96423669 8826270 1996 11 27 1996 11 27 2000 12 18

0969-0700 5 3 1996 Mar Pressure-relieving supports in an ICU. 116-21 Intensive care wards have a high incidence of pressure sores. This trial, in an eight-bed unit, aimed to compare the cost-effectiveness of constant-low-pressure and alternating-pressure support systems for preventing pressure sores. Patients without sores with a Norton risk score of < 13 were allocated to either alternating- or constant-low-pressure supports according to their hospital number. The cheapest supports were used initially, and changed for more sophisticated types if the patient's pressure areas deteriorated. None of the 23 patients using low-cost alternating-pressure supports developed open sores and only one had to be transferred to a more sophisticated mattress because of persistent erythema. Eleven out of 20 patients on constant-low-pressure mattresses or overlays developed either persistent erythema (three) or sores (eight). Ten were transferred to more expensive support systems. The mean cost of supports per patient in the alternating-pressure group was 44.50 pounds and in the constant-low-pressure group 86.20 pounds. Gebhardt K S KS Bliss M R MR Winwright P L PL Thomas J J eng Clinical Trial Journal Article Randomized Controlled Trial

ENGLAND J Wound Care CDO 9417080 N Adult Aged Aged, 80 and over Beds economics standards Comparative Study Cost-Benefit Analysis Decubitus Ulcer prevention & control Female Human Intensive Care Male Middle Age Risk Factors Support, Non-U.S. Gov't 1996 03 01 1996 03 01 ppublish 0008826270 96423669 96141915 8555924 1996 02 28 1996 02 28 2000 12 18

0959-8138 312 7023 1996 Jan 13 Evidence based medicine: what it is and what it isn't. 71-2 Sackett D L DL Rosenberg W M WM Gray J A JA Haynes R B RB Richardson W S WS eng Editorial

ENGLAND BMJ BMJ 8900488 AIM IM BMJ. 1996 Jul 20;313(7050):169-70; discussion 170-1 BMJ. 1996 Jul 20;313(7050):169; discussion 170-1 BMJ. 1996 Jul 20;313(7050):170-1 BMJ. 1996 Jul 20;313(7050):170; discussion 170-1 Clinical Competence Clinical Medicine Decision Making Decision Support Techniques Great Britain Human 1996 01 13 1996 01 13 ppublish 0008555924 96141915 20257612 10796522 2000 07 06 2000 07 06 2000 12 18

1469-493X 2 2000 Compression bandages and stockings for venous leg ulcers. CD000265 OBJECTIVES: To assess the effectiveness and cost-effectiveness of compression bandaging and stockings in the treatment of venous leg ulcers. SEARCH STRATEGY: Searches of 19 databases, hand searching of journals, conference proceedings and bibliographies. Manufacturers of compression bandages and stockings and an Advisory Panel were contacted for unpublished studies. SELECTION CRITERIA: Trials that evaluated compression bandaging or stockings, as a treatment for venous leg ulcers. There was no restriction on date or language. Ulcer healing was the primary endpoint. DATA COLLECTION AND ANALYSIS: Details of eligible studies were extracted and summarised using a data extraction sheet. Data extraction was verified by two reviewers independently. MAIN RESULTS: Twenty two trials reporting 24 comparisons were identified. Compression was more effective than no compression (4/6 trials). When multi-layered systems were compared, elastic compression was more effective than non-elastic compression (5 trials). There was no difference in healing rates between 4-layer bandaging and other high compression multi-layered systems (3 trials). There was no difference in healing rates between elastomeric multi-layered systems (4 trials). Multi-layered high compression was more effective than single layer compression (4 trials). Compression stockings were evaluated in two trials. One found a high compression stocking plus a thrombo stocking to be more effective than a short stretch bandage. The second small trial reported no difference between the compression stockings and Unna's boot. There was insufficient data to draw conclusion about the relative cost-effectiveness of different regimens. REVIEWER'S CONCLUSIONS: Compression increases ulcer healing rates compared with no compression. Multi-layered systems are more effective than single-layered systems. High compression is more effective than low compression but there are no clear differences in the effectiveness of different types of high compression. Centre for Evidence Based Nursing, Department of Health Studies, University of York, Genesis 6, York, UK, YO10 5DQ. nac2@york.ac.uk Cullum N N Nelson E A EA Fletcher A W AW Sheldon T A TA eng Journal Article Review Review, Academic

ENGLAND Cochrane Database Syst Rev DJ9 100909747 IM Bandages Human Leg Ulcer therapy 30 2000 05 05 09 2000 07 08 11 ppublish 0010796522 20257612 CD000265 http://www.update-software.com/abstracts/ab000265.htm 21276526 11382790 2001 05 30 2001 06 28

1079-5006 56 6 2001 Jun Issues and dilemmas in the prevention and treatment of pressure ulcers: a review. M328-40 Considerable dogma and rhetoric, rather than evidence-based results, have accompanied recommendations for the prevention and treatment of pressure ulcers. Therapy for pressure ulcers is generally empiric, based on anecdotal experience, or borrowed from the treatment of patients with acute wounds. The treatment of pressure ulcers is problematic because of multiple comorbidities of patients, the chronic duration of pressure ulcers, and often by the physician's relative unfamiliarity with treatment options. Issues and dilemmas in the prevention of pressure ulcers center around risk assessment, means of pressure relief, and nutritional support. Similar issues in the treatment of pressure ulcers include implementing pressure relief, nutritional support, local wound care, the best method of debridement, diagnosing infection, the use of topical growth factors, and surgical treatment. The accumulating data for the prevention and management of pressure ulcers permits an outline of clinical strategies. Division of Geriatric Medicine, Saint Louis University Health Sciences Center, Missouri, USA. thomasdr@slu.edu Thomas D R DR eng Journal Article Review Review, Tutorial

United States J Gerontol A Biol Sci Med Sci CBA 9502837 0 Growth Substances AIM IM Bacterial Infections diagnosis Bandages Debridement Decubitus Ulcer microbiology mortality prevention & control therapy Growth Substances therapeutic use Human Nutrition Risk Assessment Wound Healing physiology 164 2001 5 31 10 0 2001 6 29 10 1 ppublish 11382790 http://biomed.gerontologyjournals.org/cgi/content/full/56/6/M328 http://biomed.gerontologyjournals.org/cgi/content/abstract/56/6/M328 21261971 11368833 2001 05 22 2001 07 05

