Potential risk of SARS-CoV-2 infection among people handling linens used by COVID-19 patients before and after washing

The risk of SARS-CoV-2 infection when people handle linens is uncertain. We examined the presence of SARS-CoV-2 on linens, in the air, and on personal protective equipment (PPE) to assess potential infection risk among individuals who handle linens used by SARS-CoV-2-infected people. Patients in a hospital and an accommodation facility who tested positive for SARS-CoV-2 participated in this study in 2020. Linen samples before washing or disinfection, rinse water after washing or disinfection, air in the workplace at the hospital and an accommodation facility, and the PPE worn by linen-handling people were tested for SARS-CoV-2 RNA and viable viruses. Among 700 samples from 13 SARS-CoV-2-infected participants and their surrounding environment, SARS-CoV-2 RNA was detected from 14% (52/362) of the linens used by COVID-19 patients (cycle threshold [Ct] value: 33-40). SARS-CoV-2 RNA was detected from 8% (2/26) of rinse water after washing or disinfection, from 15% (16/104) of air samples in the workspace, and from 10% (5/52) of gowns worn by linen-handling people, all with high Ct values (> 36). No SARS-CoV-2 was isolated from any samples. The potential risk of SARS-CoV-2 infection from handling linens used by SARS-CoV-2-infected people exists but appears to below.

Evaluation of gaseous and solid waste in fermentation bedding system and its impact on animal performance: A study of breeder ducks in winter

In order to further optimize the application of fermentation bedding system and evaluate its improvements on low temperature, low humidity and other adverse environments of animal breeding in winter, we tested the waste discharge and performance of 12,921 breeder ducks from November to January. The fresh bedding materials and fermentation microbes showed significant advantages. They increased the temperature and temperature humidity index (THI) by more than 3.48 °C and 5.54, reduced the emissions of H₂S, NH₃, CO₂, fine particulate matter (PM_2.5), coarse particulate matter (PM₁₀) and total suspended particulate (TSP) by more than 29.92%, 47.21%, 13.69%, 25.90%, 23.43% and 25.94% respectively, compared to control. The stale bedding materials increased the mortality rate and breeding egg loss rate of breeder ducks by 0.17% and 4.22% significantly, reduced the healthy duckling rate and total effective hatching rate by 2.41% and 4.22%, compared to control, had limited effects on the improvement of house environments. PM_2.5, TSP, CO₂, H₂S and NH₃ were important environmental parameters affecting the productive and reproductive performance of ducks. These data can provide an insight that the fermentation bed system could reduce the waste emission of breeder ducks, improve their production and increase the health rate of their offspring. Its application in livestock farming would create a better breeding environment and economic benefits. In addition, the stale bedding materials were not recommended to recycle in fermentation bed system for cleaner production and sustainable development.

Using Sterile Flocked Swabs as an Alternative Method for Rodent Health Monitoring

Routine health monitoring is an integral part of managing SPF rodent colonies. In recent years, rack-level environmental sampling has been introduced as an adjunct method or replacement for exposure of sentinel rodents to soiled bedding. However, rack-level environmental monitoring is not compatible with rodent housing systems that have cage-level filtration. The current study investigated whether exposure of sterile flocked swabs to soiled bedding can be an alternative sampling method for routine health monitoring in mice, thus replacing the use of sentinels in soiled-bedding cages. Flocked swabs were placed in cages containing pooled samples of soiled bedding but no mice; swabs remained there for 90 d, with weekly agitation and biweekly swabbing of the cage floor to mimic the agitation of soiled bedding by sentinel mice and facilitate the collection of dust particles. Fecal samples were collected from both colony and sentinel mice. For environmental samples, exhaust debris was collected from the rack plenum, and dust samples were collected from the exhaust hose. All samples were collected on days 88 through 91 and were tested for multiple pathogens by using real-time PCR assays. To determine the diagnostic agreement of flocked swab sampling with the other methods, we used κ statistics to compare the test results from flocked swabs with those from sentinel feces, exhaust debris, and colony animal feces; we found excellent agreement between the colony feces and the flocked swab methods. The sterile flocked swab method detected all enzootic pathogens in the colonies tested. Results from flocked swab samples had the least agreement with sentinel feces, which also failed to detect the presence of fur mites. This study supports the use of sterile flocked swabs as alternative to using sentinel mice, thus conforming to the guiding principles of replacement and reduction in the use of animals for routine colony health monitoring.

