Nonblanchable erythema for predicting pressure ulcer development: a systematic review with an individual participant data meta‐analysis

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.

Adhesives for medical application - Peel strength testing and evaluation of biophysical skin response

BACKGROUND

Medical adhesives are commonly used for securing wound dressings and medical devices used for diagnostic or therapeutic purposes. Mechanical irritation of skin due to adhesive stripping and repeated application can lead to discomfort and device removal. This study aims to examine the peel strength and skin response to different medical adhesives in a cohort of healthy volunteers.

METHOD

Twelve healthy participants were recruited for peel strength testing of three candidate adhesive tapes, and evaluation of the skin response after adhesive removal. A modified ASTM D903 peel strength testing was performed at 180° peeling angle and a rate of 300 mm/min on the forehead, upper back and forearm skin. A longitudinal study was conducted on the forearm and back, with the adhesive samples left in-situ for up to 60 h for analysis of repeat application. The effects of two skin preparation approaches (water and alcohol cleaning) prior to adhesive application were also assessed. Skin biophysical properties were assessed at baseline and at various timepoints following adhesive removal using transepidermal water loss (TEWL), erythema and hydration.

RESULTS

Peel strength reduced uniformly with repeat application over prolonged periods for all the adhesive samples tested. Skin preparation with water and alcohol cleansing prior to adhesive application increased peel strength at both the back (1.1% and 2.9%), and forearm (21.3% and 20%) sites. There was statistically significant increase from baseline to post-tape application for TEWL, skin redness and hydration (p < 0.001). However, there were no statistically significant differences between adhesive types (TEWL: p = 0.38, SR: p = 0.53, HY: p = 0.46). TEWL increased the most post-adhesion across all test sites and adhesive samples with repeat application (p < 0.05). Two-way ANOVA tests revealed no statistically significant interactions between the effects of application duration and adhesive on skin redness or TEWL for both the back and forearm sites (p > 0.05), though a significant interaction was indicted for hydration at the back site (p = 0.01).

CONCLUSION

This study revealed that site and duration of adhesive application effected peel strength. The corresponding changes in skin properties identified that skin barrier function was disrupted with long-term application of adhesives. The back site was identified to be most reliable for adhesion testing and skin response assessment for future work.

Spatial and temporal changes in biophysical skin parameters over a category I pressure ulcer

In acute care facilities, the detection of pressure ulcers (PUs) relies on visual and manual examination of the patient's skin, which has been reported to be inconsistent and may lead to misdiagnosis. In skin and wound research, various biophysical parameters have been extensively employed to monitor changes in skin health. Nonetheless, the transition of these measures into care settings as part of a routine clinical assessment has been limited. This study was designed to examine the spatial and temporal changes in skin biophysical parameters over the site of a category I PU, in a cohort of hospitalised patients. Thirty patients, each presenting with a category I PU, were enrolled in the study. Skin integrity was assessed at the PU-compromised site and two adjacent areas (5 and 10 cm away). Data was collected over three sessions to examine both temporal differences and longitudinal changes. Skin integrity was assessed using two biophysical parameters, namely, transepidermal water loss (TEWL) and stratum corneum (SC) hydration. In addition, the influence of intrinsic factors, namely, incontinence and mobility status, on the parameters was evaluated. TEWL values at the sites compromised by PU were statistically significantly greater (P < .001) than corresponding values at the adjacent control sites at 5 and 10 cm, which were consistent with a normative range (<20 g/h/m2 ). By contrast, SC hydration values did not reveal clear distinctions between the three sites, with high inter-patient variation detected at the sites. Nevertheless, individual profiles were consistent across the three sessions, and the PU site was observed to be either abnormally dry or overhydrated in different individuals. No consistent temporal trend in either parameter was evident. However, intrinsic factors were shown to influence the parameters, with females, bedridden and incontinent patients presenting significantly higher TEWL and SC hydration values (P < .05). TEWL was able to identify differences in skin responses at skin sites compromised with a category I PU when compared to healthy adjacent skin sites. Accordingly, this parameter could be included in the clinical assessment for the identification of PU risk. Further studies are required to elucidate the role of hydration and skin barrier function in the development of PUs and their ability to monitor temporal changes in skin integrity.

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.

From the Cochrane Library: Foam Surfaces for Preventing Pressure Ulcers

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Effect of Baicalin on Wound Healing in a Mouse Model of Pressure Ulcers

One of the most frequent comorbidities that develop in chronically ill or immobilized patients is pressure ulcers, also known as bed sores. Despite ischemia-reperfusion (I/R)-induced skin lesion having been identified as a primary cause of pressure ulcers, wound management efforts have so far failed to significantly improve outcomes. Baicalin, or 5,6,7-trihydroxyflavone, is a type of flavonoid which has been shown to possess a variety of biological characteristics, including antioxidative and anti-inflammatory effects and protection of I/R injury. In vitro wound scratch assay was first used to assess the function of baicalin in wound healing. We established a mouse model of advanced stage pressure ulcers with repeated cycles of I/R pressure load. In this model, topically applied baicalin (100 mg/mL) induced a significant increase in the wound healing process measured by wound area. Histological examination of the pressure ulcer mouse model showed faster granulation tissue formation and re-epithelization in the baicalin-treated group. Next, baicalin downregulated pro-inflammatory cytokines (IL-6 and IL-1β), while upregulating the anti-inflammatory IL-10. Additionally, baicalin induced an increase in several growth factors (VEGF, FGF-2, PDGF-β, and CTGF), promoting the wound healing process. Our results suggest that baicalin could serve as a promising agent for the treatment of pressures ulcers.

