Non-invasive detection of local tissue responses to predict pressure ulcer development in mouse models

Dual-Modal Optical Imaging of Tissue Perfusion in Response to Cooling Stimulation Facilitates Early Detection of Pressure Ulcer

Pressure ulcers present a significant human and economic challenge, lacking a reliable method for early detection. To address this, we developed a system capable of early detection by using cooling stimulation and dynamic data acquisition techniques to monitor blood perfusion and skin temperature. The system consists of laser speckle perfusion imaging and thermal imaging. And we performed simulations to demonstrate that the system is capable of detect tissue damage across multiple layers, from superficial to deep. Testing on a rabbit ear model demonstrated that this approach, which combines dynamic perfusion and temperature parameters, effectively distinguishes early pressure ulcer areas from normal skin with a significant p value of 0.0015. This distinction was more precise compared to methods relying solely on static parameters or one parameter. Our study thereby offers a promising advancement in the proactive management and prevention of pressure ulcers.

Differences of bioelectrical impedance in the development and healing phase of pressure ulcers and erythema in mouse model

Pressure ulcers (PUs) are economically burdensome medical conditions. Early changes in pressure ulcers are associated with erythema. In this study, bioelectrical impedance was used to measure the differences between PUs and blanchable erythema. We divided 21 ICR mice into three groups: control, 1000 mmHg-1h, and 1000 mmHg-6h. Healthy skin, blanchable erythema, and PUs were induced on the dorsal skin. The results indicated an immediate increase in impedance, resistance, and reactance values in the pressure group after release, followed by a subsequent decrease until two days after release. Compared with the control group, impedance and reactance significantly increased by 30.9% (p < 0.05) and 30.1% (p < 0.01), respectively, in the 6 h-loading group immediately after release. One and two days after release, the 1 h-loading and 6 h-loading groups exhibited significantly different degrees of decline. One day after release, impedance and resistance decreased by 30.2% (p < 0.05) and 19.8% (p < 0.05), respectively, in the 1 h-loading group; while impedance, resistance, and reactance decreased by 39.2% (p < 0.01), 26.8% (p < 0.01), and 45.7% (p < 0.05), respectively, in the 6 h-loading group. Two days after release, in the 1 h-loading group, impedance and resistance decreased by 28.3% (p < 0.05) and 21.7% (p < 0.05), respectively; while in the 6 h-loading group, impedance, resistance, and reactance decreased by 49.8% (p < 0.001), 34.2% (p < 0.001), and 59.8% (p < 0.01), respectively. One and two days after release the pressure group reductions were significantly greater than those in the control group. Additionally, we monitored changes during wound healing. Distinguishing early PUs from blanchable erythema by noninvasive bioelectrical impedance technology may have applications value in early assessment of PUs.

Effect of "micromovement" in preventing intraoperative acquired pressure injuries among patients undergoing surgery in supine position

To explore the clinical effect of "micromovement" in preventing intraoperative acquired pressure injures (IAPIs) among patients experiencing surgery in supine position. A total of 200 patients accepting elective surgery in supine position from 10 May 2023 to 4 July 2023 at Shulan (Hangzhou) Hospital were selected and randomized into two groups (experimental group, n = 100; control group, n = 100). For control group patients, soft silicone foam dressing was applied to the sacrococcygeal region. On the basis of the treatment for control group patients, "micromovement" was implemented among experimental group patients. During this process, the operating table was tilted for 15° leftwards and rightwards alternately every 1 h, and the tilt angle was maintained for 5 min to prevent IAPIs. Finally, comparisons between the two groups were made in terms of the sacrococcygeal IAPI incidence, relative temperature differences (ΔT) on sacrococcygeal skin, and job satisfaction of nurses. Compared with control group patients, patients from the experimental group exhibited lower IAPI incidence (2% vs. 10%), reduced ΔT between the sacrococcygeal skin and surrounding normal skin [0 (-0.1, 0.1) vs. 0.2 (-0.2, 0.4)], and elevated job satisfaction of nurses (80% vs. 66%). All the differences were statistically significant (p < 0.05). "Micromovement" implemented intraoperatively among patients receiving surgery in supine position is able to lower the IAPI incidence by five times and elevate job satisfaction of nurses.

