Gojiro Nakagami

Ultrasound assessment of deep tissue injury in pressure ulcers: possible prediction of pressure ulcer progression.

Background: The concept of deep tissue injury under intact skin helps us understand the pathogenesis of pressure ulcers, but the best method for detecting and evaluating deep tissue injury remains to be established. Methods: Intermediate-frequency (10-MHz) ultrasonography was performed to evaluate deep tissue injury. The authors analyzed 12 patients (nine male patients and three female patients aged 16 to 92 years) who showed deep tissue injury–related abnormal findings on ultrasonography at the first examination and were followed up until the pressure ulcer reached a final stage. Results: The stage of ulcer worsened in six of 12 cases compared with baseline, and healed in the remaining six patients. The authors recognized four types of abnormal signs unique to deep tissue damage in ultrasonography: unclear layered structure, hypoechoic lesion, discontinuous fascia, and heterogeneous hypoechoic area. Unclear layered structure, hypoechoic lesion, discontinuous fascia, and heterogeneous hypoechoic area were detected at the first examination in 12, 10, seven, and five patients, respectively. Unclear layered structure and hypoechoic lesion were more commonly seen in pressure ulcers in deep tissue injury than the other features, but the follow-up study suggested that discontinuous fascia and heterogeneous hypoechoic area are more reliable predictors of future progression of pressure ulcers. Conclusions: The use of intermediate-frequency ultrasound reliably identified deep tissue injury and was believed to contribute to prevention and treatment of pressure-related ulcers. The results suggest that specific ultrasonographic characteristics may predict which pressure ulcers will progress.

Ultrasonographic and thermographic screening for latent inflammation in diabetic foot callus

AIMS Inflammation within the diabetic foot callus may be an earliest, predicting symptom of foot ulcer developing later. The purpose of this study was to identify latent inflammation within the foot callus using thermography and ultrasonography, and to investigate relationship between the inflammatory findings in callus and presence or absence of diabetes. METHODS This was a cross-sectional study of 60 cases with asymptomatic foot callus; the 30 diabetic patients and the 30 non-diabetic matched volunteers. Inflammation was defined using physiological imaging techniques; as skin temperature elevation in thermography and low echoic lesion in ultrasonography. RESULTS Sixty-three and ninety-four calli were observed in the diabetic and non-diabetic groups, respectively. The inflammation signs were detected by both of the two techniques in 10% of the calli in the diabetic group. No inflammation was noted in the non-diabetic group (p=0.014). CONCLUSIONS The inflammation signs presented here were specifically observed in the diabetic group. We consider that the physiological imaging techniques may be valuable screening tools for potential risk of diabetic foot ulcers.

Skin fragility in obese diabetic mice: possible involvement of elevated oxidative stress and upregulation of matrix metalloproteinases

Abstract:  The purpose of this study was to test the hypothesis that obese diabetic mice exhibit marked skin fragility, which is caused by increased oxidative stress and increased matrix metalloproteinase (MMP) gene expression in the subcutaneous adipose tissue. Scanning electron microscopy of skin samples from Tsumura‐Suzuki obese diabetic (TSOD) mice revealed thinner collagen bundles, and decreased density and convolution of the collagen fibres. Furthermore, skin tensile strength measurements confirmed that the dorsal skin of TSOD mice was more fragile to tensile force than that of non‐obese mice. The mRNA expressions of heme oxygenase 1 (Hmox1), a marker of oxidative stress, Mmp2 and Mmp14 were increased in the adipose tissue of TSOD mice. Antioxidant experiments were subsequently performed to determine whether the changes in collagen fibres and skin fragility were caused by oxidative stress. Strikingly, oral administration of the antioxidant dl‐α‐tocopherol acetate (vitamin E) decreased Hmox1, Mmp2 and Mmp14 mRNA expressions, and improved the skin tensile strength and structure of collagen fibres in TSOD mice. These findings suggest that the skin fragility in TSOD mice is associated with dermal collagen damage and weakened tensile strength, and that oxidative stress and MMP overexpression in the subcutaneous adipose tissue may, at least in part, affect dermal fragility via a paracrine pathway. These observations may contribute to novel clinical interventions, such as dietary supplementation with antioxidants or application of skin cream containing antioxidants, which may overcome skin fragility in obese patients with diabetes.

Comparison of two pressure ulcer preventive dressings for reducing shear force on the heel.

