Combination of thermographic and ultrasonographic assessments for early detection of deep tissue injury

Integrating technologies to enhance risk assessment for the early detection and prevention of pressure ulcers

Pressure ulcers (PU) are a globally recognised healthcare concern, with their largely preventable development prompting the implementation of targeted preventive strategies. Risk assessment is the first step to planning individualised preventive measures. However, despite the long use of risk assessment, and the >70 risk assessment tools currently available, PUs remain a significant concern. Various technological advancements, including artificial intelligence, subepidermal moisture measurement, cytokine measurement, thermography and ultrasound are emerging as promising tools for PU detection, and subsequent prevention of more serious PU damage. Given the rise in availability of these technologies, this advances the question of whether our current approaches to PU prevention can be enhanced with the use of technology. This article delves into these technologies, suggesting that they could lead healthcare in the right direction, toward optimal assessment and adoption of focused prevention strategies.

Texture differences of microchambers and macrochambers in heel pads between the elderly with and without diabetes

OBJECTIVE

This study aims to use the texture analysis of ultrasound images to distinguish the features of microchambers (a superficial thinner layer) and macrochambers (a deep thicker layer) in heel pads between the elderly with and without diabetes, so as to preliminarily explore whether texture analysis can identify the potential injury characteristics of deep tissue under the influence of diabetes before the obvious injury signs can be detected in clinical management.

METHODS

Ultrasound images were obtained from the right heel (dominant leg) of eleven elderly people with diabetes (DM group) and eleven elderly people without diabetes (Non-DM group). The TekScan system was used to measure the peak plantar pressure (PPP) of each participant. Six gray-level co-occurrence matrix (GLCM) features including contrast, correlation, dissimilarity, energy, entropy, homogeneity were used to quantify texture changes in microchambers and macrochambers of heel pads.

RESULTS

Significant differences in GLCM features (correlation, energy and entropy) of macrochambers were found between the two groups, while no significant differences in all GLCM features of microchambers were found between the two groups. No significant differences in PPP and tissue thickness in the heel region were observed between the two groups.

CONCLUSIONS

In the elderly with diabetes who showed no significant differences in PPP and plantar tissue thickness compared to those without diabetes, several texture features of ultrasound images were found to be significantly different. Our finding indicates that texture features (correlation, energy and entropy) of macrochambers could be used for early detection of soft tissue damage associated with diabetes.

The correlation between sub-epidermal moisture measurement and other early indicators of pressure ulcer development-A prospective cohort observational study. Part 1. The correlation between sub-epidermal moisture measurement and ultrasound

The correlation between sub-epidermal moisture (SEM) and other early indicators of pressure ulcer (PU) development is yet to be determined. This three-part series aims to bridge this knowledge gap, through investigating SEM and its correlation with evidence-based technologies and assessments. This article focuses on the correlation between SEM and ultrasound. A prospective cohort observational study was undertaken between February and November 2021. Patients undergoing three surgery types were consecutively enrolled to the study following informed consent. Assessments were performed prior to and following surgery for 3 days at the sacrum, both heels and a control site, using a SEM scanner and high-frequency ultrasound scanner (5-15 MHz). Spearman's rank (rs ) explored the correlation between SEM and ultrasound. A total of 60 participants were included; 50% were male with a mean age of 58 years (±13.46). A statistically significant low to moderately positive correlation was observed between SEM and ultrasound across all anatomical sites (rs range = 0.39-0.54, p < 0.05). The only exception was a correlation between SEM and ultrasound on day 0 at the right heel (rs  = 0.23, p = 0.09). These results indicate that SEM and ultrasound agreed in the presence of injury; however, SEM was able to identify abnormalities before ultrasound.

Thermal Imaging as a Method to Indirectly Assess Peripheral Vascular Integrity and Tissue Viability in Veterinary Medicine: Animal Models and Clinical Applications

Infrared thermography (IRT) is a technique that indirectly assesses peripheral blood circulation and its resulting amount of radiated heat. Due to these properties, thermal imaging is currently applied in human medicine to noninvasively evaluate peripheral vascular disorders such as thrombosis, thromboembolisms, and other ischemic processes. Moreover, tissular damage (e.g., burn injuries) also causes microvasculature compromise. Therefore, thermography can be applied to determine the degree of damage according to the viability of tissues and blood vessels, and it can also be used as a technique to monitor skin transplant procedures such as grafting and free flaps. The present review aims to summarize and analyze the application of IRT in veterinary medicine as a method to indirectly assess peripheral vascular integrity and its relation to the amount of radiated heat and as a diagnostic technique for tissue viability, degree of damage, and wound care.