The theory and practice of pressure ulcer/injury risk assessment: a critical discussion

Pressure ulcer/injury (PU) risk assessment is widely considered an essential component in clinical practice. It is a complex and broad concept that includes different approaches, such as clinical judgement, using standardised risk assessment instruments, skin assessments, or using devices to measure skin or tissue properties. A distinction between PU risk assessment and early detection is important. PU risk measures the individual's susceptibility to developing a PU under a specific exposure (primary prevention), and early detection includes the assessment of early (sub)clinical signs and symptoms to prevent progression and to support healing (secondary prevention). PU risk is measured using prognostic/risk factors or prognostic models. Every risk estimate is a probability statement containing varying degrees of uncertainty. It therefore follows that every clinical decision based on risk estimates also contains uncertainty. PU risk assessment and prevention is a complex intervention, where delivery contains several interacting components. There is a huge body of evidence indicating that risk assessment and its outcomes, the selection of preventive interventions and PU incidence are not well connected. Methods for prognostic model development and testing in PU risk research must be improved and follow state-of-the-art methodological standards. Despite these challenges, we do have substantial knowledge about PU risk factors that helps us to make better clinical decisions. An important next step in the development of PU risk prediction might be the combination of clinical and other predictors for more individualised care. Any prognostic test or procedure must lead to better prevention at an acceptable cost.

Inflammatory biomarkers in sebum for identifying skin damage in patients with a Stage I pressure ulcer in the pelvic region: A single centre observational, longitudinal cohort study with elderly patients

Pressure Ulcers (PU) are a major burden for affected patients and healthcare providers. Current detection methods involve visual assessments of the skin by healthcare professionals. This has been shown to be subjective and unreliable, with challenges associated with identifying erythema in darker colour skin. Although there exists a number of promising non-invasive biophysical techniques such as ultrasound, capacitance measurements, and thermography, the present study focuses on directly measuring the changes in the inflammatory status of the skin and underlying tissues. Therefore, in this study, we aim to analyse inflammatory cytokines collected through non-invasive sampling techniques to detect early signs of skin damage. Thirty hospitalised patients presenting with Stage I PU were recruited to evaluate the inflammatory response of skin at the site of damage and an adjacent healthy control site. Sebutapes were collected over three sessions to investigate the temporal changes in the inflammatory response. The panel of cytokines investigated included high-abundance cytokines, namely, IL-1α and IL-1RA, and low abundance cytokines; IL-6, IL-8, TNF-α, INF-γ, IL-33, IL-1β and G-CSF. Spatial and temporal differences between sites were assessed and thresholds were used to determine the sensitivity and specificity of each biomarker. The results suggest significant (P < .05) spatial changes in the inflammatory response, with upregulation of IL-1α, IL-8, and G-CSF as well as down-regulation of IL-1RA over the Stage I PU compared with the adjacent control site. There were no significant temporal differences between the three sessions. Selected cytokines, namely, IL-1α, IL-1RA, IL-8, G-CSF, and the ratio IL-1α/IL-1RA offered clear delineation in the classification of healthy and Stage-I PU skin sites, with receiver operating characteristic curves demonstrating high sensitivity and specificity. There were limited influences of intrinsic and extrinsic factors on the biomarker response. Inflammatory markers provided a high level of discrimination between the sites presenting with Stage I PU and an adjacent healthy skin site, in a cohort of elderly inpatients. Indeed, the ratio of IL-1α to IL-1RA provided the highest sensitivity and specificity, indicative that inflammatory homeostasis is affected at the PU site. There was a marginal influence of intrinsic and extrinsic factors, demonstrating the localised effects of the inflammation. Further studies are required to investigate the potential of inflammatory cytokines incorporated within Point of Care technologies, to support routine clinical use.

