Abstract
Introduction
Unrelieved pressure or friction of the skin, particularly over bony prominences, can lead to pressure ulcers in up to one third of people in hospitals or community care, and one fifth of nursing home residents. Pressure ulcers are more likely in people with reduced mobility and poor skin condition, such as older people or those with vascular disease.
Methods and outcomes
We conducted a systematic review and aimed to answer the following clinical questions: What are the effects of preventive interventions in people at risk of developing pressure ulcers? What are the effects of treatments in people with pressure ulcers? We searched: Medline, Embase, The Cochrane Library, and other important databases up to June 2010 (Clinical Evidence reviews are updated periodically, please check our website for the most up-to-date version of this review). We included harms alerts from relevant organisations such as the US Food and Drug Administration (FDA) and the UK Medicines and Healthcare products Regulatory Agency (MHRA).
Results
We found 64 systematic reviews, RCTs, or observational studies that met our inclusion criteria. We performed a GRADE evaluation of the quality of evidence for interventions.
Conclusions
In this systematic review we present information relating to the effectiveness and safety of the following interventions: air-filled vinyl boots, air-fluidised supports, alternating-pressure surfaces (including mattresses), alternative foam mattresses, constant low-pressure supports, debridement, electric profiling beds, electrotherapy, hydrocellular heel supports, low-air-loss beds (including hydrotherapy beds), low-level laser therapy, low-tech constant-low-pressure supports, medical sheepskin overlays, nutritional supplements, orthopaedic wool padding, pressure-relieving overlays on operating tables, pressure-relieving surfaces, repositioning (regular "turning"), seat cushions, standard beds, standard care, standard foam mattresses, standard tables, surgery, therapeutic ultrasound, topical lotions and dressings, topical negative pressure, and topical phenytoin.
Key Points
Unrelieved pressure or friction of the skin, particularly over bony prominences, can lead to pressure ulcers, which affect up to one third of people in hospitals or community care, and one fifth of nursing home residents.
Pressure ulcers are more likely in people with reduced mobility and poor skin condition, such as older people or those with vascular disease.
Alternative foam mattresses (such as viscoelastic foam) reduce the incidence of pressure ulcers in people at risk compared with standard hospital foam mattresses, although we don't know which is the best alternative to use.
Low-air-loss beds may reduce the risk of pressure ulcers compared with standard intensive-care beds, and pressure-relieving overlays on operating tables may reduce the risk of pressure ulcer development.
Medical sheepskin overlays may reduce the risk of pressure ulcers compared with standard care.
Hydrocellular heel supports may decrease the risk of pressure ulcers compared with orthopaedic wool padding, but air-filled vinyl boots with foot cradles and low-air-loss hydrotherapy beds may increase the risk of ulcers compared with other pressure-relieving surfaces.
We don't know if other physical interventions, such as alternating-pressure surfaces, seat cushions, electric profiling beds, low-tech constant-low-pressure supports, repositioning, or topical lotions and dressings are effective for preventing pressure ulcers. We also don't know whether pressure ulcers can be prevented by use of nutritional interventions.
In people with pressure ulcers, air-fluidised supports may improve healing compared with standard care, although they can make it harder for people to get in and out of bed independently.
We don't know whether healing is improved in people with pressure ulcers by use of other treatments such as one specific specialised support surface (including alternating-pressure surfaces, low-tech constant-low-pressure supports, low-air-loss beds, and specific seat cushions) over any other specific specialised support surface, one specific wound dressing over any other specific wound dressing, or with surgery, electrotherapy, ultrasound, low-level laser therapy, topical negative pressure, topical phenytoin, or nutritional interventions.
About this condition
Definition
Pressure ulcers (also known as pressure sores, bed sores, and decubitus ulcers) may present as persistently hyperaemic, blistered, broken, or necrotic skin, and may extend to underlying structures, including muscle and bone. Pressure ulcers are usually graded on a scale of 1 to 4, with a higher grade indicating greater ulcer severity.
Incidence/ Prevalence
Reported prevalence rates range from 4.7% to 32.1% for hospital populations, 4.4% to 33.0% for community-care populations, and 4.6% to 20.7% for nursing-home populations.