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.

Surgical Reconstruction of Stage 3 and 4 Pressure Injuries: A Literature Review and Proposed Algorithm from an Interprofessional Working Group

OBJECTIVE

Stage 3 and 4 pressure injuries (PIs) present an enormous societal burden with no clearly defined interventions for surgical reconstruction. The authors sought to assess, via literature review and a reflection/evaluation of their own clinical practice experience (where applicable), the current limitations to the surgical intervention of stage 3 or 4 PIs and propose an algorithm for surgical reconstruction.

METHODS

An interprofessional working group convened to review and assess the scientific literature and propose an algorithm for clinical practice. Data compiled from the literature and a comparison of institutional management were used to develop an algorithm for the surgical reconstruction of stage 3 and 4 PIs with adjunctive use of negative-pressure wound therapy and bioscaffolds.

RESULTS

Surgical reconstruction of PI has relatively high complication rates. The use of negative-pressure wound therapy as adjunctive therapy is beneficial and widespread, leading to reduced dressing change frequency. The evidence for the use of bioscaffolds both in standard wound care and as an adjunct to surgical reconstruction of PI is limited. The proposed algorithm aims to reduce complications typically seen with this patient cohort and improve patient outcomes from surgical intervention.

CONCLUSIONS

The working group has proposed a surgical algorithm for stage 3 and 4 PI reconstruction. The algorithm will be validated and refined through additional clinical research.

Risk factors for the development and evolution of deep tissue injuries: A systematic review

AIMS

The aim of this systematic review is to identify the current epidemiological evidence indicating the unique risk factors for deep tissue injury (DTI) compared to grade I-IV pressure injury (PI), the proportion of DTI which evolve rather than resolve and the anatomical distribution of DTI.

METHODS

A systematic literature search was undertaken using the MEDLINE and CINAHL Plus databases using the search terms 'Deep tissue injury OR DTI [Title/abstract]'. A google scholar search was also conducted in addition to hand searches of relevant journals, websites and books which were identified from reference lists in retrieved articles. Only peer-reviewed English language articles published 2009-2021 were included, with full text available online.

RESULTS

The final qualitative analysis included nine articles. These included n = 4 retrospective studies, n = 4 prospective studies and n = 1 animal study.

CONCLUSION

The literature indicates that the majority of DTI occur at the heel and sacrum although in paediatric patients they are mainly associated with medical devices. Most DTI are reported to resolve, with between 9.3 and 27% deteriorating to full thickness tissue loss. Risk factors unique to DTI appear to include anaemia, vasopressor use, haemodialysis and nicotine use although it is unclear if these factors are unique to DTI or are shared with grade I-IV PI. Factors associated with deterioration include cooler skin measured using infrared thermography and negative capillary refill. With 100% of DTI showing positive capillary refill in one study resolving without tissue loss (p = 0.02) suggesting this may be an effective prognostic indicator. More prospective studies are required focusing on establishing causal links between risk factors identified in earlier retrospective studies. Ideally these should use statistically powered samples and sufficient follow up periods allowing DTI outcomes to be reached. Further work is also needed to establish reliable diagnostic criteria for DTI in addition to more studies in the paediatric population.

A Study on Pressure Ulcer: Influencing Factors and Diagnostic Techniques

Pressure ulcer (PU) is one of the most common occurrences in bedridden subjects. Despite the standard of care, there is a huge challenge in monitoring immobile subjects in all the bodily pressure points. This increases the chance of onset of PU which in turn increases the expenditure for treating and managing the PU. Hence, we made a study on the biological and physiological factors that are responsible for the formation of PU and also on various techniques used for diagnosis. Thus, we have summarised the efficacy of various advanced diagnostic procedures with their limitations. Though there are advanced imaging techniques, risk assessment tools based on the visual inspection are widely followed in hospitals. Based on our observation, we here have identified three major areas; one being the development of mathematical modeling, the second is towards the development of non-invasive devices and finally to automate cot facility. We have also provided possible suggestions as to solutions that could be useful to researchers and for society. Thus, this review covers the present difficulty faced by bedridden subjects and respective care-takers along with the knowledge gap and a few suggestions as to future scope.