OBJECTIVE We compared the shear forces exerted over the heel between a pressure ulcer preventive dressing and a thin-film dressing in a clinical setting. Interface pressures were measured as well. DESIGN Quasi-experimental clinical trial. SETTING AND SUBJECTS Participants were 30 elderly patients (5 men, 25 women; mean age, 86.4 ± 8.0 years) hospitalized in a geriatrics hospital in Japan; all had a Braden score of less than 14 (mean, 10.1 ± 1.1). Informed consent was obtained from all the patients. A shear force and pressure sensor including a strain gauge, and an oval airbag-type pressure sensor were used. METHODS The sensor was attached to one heel using double-sided tape; then the target dressing was applied over the sensor and on the opposite heel to avoid the influence of the opposite heel on the shear force measurement. Interface pressures were measured with the patient in a stationary supine position; shear force was then measured at 0.2-second intervals, while the sheet was manually pulled at a velocity of around 5 cm/second. Shear force was determined by averaging the stable shear force lasting for 10 measurement points. RESULTS The mean interface pressures with the PPD and the film dressings were 70.7 ± 16.5 and 70.2 ± 15.2 mmHg, respectively; this difference was not statistically significant. The shear force produced during the pulling of the sheet was 2.2 ± 1.4 and 11.7 ± 5.8 N, respectively (P < .001, Wilcoxon signed-rank test). CONCLUSIONS The results of this study suggest that a dressing with a low-friction external surface (such as the pressure ulcer preventive dressing) can significantly reduce shear force. However, results also suggest that external dressings do not significantly reduce interface pressures and cannot be used as a substitute for heel elevation in an immobile patient.

Skin injuries caused by medical adhesive tape in older people and associated factors.

AIM AND OBJECTIVES This study was designed to investigate the status of skin injuries in older individuals caused by adhesive tape and the associated factors for skin injury. BACKGROUND Older individuals are susceptible to skin injuries caused by medical adhesive tape. However, the current status of such skin injuries and the associated factors involved has not been clearly elucidated. DESIGN Prospective cohort design, using comparative and descriptive statistical tests. METHODS The subjects were 155 patients aged 65 or older who were admitted to a long-term care facility and required the use of medical adhesive tape. Patients who showed no skin injuries were selected and the incidence rate and status of skin injuries that occurred during the eight-week study period were investigated. The skin injuries observed were classified by a dermatologist. The associated factors were examined statistically. Informed consent was obtained from all patients. RESULTS Skin injuries developed at 34 sites in 24 subjects. The cumulative incidence rate was 15.5%, and the incidence density was 38.0/1000 person-days. Many of the skin injuries occurred around pressure ulcers and intravenous hyperalimentation sites. Other prevalent areas included the buttocks and back, where tape is commonly used. The skin injuries were classified as contact dermatitis (70.6%), trauma (20.6%) and infection (8.8%). The ratio of skin contamination and skin mobility in patients with contact dermatitis was significantly higher than in patients without skin injury. CONCLUSION The highest incidence rate was observed in the buttock area of patients with pressure ulcers. The incidence rate of contact dermatitis was the highest. RELEVANCE TO CLINICAL PRACTICE Skin care to minimise contamination and more effective ways of applying medical adhesive tape may be needed to prevent contact dermatitis.

Prognosis of stage I pressure ulcers and related factors

The prognosis of stage I pressure ulcers cannot be predicted; therefore, nursing interventions for preventing their deterioration have not been clearly established. This study describes the clinical course of stage I pressure ulcers and prospectively investigates the factors related to their deterioration. Thirty‐one stage I pressure ulcers in 30 patients in a long‐term care facility were studied, and morphological changes were assessed every day until the ulcers healed or deteriorated. The physiological changes were assessed by ultrasonography and thermography. Twenty ulcers healed, and 11 deteriorated. The characteristics of deterioration were as follows: (1) double erythema; (2) non blanchable erythema across the whole area determined by glass plate compression; (3) erythema away from the tip of the bony prominence; and (4) expanding erythema on the following day. We analysed the sensitivity, specificity, positive predictive value, negative predictive value and positive likelihood ratio for the diagnostic utility of the indicators of deterioration double erythema and distance from the tip of bony prominence, which can be instantly assessed without the use of any special device. The values were 36·4%, 95·0%, 80·0%, 73·1% and 7·28, respectively. These results suggest that clinicians can predict the prognosis of stage I pressure ulcers by initial assessment and provide appropriate care based on the assessment.

