within 24 hours of their injury between January 1996 and September 2006. Exclusions included prior nursing home stays, ages below 16 or above 75, and unreliable baseline exams. Pressure injuries were considered present if they developed either during the acute hospitalization or the subsequent rehabilitation stay. Data on motor function were collected at baseline, discharge, and 1-year postinjury. The primary outcome was the change in the total American Spinal Injury Association (ASIA) motor scores; secondary outcomes included Functional Independence Measure (FIM) motor scores, upper and lower extremity ASIA motor scores, and mortality at 10 years postinjury. The analysis adjusted for baseline scores, sociodemographic factors, injury level, and AIS grade.
The study population had a mean age of 38.0 years and was 80.2% male. Five hundred eighty-six patients (45.7%) developed a PI, with 63.7% of these PIs developing during the acute hospital stay and 36.3% during the subsequent inpatient rehabilitation. The incidence of PIs was highest in those classified as AIS A (55.3%), followed by AIS B (42.9%), and then AIS C (26.8%). The most severe PI was staged as grade 1 in 21.8% of patients, grade 2 in 51.8%, grade 3 in 16.1%, and grade 4 in 10.4%. Developing a PI was associated with worse neurological recovery, both at discharge and at 1 year. In adjusted models, the ASIA motor scores in patients with a PI were 4.1 (95% CI: -6.6 to -1.6) points lower at discharge, further decreasing to a 9.1 (95% CI: -12.3 to -6.0) point difference at 1 year. FIM motor scores at 1 year were 8.3 points (95% CI: -11.1 to -5.5) lower in patients who developed a PI. Patients with PIs also had an increased long-term mortality risk over 10 years (HR: 1.41; 95% CI: 1.09-1.82; P = .01). In a post hoc analysis, the authors demonstrated that an infection acquired during hospitalization was also associated with worse functional outcomes. The authors concluded that PIs acquired during initial hospitalization after SCI are a potentially modifiable risk factor for poorer long-term motor recovery, decreased functional independence, and increased mortality.
Comment
Considerable variability exists in the extent of recovery following a traumatic SCI. This variability cannot be fully explained by injury severity and anatomy, a phenomenon that has been called the neuroanatomical-functional paradox. Among the possible explanations for the paradox is that systemic inflammation during the recovery process may impair neurological healing. Pressure injuries are the second most frequent secondary complication in SCI patients during the time of acute hospitalization through community reintegration and occur in up to one third of all SCI patients. They may also be a potent source of inflammation and thus could impair neurological recovery. The paradox that inflammation impairs healing is now confirmed in this important study by Kopp and colleagues. Not only were PIs associated with decreased functional recovery at the time of discharge, but the impact grew and was larger at 1-year postinjury. The magnitude of these differences is not just a statistical artifact of the large sample size but is clinically significant. Pressure injuries also impact mortality up to 10 years, although this is not a new finding. The fact that infection also hindered functional recovery provides further support for the hypothesis that systemic inflammation is one explanation for the neuroanatomical-functional paradox. One would expect that deeper PIs are associated with more inflammation. Therefore, it would have been interesting to examine whether Stage 3 and 4 PIs were associated with less functional recovery than Stage 1 and 2 PIs. Perhaps this analysis will appear in a subsequent paper. The many sequelae of PIs are well known to clinicians. Impaired functional recovery following SCI can be added to the list.
Article 4
Muir D, McLarty L, Drinkwater J, Bennett C, Birks Y, Broadway-Parkinson A, Cooksey V, Gleeson P, Holland C, Ledger L, Lowe DJ, McGoverin A, Nixon J, Perry T, Sandoz H, Rawson B, Rawson Y, Stubbs N, Walker K, Whitaker H, Coleman S. Pressure ulcer prevention for people with long-term neurological conditions (LTNCs) who self-manage care and live at home. J Tissue Viability 2024;33:753-65.