1366-5278 5 9 2001 Systematic reviews of wound care management: (5) beds; (6) compression; (7) laser therapy, therapeutic ultrasound, electrotherapy and electromagnetic therapy. 1-221 BACKGROUND: Chronic wounds such as leg ulcers, diabetic foot ulcers and pressure sores are common in both acute and community healthcare settings. The prevention and treatment of these wounds involves many strategies: pressure-relieving beds, mattresses and cushions are universally used as measures for the prevention and treatment of pressure sores; compression therapy in a variety of forms is widely used for venous leg ulcer prevention and treatment; and a whole range of therapies involving laser, ultrasound and electricity is also applied to chronic wounds. This report covers the final three reviews from a series of seven. AIMS: To assess the clinical effectiveness and cost- effectiveness of: (1) pressure-relieving beds, mattresses and cushions for pressure sore prevention and treatment; (2) compression therapy for the prevention and treatment of leg ulcers; (3) low-level laser therapy, therapeutic ultrasound, electrotherapy and electromagnetic therapy for the treatment of chronic wounds. METHODS - DATA SOURCES: Nineteen electronic databases, including MEDLINE, CINAHL, EMBASE and the Cochrane Controlled Trials Register (CENTRAL), were searched. Relevant journals, conference proceedings and bibliographies of retrieved papers were handsearched. An expert panel was also consulted. METHODS - STUDY SELECTION: Randomised controlled trials (RCTs) which evaluated these interventions were eligible for inclusion in this review if they used objective measures of outcome such as wound incidence or healing rates. RESULTS - BEDS, MATTRESSES AND CUSHIONS FOR PRESSURE SORE PREVENTION AND TREATMENT: A total of 45 RCTs were identified, of which 40 compared different mattresses, mattress overlays and beds. Only two trials evaluated cushions, one evaluated the use of sheepskins, and two looked at turning beds/kinetic therapy. RESULTS - COMPRESSION FOR LEG ULCERS: A total of 24 trials reporting 26 comparisons were included (two of prevention and 24 of treatment strategies). RESULTS - LOW-LEVEL LASER THERAPY, THERAPEUTIC ULTRASOUND, ELECTROTHERAPY AND ELECTROMAGNETIC THERAPY: Four RCTs of laser (for venous leg ulcers), 10 of therapeutic ultrasound (for pressure sores and venous leg ulcers), 12 of electrotherapy (for ischaemic and diabetic ulcers, and chronic wounds generally) and five of electromagnetic therapy (for venous leg ulcers and pressure sores) were included. Studies were generally small, and of poor methodological quality. CONCLUSIONS (1) Foam alternatives to the standard hospital foam mattress can reduce the incidence of pressure sores in people at risk, as can pressure-relieving overlays on the operating table. One study suggests that air-fluidised therapy may increase pressure sore healing rates. (2) Compression is more effective in healing venous leg ulcers than is no compression, and multi-layered high compression is more effective than single-layer compression. High-compression hosiery was more effective than moderate compression in preventing ulcer recurrence. (3) There is generally insufficient reliable evidence to draw conclusions about the contribution of laser therapy, therapeutic ultrasound, electrotherapy and electromagnetic therapy to chronic wound healing. Department of Health Studies, University of York, UK. Cullum N N Nelson E A EA Flemming K K Sheldon T T eng Journal Article Review Review, Academic

England Health Technol Assess CUT 9706284 IM Bandages Beds Decubitus Ulcer prevention & control therapy Electric Stimulation Therapy Electromagnetic Fields Great Britain Human Lasers therapeutic use Randomized Controlled Trials Support, Non-U.S. Gov't Ultrasonic Therapy Wound Healing 184 2001 5 23 10 0 2001 7 6 10 1 ppublish 11368833 http://www.ncchta.org/htapubs.htm#509 http://www.ncchta.org/execsumm/summ509.htm 97257649 9104123 1997 05 22 1997 05 22 2000 12 18

0966-0461 6 3 1997 Feb 13-26 Evaluation of the new Cairwave Therapy System in one hospital trust. 167-70 The Pegasus Airwave mattress has been used for many years in the Eastbourne NHS Trust and has proven its efficiency in the prevention of pressure sores. Pegasus has now produced a new, improved, model: the Cairwave Therapy System. This article looks at criteria that may be used to determine whether the new model is suitable for patient care. The evaluation took the form of a randomized controlled study in which 12 mattresses were randomly allocated to patients--six Airwave mattresses and six Cairwave Therapy Systems--over a 4-month period. The results of the evaluation showed that patients found the mattress comfortable. An encompassing cover reduced the risk of cross-infection, rehabilitation was supported by the firm edges of the bed and patient movement was easier due to the soft cover. During the trial all patients remained free from pressure sores. Eastbourne Hospitals NHS Trust. Hampton S S eng Clinical Trial Journal Article Randomized Controlled Trial

ENGLAND Br J Nurs BIG 9212059 N Beds standards Decubitus Ulcer prevention & control Equipment Design Evaluation Studies Human Infection Control Lifting Patient Acceptance of Health Care Posture 1997 02 13 1997 02 13 ppublish 0009104123 97257649 88203252 3362700 1988 06 02 1988 06 02 2000 12 18

0954-7762 84 13 1988 Mar 30-Apr 5 Tissue viability. Action against pressure sores. 68-73 Hibbs P P eng Journal Article

ENGLAND Nurs Times O9U 0423236 N Beds Decubitus Ulcer prevention & control Human Nursing Assessment Nursing Care 1988 03 05 1988 03 05 ppublish 0003362700 88203252 86313023 3638661 1986 10 23 1986 10 23 2000 12 18

0954-7762 82 32 1986 Aug 6-12 Pressure sores. Airwaves take the pressure. 67-71 Livesley B B eng Journal Article

ENGLAND Nurs Times O9U 0423236 N Aged Beds Decubitus Ulcer physiopathology prevention & control Human Risk 1986 08 06 1986 08 06 ppublish 0003638661 86313023 97129450 8973958 1997 03 19 1997 03 19 2000 12 18