A multicentre study on spontaneous in-cage activity and micro-environmental conditions of IVC housed C57BL/6J mice during consecutive cycles of bi-weekly cage-change

Mice respond to a cage change (CC) with altered activity, disrupted sleep and increased anxiety. A bi-weekly cage change is, therefore, preferred over a shorter CC interval and is currently the prevailing routine for Individually ventilated cages (IVCs). However, the build-up of ammonia (NH₃) during this period is a potential threat to the animal health and the literature holds conflicting reports leaving this issue unresolved. We have therefor examined longitudinally in-cage activity, animal health and the build-up of ammonia across the cage floor with female and male C57BL/6 mice housed four per IVC changed every other week. We used a multicentre design with a standardised husbandry enabling us to tease-out features that replicated across sites from those that were site-specific. CC induce a marked increase in activity, especially during daytime (~50%) when the animals rest. A reduction in density from four to two mice did not alter this response. This burst was followed by a gradual decrease till the next cage change. Female but not male mice preferred to have the latrine in the front of the cage. Male mice allocate more of the activity to the latrine free part of the cage floor already the day after a CC. A behaviour that progressed through the CC cycle but was not impacted by the type of bedding used. Reducing housing density to two mice abolished this behaviour. Female mice used the entire cage floor the first week while during the second week activity in the latrine area decreased. Measurement of NH₃ ppm across the cage floor revealed x3 higher values for the latrine area compared with the opposite area. NH₃ ppm increases from 0–1 ppm to reach ≤25 ppm in the latrine free area and 50–100 ppm in the latrine area at the end of a cycle. As expected in-cage bacterial load covaried with in-cage NH₃ ppm. Histopathological analysis revealed no changes to the upper airways covarying with recorded NH₃ ppm or bacterial load. We conclude that housing of four (or equivalent biomass) C57BL/6J mice for 10 weeks under the described conditions does not cause any overt discomfort to the animals.

Detection and Transmission of Proteus mirabilis in Immunodeficient Mice

The exclusion of opportunistic pathogens is important for protecting animal health and ensuring desired research outcomes in highly immunodeficient mice. Proteus mirabilis has been associated with gastrointestinal tract lesions, septicemia, pyelonephritis, splenomegaly, and hepatitis and can influence select mouse models. To inform health-surveillance practices after we experienced difficulty in excluding P. mirabilis from our mouse colony, we aimed to determine the likelihood of detecting P. mirabilis-positive immunocompromised (SRG), immunovague (Fbn1+/-), and immunocompetent (CD1) colony mice through culture and PCR testing; to evaluate transmission via 2 sentinel-based approaches (direct contact and indirect dirty-bedding transfer); and to further characterize associated pathology. We hypothesized that immunocompromised mice would be better detectors and transmitters of P. mirabilis. Multiple logistic regression models were used for analysis and included PCR copy number, repeated testing, age, sex, and antibiotic-treated (trimethoprim-sulfamethoxazole) diet as covariates. Repeated testing over 10 wk showed that P. mirabilis -colonized immunocompromised colony mice were 95 times more likely than immunocompetent mice to test positive by culture and 30 times more likely by PCR assay. Sentinel mice were 15 times more likely to test positive by PCR assay for P. mirabilis when exposed by direct contact compared with dirty bedding and 18 times more likely to test positive when exposed to positive immunocompromised as compared with immunocompetent colony mice. After 10 wk of exposure, 3.8% of dirty-bedding sentinel PCR tests were positive, as compared with 30.7% of contact sentinels. Only immunocompromised mice on antibiotic diet (37.5%) developed lesions of the urogenital tract and abdominal cavity consistent with known pathology of P. mirabilis. Our findings suggest that PCR testing of dirty-bedding sentinels alone is not sufficient for the detection of P. mirabilis in mouse colonies. Direct-contact sentinels and testing of colony mice-especially if immunocompromised-with adjunct culture may facilitate successful bioexclusion.

Effectiveness of treatment of bedding and feces of laboratory animal with ozone

BACKGROUND

The incineration and burying of the soiled bedding of laboratory animals, as well as using detergents to treat their feces, is hazardous to the environment. This highlights the need for an alternative, environmentally friendly solution for the treatment of the waste of laboratory animal facilities. This study aims to evaluate the efficacy of ozone disinfection of the soiled bedding and feces of laboratory animals.