Advance in topical biomaterials and mechanisms for the intervention of pressure injury

Pressure injuries (PIs) are localized tissue damage resulting from prolonged compression or shear forces on the skin or underlying tissue, or both. Different stages of PIs share common features include intense oxidative stress, abnormal inflammatory response, cell death, and subdued tissue remodeling. Despite various clinical interventions, stage 1 or stage 2 PIs are hard to monitor for the changes of skin or identify from other disease, whereas stage 3 or stage 4 PIs are challenging to heal, painful, expensive to manage, and have a negative impact on quality of life. Here, we review the underlying pathogenesis and the current advances of biochemicals in PIs. We first discuss the crucial events involved in the pathogenesis of PIs and key biochemical pathways lead to wound delay. Then, we examine the recent progress of biomaterials-assisted wound prevention and healing and their prospects.

Myoglobin-derived iron causes wound enlargement and impaired regeneration in pressure injuries of muscle

The reasons for poor healing of pressure injuries are poorly understood. Vascular ulcers are worsened by extracellular release of hemoglobin, so we examined the impact of myoglobin (Mb) iron in murine muscle pressure injuries (mPI). Tests used Mb-knockout or treatment with deferoxamine iron chelator (DFO). Unlike acute injuries from cardiotoxin, mPI regenerated poorly with a lack of viable immune cells, persistence of dead tissue (necro-slough), and abnormal deposition of iron. However, Mb-knockout or DFO-treated mPI displayed a reversal of the pathology: decreased tissue death, decreased iron deposition, decrease in markers of oxidative damage, and higher numbers of intact immune cells. Subsequently, DFO treatment improved myofiber regeneration and morphology. We conclude that myoglobin iron contributes to tissue death in mPI. Remarkably, a large fraction of muscle death in untreated mPI occurred later than, and was preventable by, DFO treatment, even though treatment started 12 hr after pressure was removed. This demonstrates an opportunity for post-pressure prevention to salvage tissue viability.

Development of a method to identify persistent and blanchable redness by skin blotting in mice

Persistent and blanchable redness (PBR) is not currently included in category I pressure injury (PI), which is defined as non-blanchable redness (NBR). However, PBR progresses to PI in a clinical setting. Therefore, it should be clinically managed as category I PI, and a method to distinctly identify PBR is needed. This study aimed to examine whether PI-related biomarkers can distinguish PRB from transient redness (TR) and NBR using skin blotting. TR, PBR, and NBR models were established by the different conditions of dorsal skin compression. Redness observation and skin blotting were performed, and the skin tissue samples were subjected to histological and molecular biological analyses. The vascular endothelial growth factor (Vegf) b, heat shock protein (Hsp) 90aa1, tumour necrosis factor, interleukin (Il) 1b, and Il6 messenger ribonucleic acid levels were significantly different between the three models. The VEGF-A, VEGF-B, IL-1β, and IL-6 protein levels were different between the three models. Although the results of skin blot examinations were inconsistent with those of the expression analysis of tissue, HSP90α and IL-1β are suggested to be potential markers to distinguish PBR from TR and NBR.

The role of proinflammatory cytokines in the detection of early pressure ulcer development: a systematic review

OBJECTIVE

Pressure ulcers (PUs) commonly occur over bony prominences and are notoriously difficult to treat. Proinflammatory cytokines are substances that initiate the inflammatory process preceding PU development. The aim of this review was to assess whether the increased presence of proinflammatory cytokines could potentially be used as an early detection system for PU development.

METHOD

A systematic search of publications using MEDLINE, CINAHL, and Cochrane databases was conducted in August 2020. Data were extracted and a narrative synthesis was undertaken. The evidence-based librarianship (EBL) checklist assessed the methodological quality of the included studies. The systematic review included original research studies, prospective design, and human studies written in English. Retrospective studies, animal studies, conference papers, opinion papers and qualitative methodology were excluded. No restrictions on the date of publication and study setting were applied.