The aim of this study was to better understand how people with long-term neurological conditions (LTNCs) living at home meet the challenges of PI prevention and management. To gain this knowledge, the authors employed a participatory methodology that allows patients and caregivers to be actively engaged in the research protocol development, data collection, and analysis, which is then used to develop a Theory of Change (ToC) pathway to guide the development of future multicomponent interventions. The 2-year study was conducted in the United Kingdom and engaged 74 people with LTNCs, their informal caregivers, paid personal assistants, healthcare providers, community stakeholders, and researchers. Although 31 people had LTNCs, many of these people had other roles, such as being caregivers. Data were collected and analyzed through 4 interlinked work packages that included work groups guiding the study conduct, semi-structured interviews, focus groups, and full-day workshops. Further program oversight was managed by a multidisciplinary program coordinating group, which met twice a month, and a program steering committee with 6 independent members who met twice yearly. Through this detailed process, 8 themes were identified that impact PI prevention: (1) learning/accessing information was challenging and inconsistent, (2) safe routines to minimize harm need to also consider mental health and emotional well-being, (3) potential support provided by peers and outside agencies, (4) challenges in navigating complex systems to ensure care coordination, (5) the impact of life events on PI care and the need to adapt and react to change, (6) changing perceptions of PI risk, (7) the need for risk negotiation with healthcare providers in joint decision-making, and (8) challenges to caregivers in their supporting roles. The resulting ToC pathway supports diverse interventions addressing the need for awareness-raising material on PI risk, the development of personalized safe routines, guidance on care escalation, and a framework to improve communication among stakeholders. The authors conclude by emphasizing the complexities involved in addressing PI prevention for people with LTNCs living at home.
Comment
Pressure injuries are extremely common among people living in the community, although estimates vary widely. Rates for people living at home with LTNCs are undoubtedly higher. Efforts at preventing PI at home should be an important focus, but a recent integrative review has shown that limited knowledge is available on this topic. The current article by Muir and colleagues highlights some of the reasons related to the challenges in preventing PIs at homes. Hard as it may be to prevent PIs in acute and long-term care settings, it is infinitely more complex in community settings. Through their detailed engagement with patients, informal caregivers, personal assistants, and healthcare providers, Muir and colleagues provide tremendous insights into how complex things really are. Even something as simple as negotiations between patients and providers on whether to engage in risky behaviors must resolve a system "geared at telling me what not to do (to prevent pressure injuries) and not supporting me with the things I wanted to do." Education is often promoted to improve care, and programs have been shown to increase knowledge among older people living in the community. However, as this article well illustrates, it would be naïve to think that education would be sufficient given the many barriers in community settings. A recent small clinical trial from Iran demonstrated that extensive caregiver empowerment through education, ongoing follow-up via an app, and twice weekly phone calls can reduce PI incidence in stroke patients discharged home. It is these types of intensive interventions that understand and address the concerns of all community stakeholders that will be required to make a meaningful dent in community-acquired PIs. An intervention study from Muir and colleagues that makes use of their ToC pathway is greatly anticipated.
Article 5
Levine JM, Samuels E, Le S, Spinner R. Pressure injuries and wound care: a lost geriatric syndrome. J Am Geriatr Soc 2024;72:2611-12.
Pressure injuries have long been considered a geriatric syndrome. Nevertheless, the authors were concerned that research on PIs is relatively underrepresented in the geriatrics literature, especially when compared with other geriatric syndromes such as frailty and dementia. This article examined the representation of wound care research in geriatrics over the past 30 years. The authors conducted online searches of Journal of the American Geriatrics Society (JAGS) articles from 1991 to 2021 and American Geriatrics Society (AGS) Annual Meeting abstracts from 1990 to 2020. The keywords "wound," "ulcer," "decubitus," and "sore," along with "dementia" and "frailty," were used. In addition, AGS Annual Meeting programs from 2004 to 2021 were reviewed, excluding 2020 due to the COVID-19 pandemic, to assess the presence of wound-related topics during meeting preconferences and main sessions.
The search identified 62 wound-related articles in JAGS, only 28 of which had a coauthor from a US geriatrics program. Twenty-two articles (with 13 from US programs) were published from 1991 to 2000; 28 articles (with 13 from US programs) were published from 2001 to 2010; and from 2011 to 2021 there were only 12 articles (2 from US programs) [Unpublished data provided by Jeffrey Levine, MD, personal communication, February 5, 2025]. Moreover, many of these articles were editorials or reviews rather than original research. Among 16,621 AGS meeting abstracts between 1990 and 2020, only 119 (0.72%) focused on wound care, compared with 913 (5.5%) on dementia and 299 (1.8%) on frailty. Although the annual number of frailty and dementia abstracts has increased dramatically over the past 15 years, PI abstracts have remained constant at fewer than 10 per year. Of the 86 PI-related abstracts presenting clinical research rather than case reports, the most common topics were risk assessment and prevention (25.6%), wound care education (17.4%), and epidemiology/natural history (16.3%). Between 2005 and 2021, AGS meetings included 3 symposia and 5 preconference sessions on wound care, all led by faculty from 3 US geriatric programs. The authors conclude that the field of geriatrics, especially in the US, has provided suboptimal attention to the field of PIs.