1063-6528 4 4 1996 Dec Seat cushion design for elderly wheelchair users based on minimization of soft tissue deformation using stiffness and pressure measurements. 320-7 A method for designing seat support surfaces using interface pressure and soft tissue stiffness criteria was evaluated. An algorithm designed to drive a rigid support surface on a programmable seating system to a shape for which the externally applied pressure is inversely related to the measured stiffness of adjacent soft tissue was evaluated on 30 elderly subjects (age 65 years or older). The resulting support surface shapes were transferred to compliant foam cushions and evaluated using interface pressure measurements. Pressure and stiffness measurements on the seating system indicated the surface shape control algorithm met the desired programmed criteria by achieving an inverse relationship between pressure and stiffness, as it converged to an "optimal" support surface shape. Evaluation of interface pressures on the compliant foam cushions showed that the pressure distributions on the cushions contoured to the optimal surface shapes were more uniform and had lower values than distributions on flat foam cushions and foam cushions contoured to shapes measured using state-of-the-art load-deflection devices. The results suggest that support surfaces designed using tissue stiffness as a criteria can provide loading conditions intended to minimize relative deformation and, thus, stress in load-bearing soft tissue. University of Pittsburgh, Department of Rehabilitation Science and Technology, PA 15260, USA. Brienza D M DM Karg P E PE Brubaker C E CE eng R01-HD30161 HD NICHD Journal Article Review Review, Tutorial

UNITED STATES IEEE Trans Rehabil Eng CL4 9413994 IM Aged Biomechanics Decubitus Ulcer prevention & control therapy Equipment Design Human Models, Theoretical Soft Tissue Injuries prevention & control Support, U.S. Gov't, P.H.S. Wheelchairs 27 1996 12 01 1996 12 01 ppublish 0008973958 97129450 74145250 4595834 1974 06 17 1974 06 17 2000 12 18

0003-9993 55 4 1974 Apr Decubitus ulcers: role of pressure and friction in causation. 147-52 Dinsdale S M SM eng Journal Article

UNITED STATES Arch Phys Med Rehabil 8BK 2985158R 0 Radioisotopes 7440-17-7 Rubidium AIM IM Adipose Tissue blood supply Animal Decubitus Ulcer etiology Female Methods Paraplegia complications Pressure adverse effects Radioisotope Dilution Technique Radioisotopes Regional Blood Flow Rubidium diagnostic use Skin blood supply Swine Time Factors 1974 04 01 1974 04 01 ppublish 0004595834 74145250 89328836 2754625 1989 09 07 1989 09 07 2000 12 18

0748-7711 26 3 1989 Summer Theoretical prediction of a time-at-pressure curve for avoiding pressure sores. 27-34 A theoretical development of the pressure versus time curve for the onset of pressure sores is presented which is based upon the use of dimensional analysis. Comparison with available experimental data from humans and from dogs and swine indicate that this approach agrees well with experiment and also shows some promise for predicting the effects of skin elastic modulus and skin blood flow on the allowable pressures which can be safely tolerated by specific individuals. Rehabilitation R&D Center, VA Medical Center, Palo Alto, CA 94304. Sacks A H AH eng Journal Article

UNITED STATES J Rehabil Res Dev JRD 8410047 IM Decubitus Ulcer prevention & control Human Models, Biological Time Factors 1989 01 01 1989 01 01 ppublish 0002754625 89328836 89335164 3254699 1989 09 14 1989 09 14 2000 12 18

0898-1655 1 1 1988 Feb Vertical shear existence in animal pressure threshold experiments. 18-24 Bennett L L Lee B Y BY eng Journal Article

UNITED STATES Decubitus AFV 8901610 N Animal Decubitus Ulcer etiology Disease Models, Animal Manometry Pressure adverse effects 1988 02 01 1988 02 01 ppublish 0003254699 89335164 94004556 8401275 1993 11 16 1993 11 16 2000 12 18

0967-3334 14 3 1993 Aug Air-fluidized beds and their ability to distribute interface pressures generated between the subject and the bed surface. 359-64 Pressures were measured under five anatomical sites prone to pressures sores for ten subjects, supine and sitting on two different air-fluidized beds. The beds were the Clinitron (trademark, SSI) and the Fluidair Plus (trademark, KCI Mediscus). Mean supine pressures were less than 4 kPa under four sites. The average supine buttock pressure was 2.65 kPa. This increased to 3.71 kPa upon sitting up, though pressures did not rise above the accepted capillary closing pressure, on either bed. Low interface pressures at these sites were due to good moulding between subject and bed. Heel pressures averaging 7.08 kPa, were a factor of 2.67 times greater than buttock pressure, and were higher than expected considering the depth the heels sunk to in both beds. This exceeded the accepted capillary closing pressure and was attributed to covering sheets preventing true floatation at the heels. Regional Medical Physics Department, Freeman Hospital, Newcastle upon Tyne, UK. Allen V V Ryan D W DW Murray A A eng Journal Article

ENGLAND Physiol Meas BN5 9306921 IM Adult Beds Decubitus Ulcer prevention & control Female Human Male Support, Non-U.S. Gov't 1993 08 01 1993 08 01 ppublish 0008401275 94004556 93368125 8361161 1993 09 28 1993 09 28 2000 12 18

0141-5425 15 4 1993 Jul Accuracy of interface pressure measurement systems. 344-8 Interface pressure measurement is needed to assess beds designed to prevent pressure sores, so it is therefore important to establish the accuracy of interface pressure measuring systems. In this study, the Talley SA500 pressure evaluator (with 28 mm and 100 mm sensor pads), the DIPE (with 100 mm sensor pad), and a water-filled bladder system (with 0.1 ml and 0.3 ml water) were assessed. Measurement errors were evaluated using a loading system with pressures up to 7.4 kPa (55 mm Hg) in steps of 0.9 kPa (6.9 mm Hg). All systems tested over-measured interface pressure, the error being approximately linearly proportional to the loading pressure. The repeatability for a given system was approximately constant. The mean error (+/- SD) (%) and repeatability (kPa) for the systems were: 28 mm Talley 12 +/- 1%, +/- 0.07 kPa; 100 mm Talley 15 +/- 1%, +/- 0.07 kPa; DIPE 27 +/- 3%, +/- 0.12 kPa; 0.1 ml water bladder 17 +/- 1%, +/- 0.13 kPa; 0.3 ml water bladder 26 +/- 3%, +/- 0.07 kPa. Different interfaces affected accuracy markedly, and repeatability was affected when an inhomogeneous interface was used. The study shows that the errors associated with interface pressure measurement systems can be substantial, and can vary from one system to another. Regional Medical Physics Department, Freeman Hospital, Newcastle-upon-Tyne, UK. Allen V V Ryan D W DW Lomax N N Murray A A eng Journal Article

