European Pressure Ulcer Advisory Panel

A study of the histopathology of moisture lesions

Ronald Houwing, The Netherlands

Skin problems are known to be particularly severe among nursing home residents with incontinence and immobility. As the skin of buttocks and perineal area is not designed for sustained tissue loading superficial and deep PU are frequent in this area. Recently, in Europe and the USA superficial skin loss in incontinent and immobile patients are singled out from early stages of PU as a distinct entity. This kind of lesions named ‘moisture lesions’ or ‘moisture-associated-skin-damage’ (MASD) are considered to have a pathophysiologic mechanism different from superficial PU lesions, with moisture as the primary cause. The prevalence of incontinence associated skin lesions in Dutch healthcare institutions is estimated to be 11%.

We investigated whether moisture lesions form a definite entity and can be distinguished from PU. The histopathology of skin biopsies from twelve patients with moisture lesions, diagnosed according to the EPUAP statement, was investigated.

Two distinct histopathological patterns were observed:

1. An ischemic pattern, with a partly avital epidermis, edema in the dermis with vascular dilatation, engorgement of erythrocytes, and a diffuse infiltration of polymorphonuclear cells.
2. The other pattern showed hyperplastic changes of the epidermis with elongated rete ridges and dilated blood vessels, sometimes with subepidermal blisters and a partial loss of the epidermis.

Conclusion

These different patterns could not be related to differences in clinical aspect of the skin lesions where the biopsies were taken from. The skin biopsies, however, were only 5 mm in diameter, representing only a small part of the clinical lesion. For that reason it is possible that both histological patterns exist in the same clinical lesion. None of the skin biopsies showed a histopathological pattern compatible with that of irritant contact dermatitis.

Based on these results the pathogeneses, classification and prevention guidelines involving ‘moisture lesions’ can be discussed along the following questions:

1. What is the pathophysiological mechanism for each of the two histopathological patterns found in moisture lesions?
2. Is moisture the only cause of moisture lesions?
3. How should the guidelines on prevention and treatment of skin lesions in incontinent patients be formulated?

Comparison of two skin examination methods for Grade 1 pressure ulcer identification

Lahmann N.A., Dassen T. and Kottner J. Charité

Universitätsmedizin Berlin, Department of Nursing Science

Introduction

The correct and precise identification and classification of pressure ulcers is of utmost importance in clinical practice and research, Two different skin examination methods were compared regarding their impact on observed grade 1 pressure ulcer prevalence.

Method

Since 2004 the ‘Department of Nursing Science’ at the Charité-Universitätmedizin Berlin has conducted annual nationwide surveys on the prevalence of pressure ulcers in German nursing homes and hospitals. Participating institutions were placed in the control and intervention groups randomly in order to prevent systematic bias. Skin observation in the intervention group (n = 4667) was conducted with a transparent disc. In the control group (n = 5095) skin examination was conducted as usual.

Results

Both groups were highly comparable regarding demographic characteristics, pressure ulcer risk, and proportions of persons being at risk. Grade 1 pressure ulcer prevalence in the intervention group was 3.9% and in the control group 7.1% (p < .001). Most were observed at the bottom (n = 291), heels (n = 225), and sacrum (n = 128). The odds ratio for the disc-method, controlled for age, sex, bmi, Braden scale score and whether the participant was a nursing home resident or a hospital by logistic regression, for identifying at least one grade 1 pressure ulcer as opposed to the finger method was 1.8 (95%CI 1.5-2.2) that means the chance to diagnose a grade 1 pressure ulcer increased by 80% when the finger method was used.

Summary

Grade 1 pressure ulcer prevalence was twice as high in the group that used the finger method than in the group that used the a transparent disk device (p < 0.001). The probability of grade 1 pressure ulcer detection was lower, when the transparent disc was used (p < 0.001).

Repeatability of high frequency ultrasound scanning in pressure ulcer prevention: can it be achieved?

C Adams, A Moorhead, M Stinson, A Porter-Armstrong, E Gardner, J Donnelly, S Deegan, J Nixon, D Bader, C Lyder

Introduction

High frequency ultrasound scanning (HFUS), at a frequency of 20MHz, allows real-time two-dimensional imaging of internal structures in a non-invasive manner and can identify areas of oedema underlying the skin. To date, no studies exploring the repeatability of HFUS in pressure ulcer examination have been published. The aim of the study was to investigate the inter- and intra-rater repeatability of HFUS.

Methods

This study was conducted with a convenience sample of 24 healthy able-bodied adults (21 females, 3 males; 32.08 ± 12.25 years; BMI 24.94 ± 5.57) with intact skin on their heels and seating interface (‘at risk’ sites of pressure ulcer development). Written informed consent was obtained prior to commencement of data collection. Three points on both heels (lateral, posterior and medial aspects) and seating interface (coccyx, and left and right ischial tuberosities) were marked by researcher one and scanned by two researchers on two consecutive days. Researchers were blinded to each other’s scanning. HFUS images were qualitatively analysed by two researchers blinded to each other to determine if images were ‘normal’ or ‘abnormal’. In an attempt to quantitatively analyse the images, a novel method of pixel intensity summation was applied to the images. Statistical analysis was conducted using SPSS Version 11.5.

Results

Qualitative visual analysis showed very good agreement (0.88 kappa statistic) between both researchers and 83% of the images were classified as normal. Intraclass correlation coefficients (ICCs) conducted on pixel intensity summation results showed generally low inter- and intra-rater repeatability (25% moderate or high ICCs; ICC ≥ 0.6).

Conclusions

Differences in images taken by different researchers on separate occasions may be due to probe placement or orientation or tissue characteristic variations from day to day. Although quantitative ICCs showed low inter- and intra-rater repeatability, qualitative visual analysis showed better agreement. In practice, clinicians aim to determine if the images are ‘normal’ or ‘abnormal’, thus qualitative visual analysis appears to be the gold standard in HFUS interpretation. Quantitative methods of analysing HFUS images, in relation to pressure ulcer prevention, require further exploration.