Detection of Pseudomonas aeruginosa quorum sensing signals in an infected ischemic wound: An experimental study in rats

Quorum sensing is a cell‐to‐cell communication that occurs via autoinducers, regulating a number of bacterial virulence factors including the opportunistic wound pathogen Pseudomonas aeruginosa, which uses the N‐(3‐oxododecanoyl)‐homoserine lactone as one of the two main autoinducers; however, little is known about its role in chronic wound infection. This study was designed to quantify this autoinducer from P. aeruginosa‐infected wounds with the aim of examining the possible use of autoinducers as an indicator of chronic wound infection. Pressure‐induced ischemic wounds were infected with P. aeruginosa (N=12) or uninfected as a control (N=12). The autoinducer was quantified by bioassay method employing Escherichia coli DH5α (pJN105L, pSC11) or Agrobacterium tumefaciens NTL4 (pZLR4) reporter, which expresses β‐galactosidase when exposed to P. aeruginosa quorum sensing signals. The average concentration of autoinducer was 0.33 pmol/g at day 3 and 0.49 pmol/g at day 7 in the infected wounds, as detected from tissue samples. A linear correlation between autoinducer concentration and bacterial counts was observed. No autoinducer was detected in tissue samples from the uninfected control group. Our findings indicate that the quantification of autoinducers is possible and quorum sensing system could play a role in in vivo wound infection models, and also suggest possible clinical implications of autoinducer signal quantification in diagnosis of chronic wound infection.

Quantitative evaluation of elderly skin based on digital image analysis

Background: The evaluation of the skin state when it is healthy at the time of examination, but predisposed to disease, is based solely on the subjective assessment of clinicians. This assessment may vary from moment to moment and from rater to rater.

Preventive Effects of Salacia reticulata on Obesity and Metabolic Disorders in TSOD Mice.

The extracts of Salacia reticulata (Salacia extract), a plant that has been used for the treatment of early diabetes, rheumatism and gonorrhea in Ayurveda, have been shown to have an anti-obesity effect and suppress hyperglycemia. In this study, the effects of Salacia extract on various symptoms of metabolic disorder were investigated and compared using these TSOD mice and non-obese TSNO mice. Body weight, food intake, plasma biochemistry, visceral and subcutaneous fat (X-ray and CT), glucose tolerance, blood pressure and pain tolerance were measured, and histopathological examination of the liver was carried out. A significant dose-dependent decline in the gain in body weight, accumulation of visceral and subcutaneous fat and an improvement of abnormal glucose tolerance, hypertension and peripheral neuropathy were noticed in TSOD mice. In addition, hepatocellular swelling, fatty degeneration of hepatocytes, inflammatory cell infiltration and single-cell necrosis were observed on histopathological examination of the liver in TSOD mice. Salacia extract markedly improved these symptoms upon treatment. Based on the above results, it is concluded that Salacia extract has remarkable potential to prevent obesity and associated metabolic disorders including the development of metabolic syndrome.

Exploring the prevalence of skin tears and skin properties related to skin tears in elderly patients at a long-term medical facility in Japan.

The identification of appropriate skin tear prevention guidelines for the elderly requires clinicians to focus on local risk factors such as structural alterations of the epidermis and dermis related to skin tears. The aim of this cross‐sectional study is to explore the prevalence of skin tears and to explore skin properties related to skin tears in elderly Japanese patients at a long‐term medical facility. After doing the prevalence study, 18 participants with skin tears and 18 without were recruited and an evaluation of their skin properties using 20‐MHz ultrasonography, skin blotting and also Corneometer CM‐825, Skin‐pH‐meterPH905, VapoMeter, Moisture Meter‐D and CutometerMPA580 was undertaken. A total of 410 patients were examined, the median age was 87 years and 73·2% were women. The prevalence of skin tears was 3·9%, and 50% of skin tears occurred on the dorsal forearm. The changes in skin properties associated with skin tears included increased low‐echogenic pixels (LEP) by 20‐MHz ultrasonography, decreased type IV collagen and matrix metalloproteinase‐2, and increased tumour necrosis factor‐α by skin blotting. In conclusion, this study suggests that increased dermal LEP, including solar elastosis, may represent a risk factor for skin tears; this indicates that skin tear risk factors might not only represent chronological ageing but also photoageing.