Aetiology/ Risk factors
Pressure ulcers are caused by unrelieved pressure, shear, or friction. They are most common below the waist and at bony prominences, such as the sacrum, heels, and hips. They occur in all healthcare settings. Increased age, reduced mobility, impaired nutrition, vascular disease, faecal incontinence, and skin condition at baseline consistently emerge as risk factors. However, the relative importance of these and other factors is uncertain.
Prognosis
There are few data on prognosis of untreated pressure ulcers. The presence of pressure ulcers has been associated with a two- to four-fold increased risk of death in elderly people and people in intensive care. However, pressure ulcers are a marker for underlying disease severity and other comorbidities, rather than an independent predictor of mortality.
Aims of intervention
To prevent formation of a pressure ulcer; heal existing pressure ulcers; and improve quality of life, with minimal adverse effects of treatment.
Outcomes
Prevention of pressure ulcers, severity of pressure ulcers. Healing rates: rate of change of area and volume, time to heal, severity of pressure ulcers. Adverse effects of treatment. Interface pressure recorded at various anatomical sites is a surrogate outcome that is sometimes used in studies of preventive interventions, but has not yet been linked to clinical outcomes.
Methods
Clinical Evidence search and appraisal June 2010. The following databases were used to identify studies for this systematic review: Medline 1966 to June 2010, Embase 1980 to June 2010, and The Cochrane Database of Systematic Reviews, May 2010 [online] (1966 to date of issue). When editing this review we used The Cochrane Database of Systematic Reviews 2010, Issue 2. An additional search within The Cochrane Library was carried out for the Database of Abstracts of Reviews of Effects (DARE) and Health Technology Assessment (HTA). We also searched for retractions of studies included in the review. Abstracts of the studies retrieved from the initial search were assessed by an information specialist. Selected studies were then sent to the contributor for additional assessment, using predetermined criteria to identify relevant studies. Study design criteria for inclusion in this review were: published systematic reviews of RCTs and RCTs in any language, with any level of blinding, and containing any number of individuals with any level of loss to follow-up. There was no minimum length of follow-up required to include studies. We included studies described as "open", "open label", and not blinded. We included systematic reviews of RCTs and RCTs where harms of an included intervention were studied applying the same study design criteria for inclusion as we did for benefits. We reviewed all RCTs that used objective clinical outcome measures. For many trials we could not be sure that the size of pressure ulcers was distributed evenly between groups at baseline. Unequal distribution of wound size at baseline would have an impact on all measures of wound healing. Ideally, studies of treatment should stratify randomisation by initial wound area and include enough participants to ensure even distribution of baseline wound size. A further difficulty in assessing the trials of pressure ulcer prevention and treatment is that it can be difficult to determine from reports whether an RCT of a new device, for example a mattress, is sufficiently similar to be assessed with previously described mattresses, or whether it constitutes a new device. It can therefore be difficult to combine data from RCTs and assess overall effects of treatment options. In addition we use a regular surveillance protocol to capture harms alerts from organisations such as the FDA and the MHRA, which are added to the reviews as required. To aid readability of the numerical data in our reviews, we round many percentages to the nearest whole number. Readers should be aware of this when relating percentages to summary statistics such as relative risks (RRs) and odds ratios (ORs). We have performed a GRADE evaluation of the quality of evidence for interventions included in this review (see table). The categorisation of the quality of the evidence (high, moderate, low, or very low) reflects the quality of evidence available for our chosen outcomes in our defined populations of interest. These categorisations are not necessarily a reflection of the overall methodological quality of any individual study, because the Clinical Evidence population and outcome of choice may represent only a small subset of the total outcomes reported, and population included, in any individual trial. For further details of how we perform the GRADE evaluation and the scoring system we use, please see our website (www.clinicalevidence.com).
Table.