METHODS

Two grams of soiled beddings were randomly sampled from the cages of mice and rats. These samples were mixed in a beaker with 40ml saline. Ozone was piped into the beaker at a concentration of 500mg/h. Samples were taken from the beaker at time 0min, 30min, 45min and 60min after ozone treatment for microbiological culturing in an incubator for 48h. Colony form unit of each plate (CFU/plate) at each time point were counted, the mean CFU/plate at each time point after ozone treatment were compared with that present at time zero. Feces of rabbits and dogs were treated and pathogens were counted the similar way as that of bedding of the mice and rats; samples being taken at 0min, 15min, 30min, 45min and 60min.

RESULTS

Pathogens were observed in beddings of both mice and rats as well as in feces of rabbits and dogs. Ozone treatment for 30min killed more than 93% of pathogens in the bedding of the two rodent species and 60min of treatment killed over 99% of pathogens. Treatment of rabbit and dog feces for 30min killed over 96% pathogens present, and 60min's treatment killed nearly all the pathogens. Both Gram positive and Gram negative pathogens were sensitive to ozone treatment.

CONCLUSION

Ozone treatment of bedding and feces is an effective and environment friendly way to deal with the waste of animal facilities, saving energy and potentially enabling their reuse as fertilizer.

What is the better choice for nurses? Alternating air pressure mattresses versus static air mattresses to prevent pressure ulcers in elderly hospitalized patients: A protocol for systematic review and meta-analysis

BACKGROUND

Evidence on the comparative effectiveness between commercially available support surfaces in preventing pressure ulcer development is lacking. The purpose of this study was to compare the efficacy and safety of alternating air pressure mattresses (AAPMs) versus static air mattresses to prevent pressure ulcers in elderly hospitalized patients and to provide evidence for clinical practice.

METHODS

The electronic databases of Cochrane Library, EMBASE, PubMed, and Web of Science will be searched in April 2022 using the following key terms: "pressure ulcers," "support surface," and "pressure mattresses," for all relevant studies. Only English publications are included. The primary outcome is the incidence of pressure ulcers; secondary outcomes include patient satisfaction, cost, and other bedridden complications. The Cochrane risk of bias tool will be independently used to evaluate the risk of bias of included randomized cohort studies by 2 reviewers. A modified version of the Downs and Black tool is adopted to evaluate the quality of nonrandomized cohort studies. All outcomes are pooled on random-effect model.

RESULTS

We hypothesized that group with AAPMs will provide better therapeutic benefits compared with control group.

CONCLUSIONS

It is worthy to critically review the evidence of the assessment of AAPMs and static air mattresses to inform clinical practice.

OSF REGISTRATION NUMBER

10.17605/OSF.IO/MYPZ2.

Linen: The New Frontier in Infection Control and Prevention

Personnel follow hospital policies and regulatory guidelines to prevent surgical site infections. However, a potentially contaminated item may be overlooked-the linen. When perioperative team members transport patients to the OR, the linen on the beds and transport carts can contain a variety of microorganisms. Textile surfaces can serve as reservoirs for microorganisms that can be transferred to health care providers, patients, and the environment. These pathogens may then infect patients, particularly those who are immunocompromised or have direct portals of entry (eg, catheters, incision sites). This article provides an overview of how microorganisms that cause health care-associated infections can survive and thrive on hospital linen and related equipment; discusses the linen laundering, transport, and storage processes and best practices; and discusses antimicrobial interventions-including a silver-ion laundering additive that was added as an infection prevention measure to the laundry production cycle at a medical center's contracted laundry facility.

Bedding as an Enrichment Strategy in Group-housed Mauritian Cynomolgus Macaques (Macaca fascicularis)

The research community is committed to improving the well-being of nonhuman primates by providing opportunities to express species-specific behaviors such as foraging. In the wild, macaques spend a large part of their day foraging; this behavior is greatly limited in captivity. Bedding (wood shavings substrate) has been shown to promote foraging in rhesus macaques. However, the amount of bedding needed to affect these changes is unknown. Further, few studies have examined other benefits of bedding, including its potential to reduce noise levels, which can negatively impact welfare. We examined the use of bedding substrate in male Mauritius cynomolgus macaques (2-3-y-old) living in one of 2 social groups with either a full bale of bedding (that is, approximately 6 in of substrate) or a half bale (approximately 3 in) added to the pens for 10 d, followed by 4 d without bedding. We performed focal observations on 8 monkeys biweekly for 8 wk and used a dosimeter to measure sound in the room for 42 d. As expected, monkeys spent significantly more time foraging and less time self-grooming when bedding was present than when it was not. The amount of bedding did not make a difference. The presence of bedding did not affect social grooming or aggression, although it did help to dampen sound. Both peak and mean sound levels were lower with a full bale of bedding than with no bedding. Taken together, these results suggest that bedding is an effective enrichment strategy that can improve welfare of group-housed macaques.