ENGLAND J Biomed Eng K6K 7906074 IM Beds Calibration Pressure Reproducibility of Results Support, Non-U.S. Gov't Transducers 1993 07 01 1993 07 01 ppublish 0008361161 93368125 93368122 8361158 1993 09 28 1993 09 28 2000 12 18

0141-5425 15 4 1993 Jul Repeatability of subject/bed interface pressure measurements. 329-32 The repeatability of a technique for measuring interface pressures has been assessed. Pressure was measured using a Talley SA500 Pressure Evaluator under six anatomical sites (occiput, scapula, elbow, sacrum, buttock, and heel) of six healthy subjects lying supine on a Clinifloat mattress (trademark, SSI). For each site of each subject, four repeat readings were taken per day on four separate days. Mean pressures varied significantly between subjects (p < 0.02), though differences in mean pressures between sites were greater. Pressure was not significantly related to subject mass. The overall repeatability of the technique was +/- 0.77 kPa (+/- 5.8 mm Hg) which was much smaller than the range of pressures found under different sites (2.72 kPa or 20.4 mm Hg at the sacrum to 9.00 kPa or 67.5 mm Hg at the heel). Repeatability varied from site to site, from +/- 0.47 kPa (+/- 3.5 mm Hg) at the buttocks to +/- 1.20 kPa (+/- 9.0 mm Hg) at the heel. Measurements were found to vary significantly more between days than between repeats on the same day (p < 0.02). Regional Medical Physics Department, Freeman Hospital, Newcastle upon Tyne. Allen V V Ryan D W DW Murray A A eng Journal Article

ENGLAND J Biomed Eng K6K 7906074 IM Adult Back Beds Elbow Heel Human Male Pressure Reproducibility of Results Support, Non-U.S. Gov't 1993 07 01 1993 07 01 ppublish 0008361158 93368122 94083242 8260338 1994 01 27 1994 01 27 2000 12 18

0007-0947 47 4 1993 Jul-Aug Potential for bed sores due to high pressures: influence of body sites, body position, and mattress design. 195-7 Pressures were measured on 10 subjects, supine and sitting, under six anatomical sites prone to bed sores on three different mattresses. Studied were the Clinifloat and Therarest specialist replacement mattresses, and a standard hospital mattress. Mean supine pressures were less than 5 kPa under four sites. Average supine buttock pressure was 2.93 kPa. Occiput and heel pressures were much higher than under other sites, being on average 2.6 and 4.5 times greater respectively than the mean buttock pressure. On sitting up, buttock pressure increased by a factor of 1.7 on average, to a level higher than the accepted capillary closing pressure. Measurements were consistent with mattress design, specific features of which can significantly affect pressure under certain sites. Regional Medical Physics Department, Freeman Hospital, Newcastle upon Tyne. Allen V V Ryan D W DW Murray A A eng Clinical Trial Controlled Clinical Trial Journal Article

ENGLAND Br J Clin Pract AVK 0372546 IM Beds Decubitus Ulcer etiology Equipment Design Female Human Male Posture physiology Pressure adverse effects Support, Non-U.S. Gov't 1993 07 01 1993 07 01 ppublish 0008260338 94083242 98396868 9728675 1998 11 30 1998 11 30 2000 12 18

1350-4533 20 4 1998 Jun Pressure variation under the ischial tuberosity during a push cycle. 242-56 The present study is devoted to the variation of the magnitude of the compressive loading acting on the soft seating parts of a disabled person and the related pressure distribution under the ischial tuberosity during wheelchair propulsion. A combined experimental and computational approach was designed to predict correctly the change in magnitude of the maximum internal shear and compressive stresses produced by different propulsion speeds, cushion characteristics and body position of the subject. The results obtained show that the vertical force acting on the seating parts increases with the propulsion speed and exceeds the body weight by more than 100%. The related pressure under the ischial tuberosity shows a significant increase of 125% on the tissue/seat interface and an estimated increase of 185% in the peak compressive stress. It is concluded that computer modelling using a quasi-static approach provides a reliable estimate of the pressure values by the observed loading frequencies of 0-4 Hz. It can also be noted that the time independent material model utilised for the bulky soft tissue proved adequate for the estimate of the pressure level occurring under the ischial tuberosity during a push cycle. Brunel University, Isleworth, Middlesex, UK. Peter.Dabnichki@brunel.ac.uk Dabnichki P P Taktak D D eng Journal Article

ENGLAND Med Eng Phys BZU 9422753 IM Biomechanics Biomedical Engineering Biophysics Computer Simulation Human Ischium physiology Movement Pressure Stress, Mechanical Transducers Wheelchairs 1998 09 05 02 14 1998 09 05 02 14 ppublish 0009728675 98396868 89374773 2775477 1989 10 18 1989 10 18 2000 12 18

0898-1655 2 3 1989 Aug Interface pressure confusion. 8 Krouskop T A TA Garber S L SL eng Letter

UNITED STATES Decubitus AFV 8901610 N Decubitus. 1989 Nov;2(4):8-10 Beds standards Data Collection standards Decubitus Ulcer prevention & control Human Pressure Reference Standards 1989 08 01 1989 08 01 ppublish 0002775477 89374773 87013180 3762115 1986 11 18 1986 11 18 2000 12 18