A model for predicting 7-day pressure injury outcomes in paediatric patients: A machine learning approach

AIMS

We sought to explore factors associated with early pressure injury progression and build a model for predicting these outcomes using a machine learning approach.

DESIGN

A retrospective cohort study.

METHODS

In this study, we recruited paediatric patients, with hospital-acquired stage I pressure injury or suspected deep tissue injury, who met the inclusion criteria between 1 January 2015-31 October 2018. We divided patients into two groups, namely healing or delayed healing, then followed them up for 7 days. We analysed patient pressure injury characteristics, demographics, treatment, clinical situation, vital signs, and blood test results, then build prediction models using the Random Forest and eXtreme Gradient Boosting approaches.

RESULTS

The best prediction model, trained and tested using Random Forest with 10 variables, achieved an accuracy, sensitivity, specificity, and area under the curve of 0.82 (SD 0.06), 0.80 (SD 0.08), 0.84 (SD 0.08), and 0.89 (SD 0.06), respectively. The most contributing variables, in order of importance, included serum creatinine, red blood cell, and haematocrit.

CONCLUSION

An awareness of specific conditions and areas that could lead to delayed healing pressure injury in paediatric patients is needed.

IMPACT

This evidence-based prediction model, coupled with the aforementioned clinical indicators, is expected to enhance early prediction of outcomes in paediatric patients thereby improve the quality of care and the outcome of children with PIs.

Application of infrared thermography in the early warning of pressure injury: A prospective observational study

AIMS AND OBJECTIVES

To verify the ability of infrared thermography in objectively identifying pressure injury and its application value in the early warning of pressure injury.

BACKGROUND

There is subjectivity in assessing the risk of pressure injury as well as diagnosis in clinical settings, which makes early detection and prevention difficult.

DESIGN

Prospective, cohort study.

METHOD

Four hundred and fifteen patients admitted to the adult intensive care units were enrolled by a convenience sampling method, and they received a follow-up monitoring for 10 days. The risk of pressure injury was assessed via Braden scale, and thermal images of sacral area were obtained by infrared thermal imager once a day. The predictive effects of infrared thermography and Braden scale on pressure injury were compared by the receiver operating characteristic curve from which the optimal cut-off value of skin temperature for predicting pressure injury was determined. The effect of skin temperature on pressure injury was described and compared, using Kaplan-Meier curve and Cox proportional hazard regression model, respectively. We followed STROBE checklist for reporting the study.

RESULTS

The relative temperature of sacral area was negatively correlated with the risk of pressure injury. The efficiency of infrared thermography for diagnosing pressure injury was better than that of Braden scale. Based on the relative temperature optimal cut-off value (-0.1°C), Kaplan-Meier curve and Cox proportional hazard regression model analysis showed the incidence of pressure injury with relative temperature below -0.1°C was higher than the group with relative temperature above -0.1°C.

CONCLUSIONS

Infrared thermography can objectively and accurately identify local hypothermia warnings of pressure injury before visual recognition. The application of infrared thermography into routine pressure injury risk assessment provides a timely and reliable method for nursing practitioners.

RELEVANCE TO CLINICAL PRACTICE

Infrared thermography has great value of clinical application in daily pressure injury assessment. It is of great significance to make a faster and more objective clinical judgement for patients at risk of pressure injury.

Skin temperature and vascular attributes as early warning signs of pressure injury

OBJECTIVES

This study aimed to validate the skin temperature on sacral region and vascular attributes as early warning signs of pressure injury.

METHODS

Totally 415 patients admitted to the adult intensive care unit from August 2018 to April 2019 were prospectively screened. Daily blood pressure and blood glucose affecting vascular attributes and the relative skin temperature of sacral region were measured for 10 consecutive days. Collect the changes of these indicators during the occurrence of pressure injury. The optimal cut-off values of indicators were determined by X-tile analysis. The risk ratios of indicators associated with pressure injury were compared using the Cox proportional hazards regression model.

RESULTS

There were no obvious interactions among blood pressure, blood glucose and relative skin temperature (P > 0.05). The optimal cutoff value for above indicators was 63.5 mmHg, 9.9 mmol/L and -0.1 °C, respectively. The incidence of pressure injury peaked on the 4th and 5th day after hospitalization when categorizing the patients into low- and high-risk groups according to the cutoff values (P < 0.05). Based on relative skin temperature, patients in the high-risk group were more likely to develop pressure injury (hazard ratio = 6.36, 95% confidence interval = 3.91, 10.36), when compared to the other two indicators of blood pressure and blood glucose.