Pressure redistributing static chairs for preventing pressure ulcers

BACKGROUND

Sitting can be viewed as a therapeutic intervention and an important part of a person's recovery process; but the risk of ulceration must be mitigated. Interventions for ulcer prevention in those at risk from prolonged sitting include the use of specialist cushions and surfaces, especially for wheelchair users. Whilst there is interest in the effects of different pressure redistributing cushions for wheelchairs, the benefits of pressure redistributing static chairs, compared with standard chairs, for pressure ulcer development in at-risk people are not clear.

OBJECTIVES

To assess the effects of pressure redistributing static chairs on the prevention of pressure ulcers in health, rehabilitation and social care settings, and places of residence in which people may spend their day.

SEARCH METHODS

In June 2021 we searched the following electronic databases to identify reports of relevant randomised clinical trials: the Cochrane Wounds Specialised Register, the Cochrane Central Register of Controlled Trials (CENTRAL), Ovid MEDLINE, Ovid Embase and EBSCO CINAHL Plus (Cumulative Index to Nursing and Allied Health Literature). We also searched clinical trials registers for ongoing and unpublished studies, and reference lists of relevant systematic reviews, meta-analyses and health technology reports. There were no restrictions by language, date of publication or study setting.

SELECTION CRITERIA

We sought to include published or unpublished randomised controlled trials that assessed pressure redistributing static chairs in the prevention or management of pressure ulcers.

DATA COLLECTION AND ANALYSIS

Two review authors independently performed study selection. We planned that two review authors would also assess the risk of bias, extract study data and assess the certainty of evidence according to GRADE methodology.

MAIN RESULTS

We did not identify any studies that met the review eligibility criteria, nor any registered studies investigating the role of pressure redistributing static chairs in the prevention or management of pressure ulcers.

AUTHORS' CONCLUSIONS

Currently, there is no randomised evidence that supports or refutes the role of pressure redistributing static chairs in the prevention or management of pressure ulcers. This is a priority area and there is a need to explore this intervention with rigorous and robust research.

Co-digestion of deep bedding and wastewater from pig farming: A new strategy for bioenergy increase and biofertilizer recovery

In the present study, a pilot-scale plug flow reactor was used for anaerobic co-digestion of swine wastewater (SWW) and deep bedding (DB). The reactor was operated with organic loads between 315.6 and 782.8 kgCOD d^-1 in winter and summer. The experiment was conducted in 4 phases with the addition of DB in SWW in proportions of 0, 5, 10 and 15 tons. Biogas productions 3 times higher were recorded when 15 ton of DB were applied, generating 634.5 kWh d^-1 of bioenergy in summer and 267 kWh d^-1 in winter. Application of DB in winter promoted stability in biogas production. CH₄ concentrations from 60 to 68% were recorded in winter and from 61 to 72% in summer. Methane yield was maximum in summer with application of 15 ton of DB (0.343 m³ KgCOD_Rem^-1). Removals of volatile solids and COD were within the ranges of 60-70 and 61-84%, respectively. There was no accumulation of volatile fatty acids (VFAs), nor pronounced decrease of pH in the reactor. The biofertilizer produced in all experimental stages can be used for agricultural cultivation with application rate defined based on the concentrations of Na and K to avoid soil salinization.