GRADE Evaluation of interventions for Pressure ulcers.
| Important outcomes | Healing rates, Prevention of pressure ulcers | ||||||||
| Studies (Participants) | Outcome | Comparison | Type of evidence | Quality | Consistency | Directness | Effect size | GRADE | Comment |
| What are the effects of preventive interventions in people at risk of developing pressure ulcers? | |||||||||
| 6 (2117) | Prevention of pressure ulcers | Foam alternatives versus standard hospital mattress | 4 | –1 | 0 | 0 | 0 | Moderate | Quality point deducted for incomplete reporting of results |
| 5 (795) | Prevention of pressure ulcers | Different foam alternatives versus each other | 4 | –1 | 0 | –2 | 0 | Very low | Quality point deducted for incomplete reporting of results. Directness points deducted for underpowered RCTs and small number of comparators |
| 5 (1402) | Prevention of pressure ulcers | Pressure-relieving overlays on operating tables versus standard table alone | 4 | −1 | −1 | −1 | 0 | Very low | Quality point deducted for weak methods. Consistency point deducted for conflicting results between RCTs. Directness point deducted for early termination of 1 RCT |
| 3 (283) | Prevention of pressure ulcers | Low-air-loss beds versus standard intensive-care beds/alternating-pressure mattresses | 4 | –2 | 0 | 0 | 0 | Low | Quality points deducted for incomplete reporting of intervention and weak methods |
| 2 (730) | Prevention of pressure ulcers | Medical sheep skin overlays versus standard care | 4 | 0 | 0 | –2 | +1 | Moderate | Directness points deducted for selective exclusion of high-risk participants and no intention-to-treat analysis. Effect size point added for RR <0.5 |
| 2 (409) | Prevention of pressure ulcers | Alternating-pressure surfaces versus standard foam mattress | 4 | −3 | 0 | −1 | +1 | Very low | Quality points deducted for unclear allocation concealment, blinding, and incomplete reporting of results. Directness point deducted for no intention-to-treat analysis. Effect size point added for RR <0.5 |
| 10 (1606) | Prevention of pressure ulcers | Alternating-pressure surfaces versus constant-low-pressure supports | 4 | −1 | 0 | −1 | 0 | Low | Quality point deducted for weak methods. Directness point deducted for unclear clinical relevance (heterogeneity in comparators, and wide confidence intervals not excluding clinically important effect) |
| 4 (2153) | Prevention of pressure ulcers | Alternating-pressure surfaces versus each other | 4 | −1 | 0 | −1 | 0 | Low | Quality point deducted for weak methods. Directness point deducted for 3 underpowered RCTs |
| 4 (473) | Prevention of pressure ulcers | Seat cushions versus each other | 4 | –1 | 0 | –1 | 0 | Low | Quality point deducted for weak methods. Directness point deducted for underpowered individual trials |
| 1 (70) | Prevention of pressure ulcers | Electric profiling beds to prevent pressure ulcers versus standard hospital beds | 4 | –1 | 0 | –1 | 0 | Low | Quality point deducted for sparse data. Directness point deducted for small number of events (no events in either group) |
| 5 (1475) | Prevention of pressure ulcers | Nutritional supplements versus control | 4 | –3 | 0 | –2 | 0 | Very low | Quality points deducted for unclear randomisation, lack of blinding, and high withdrawal rates. Directness points deducted for no intention-to-treat analysis and no between-group analysis in 1 RCT |
| 4 (1055) | Prevention of pressure ulcers | Repositioning versus control, usually standard care | 4 | –2 | 0 | –1 | 0 | Very low | Quality points deducted for weak methods and incomplete reporting of results. Directness point deducted for co-intervention in 1 RCT (change of mattress as well as frequency of repositioning) |
| 1 (46) | Prevention of pressure ulcers | Repositioning at 30 degree tilt versus a 90 degree lateral and supine position | 4 | –2 | 0 | –1 | 0 | Very low | Quality points deducted for sparse data and incomplete reporting of results. Directness point deducted for short follow-up (24 hours) |
| 3 (618) | Prevention of pressure ulcers | Topical lotions and dressings versus placebo or other lotions and dressings | 4 | –2 | 0 | –1 | 0 | Very low | Quality points deducted for incomplete reporting of results and poor follow-up. Directness point deducted for no intention-to-treat analysis |
| 1 (52) | Prevention of pressure ulcers | Air-filled vinyl boot versus hospital pillow | 4 | –2 | 0 | 0 | 0 | Low | Quality points deducted for sparse data and incomplete reporting of results |
| 1 (111) | Prevention of pressure ulcers | Hydrocellular heel supports versus orthopaedic wool padding/standard care | 4 | –2 | 0 | 0 | 0 | Low | Quality points deducted for sparse data and no intention-to-treat analysis |
