EUROPEAN PRESSURE ULCER ADVISORY PANEL

Following the discussions regarding how support surfaces should be evaluated (reported in the EPUAP Review, Issue 1.3), a further meeting to discuss this topic was held on 2 September 1999 at the Amsterdam Medical Centre. Organised by Michael Clark (Wales) and Kate O’Dea (England), almost fifty participants drawn from the clinical, academic and commercial sectors discussed how evaluations of support surfaces should be conducted and reported. Chaired by Professor Harding (Wales), participants reviewed the earlier discussions reported in the EPUAP Review. This review was followed by presentations upon the role of national regulatory bodies (Dr Boumans, Netherlands) and the progress of the International Standards Organisation (ISO) working group on the use of wheelchair cushions in pressure ulcer management (Prof Ferguson-Pell, England). Each presentation generated considerable debate – what did we know about the effects of beds and mattresses on pressure ulcer development, what was the key clinical indicator of failure of a support surface and how should early signs of pressure damage be identified being consistent themes across the symposium. Many participants felt that they had ‘heard all these debates before’ over a number of years with no progress or action taken. This sense of deja-vu evaporated during the closing summary by Keith Harding when he, as out-going President of the EPUAP, issued a challenge to participants. Professor Harding proposed that three working groups be established and have their initial meetings during the Third Open Meeting of the EPUAP.

These working groups were to tackle:

• A systematic review of the effects of beds and mattresses upon intermediate outcome measures such as interface pressure and the potential effects of such outcomes on pressure ulcer development.
• How laboratory evaluations of beds and mattresses should be conducted and reported.
• How clinical evaluations of beds and mattresses should be conducted and reported.

All three groups were to concentrate upon beds and mattresses due to the concurrent work by the ISO on cushions. Each working group was challenged to report its findings for debate and discussion during the Fourth Open Meeting of the EPUAP in September 2000. So the clock is running and each group has a considerable body to work to undertake before facing the participants in Pisa!

The systematic review group is chaired by Michael Clark (Wales) with five members; Tom Defloor (Belgium), Barend ten Haar (England), Jacqui Fletcher (England), Linda Russell (England) and Mark Collier (England). This group has prepared their plan of work for identifying relevant literature along with a data extraction form for use when reviewing papers. Both of these items are shown below, and the group would welcome any feedback and comments from other members of the EPUAP.

Title:

Physical effects upon human soft tissues produced by pressure-redistributing beds and mattresses.
Date of draft protocol: 26 October 1999
Date next revision expected: 30 November 1999
Potential Conflicts of Interest: None

Background:
Pressure ulcers (also known as bedsores, decubitus ulcers and pressure sores) are areas of localised damage to the skin and underlying tissue caused by pressure, shear or abrasion. They usually occur over bony prominences such as the sacrum, heels, hips and elbows (David et al. 1983), most often in immobile elderly people (for example elderly orthopaedic patients), people with severe, acute illness (such as people in Intensive Care Units) and in people with neurological problems (for example in people with spinal cord injuries), (Bridel-Nixon 1997).

Pressure ulcers have been recorded as occurring in 4–10% of patients admitted to a UK District General Hospital (the precise rate depends on case-mix), (Clark and Watts 1994) and in an unknown number of patients in community care settings. They represent a major burden of sickness and reduced quality of life for patients and their carers, and are costly to health service providers.

It is commonly thought that most pressure ulcers are avoidable, and pressure ulcer prevention is an aspect of health care usually managed by nurses (David et al. 1983). A large component of pressure ulcer prevention involves the use of special beds and mattresses claimed to either reduce or distribute the loading upon bony prominences (Clark 1998). Few randomised controlled trials comparing different beds and mattresses have been reported, and where available these studies tend to be methodologically weak (Cullum et al. 1995).

Laboratory investigations of indirect outcome measures (such as reductions in tissue loading) are widely available in the literature. However this body of data has rarely been used to guide mattress selection due to the wide range of methodologies reported (Clark and Rowland 1989, Clark 1994). Nor has this material been of prime importance in guiding product design.