RESULTS

The six studies included were conducted between 2015 and 2019, 50% (n=3) used an experimental study design. The mean sample size was 15 participants (standard deviation=1.72). A total of seven proinflammatory cytokines were analysed. Statistically significant differences were found among inflammatory mediators. Overall results showed that the concentration of interleukin (IL)-1α significantly increased in each study. The EBL score varied between 77-88%. In total, 100% (n=6) of the studies scored ≥75%, reflecting validity.

CONCLUSION

It is not yet certain that monitoring proinflammatory cytokines represents a noninvasive method that could potentially direct preventative measures to those who are identified as at high risk for developing PUs. IL-1α potentially may be elevated for other health conditions, not just PUs. Future studies are therefore recommended.

Sampling the skin surface chemistry for diagnosis and prognosis

Skin and wound blotting are non‐invasive techniques used to sample the skin and wound surface chemistry, whereby a nitrocellulose membrane is applied to an intact or broken cutaneous surface to detect biomarkers. However, there has been no comprehensive review of the evidence for the techniques used and data obtained to date. The primary aim of this study was to review the utilities of surface blotting for the diagnosis and prognosis of physiological, pre‐disease, and pathological states. The secondary aim was to summarise the procedural steps. A systematic literature search was conducted on 9 July 2021 using Medline, Embase, and Google Scholar databases. Investigators used McMaster's Critical Review Form for Quantitative Studies to assess quality, then performed a narrative synthesis reporting according to Preferred Reporting Items for Systematic Reviews and Meta‐Analyses (PRISMA) guidelines. Twenty‐five studies were reviewed. Eighteen studies were of good quality, and seven were of moderate quality. These studies conducted skin and wound blotting on 176 animals and 1546 humans. Studies reported physiological and pathological states for diagnosis and prediction of conditions, including skin tears, wound healing, biofilm detection, and skin barrier function. The four steps for blotting are surface preparation, blot preparation, application and removal of blot, and analysis. This review demonstrates that blotting can determine the skin and wound surface chemistry using a versatile and reproducible technique. However, future research is needed to validate the technique and skin biomarkers identified.

Polymorphism analysis of candidate risk genes for pressure injuries in older Japanese patients: A cross-sectional study at a long-term care hospital

Advances in patient care for pressure injuries (PIs) have reduced the prevalence of PIs in Japan, although not in recent years. Several single-nucleotide polymorphisms (SNPs) have been identified in genes potentially associated with PIs. However, individual variance among PI risks require targeted investigations that may lead to the identification of PI susceptibilities or preventive care options that directly influence PI development pathways. This cross-sectional study examined the association between PIs and SNPs in genes related to tissue tolerance in patients in a long-term care hospital in Japan. A total of 178 participants (130 control, 20 with superficial PI history, and 28 with deep PI history) were enrolled in this study of eight SNPs in hypoxia inducible factor 1 subunit alpha (HIF1A), vascular endothelial growth factor C (VEGFC), heat shock protein 90 alpha family class A member 1 (HSP90AA1), myostatin (MSTN), and vitamin D receptor (VDR). The primary outcome was a history of superficial and deep PIs in the last 6 months. SNPs were examined by real-time polymerase chain reaction, followed by multivariate logistic regression analyses of the associations between the SNPs and PI history. The results showed a significant association between VEGFC rs1485766 and the history of superficial PIs (odds ratio = 2.95; 95% confidence interval = 1.07-8.11; p = 0.04). Stratified analysis using the Braden Scale (≤14) indicated a significant association between HIF1A rs11549465 and deep PIs (p = 0.04). Our study demonstrated that VEGFC rs1485766 and HIF1A rs11549465 were associated with superficial and deep PI susceptibilities, respectively.