CONCLUSION

Stringent skin temperature and vascular attributes measurements were necessary for preventing pressure injury. Nursing measures should be taken according to warning sings to reduce the incidence of pressure injury.

Ultrasound assessment of deep tissue on the wound bed and periwound skin: A classification system using ultrasound images

AIMS

Given the utility of ultrasonography in assessing pressure injury, some ultrasonographic findings have already been used as indicators of deep tissue pressure injury. Despite reports showing that a cloud-like ultrasonographic pattern reflected the presence of deep tissue necrosis, identifying cloud-like patterns was difficult given the presence of similar findings, such as a cobblestone-like pattern. This case series reports patients with pressure injuries who presented with a cloud-like (five cases) and cobblestone-like (four cases) pattern during ultrasonography.

METHODS

This study was conducted at a Japanese university hospital. Participants included patients who underwent routine examination by an interdisciplinary pressure injury team. Pressure injury severity was assessed using the DESIGN-R® scoring system and the wound size were measured using ImageJ software based on the wound photograph.

RESULTS

Among the five cases showing a cloud-like pattern upon ultrasonography, all exhibited an increase in the total DESIGN-R® score, while three exhibited an increase in wound size. On the other hand, all four cases showing a cobblestone-like pattern displayed no increase in the total DESIGN-R® score and a decrease in wound size.

CONCLUSION

This study suggested that distinguishing between cloud-like and cobblestone-like ultrasonography patterns is necessary for determining the presence or absence of deep tissue pressure injury. In order to comprehensively assess pressure injuries with ultrasonography, future studies should be conducted in a large number of participants.

Thermographic Characterization of Cutaneous Ulcers of Different Etiologies

The characterization of the temperature of skin ulcers may provide preliminary diagnostic evidence. The aim of this study was to characterize cutaneous ulcers of different etiologies by infrared thermography. 122 cutaneous ulcers of 87 patients (age 60.1 ± 15.7 years) were evaluated, allocated into five groups: venous ulcers (VU) n = 26, arterial ulcers (AU) n = 20, mixed ulcers (MU) n = 25, pressure ulcers (PU) n = 29, and neuropathic ulcers (NU) n = 22. The cutaneous temperature was recorded by infrared thermography (FLIR-450™); we also evaluated the ulcer area, the ankle brachial index (ABI), the range of motion (ROM) of the ankle, and pain. For the different variables, the statistical analysis was performed using the Kruskal Wallis test, ANOVA, the chi-squared test, and the Spearman test (SPSS™ software version 20, p < 0.05). A significant difference was found between the temperatures of PU and NU. The ABI was significantly lower in the MU and AU groups, and pain was also higher in these groups. The ROM was decreased in all groups, and the MU and VU groups had the lowest ROM. There was no correlation between temperature and the clinical findings (ABI, ROM, and pain). There was a moderate correlation in the analysis between the temperature and the area of the ulcer in the PU group, as larger ulcers had lower temperatures. It is possible to characterize cutaneous ulcers by infrared thermography, and there are temperature differences among ulcers with different etiologies.

Evaluation of infrared technology to detect category I and suspected deep tissue injury in hospitalised patients

OBJECTIVE

To evaluate the use of an infrared thermography device in assessing skin temperature among category I pressure ulcer (PU) and/or suspected deep tissue injuries (SDTI) with intact skin.

METHODS

An observational cross-sectional study design was used. Adult inpatients (cases) who had a category I PU or suspected deep tissue injury (skin intact) on the sacral or heel during the study period (March to April 2018) were recruited. Patients without a PU were also recruited to act as control. Thermal images of the patient's PU site and non-PU site were taken within 24 hours of PU occurrence. Thermal images of the control patients (no PU) were also taken. Each PU case was matched to three control patients in terms of age, gender, race and anatomical sites. All thermal images were taken using a portable CAT S60 Thermal Imaging Rugged Smartphone (Caterpillar Inc., US) that provided readings of the skin temperature in degrees Celsius.

RESULTS

A total of 17 cases and 51 controls were recruited. Among the cases, the mean difference in skin temperature between the PU site (mean: 31.14°C; standard deviation [SD]: 1.54) and control site within the cases (mean: 28.93°C; SD: 3.47) was significant (difference: 2.21±3.66°C; p=0·024). When comparing between all cases and controls, the mean temperature difference was non-significant. When comparing between the category I PU and suspected deep pressure injury cases, the mean difference was also non-significant.