| 1 (98) | Prevention of pressure ulcers | Low-air-loss hydrotherapy beds versus other specialised support surfaces | 4 | –2 | 0 | 0 | 0 | Low | Quality points deducted for sparse data and weak methods |
| What are the effects of treatments in people with pressure ulcers? | |||||||||
| 3 (202) | Healing rates | Air-fluidised supports versus standard care | 4 | –1 | 0 | –1 | 0 | Low | Quality point deducted for incomplete reporting of results. Directness point deducted for no intention-to-treat analysis |
| 5 (372) | Healing rates | Alternating-pressure surfaces versus standard/other care | 4 | –2 | 0 | 0 | 0 | Low | Quality points deducted for incomplete reporting of results and poor study completion rate |
| at least 32 (at least 208) | Healing rates | Debridement versus no debridement or different debriding agents versus each other | 4 | –3 | 0 | 0 | 0 | Very low | Quality points deducted for incomplete reporting of results, weak methods, and poor trial completion |
| 7 (at least 396) | Healing rates | Hydrocolloid dressings versus gauze soaked in saline, hypochlorite, or povidone iodine | 4 | –1 | 0 | –1 | 0 | Low | Quality point deducted for weak methods. Directness point deducted for significance of meta-analysis result being sensitive to the method of calculation |
| 15 (unclear) | Healing rates | Hydrocolloid dressings versus non-hydrocolloid dressings other than gauze soaked in saline, hypochlorite, or povidone iodine | 4 | –2 | 0 | 0 | 0 | Low | Quality points deducted for weak methods and incomplete reporting of results |
| 6 (154) | Healing rates | Electrotherapy versus sham electrotherapy or standard treatment | 4 | –2 | 0 | 0 | 0 | Low | Quality points deducted for weak methods and incomplete reporting of results |
| 4 (360) | Healing rates | Low-air-loss beds versus standard beds or standard care | 4 | –1 | 0 | –1 | 0 | Low | Quality point deducted for incomplete reporting of results. Directness point deducted for no statistical analysis between groups for 2 analyses |
| 2 (104) | Healing rates | Low-level laser treatment versus standard care or sham treatment | 4 | –2 | 0 | 0 | 0 | Low | Quality points deducted for sparse data and incomplete reporting of results |
| 1 (120) | Healing rates | Low-tech constant-low-pressure supports versus each other | 4 | –2 | 0 | 0 | 0 | Low | Quality points deducted for sparse data and incomplete reporting of results |
| 9 (400) | Healing rates | Nutritional supplements versus control | 4 | –2 | 0 | –1 | 0 | Very low | Quality points deducted for weak methods and incomplete reporting of results. Directness point deducted for no intention-to-treat analysis in some trials |
| 2 (235) | Healing rates | Seat cushions versus each other or standard care | 4 | –2 | 0 | –1 | 0 | Very low | Quality points deducted for incomplete reporting of results and weak methods. Directness point deducted for no intention-to-treat analysis (selective exclusion of participants from analysis) |
| 2 (128) | Healing rates | Ultrasound versus sham ultrasound | 4 | –3 | 0 | 0 | 0 | Very low | Quality points deducted for sparse data, weak methods, and incomplete reporting of results |
| 1 (18) | Healing rates | Ultrasound plus ultraviolet light versus standard care or versus laser treatment | 4 | –3 | 0 | 0 | 0 | Very low | Quality points deducted for sparse data, weak methods, and small number of events (3 failures in total in trial) |
| 2 (57) | Healing rates | Topical negative pressure versus control | 4 | –3 | 0 | 0 | 0 | Very low | Quality points deducted for sparse data, weak methods, and differences between groups at baseline |
| 3 (159) | Healing rates | Topical phenytoin versus control/standard treatment | 4 | –2 | –1 | –1 | 0 | Very low | Quality points deducted for sparse data and weak methods. Consistency point deducted for conflicting results. Directness point deducted for baseline differences |
We initially allocate 4 points to evidence from RCTs, and 2 points to evidence from observational studies. To attain the final GRADE score for a given comparison, points are deducted or added from this initial score based on preset criteria relating to the categories of quality, directness, consistency, and effect size. Quality: based on issues affecting methodological rigour (e.g., incomplete reporting of results, quasi-randomisation, sparse data [<200 people in the analysis]). Consistency: based on similarity of results across studies. Directness: based on generalisability of population or outcomes. Effect size: based on magnitude of effect as measured by statistics such as relative risk, odds ratio, or hazard ratio.