Identification of microRNAs responsive to shear loading in rat skin

Pressure injuries (PIs) are localised skin injuries that result from pressure with or without shear force. Shear force is more destructive than pressure in clinical settings. Therefore, determining the critical external forces is important for selecting the appropriate care to prevent PIs. To quantitatively distinguish pressure and shear loading with high specificity, we focused on microRNAs (miRs). This study aimed to identify the miRs that are distinguishable between pressure with and without shear loading in rat skin. Microarray analysis identified six candidate miRs from the comparisons among the pressure, shear, and unloaded groups. We analysed the expression levels of the candidate miRs in the process of PI development using real‐time reverse transcriptase polymerase chain reaction. In the pressure and shear groups, miR‐92b expressions at 6 hours after loading were 2.3 ± 1.3 and 2.9 ± 1.0, respectively, which were significantly higher than those in the control group (P = .014 and .004, respectively). miR‐877 expression at 6 hours after loading was significantly increased only in the shear group (2.8 ± 0.9) compared with the control group (P = .016). These results indicate that miR‐92b and miR‐877 are promising biomarkers to determine for which external force healthcare professionals should intervene.

The identification of biophysical parameters which reflect skin status following mechanical and chemical insults

BACKGROUND

Skin is constantly exposed to mechanical and chemical insults, in the form of prolonged loading, overhydration or exposure to irritants. An array of non-invasive biophysical tools has been adopted to monitor the changes in skin response. The present study aims to identify a set of robust parameters sensitive to mechanical and chemical challenges to skin integrity.

MATERIALS AND METHODS

Eleven healthy participants were recruited to evaluate the skin response following mechanical loading, tape stripping, overhydration and chemical irritation. Forearm skin responses were recorded at baseline and at three time points following the insult. Measurements included transepidermal water loss, sub-epidermal moisture, erythema and laser Doppler imaging. Thresholds were informed by basal values, and the sensitivity of parameters to detect skin changes was evaluated.

RESULTS

High degree of variability in skin response was observed with selected biophysical parameters, such as sub-epidermal moisture, laser Doppler imaging and erythema, even in the absence of an applied insult. Temporal skin response revealed distinct response profiles during each evoked insult. Indeed, the sensitivity of the biophysical parameters was influenced by the threshold values and time point of measurement. Some statistically significant correlations were determined between the biophysical parameters.

CONCLUSION

The study revealed that thresholds derived from single biophysical parameters were limited in detecting skin changes following insults. A complementary evaluation using combined parameters has the potential to provide a more sensitive assessment. Further research is required to identify robust biophysical parameters, to aid the early detection of skin damage in clinical settings.

Validity of skin blot examination for albumin and nerve growth factor β to detect itching of the skin in Indonesian older adults

AIM

Itching, a common skin disorder, impacts the quality of life of individuals. Itchy skin occurs more with increasing age and the prediction of itchy skin prognosis is necessary to provide good skincare. This study validated biomarkers in skin blotting to identify and measure itching sensation as well as conventional methods to measure skin barrier function.

MATERIALS AND METHODS

From a cross-sectional study conducted in Long-term Care (LTC) facilities in Indonesia itching symptoms were obtained through a questionnaire. Skin conditions were assessed using photographs, stratum corneum (SC) hydration, skin pH, and skin blotting for biomarkers: albumin, interleukin 2 (IL2), nerve growth factor β (NGFβ), and thymic stromal lymphopoietin (TSLP). Association of skin measurements with the presence of skin blotting and trends analysis were conducted.

RESULTS

Altogether, 564 LTC residents (average age, 70 years) participated. The SC hydration, skin pH, albumin, and NGFβ were associated with the presence of itch (p value= <0.001, <0.001, <0.001, and <0.001, respectively). The signal levels of skin blotting biomarkers were higher in itch group than in the non-itch group. Additionally, the higher quantile of SC hydration was significantly associated with a lower intensity level of NGFβ and TSLP (p value = 0.005, 0.003, respectively). The lower quantile of skin pH (better skin condition) was significantly associated with lower albumin, NGFβ, and TSLP (p value = 0.048, 0.035, and <0.001, respectively).

CONCLUSION

The albumin, NGFβ, and TSLP could be a candidate for measurement of itchy skin among older adult with disrupted skin barrier function and local skin inflammation.