CONCLUSION

Using infrared thermography technology at the bedside to measure skin temperature will support the clinical diagnosis of patients with skin types I to III. However, there is a need for a more accurate and objective measurement to identify and diagnose early category I PU or suspected deep tissue injury in adult patients with darker skin types 4 and above, enabling early initiation of preventive measures in the hospital acute care setting.

Pressure Injury Prevention: A Survey

Pressure injuries are caused by prolonged pressure to an area of the body, which can result in open wounds that descend to the bone. Pressure injuries should not occur in healthcare settings, and yet, they still affect 2.5 million patients in the United States and have an impact on quality of life. Pressure injuries come at a cost of $11 billion in the United States, and 90% of pressure injuries are a secondary condition. In this paper, we survey the literature on preventative techniques to address pressure injures, which we classify into two categories: active prevention strategies and sensor-based risk-factor monitoring. Within each category of techniques, we discuss the literature and assess each class of strategies based on its commercial availability, results of clinical trials when available, the ability for the strategy to save time for healthcare staff, and whether the technique can be tuned to an individual. Based on our findings, the most promising current solutions, supplementary to nursing guidelines, are electrical stimulation, pressure monitoring, and inertial measurement unit monitoring. We also find a need for a clinical software system that can easily integrate with custom sensors, use custom analysis algorithms, and provide visual feedback to the healthcare staff.

Phantom testing of the sensitivity and precision of a sub-epidermal moisture scanner

The majority of pressure ulcers (PUs) including deep tissue injuries (DTIs) are preventable, and even reversible if detected in their early phase. One of the greatest barriers in PU prevention is that clinicians traditionally depended on subjective and qualitative techniques, particularly routine visual skin assessments that would only document existing, macroscopic PUs/DTIs, rather than preventing them or detecting them at their microscopic phase. At the early phase of cell damage, when a forming PU is still microscopic, there is a local increase in extracellular fluid contents within affected tissues, which is called sub-epidermal moisture (SEM). This new understanding has led to an emerging technology, a SEM Scanner (BBI LLC, Bruin Biometrics) that has been designed to effectively examine the health status of tissues, by measuring local changes in the biophysical SEM marker. In the present work, the SEM Scanner was tested under controlled laboratory conditions to experimentally determine its sensitivity and precision in identifying small (1 mL) water content changes in phantoms of the human heel and skull/face, which simulated common PU development scenarios. In both phantom configurations, the locally increased water contents resulted in consistent, statistically significant elevated SEM readings, which confirms that the SEM Scanner is able to detect fluid content changes that are as small as 1 mL. In agreement with a simplified theoretical (mathematical) SEM model, which was also developed here, changes in water contents had a consistent trend of effect on SEM delta values, which increased with each 1 mL increment in intra-tissue-substitute water contents.

Using Alternative Light Source Technology to Enhance Visual Inspection of the Skin

BACKGROUND

The identification of deep tissue pressure injury (DTPI) in the early stages of evolution presents a challenge, as skin compromise is only visually apparent when evidence of damage reaches its outer layers.

CASE DESCRIPTION

We describe use of an alternative light source (ALS) to enhance visual skin assessment in 3 cases. Case 1 was a 47-year-old African American man with a hyperpigmented inner buttocks and a mixture of partial- and shallow full-thickness skin loss from incontinence-associated dermatitis and friction. Case 2 was a 62-year-old African American woman with a gluteal cleft DTPI. Case 3 was a 57-year-old African American woman with a stage 3 pressure injury of the right buttock.

CONCLUSION

The ALS enabled visualization of skin nuances not visible to the unaided eye. Based on this experience, we conclude that use of an ALS provided additional visual details when compared to traditional visual inspection. We found that as the ALS interplays with skin layers, penetrating and absorbing at differing depths, compromised skin appeared darker and more distinct when compared to adjacent, intact skin. Additional research is needed to determine whether the ALS enables earlier pressure injury detection, timelier and more effective intervention, decreased morbidity, and cost savings.