Glossary
- Air-fluidised supports
Membranes that cover a layer of particles that are fluidised by having air forced through them. The airflow can be turned off, which makes the surface solid again, to allow the person to be moved. People find it difficult to get in and out of these beds independently; therefore, they are usually reserved for people who spend most of the day in bed.
- Alternating-pressure surfaces
Mattresses or overlays made of one or two layers of parallel air sacs. Alternate sacs are inflated and deflated, which provides alternating pressure and release for each area of skin.
- Dextranomer paste
Anhydrous, porous beads 0.1 mm to 0.3 mm in diameter. These beads are hydrophilic and absorb and adsorb exudate, wound debris, and bacteria, depending on particle size.
- Electrotherapy
The application of electrical fields by placing electrodes near a wound. Treatments include pulsed electromagnetic therapy, low-intensity direct current, negative-polarity and positive-polarity electrotherapy, and alternating-polarity electrotherapy.
- Low- or high-tech constant-low-pressure supports
Mattresses, overlays, and cushions made of high-density or contoured foam or filled with fibre, gel, water, beads, or air. They increase the area of contact between the person and the support surface and thus reduce the pressure at the interface. See also air-fluidised supports, low-air-loss beds, and low-air-loss hydrotherapy beds.
- Low-air-loss beds
Mattresses that consist of inflatable upright sacs of semipermeable fabric. Inflation of the sacs increases the area of contact between the individual and the support surface and reduces the pressure on the skin. People find it difficult to get in and out of these beds independently; therefore, they are usually reserved for people who spend most of the day in bed.
- Low-air-loss hydrotherapy beds
A mattress that consists of cushions covered by a permeable, fast-drying filter sheet, through which air is circulated. The bed also contains a urine-collecting device.
- Low-quality evidence
Further research is very likely to have an important impact on our confidence in the estimate of effect and is likely to change the estimate.
- Moderate-quality evidence
Further research is likely to have an important impact on our confidence in the estimate of effect and may change the estimate.
- Therapeutic ultrasound
The application of ultrasound to a wound with a transducer and water-based gel. The power of ultrasound waves used in wound healing is low to avoid heating the tissues.
- Topical negative pressure
Negative pressure (suction) applied to a wound through an open-cell dressing (e.g., foam or felt).
- Very low-quality evidence
Any estimate of effect is very uncertain.
Disclaimer
The information contained in this publication is intended for medical professionals. Categories presented in Clinical Evidence indicate a judgement about the strength of the evidence available to our contributors prior to publication and the relevant importance of benefit and harms. We rely on our contributors to confirm the accuracy of the information presented and to adhere to describe accepted practices. Readers should be aware that professionals in the field may have different opinions. Because of this and regular advances in medical research we strongly recommend that readers' independently verify specified treatments and drugs including manufacturers' guidance. Also, the categories do not indicate whether a particular treatment is generally appropriate or whether it is suitable for a particular individual. Ultimately it is the readers' responsibility to make their own professional judgements, so to appropriately advise and treat their patients. To the fullest extent permitted by law, BMJ Publishing Group Limited and its editors are not responsible for any losses, injury or damage caused to any person or property (including under contract, by negligence, products liability or otherwise) whether they be direct or indirect, special, incidental or consequential, resulting from the application of the information in this publication.