[Pressure sores-A multilayered challenge]

Pressure sores occur when soft tissue of the skin, subcutaneous fat tissue or musculature is exposed to pressure or friction over a long period of time, which leads to local ischemia with subsequent necrosis. All areas of the skin lying over bones with only a thin layer of soft tissue are predilection sites. In older patients the risk factors for the development of a pressure sore must be systematically documented at admission and during the course of the disease. Accordingly, the necessary prophylactic procedures must be initiated. The classification of the European Pressure Ulcer Advisory Panel (EPUAP) is used to describe a pressure sore. For the differential diagnosis, incontinence-associated dermatitis and a manifest peripheral artery occlusive disease must be excluded. The treatment consists of positioning procedures and local and systemic supportive wound treatment. In cases of deep pressure sores, coverage by plastic surgery can effectively accelerate healing. The multiprofessional geriatric team has the appropriate prerequisites for comprehensive treatment of pressure sores.

International comparison of pressure ulcer measures in long-term care facilities: Assessing the methodological robustness of 4 approaches to point prevalence measurement

INTRODUCTION

Pressure ulcer indicators are among the most frequently used performance measures in long-term care settings. However, measurement systems vary and there is limited knowledge about the international comparability of different measurement systems. The aim of this analysis was to identify possible avenues for international comparisons of data on pressure ulcer prevalence among residents of long-term care facilities.

MATERIAL AND METHODS

A descriptive analysis of the four point prevalence measurement systems programs used in 28 countries on three continents was performed. The criteria for the description and analysis were based on the scientific literature on criteria for indicator selection, on issues in international comparisons of data and on specific challenges of pressure ulcer measurements.

RESULTS

The four measurement systems use a prevalence measure based on very similar numerator and denominator definitions. All four measurement systems also collect data on patient mobility. They differ in the pressure ulcer classifications used and the requirements for a head-to-toe resident examination. The regional or country representativeness of long-term care facilities also varies among the four measurement systems.

CONCLUSIONS

Methodological differences among the point prevalence measurement systems are an important barrier to reliable comparisons of pressure ulcer prevalence data. The alignment of the methodologies may be improved by implementing changes to the study protocols, such as aligning the classification of pressure ulcers and requirements for a head-to-toe resident skin assessment. The effort required for each change varies. All these elements need to be considered by any initiative to facilitate international comparison and learning.

Effectiveness of interventions to prevent pressure injury in adults admitted to acute hospital settings: A systematic review and meta-analysis of randomised controlled trials

BACKGROUND

Hospital-acquired pressure injuries cause significant harm to afflicted individuals, and financially burden hospitals. Most pressure injuries are avoidable with the use of preventative interventions. However, within acute hospital settings the effectiveness of pressure injury preventative interventions, as demonstrated by high-level evidence, requires examination.

OBJECTIVE

Analyse the effectiveness of interventions to prevent pressure injury in adults admitted to acute hospital settings.

DESIGN

Systematic review and meta-analysis of randomised controlled trials.

DATA SOURCES

CINAHL, MEDLINE, Scopus, Web of Science and Embase were searched in May/June 2019. In April 2020, searches were updated to the end of 2019.

METHODS

Randomised controlled trials which investigated the effectiveness of pressure injury preventative interventions on pressure injury incidence, within adults admitted to acute hospital settings, were included. Trials limited to pressure injury treatment or specialty areas, and non-English reports, were excluded. Screening, extraction and risk-of-bias assessment were undertaken independently by two reviewers, with a third as arbitrator. Included studies were grouped by intervention type. Studies were synthesised narratively, and meta-analysis was undertaken where study interventions were similar. Using a random-effects model, primary meta-analyses were undertaken using intention-to-treat data.

RESULTS

Of 2000 records, 45 studies were included in the systematic review which investigated nine different intervention types: continence management, heel protection devices, medication, nutrition, positioning, prophylactic dressings, support surfaces, topical preparations and bundled interventions. All studies were judged to be at unclear or high risk-of-bias. Several meta-analyses were undertaken, pooled by intervention type. Most pooled samples were heterogeneous. Based on intention-to-treat data, only one intervention demonstrated a statistically significant effect: Australian medical sheepskin surfaces compared to other standard care surfaces (risk ratio 0.42, p = 0.006, I² = 36%), but included studies were limited by bias and age. Following per protocol meta-analyses, only two intervention types demonstrated a significant effect: support surfaces (active versus other comparison [risk ratio = 0.54, p = 0.005, I² = 43%] and standard surfaces [risk ratio = 0.31, p < 0.001, I² = 0%]; and reactive versus other comparison surfaces [risk ratio = 0.53, p = 0.03, I² = 64%]) and heel protection devices versus standard care (risk ratio = 0.38, p < 0.001, I² = 36%).

CONCLUSIONS

Only one intervention was supported by intention-to-treat meta-analysis. Significantly, all trials were at unclear or high risk-of-bias; and there were several limitations regarding heterogeneity across trials and trial outcomes. Further large-scale, high-quality trials testing pressure injury preventative interventions are required to establish effectiveness within acute hospital settings. Attention should be paid to true intention-to-treat analysis, and acute and intensive care settings should be reported separately. PROSPERO registration number:CRD42019129556.

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.