Color Doppler Ultrasonography to Evaluate Hypoechoic Areas in Pressure Ulcers: A Report of Two Cases

Ultrasound (US) is frequently used for evaluating inflammation of subcutaneous tissue caused by pressure ulcers (PUs), but color Doppler mode (CDM) helps to better identify inflammatory edema in subcutaneous fat and necrotic tissue in PUs. We report two cases where inflammatory edema in subcutaneous fat and necrotic tissue in PUs are identified using small US equipment with CDM. Case 1 – An 82-year-old male presented with cerebral infarction and a Category III PU in the sacral region. B-mode gray-scale US imaging (B-mode imaging) revealed a thickened layer of subcutaneous fat with fat lobules and homogeneous cobblestone appearance with fluid accumulation within the echo-free space. CDM did not identify any color signal (CS) in hypoechoic areas. Case 2 – A 29-year-old female presented with cytopenia and decreased renal function with a Category IV PU with undermining in the coccyx region. B-mode imaging distinguished the necrotic tissue, indicating a diffuse hypoechoic area with no layers, unclear borders, and uneven gray level (cloud-like image) in the subcutaneous fat. Similar B-mode imaging findings were obtained in inflammatory edema with cobblestone appearance. CDM did not detect a CS in the hypoechoic areas but confirmed peripheral hypervascularity. CDM imaging identified inflammatory edema in the subcutaneous fat and necrotic tissue in PUs. Specifically, CDM may better evaluate early-stage PUs with necrotic tissue by distinguishing necrosis from intense inflammatory edema.

Ultrasonography Detects Deep Tissue Injuries in the Subcutaneous Layers of the Buttocks Following Spinal Cord Injury

Background: Ultrasonography may have potential as an effective diagnostic tool for deep tissue injury (DTI) in tissues overlying bony prominences that are vulnerable when under sustained loading in sitting. Methods: Three cases of DTI in the fat and muscle layers overlying the ischial tuberosity of the pelvis in 3 persons with spinal cord injury (SCI) with different medical histories and abnormal tissue signs are described. Conclusion: There is a need for prospective studies using a reliable standardized ultrasonography protocol to diagnose DTI and to follow its natural history to determine its association with the development of pressure injuries.

Accuracy of ultrasound, thermography and subepidermal moisture in predicting pressure ulcers: a systematic review

OBJECTIVE

Our aims were to: establish the clinical significance of ultrasound, thermography, photography and subepidermal moisture (SEM) measurement; determine the accuracy of ultrasound, thermography, photography and SEM measurement in detecting skin/tissue damage; determine the relative accuracy of one of these assessment methods over another; make recommendations for practice pertaining to assessment of early skin/tissue damage.

METHOD

The following databases, Cochrane Wounds Group Specialised Register, The Cochrane Central Register of Controlled Trials, Ovid MEDLINE, Ovid EMBASE, Elsevier version, EBSCO CINAHL, ClinicalTrials.gov , WHO International Clinical Trials Registry (ICTR) and The EU Clinical Trials Register were searched for terms including; thermography, ultrasound, subepidermal moisture, photograph and pressure ulcer.

RESULTS

We identified four SEM, one thermography and five ultrasound studies for inclusion in this review. Data analysis indicated that photography was not a method which allowed for the early prediction of PU presence. SEM values increased with increasing tissue damage, with the sacrum and the heels being the most common anatomical locations for the development of erythema and stage I PUs. Thermography identified temperature changes in tissues and skin that may give an indication of early PU development; however the data were not sufficiently robust. Ultrasound detected pockets of fluid/oedema at different levels of the skin that were comparable with tissue damage. Thus, SEM and ultrasound were the best methods for allowing a more accurate assessment of early skin/tissue damage. Using the EBL Critical Appraisal Tool the overall validities of the studies varied between 33.3-55.6%, meaning that there is potential for bias within all the included studies. All of the studies were situated at level IV, V and VII of the evidence pyramid. Although the methodological quality of the studies warrants consideration, these studies showed the potential that SEM and ultrasound have in early PU detection.

CONCLUSION

SEM and ultrasound are promising in the detection and prediction of early tissue damage and PU presence. However, these methods should be further studied to clarify their potential for use more widely in PU prevention strategies.

Visualization of Blood Flow in an Undermined Pressure Ulcer Revealed by Sonographic Imaging and Clutter Suppression Post-Processing

The authors report a case of a middle-age man presenting with a category IV pressure ulcer (PU) over the sacrum. Undermining of the PU was assessed with the aid of gray-scale sonography (US), color Doppler US, power Doppler US, and a microvascular imaging technique employing advanced clutter suppression. Clutter suppression post-processing the study allowed for the evaluation of low-velocity microvascular flow in the undermined PU and facilitated the choice of appropriate treatment.