References
- 1.European Pressure Ulcer Advisory Panel (EPUAP). Guideline on treatment of pressure ulcers. Oxford: EPUAP, 1999. Available at http://www.epuap.org/gltreatment.html (last accessed 24 March 2011). [Google Scholar]
- 2.Kaltenhaler E, Whitfield MD, Walters SJ, et al. UK, USA, and Canada: how do their pressure ulcer prevalence and incidence data compare? J Wound Care 2001;10:530–535. [DOI] [PubMed] [Google Scholar]
- 3.Reed RL, Hepburn K, Adelson R, et al. Low serum albumin levels, confusion and faecal incontinence: are these risk factors for pressure ulcers in mobility-impaired hospitalised adults? Gerontology 2003;49:255–259. [DOI] [PubMed] [Google Scholar]
- 4.Allman RM. Pressure ulcer prevalence, incidence, risk factors, and impact. Clin Geriatr Med 1997;13:421–436. [PubMed] [Google Scholar]
- 5.Thomas DR, Goode PS, Tarquine PH, et al. Hospital acquired pressure ulcers and risk of death. J Am Geriatr Soc 1996;44:1435–1440. [DOI] [PubMed] [Google Scholar]
- 6.Clough NP. The cost of pressure area management in an intensive care unit. J Wound Care 1994;3:33–35. [DOI] [PubMed] [Google Scholar]
- 7.McInnes E, Cullum NA, Bell-Syer SE, et al. Support surfaces for pressure ulcer prevention. In: The Cochrane Library, Issue 2, 2010. Chichester, UK: John Wiley & Sons, Ltd. Search date 2008. 18843621 [Google Scholar]
- 8.Reddy M, Gill SS, Rochon PA. Preventing pressure ulcers: a systematic review. JAMA 2006;296:974−984. [DOI] [PubMed] [Google Scholar]
- 9.Theaker C, Kuper M, Soni N. Pressure ulcer prevention in intensive care – a randomised control trial of two pressure-relieving devices Anaesthesia 2005;60:395–399. [DOI] [PubMed] [Google Scholar]
- 10.Nixon J, Nelson EA, Cranny G, et al. Pressure relieving support surfaces: a randomised evaluation. Health Technol Assess 2006;10:1–163. [DOI] [PubMed] [Google Scholar]
- 11.Nixon J, Cranny G, Iglesias C, et al. Randomised, controlled trial of alternating pressure mattresses compared with alternating pressure overlays for the prevention of pressure ulcers: PRESSURE (pressure relieving support surfaces) trial. BMJ 2006;332:1413−1417. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 12.Iglesias C, Nixon J, Cranny G, et al. Pressure relieving support surfaces (PRESSURE) trial: Cost effectiveness analysis. BMJ 2006;332:1416−1418. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 13.Langer G, Schloemer G, Knerr A, et al. Nutritional interventions for preventing and treating pressure ulcers. In: The Cochrane Library, Issue 2, 2010. Chichester, UK: John Wiley & Sons, Ltd. Search date 2002. [Google Scholar]
- 14.Ek AC, Unosson M, Larsson J, et al. The development and healing of pressure sores related to the nutritional state. Clin Nutr 1991;10:245−250. [DOI] [PubMed] [Google Scholar]
- 15.Cullum N, Deeks JJ, Fletcher AW, et al. Preventing and treating pressure sores. Qual Health Care 1995;4:289–297. Search date 1995. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 16.Defloor T, De Bacquer D, Grypdonck MH. The effect of various combinations of turning and pressure reducing devices on the incidence of pressure ulcers. Int J Nurs Stud 2005;42:37–46. [DOI] [PubMed] [Google Scholar]
- 17.Young T. The 30 degree tilt position vs the 90 degree lateral and supine positions in reducing the incidence of non-blanching erythema in a hospital inpatient population: a randomised controlled trial. J Tissue Viability 2004;14:88−86. [DOI] [PubMed] [Google Scholar]
- 18.O'Meara SM, Cullum NA, Majid M, et al. Systematic review of antimicrobial agents used for chronic wounds. Br J Surg 2001;88:4–21. Search date 2000. [DOI] [PubMed] [Google Scholar]
- 19.Torra i Bou JE, Segovia Gomez T, Verdu Soriano J, et al. The effectiveness of a hyperoxygenated fatty acid compound in preventing pressure ulcers. J Wound Care 2005;14:117–121. [DOI] [PubMed] [Google Scholar]
- 20.Torra i Bou JE, Rueda Lopez J, Canames G, et al. Heel pressure ulcers. Comparative study between heel protective bandage and hydrocellular dressing with special form for the heel. Rev Enferm 2002;25:50–56. [in Spanish] [PubMed] [Google Scholar]