Root GS and NADH-GDH Play Important Roles in Enhancing the Ammonium Tolerance in Three Bedding Plants

Ammonium is a paradoxical nutrient because it is more metabolically efficient than nitrate, but also causes plant stresses in excess, i.e., ammonium toxicity. Current knowledge indicates that ammonium tolerance is species-specific and related to the ammonium assimilation enzyme activities. However, the mechanisms underlying the ammonium tolerance in bedding plants remain to be elucidated. The study described herein explores the primary traits contributing to the ammonium tolerance in three bedding plants. Three NH4+:NO3− ratios (0:100, 50:50, 100:0) were supplied to salvia, petunia, and ageratum. We determined that they possessed distinct ammonium tolerances: salvia and petunia were, respectively, extremely sensitive and moderately sensitive to high NH4+ concentrations, whereas ageratum was tolerant to NH4+, as characterized by the responses of the shoot and root growth, photosynthetic capacity, and nitrogen (amino acid and soluble protein)-carbohydrate (starch) distributions. An analysis of the major nitrogen assimilation enzymes showed that the root GS (glutamine synthetase) and NADH-GDH (glutamate dehydrogenase) activities in ageratum exhibited a dose-response relationship (reinforced by 25.24% and 6.64%, respectively) as the NH4+ level was raised from 50% to 100%; but both enzyme activities were significantly diminished in salvia. Besides, negligible changes of GS activities monitored in leaves revealed that only the root GS and NADH-GDH underpin the ammonium tolerances of the three bedding plants.

Performance and Consistency of Circulating Warm Water Blankets for Rodents

General anesthesia as used for rodent research can have adverse effects on physiologic mechanisms. Thermoregulation is often greatly inhibited, with resultant deleterious effects on cardiac and respiratory function. These potential effects can be mitigated by providing external heat support. The circulating warm water blanket and associated heat pump are often used in rodent procedures. The current study demonstrated that the heating pump and water blanket require quality control assessment to ensure adequate function. Our data showed that of the 6 pumps tested, 5 were able to achieve a temperature that met or exceeded the documented thermoneutral zone for mice. Pumps required 20 min of warming to reach their maximal attainable temperatures for the designated user setting. Although the pumps reached a temperature that was sufficient to provide external thermal support, only 1 of the 6 pumps reached the temperature that was set by the user during the trial. Surface temperatures across the water blanket were recorded to analyze whether a difference in heat support was influenced by animal placement along the water blanket; however, the location points did not yield statistically different results. Two pumps were eliminated from the study due to failure to pass the preparation phase of the trial. The results of this study support the need for facilities to establish quality control measures to ensure that heat support systems are functioning at a level required to maintain normothermia during anesthetic procedures.

The Mystery of Mount Vesuvius's Crosses: Belief, Credulity, and Credibility in Post-Reformation Catholicism

In the summer of 1660, Mount Vesuvius began to erupt. After about a month, the volcano quieted down, but a strange and upsetting phenomenon started to manifest: all over the city of Naples and in the neighboring communities, a series of red and black crosses appeared on people's linens, clothes, and bodies. This essay focuses on this mysterious appearance and on the debate it provoked, using it as a case study to investigate the relationship between credulity, credibility, and belief in post-Reformation Catholicism.

Behavioral and Physiologic Effects of Dirty Bedding Exposure in Female ICR Mice

Exposure of sentinel mice to dirty bedding is commonly used in health monitoring programs to screen colonies for clinical and subclinical disease. Despite the potential stressors present in dirty bedding, including but not limited to microorganisms, pheromones, and ammonia, it is unknown whether sentinel mice exposed to soiled bedding experience stress. In this study, select behavioral and physiologic changes associated with stress were assessed in female ICR mice exposed to dirty bedding. Behavioral parameters included evaluation in the home cage and selected behavioral tests; physiologic measurements included neutrophil:lymphocyte ratio and weight. Mice in the acute group were exposed for 24 h whereas mice in the chronic group were exposed for 4 wk. Mice in the chronic group exposed to dirty bedding weighed less at days 21 and 28 than did control mice. Chronic mice exposed to dirty bedding also exhibited decreased net weight gain over the entire study period as compared with control mice. No significant differences were detected in the other behavioral and physiologic parameters measured. These results indicate that dirty bedding exposure may affect sentinel mice, but further investigation is needed to determine the specific mechanism(s) behind the weight difference.

Successful Outcome of Transfixation Technique with Linen in Dorsal Wrist Ganglion: A Descriptive Cross-sectional Study

INTRODUCTION

Ganglion is a commonly encountered soft tissue tumor. Most commonly patients seek treatment for cosmetic issues. There are a variety of treatment options available but very few are effective and cosmetically acceptable. Common treatment techniques have either high recurrence rates or have complications. Treatment by transfixation with linen suture under local anaesthesia on an outpatient basis is an upcoming treatment. The objective of the study is to find out the prevalence of successful outcome of transfixation techniques in treatment of dorsal wrist ganglion.