0141-5425 8 4 1986 Oct Pressure distribution under the ischium of normal subjects. 353-7 This paper describes the development of a system for measuring pressure distribution at the patient-support interface. The instrument uses pneumatic techniques under microcomputer control to measure pressures, with an overall accuracy of 3 per cent of full scale. The instrument has been used to investigate the pressure distribution under the ischium of four normal subjects, using a rectangular matrix. The study demonstrated a small variability in pressure distribution with a subject sitting still. Repositioning the subjects produced large variations in pressure readings, as a result of postural changes, which must be taken into account in the design of seating trials. Bader D L DL Hawken M B MB eng Journal Article

ENGLAND J Biomed Eng K6K 7906074 IM Adult Biomedical Engineering Decubitus Ulcer prevention & control Human Interior Design and Furnishings Ischium physiology Male Pressure 1986 10 01 1986 10 01 ppublish 0003762115 87013180 20041839 10576420 1999 12 07 1999 12 07 2000 12 18

1350-4533 21 5 1999 Jun A new method of assessing the mechanical properties of patient support systems (PSS) using a phantom. A preliminary communication. 293-301 Pressure ulcers are a major problem worldwide believed to affect over 5% of all hospital in-patients, and countless others in the community at large. Many types of Patient Support Systems (PSS) are sold as pressure ulcer prevention equipment, but no consensus exists as to their mechanical efficacy. The use of human volunteers to assess the mechanical properties of PSS introduces non-repeatability and variability in results which cannot give a statistically significant difference in performance between systems. Mechanical testing without human volunteers provides faster evaluations of PSS, with improved precision and repeatability. An instrumented articulated anthropometric phantom has been developed to investigate the distortion of simulated soft body "tissues" of the buttock and sacral areas due to precise and repeatable static loading on a PSS. The weight of the phantom can be adjusted to 50, 70 and 90 kg and can be applied with the torso inclined at 0 degrees, 45 degrees and 80 degrees. Validation of the phantom by measuring interface pressure using a force sensing array mat indicates that the phantom represents realistic physiological loading conditions. The new method of measuring the distortion of the "artificial tissues" provides a highly selective ranking of PSS. Centre for Disability Research and Innovation, Royal Free and University College Medical School, Institute of Orthopaedics, Stanmore, Middlesex, UK. Bain D S DS Scales J T JT Nicholson G P GP eng Journal Article

ENGLAND Med Eng Phys BZU 9422753 IM Adult Beds Biomechanics Decubitus Ulcer physiopathology prevention & control Human Male Manikins Materials Testing Pressure Support, Non-U.S. Gov't 1999 11 27 09 1999 11 27 09 ppublish 0010576420 20041839 90368278 2394540 1990 10 10 1990 10 10 2000 12 18

0342-5282 13 1 1990 The role of alternating air and Silicore overlays in preventing decubitus ulcers. 57-65 Patients with chronic neurological diseases who were at high risk of decubitus ulcers were randomly assigned to alternating air on silicore mattress overlays for a period of 3 months. Of 148 subjects who completed the trial, more than 50% in each group developed one or more ulcers. No statistically significant differences between groups were found in the incidence, severity, healing duration or the location of the ulcers; with the exception of a significant difference (p less than 0.001) in the categorical location of the trochanters. School of Rehabilitation Medicine, University of British Columbia, Canada. Conine T A TA Daechsel D D Lau M S MS eng Clinical Trial Journal Article Randomized Controlled Trial

ENGLAND Int J Rehabil Res GRL 7805421 7440-21-3 Silicon IM Adolescence Adult Air Beds Decubitus Ulcer complications epidemiology prevention & control Equipment Design Human Incidence Materials Testing Middle Age Nervous System Diseases complications Silicon Support, Non-U.S. Gov't 1990 01 01 1990 01 01 ppublish 0002394540 90368278 95038016 7950617 1994 12 09 1994 12 09 2000 12 18

0959-8138 309 6958 1994 Oct 1 Pressure sores. 853-7 Department of Surgery, University Hospital of South Manchester. Vohra R K RK McCollum C N CN eng Journal Article Review Review, Tutorial

ENGLAND BMJ BMJ 8900488 AIM IM BMJ. 1994 Nov 26;309(6966):1436 BMJ. 1994 Nov 26;309(6966):1436-7 BMJ. 1995 Jan 14;310(6972):126 Decubitus Ulcer etiology prevention & control therapy Human Risk Factors 68 1994 10 01 1994 10 01 ppublish 0007950617 95038016 95135186 7833708 1995 02 27 1995 02 27 2000 12 18

0959-8138 310 6972 1995 Jan 14 Pressure sores. Clinical trials best way of assessing different matresses. 126 Bliss M R MR eng Comment Letter

ENGLAND BMJ BMJ 8900488 AIM IM BMJ. 1994 Oct 1;309(6958):853-7 Beds Clinical Trials Decubitus Ulcer prevention & control Human Pressure 1995 01 14 1995 01 14 ppublish 0007833708 95135186 98315711 9651895 1998 09 09 1998 09 09 2000 12 18

0748-7711 35 2 1998 Jun Assessment of alternating air mattresses using a time-based interface pressure threshold technique. 225-30 Laboratory evaluation techniques for support surfaces have centered largely around interface pressure (IP) measurement, typically analyzing discrete maximum and minimum levels, or calculating the average pressure. Nowadays, alternating pressure air mattresses (APAMs) are used increasingly for the prevention and treatment of pressure sores. Pressure relief (PR) provided by an APAM is time-varying. A computerized system that measures IP, air pressure, and pressure-time characteristics of dynamic support surfaces has been developed for performance assessment. Using this system, IP was recorded continuously and the durations of pressures below three thresholds (30, 20, and 10 mmHg) were calculated automatically. Fifteen sound volunteers were used to evaluate the pressure-relieving characteristics of four APAMs, including one overlay. Results indicated significant differences (p < 0.001) between products when durations below 20 and 10 mmHg thresholds were analyzed, showing some devices were only capable of momentarily relieving pressure. Maximum contact pressures on the sacrum were significantly lower (p < 0.0001) on devices where inflation pressure was adjusted according to the body mass of the subject. With further clinical validation, this tool could assist in the selection of alternating surfaces of any description. Department of Rehabilitation, University of Salford, UK. s.rithalia@rehab.salford.ac.uk Rithalia S V SV Gonsalkorale M M eng Journal Article