- 21.Cullum N, Nelson EA, Flemming K, et al. Systematic reviews of wound care management: (5) beds; (6) compression; (7) laser therapy, therapeutic ultrasound, electrotherapy and electromagnetic therapy. Health Technol Assess 2001;5:1–221. Search date 2000. [DOI] [PubMed] [Google Scholar]
- 22.Reddy M, Gill SS, Kalkar SR, et al. Treatment of pressure ulcers: a systematic review. JAMA 2008;300:2647–2662. [DOI] [PubMed] [Google Scholar]
- 23.Bradley M, Cullum N, Sheldon T. The debridement of chronic wounds: a systematic review. Health Technol Assess 1999;3:1–78. Search date 1998. [PubMed] [Google Scholar]
- 24.Bradley M, Cullum N, Nelson EA, et al. Systematic reviews of wound care management: (2). Dressings and topical agents used in the healing of chronic wounds. Health Technol Assess 1999;3:1–35. Search date 1997. [PubMed] [Google Scholar]
- 25.Altman DG, Deeks JJ, Sackett DL. Odds ratios should be avoided when events are common. BMJ 1998;317:1318. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 26.Houghton PE, Campbell KE, Fraser CH, et al. Electrical stimulation therapy increases rate of healing of pressure ulcers in community-dwelling people with spinal cord injury. Arch Phys Med Rehabil 2010;91:669–678. [DOI] [PubMed] [Google Scholar]
- 27.Gentzkow GD, Pollack SV, Kloth LC, et al. Improved healing of pressure ulcers using dermapulse, a new electrical stimulation device. Wounds 1991;3:158–170. [Google Scholar]
- 28.Adunsky A, Ohry A. Decubitus direct current treatment (DDCT) of pressure ulcers: results of a randomized double-blinded placebo controlled study. Arch Gerentol Geriatr 2005;41:261–269. [DOI] [PubMed] [Google Scholar]
- 29.Bennett RG, Baran PJ, DeVone L, et al. Low airloss hydrotherapy versus standard care for incontinent hospitalized patients. J Am Geriatr Soc 1998;46:569–576. [DOI] [PubMed] [Google Scholar]
- 30.Cereda E, Gini A, Pedrolli C, et al. Disease-specific, versus standard, nutritional support for the treatment of pressure ulcers in institutionalized older adults: a randomized controlled trial. J Am Geriatr Soc 2009;57:1395–1402. [DOI] [PubMed] [Google Scholar]
- 31.Desneves KJ, Todrovic BE, Cassar A, et al. Treatment with supplementary arginine, vitamin C and zinc in patients with pressure ulcers: a randomised controlled trial. Clin Nutr 2005;24:979–987. [DOI] [PubMed] [Google Scholar]
- 32.Lee SK, Posthauer ME, Dorner B, et al. Pressure ulcer healing with a concentrated, fortified, collagen protein hydrolysate supplement: a randomized controlled trial. Advances Skin Wound Care 2006;19:92−96. [DOI] [PubMed] [Google Scholar]
- 33.Rosenthal MJ, Felton RM, Natasi AE, et al. Healing of advanced pressure ulcers by a generic total contact seat: 2 randomized comparisons with low air loss bed treatments. Arch Phys Med Rehabil 2003;84:1733–1742. [DOI] [PubMed] [Google Scholar]
- 34.Akbari Sari A, Flemming K, Cullum NA, et al. Therapeutic ultrasound for pressure ulcers. In: The Cochrane Library, Issue 2, 2010. Chichester, UK: John Wiley & Sons, Ltd. Search date 2008. [Google Scholar]
- 35.Ubbink DT, Westerbros SJ, Evans D, et al. Topical negative pressure for treating chronic wounds. In: The Cochrane Library, Issue 2, 2010. Chichester, UK: John Wiley & Sons, Ltd. Search date 2007. [Google Scholar]
- 36.Van Den Boogaard M, De Laat E, Spauwen P, et al. The effectiveness of topical negative pressure in the treatment of pressure ulcers: a literature review. Eur J Plast Surg 2008;31:1–7. [Google Scholar]
- 37.Rhodes RS, Heyneman CA, Culbertson VL, et al. Topical phenytoin treatment of stage II decubitus ulcers in the elderly. Ann Pharmacother 2001;35:675–681. [DOI] [PubMed] [Google Scholar]
- 38.Hollisaz MT, Khedmat H, Yari F. A randomized clinical trial comparing hydrocolloid, phenytoin and simple dressings for the treatment of pressure ulcers. BMC Dermatol 2005;4:18. [DOI] [PMC free article] [PubMed] [Google Scholar]