Objectives:
To conduct a systematic review of reliable evaluations of the effect of specialised beds and mattresses upon tissue loading (including direct pressure and shear forces) skin temperature and humidity.

The specific questions to be answered are: a) do the patterns of tissue loading (and changes in skin temperature and humidity) produced while resting upon beds and mattresses reduce microcirculatory flow (and hence promote circumstances that may generate pressure ulcers); and b) can a set of parameters (including tissue loading, skin temperature and humidity) be identified that may reduce the risk of pressure ulcer development?

Criteria for considering studies for this review:

Types of studies
Studies must report the effect of specialised beds and mattresses upon tissue loading, skin temperature and humidity and/or the effects of such tissue loading, skin temperature and humidity changes upon microcirculatory flow. Studies that report the development of pressure ulcers upon beds and mattresses will not be included. All study designs will be considered for inclusion if the study reports primary data upon the loading produced by beds and mattresses, or the effects of such loads upon microcirculatory flow. This review will only consider articles published in English, inclusion of non-English language articles may occur following the release of the draft review in 2000.

Types of participants
Only studies that report the effect of beds and mattresses (and/or the effects of the tissue loading such devices may produce) upon human soft tissues will be included. Animal models will not be included in this review.

Types of interventions
The primary interventions will be specialised beds and mattresses intended to be used in the care of patients likely to develop pressure ulcers. The role of the ‘standard’ hospital mattress upon tissue loading and microcirculatory flow will also be considered. Studies that report the use of seat cushions will not be included.

Types of outcome measures

1. The loads applied by beds and mattresses described either as pressures or as forces.
2. Changes in skin temperature following use of beds and mattresses
3. Changes in skin humidity following use of beds and mattresses
4. Changes in microcirculatory flow that occurs during use of beds and mattresses.

Search strategy for identification of studies:

The electronic data-bases MEDLINE and CINHAL will be queried using combinations of search terms including, but not limited to, ‘Pressure ulcer’, ‘Decubitus ulcer’, ‘Beds’, ‘Mattresses’, ‘Pressure’, ‘Temperature’, ‘Blood flow’, ‘Lymphatic flow’ and ‘Humidity’. Hand-searching of relevant journals (Care-Science and Practice, Journal of Tissue Viability) and conference proceedings (European Wound Management Association, European Pressure Ulcer Advisory Panel) will also be undertaken. Relevant researchers and manufacturers will be contacted to identify unpublished data.

Methods of the review:

References identified from searches will be entered into a bibliographic software package (EndNote).

Details of eligible studies will be extracted and summarised using a data extraction sheet (see below). If data are missing from reports then attempts will be made to contact the authors to complete the information required for the critical appraisal. Studies that have been published in duplicate will be included only once. Data extraction will be undertaken by one reviewer then checked independently for accuracy by a second. Any disagreement will be resolved by discussion.

Each study will be individually critically appraised using a checklist to assess methodological quality (factors such as calibration of instrumentation, reporting of outcome data, heterogeneity of test population). By collecting data on these factors, it may be possible to construct a hierarchy of evidence, reflecting weaknesses in study design. This will allow studies to be weighted according to their reliability, and therefore to be given appropriate weighting in any analysis.

The method of synthesising the studies will depend upon the quality, design and heterogeneity of studies identified. It may be that results will be combined in a mainly qualitative manner, but where studies are sufficiently similar, attempts will be made to quantitatively pool them. Production of the review will be made using the software package, RevMan 4.03.

References

References not included in this version of the protocol.

The working group reviewing laboratory evaluations of beds and mattresses is chaired by Alastair Mcleod (England) and is organised into a series of national groups. For example, in the UK the national group is led by Ian Swain (England) and has eighteen active members drawn from commercial (four members), academic (eight members) and clinical (six members) settings. The activities of the laboratory evaluation working group will be considered in detail in the next issue of the EPUAP Review.

Finally the clinical evaluation working group is chaired by Jeen Haalboom (Netherlands) and has fifteen active members drawn from seven European countries. Once again the activities of this group will be reported in the next issue of the EPUAP Review.