UNITED STATES J Rehabil Res Dev JRD 8410047 IM Beds Comparative Study Decubitus Ulcer prevention & control Equipment Design Evaluation Studies Human Materials Testing Pressure Transducers, Pressure 1998 07 04 02 13 1998 07 04 02 13 ppublish 0009651895 98315711 98115188 9453098 1998 03 10 1998 03 10 2000 12 18

0309-3646 21 3 1997 Dec Pressure relief characteristics in alternating pressure air cushions. 229-33 In this study a computerised system was used which continuously measured air pressure, interface pressure and pressure-time cycle characteristics of an alternating pressure air cushion (APAC), and calculated the time the interface pressure remained below three chosen thresholds of 20, 40 and 60 mm Hg. Ten healthy volunteers were used to evaluate the pressure relieving characteristics of four APACs. Results indicated significant differences between products when the threshold periods were analysed, showing some devices were not capable of relieving interface pressures below 20 mm Hg. Though deflation pressure decreased to nearer zero, interface pressure did not follow suit. Department of Rehabilitation, University of Salford, England, UK. Attard J J Rithalia S V SV Kulkarni J J eng Clinical Trial Journal Article

DENMARK Prosthet Orthot Int OZZ 7707720 IM Adult Anthropometry Computer-Aided Design Decubitus Ulcer prevention & control Equipment Design Female Human Male Pressure Reference Values Signal Processing, Computer-Assisted Surface Properties Wheelchairs 1998 02 07 08 44 1998 02 07 08 44 ppublish 0009453098 98115188 98112203 9450404 1998 02 19 1998 02 19 2000 12 18

1076-2191 10 7 1997 Nov-Dec Principles of alternating pressure surfaces. 30-6 Alternating pressure air mattresses (APAMs) have been in clinical use for nearly 50 years, yet little has been published on their design rationale. Although early systems were recognized as an effective tool in preventing pressure ulcers, serious quality and reliability problems hampered their use. Today, several types of APAMs, including overlays and mattress replacements, are routinely used in the prevention and treatment of pressure ulcers in many clinical settings. Caution must be exercised, however, when comparing interface pressure measurements on APAMs and static surfaces. This paper discusses some of the characteristics of alternating surfaces that may have an effect on the body. Huntleigh Healthcare, Luton, England. McLeod A G AG eng Journal Article Review Review, Tutorial

UNITED STATES Adv Wound Care BZW 9432971 N Air Beds standards supply & distribution Decubitus Ulcer prevention & control Human Pressure 51 1998 02 05 07 41 1998 02 05 07 41 ppublish 0009450404 98112203 97450287 9305275 1997 10 14 1997 10 14 2000 12 18

0003-9993 78 9 1997 Sep Transcutaneous oxygen measurement in stroke: circulatory disorder of the affected leg? 998-1002 OBJECTIVE: To identify variances in the microcirculation of the affected leg of stroke patients and to correlate them with a number of variables that are clinically associated with a possible circulatory disorder ("cold leg"). DESIGN: Survey. SETTING: Large regional (tertiary care) rehabilitation center. PATIENTS: From 93 acute, first-ever stroke patients admitted for stroke rehabilitation, 10 individuals were selected. Patients with vascular or cardiopulmonary pathology and severe cognitive or speech impairments were excluded. MAIN OUTCOME MEASURES: A clinical assessment of the following variables was performed: subjective complaints of the affected leg, medication, walking performance, degree of lower-leg edema, trophic pathology, voluntary muscle activity of the dorsal flexors of the affected foot, and the degree of spasticity of the calf muscles. The microcirculation of the affected leg was registered via transcutaneous oxygen measurement (TcPO2). RESULTS: The clinical picture associated with a circulatory disorder ("cold leg") was partially and modestly present in seven patients. The TcPO2 values showed no differences between the paretic and nonparetic lower legs, nor did values change in the course of time after stroke: mean 77.9 mmHg (range 42-124) versus 86.1 (41-124) after 8 weeks (n = 10, p = .17); 76.9 (45-96) versus 73.1 (50-96) after 14 weeks (n = 9, p = .38); and 65.8 (44-88) versus 65.8 (37-78) after 20 weeks (n = 8, p = .48). The clinical symptoms could not be objectified in relation to the microcirculation. CONCLUSIONS: In selected stroke patients, no differences were established between microcirculation in both lower legs. TcPO2 measurement does not seem to be a suitable method for clinical research on this topic. Department of Rehabilitation, Sint Maartenskliniek, Nijmegen, The Netherlands. Lem F C FC de Vries J J eng Journal Article

UNITED STATES Arch Phys Med Rehabil 8BK 2985158R AIM IM Adult Aged Blood Gas Monitoring, Transcutaneous Cerebrovascular Disorders complications rehabilitation Female Hemiplegia blood etiology pathology physiopathology Human Leg blood supply pathology Male Microcirculation Middle Age Muscle Spasticity Skin Temperature Walking 1997 09 26 1997 09 26 ppublish 0009305275 97450287 88139449 3343264 1988 03 31 1988 03 31 2000 12 18

0021-9355 70 2 1988 Feb Transcutaneous oxygen tension as a predictor of success after an amputation. 203-7 We measured local transcutaneous oxygen tension at the foot and proximal and distal to the knee in 162 patients who then had 206 amputations. When the values for oxygen tension at the foot and distal to the knee were compared with the success or failure of healing after an amputation of the foot or distal to the knee, respectively, a clearly increasing probability of failure was correlated with decreasing transcutaneous oxygen tension. However, even at a tension of zero the probability of failure was not 100 per cent. The results were similar for diabetic and non-diabetic patients. Preoperative values for transcutaneous oxygen tension were a much more consistent predictor of success or failure of healing after an amputation of the foot or distal to the knee than were measurements of systolic blood pressure at the ankle, but neither was predictive of the outcome after an above-the-knee amputation. Department of Orthopaedics, University of Washington, Seattle 98195. Wyss C R CR Harrington R M RM Burgess E M EM Matsen F A FA 3rd eng Journal Article

