Evid Based Nurs 12:81 doi:10.1136/ebn.12.3.81
  • Treatment

Review: alternative-foam mattresses and some operating-table overlays reduce pressure ulcers more than standard surfaces


Do pressure-relieving surfaces reduce pressure ulcers more than standard support surfaces? Are some types of pressure-relieving surfaces more effective than others?


Included studies were randomised controlled trials (RCTs) that compared beds, mattresses, mattress overlays, and cushions in patients at risk of pressure ulcers and reported objective outcomes. Outcomes included incidence of new pressure ulcers.


Medline, CINAHL, EMBASE/Excerpta Medica, CINAHL, Cochrane Wounds Group Specialised Register, CENTRAL, and Cochrane Library (all to Feb 2008), and reference lists were searched. Experts and manufacturers were contacted. 52 RCTs were included.


Constant low-pressure (CLP) supports. Of 8 RCTs comparing CLP supports with standard mattresses, 5 showed a benefit for alternative-foam mattresses (pooled risk reduction [RR] 60%, 95% CI 26 to 79). Water beds (1 RCT, RR 65%, CI 21 to 85) and Beaufort bead beds (1 RCT, RR 68%, CI 24 to 86) reduced pressure ulcers, but viscoelastic foam trolley mattresses did not (1 RCT). In 5 RCTs, a benefit for 1 type of alternative-foam mattress over another was found for Vaperm v Clinifloat (1 RCT, RR 64%, CI 41 to 78) and Maxifloat Foam Mattress replacement v Iris Foam Overlay (1 RCT, RR 58%, CI 4 to 82). In 11 often-underpowered or flawed RCTs, a benefit for 1 type of CLP support over another was found for Optima CLP mattress v standard hospital mattress (1 RCT, RR 94%, CI 1 to 100), foam body support v usual care (1 RCT, RR 85%, CI 53 to 95), and medical sheepskins v usual care (2 RCTs, pooled RR 58%, CI 19 to 78).

Alternating pressure (AP) supports. 2 low-quality RCTs showed that AP surfaces reduced pressure ulcers more than a standard hospital mattress (pooled RR 69%, CI 42 to 83). 10 RCTs compared AP devices with CLP devices and found no difference between groups (pooled RR 15%, CI −13 to 36). Of 5 RCTs comparing different AP devices, none showed a benefit for 1 AP device over another. 2 pooled RCTs showed that low air-loss beds reduced pressure ulcers more than standard ICU beds (pooled RR 67%, CI 33 to 84). 1 RCT showed no difference between low air-loss hydrotherapy and standard-care beds.

Other pressure supports. 2 small RCTs showed no difference in pressure ulcers between kinetic turning tables and standard care. No pressure ulcers developed in groups assigned to a profiling bed with pressure-reducing foam mattress/cushion combination or to a flat-based bed with pressure-reducing foam mattress/cushion. Of 5 RCTs evaluating operating-table overlays, 1 showed a benefit for a viscoelastic polymer pad over a standard table (RR 47%, CI 15 to 67), and 2 showed a benefit for the Micropulse alternating system applied during and after surgery (pooled RR 79%, CI 30 to 94). 4 RCTs showed no difference between types of seat cushions.


Alternative-foam mattresses and medical sheepskins reduce pressure ulcers more than standard hospital mattresses or surfaces. Evidence for different types of alternating-pressure and constant low-pressure devices do not clearly favour one type over another. Some pressure-relieving overlays on operating tables reduce pressure ulcers. Different types of cushions do not differ for pressure ulcer incidence.


McInnes E, Bell-Syer SE, Dumville JC, et al. Support surfaces for pressure ulcer prevention. Cochrane Database Syst Rev 2008;(4):CD001735.

Clinical impact ratings: Elderly Care 7/7; General/internal medicine 6/7; Haematology (except oncology) 5/7; Home nursing 6/7; Palliative care 6/7; Perioperative 7/7; Rehabilitation 6/7; Surgery 6/7; Wound care 6/7


  • Source of funding: NIHR; NHS Health Technology Assessment Programme, UK; National Institute of Clinical Excellence Guidelines Programme, UK.


The review by McInnes et al highlights the uncertainties in the research on pressure ulcer prevention. It is not able to provide discrete, clear answers to the question of which pressure ulcer prevention device is best in a given situation. It does, however, confirm that those at risk of pressure ulcers benefit from a foam alternative (such as those made from high-specification foam) as a replacement for, or adjunct to, standard hospital mattresses.

This review is based on RCTs and controlled clinical trials (obtained by extensive searching), with meta-analysis where appropriate. However, with some exceptions, most of the studies are of poor quality. Therefore, the tentative nature of the review findings is appropriate. The review provides some interesting information about the potential of some types of pressure-relieving overlays on operating tables to reduce pressure ulcers.

Research in the field of pressure ulcer prevention is not yet of sufficient quality to provide clinicians with reliable knowledge to aid all decision making. Instead, groups of experienced clinicians and professional organisations need to continue to interpret the messy uncertainties of our current knowledge base and create consensus-developed guidelines.1 In addition, we need to persuade the manufacturers of pressure-relieving devices to collaborate with clinicians and researchers on large well-designed multicentre trials so that the very best quality knowledge is developed.


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