Comment
Geriatric syndromes refer to "multifactorial health conditions that occur when the accumulated effects of impairments in multiple systems render an older person vulnerable to situational challenges." Pressure injuries clearly meet this definition, and one might expect that geriatricians in the United States would be at the forefront of research, as they are for other geriatric syndromes such as frailty, falls, and delirium. Sadly, as highlighted in this article by Levine and colleagues, this is not the case. It is stunning that between 2011 and 2021, there were only 12 articles on PIs in JAGS, with only 2 from US geriatric programs. Many of the published articles represent reviews and editorials rather than original research. Having closely followed the PI literature for a number of years, articles by geriatricians do not appear in other journals either. In trying to understand these numbers, one could postulate that all the important research questions have been answered. However, it is only necessary to look at the latest Clinical Practice Guideline to know this is not true. There is little evidence for most recommended practices. There is a clear need for research in all areas of PI care, and recognizing their multifactorial etiology, multidisciplinary involvement in PI research should be desired. The challenge will be how to get US geriatricians involved again in this research, especially given that few programs now seem to have expertise in this area.
Article 6
Melnychuk I, Servetnyk I. Kennedy terminal ulcers and Trombley-Brennan terminal tissue injuries: Mystery solved? Adv Skin Wound Care 2024;37:233-7.
The skin goes through changes at the end of life. The pathophysiology of these terminal skin lesions, including Kennedy terminal ulcers and Trombley-Brennan terminal tissue injuries, is not well understood. The authors hypothesize that these lesions often develop in the setting of hypotension and at the end of life due to anatomic aberrancies of the arteries. The blood supply to the sacrum and coccyx typically comes from the median sacral artery (MSA) and the lateral sacral arteries (LSA). The MSA is a small artery, 2 to 4 cm in length and only 2 mm in width, that comes off the infrarenal aorta. However, in 6% of individuals, the MSA originates from a lumbar artery, and in 4% of individuals, it arises from the common iliac artery. The LSAs typically originate from the posterior division of the common iliac artery, but many variations exist. The authors note that a small subset of the population is born with a missing MSA (2.1%) and/or LSA (0.3%), leading to extensive reliance on collateral circulation. The superior gluteal artery is an important source of collateral circulation but often shares a trunk with several other arteries that may limit flow in the setting of hypotension. The authors then use Poiseuille Law, which explains the flow of a fluid through a pipe, to examine the effect of anomalous arterial circulation. Per Poiseuille Law, the flow rate is proportional to the pressure difference between the ends of the pipe and the fourth power of its radius. When the MSA comes off the infrarenal aorta, with its diameter of 2 cm, the pressure gradient between the ends of the "pipe" will be 10,000-fold. In contrast, when the MSA is aberrant and comes off a lumbar artery with its diameter of 0.3 cm, the pressure gradient will be 5-fold. The much smaller pressure gradient between the ends of the MSA when arising off a lumbar artery means a markedly reduced blood flow even under normal circumstances. This lower flow is further exacerbated in the setting of hypotension. Thus, terminal skin lesions may arise due to low blood flow and tissue ischemia in people prone to these lesions due to an anomalous circulation. The authors emphasize that further research is required to support this hypothesis.
Comment
Necrosis of skin in the sacral and buttocks area in the final hours of life, known as Kennedy terminal ulcers, was described in 1989. Since then, the overlapping concepts of skin changes at life's end and skin failure have become increasingly accepted. It is thought that, at least in critically ill patients, skin failure is the result of hypoperfusion, although other factors may also be important. Yet for many clinicians, there has always been something a little unsettling about the concept. If skin is "failing," why is there this particular predilection for ulceration to occur over the sacrum as opposed to other locations? Moreover, why is it that terminal ulcers only develop in a small fraction of the people who are dying? This article by Melnychuk and Servetnyk provides a plausible explanation. Anatomic anomalies in the arterial circulation are not uncommon and may result in blood circulation that is adequate in normal times, but insufficient in the setting of hypotension and imminent death. The inadequate circulation then leads to tissue death. These skin lesions are predominantly ischemic and not the result of tissue deformation from pressure and shear forces. It is important to emphasize that this is only a hypothesis and there is little evidence as yet to support it. But it does provide a cogent explanation for the 2 questions that have long perplexed the field about Kennedy terminal ulcers. More research is needed, although the form of the research needed to support this hypothesis is unclear.
CONCLUSIONS
The year 2024 was another fascinating year for PI research, and the authors were struck by the tremendous diversity and richness in this literature. The authors believe that the highlighted articles are ones that clinicians need to be aware of as they struggle to remain current with the many advances in the field. Notably, this year, the authors have not selected any clinical trials. The ones published, in the authors' opinion, did not meet the criteria for quality and impact. Hopefully, this will change for next year.