UNITED STATES J Bone Joint Surg Am HJR 0014030 AIM IM Amputation Ankle blood supply Blood Gas Monitoring, Transcutaneous Blood Pressure Diabetes Mellitus blood physiopathology Foot blood supply surgery Human Leg blood supply surgery Middle Age Regional Blood Flow Support, U.S. Gov't, Non-P.H.S. Wound Healing 1988 02 01 1988 02 01 ppublish 0003343264 88139449 79017890 29431 1978 11 18 1978 11 18 2000 12 18

0515-2720 68 1978 tcPCO2 electrode design, calibration and temperature gradient problems. 118-22 Transcutaneous PCO2 electrodes habe been constructed and evaluated on adults and children. Glass pH and silver reference electrodes were used at 44--45 degrees C, with either circulating water and a copper jacket, or with internal electrical heating. The skin surface PCO2 at 44 degrees C is about 1.33 times PaCO2 plus 3 mmHg when measured with electrodes calibrated in gas at 44 degrees C. Three temperature effects combine in this ratio: Heating raises blood PCO2 4.5%/degrees C, skin metabolism adds about 3 mmHg, and the cooling of the electrode active surface by skin increases electrode reading. Response time to step changes of PaCO2 was about 3 min to 63%, of which 1.2 min was sensor delay, the remainder skin CO2 washout. It was found important to use ethylene glycol-water mixtures rather than water for electrolyte to avoid bubble generation and drift. Heat transfer through the pH glass electrode has been increased by enlarging the internal silver electrode to virtually fill the entire glass electrode. Time required for initial vasodilation and stabilization is similar to that of tcPO2 electrodes, and accuracy of determination of PaCO2 appears to be better than +/- mmHg. Severinghaus J W JW Stafford M M Bradley A F AF eng Journal Article

DENMARK Acta Anaesthesiol Scand Suppl 08Q 0370271 0 Electrolytes 0 Ethylene Glycols 124-38-9 Carbon Dioxide IM Adult Blood Gas Analysis instrumentation Calibration Carbon Dioxide blood Electrodes Electrolytes Ethylene Glycols Heat Human Hydrogen-Ion Concentration Partial Pressure Skin Temperature 1978 01 01 1978 01 01 ppublish 0000029431 79017890 82026562 6793311 1981 12 22 1981 12 22 2000 12 18

0090-3493 9 10 1981 Oct Cutaneous blood flow and its relationship to transcutaneous O2/CO2 measurements. 736-41 Beran A V AV Tolle C D CD Huxtable R F RF eng 23123-02 PHS Journal Article

UNITED STATES Crit Care Med DTF 0355501 124-38-9 Carbon Dioxide 7782-44-7 Oxygen AIM IM Blood Gas Analysis instrumentation Carbon Dioxide blood Human Membranes, Artificial Oxygen blood Partial Pressure Plethysmography Regional Blood Flow Skin blood supply metabolism Skin Temperature Support, U.S. Gov't, P.H.S. 1981 10 01 1981 10 01 ppublish 0006793311 82026562 87077303 3790912 1987 02 05 1987 02 05 2000 12 18

0007-1323 73 11 1986 Nov Oxygen inhalation induced changes in the skin as measured by transcutaneous oxymetry. 882-5 Transcutaneous oxygen (PtcO2) measurements were made on 46 patients with severe ischaemia of the lower limbs and on 17 age-matched controls. Values breathing air, 100 per cent oxygen and the rate of change of PtcO2 breathing oxygen were recorded. Of 29 below knee amputations there were 4 failures; 16 had PtcO2 values less than 35 mmHg, but 12 of the 16 healed. When the rate of change of PtcO2 during oxygen inhalation was greater than 9 mm Hg/min all below knee amputations healed; all 4 failures were found to have values less than 9 mm Hg/min while only one patient with a value of less than 9 mm Hg/min healed a below knee amputation. This study shows that low PtcO2 values are a poor indication of healing potential. A more reliable index of skin viability is provided by the dynamic measurement of PtcO2 changes during oxygen inhalation. The addition of an oxygen inhalation test, when making PtcO2 measurements, greatly enhances the applicability of the technique in the assessment of the oxygen supply to the skin. McCollum P T PT Spence V A VA Walker W F WF eng Journal Article

ENGLAND Br J Surg B34 0372553 AIM IM Aged Amputation Blood Gas Monitoring, Transcutaneous Human Ischemia blood surgery Leg blood supply surgery Middle Age Oxygen Inhalation Therapy Skin physiopathology 1986 11 01 1986 11 01 ppublish 0003790912 87077303 20297583 10839091 2000 06 08 2000 06 08 2000 12 18

0965-206X 10 1 2000 Jan Assessment of alternating-pressure air mattresses using a time-based pressure threshold technique and continuous measurements of transcutaneous gases. 13-20 Alternating-pressure air mattresses (APAMs) are used increasingly for the prevention and treatment of pressure sores. Laboratory evaluation techniques have centred largely on interface pressure (IP) measurement, typically analysing discrete maximum and minimum levels, or average pressure. However, since pressure relief varies with time, a time-based analysis technique has been developed for performance assessment. IP was recorded continuously, and the duration of pressures below three thresholds (30, 20 and 10 mmHg) was calculated automatically using a computerized rig. Fifteen healthy volunteers were used to evaluate the pressure-relieving characteristics of four APAMs, including one overlay. Results indicated significant differences (P < 0.001) between products when durations below the 20 and 10 mmHg thresholds were analysed, showing that some devices were only capable of momentarily relieving pressure. Maximum contact pressures on the sacrum were significantly lower (P < 0.0001) on devices whose inflation pressure was adjusted according to subject's body mass. This technique could assist in the selection of alternating or dynamic surfaces of any description with further clinical validation. School of Health Care Professions, University of Salford. Rithalia S V SV Heath G H GH Gonsalkorale M M eng Clinical Trial Journal Article

ENGLAND J Tissue Viability DCA 9306822 N Adult Beds standards Body Mass Index Decubitus Ulcer metabolism physiopathology prevention & control Female Human Male Oximetry Pressure Skin blood supply 2000 06 06 09 2000 06 10 09 ppublish 0010839091 20297583 20483419 11030502 2000 10 13 2000 10 25

0003-9993 81 10 2000 Oct Quantification of pressure relief using interface pressure and tissue perfusion in alternating pressure air mattresses. 1364-9 OBJECTIVE: To examine whether the interface pressure (IP) relief provided by alternating pressure air mattresses (APAMs) is matched with maintenance of tissue perfusion over the points of contact by measuring transcutaneous oxygen and carbon dioxide (tcPO2, tcPCO2). DESIGN: Comparative analysis of 2 APAMs with a 2-parameter continuous time-based method for quantifying pressure relief (PR) and transcutaneous gas measurement for assessing tissue perfusion. SETTING: Rehabilitation research facility in a university hospital. PARTICIPANTS: Eleven able-bodied adult postgraduate student volunteers. MAIN OUTCOME MEASURES: Two full-replacement APAM systems were used. For each mattress the mean maximum and minimum interface pressures; mean peak air pressures in the mattresses; interface pressure durations below 30, 20, and 10 mmHg over a 60-minute period; mean maximum tcPCO2 and minimum tcPO2; and mean area under the tcPO2 and tcPCO2 curves were measured for each subject. RESULTS: IP on the sacrum was held below thresholds of 30, 20, and 10 mmHg longer on a 2-cell, low pressure system than on a 3-cell, high pressure system (p < .001). Integrated over time, tcPO2 levels also indicated that the 2-cell system retained oxygen levels closer to the unloaded baseline than did the 3-cell system (p < .01). tcPCO2 levels did not rise significantly (p > 0.1) compared with the baseline measurement in both mattresses. CONCLUSIONS: PR was sensitive to the design of the APAM, especially its inflation pressure, cycle time, and inflation sequence. If future trials demonstrate that PR values and transcutaneous blood gas measurements correlate significantly with the clinical incidence of pressure sore formation, then this technique may prove useful in assessing the effectiveness of alternating pressure support surfaces. School of Health Care Professions, University of Salford, UK. Rithalia S V SV Gonsalkorale M M eng Clinical Trial Journal Article

UNITED STATES Arch Phys Med Rehabil 8BK 2985158R AIM IM Adult Air Pressure Area Under Curve Beds Blood Gas Monitoring, Transcutaneous Comparative Study Decubitus Ulcer prevention & control Equipment Design Female Human Male Middle Age Partial Pressure Rehabilitation Sacrum Skin blood supply Statistics, Nonparametric 2000 10 13 11 2001 2 28 10 1 ppublish 0011030502 20483419 98199354 9538531 1998 04 24 1998 04 24 2000 12 18

0140-0118 35 6 1997 Nov Can blood flow in separate small tubes be quantitatively assessed by high-resolution laser Doppler imaging? 575-80 A method is suggested for quantitative flow assessment of whole-blood perfusing tubes with diameters in the range from 500 microns to 1.5 mm, for velocities below 9 mm s-1. The algorithm is based both on the Doppler broadening of backscattered laser light and the magnitude of the diameter of the perfused tube. A bandwidth-modified high-resolution laser Doppler perfusion imaging system is used to record the Doppler broadening. A flow model, consisting of a linearly narrowing tube (inner diameter 620-1330 microns), is connected to a precision infusion pump and perfused by human whole blood of volume flows ranging from 0 to 6.6 mm3 s-1. Empirical data are fitted into a regression model, and the parameters of the algorithm can be determined, resulting in a correlation coefficient of 0.975 between the predicted and true volume flows. Using this algorithm, volume flows in tubes of inner diameters of 500 microns, 750 microns and 1.4 mm are predicted, with accuracies corresponding to correlation coefficients of 0.994, 0.993 and 0.996. Department of Biomedical Engineering, Linköping University, Sweden. marli@imt.liv.se Lindén M M eng Journal Article

ENGLAND Med Biol Eng Comput LPN 7704869 IM Algorithms Blood Flow Velocity Blood Vessels ultrasonography Hemorheology methods Human Laser-Doppler Flowmetry methods Models, Cardiovascular Support, Non-U.S. Gov't 1998 04 16 02 24 1998 04 16 02 24 ppublish 0009538531 98199354 90091365 2689062 1990 01 26 1990 01 26 2000 12 18

0144-5979 9 6 1989 Dec Local skin pressure and its effects on skin microcirculation as evaluated by laser-Doppler fluxmetry. 535-45 The effect of prolonged local pressure on the skin microcirculation was investigated in the regions of the sacrum and gluteus maximus muscle to determine the aetiology of pressure sores. Thirty normal subjects (15 female, 15 male) were investigated. The subjects were divided into three age groups: group 1, less than or equal to 35 years; group 2, 36-64 years; and group 3, greater than or equal to 65 years. Local pressure was applied with a specially designed instrument according to the sequence 0----110----0----110----0----mmHg. Skin blood cell flux (SBF) was measured with a laser-Doppler technique and the local skin temperature measured with a thermistor. No significant differences were seen in SBF due to sex or age. However, differences between the two areas studied were observed. SBF was maximal over the sacrum at 12-50 mmHg (1.6-6.7 kPa) applied pressure. With further pressure increases, the SBF signal decreased successively, reaching minimum level at 110 mmHg (14.6 kPa), where it was approximately 43% below the initial value. The SBF in the gluteus region showed a more stable pattern, with a maximum SBF at 13-60 mmHg (1.7-8.0 kPa). At both locations, an increased SBF at zero pressure was seen when the pressure was decreased from 110 to 0 mmHg. The skin temperature (n = 7) increased by 2.7 degrees C (range 1.9-3.5 degrees C) over the gluteus and by 1.3 degrees C (range 0.8-2.5 degrees C) over the sacrum. This increase was more rapid over the gluteus region. Concomitantly a temperature-dependent increase of SBF could be seen. It is concluded that a cause for the greater frequency of pressure sores over the sacrum than over the gluteus region is the comparatively poorer regulation of microvascular flow in this area. Karolinska Institutet, Department of Geriatric Medicine, Huddinge Hospital, Stockholm, Sweden. Schubert V V Fagrell B B eng Journal Article

ENGLAND Clin Physiol DKG 8309768 IM Adult Aged Blood Flow Velocity physiology Buttocks Decubitus Ulcer