METHODS

This study is a descriptive cross-sectional study undertaken at a tertiary care center from November 2018 to May 2020. Ethical approval was taken from the same institution. Convenient sampling method was used. Patients presenting with dorsal wrist ganglion and consenting for the transfixation underwent the procedure. All the patients were operated under local anesthesia. Statistical analysis was done using Statistical Package for Social Sciences version 24.0. Point estimate was done at 95% Confidence Interval and frequency and percentage were calculated.

RESULTS

Out of 30 cases, 29 (96.66%) have got successful outcomes with transfixation techniques. Among 30 patients, recurrences were seen in 2 (6.66%) cases. Patient satisfaction was high in 27 (90 %) cases. No complication was encountered.

CONCLUSIONS

Transfixation technique had good results in terms of low recurrence rate, percentage resolution in size and high patient satisfaction.\ Keywords: ganglion cyst; treatment; minimally invasive.

Effect of biochar particles applied in bedding course of the innovative permeable pavement on enhancing nitrogen removal

Coconut shell biochar and bamboo biochar were added to the bedding courses of permeable pavements to improve nitrogen removal efficiency. This was expected to be particularly effective for innovative permeable pavements that increase evaporation of stored rainwater. The effects of the rainfall intensity and ambient temperature on nitrogen removal were assessed. The NO₃^--N removal rate for the pavements with biochar added and the blank controls were 48.6%-54.0% and 10.8%, respectively, at a rainfall intensity of 10 mm/h and temperatures of 22-28 °C. The total nitrogen removal rates for the pavements with biochar added and the blank controls were 52.6%-57.7% and 20%, respectively. Adding coconut shell and bamboo biochar improved denitrification without causing organic matter to be leached. Increasing the rainfall intensity and decreasing the temperature caused less nitrogen to be removed. The total nitrogen balance indicated that the innovative pavements and conventional pavements with the same biochar amendments removed 781.58 and 733.30 mg of nitrogen, respectively, suggesting that adding biochar improved the performances of the innovative pavements more than the conventional pavements. Quantitative polymerase chain reaction assays of bedding course samples indicated that adding biochar markedly increased the abundances of denitrifying microorganisms.

Beds, overlays and mattresses for preventing and treating pressure ulcers: an overview of Cochrane Reviews and network meta-analysis

BACKGROUND

Pressure ulcers (also known as pressure injuries, pressure sores and bed sores) are localised injuries to the skin or underlying soft tissue, or both, caused by unrelieved pressure, shear or friction. Specific kinds of beds, overlays and mattresses are widely used with the aim of preventing and treating pressure ulcers.

OBJECTIVES

To summarise evidence from Cochrane Reviews that assess the effects of beds, overlays and mattresses on reducing the incidence of pressure ulcers and on increasing pressure ulcer healing in any setting and population. To assess the relative effects of different types of beds, overlays and mattresses for reducing the incidence of pressure ulcers and increasing pressure ulcer healing in any setting and population. To cumulatively rank the different treatment options of beds, overlays and mattresses in order of their effectiveness in pressure ulcer prevention and treatment.

METHODS

In July 2020, we searched the Cochrane Library. Cochrane Reviews reporting the effectiveness of beds, mattresses or overlays for preventing or treating pressure ulcers were eligible for inclusion in this overview. Two review authors independently screened search results and undertook data extraction and risk of bias assessment using the ROBIS tool. We summarised the reported evidence in an overview of reviews. Where possible, we included the randomised controlled trials from each included review in network meta-analyses. We assessed the relative effectiveness of beds, overlays and mattresses for preventing or treating pressure ulcers and their probabilities of being, comparably, the most effective treatment. We assessed the certainty of the evidence using the GRADE approach.

MAIN RESULTS

We include six Cochrane Reviews in this overview of reviews, all at low or unclear risk of bias. Pressure ulcer prevention: four reviews (of 68 studies with 18,174 participants) report direct evidence for 27 pairwise comparisons between 12 types of support surface on the following outcomes: pressure ulcer incidence, time to pressure ulcer incidence, patient comfort response, adverse event rates, health-related quality of life, and cost-effectiveness. Here we focus on outcomes with some evidence at a minimum of low certainty. (1) Pressure ulcer incidence: our overview includes direct evidence for 27 comparisons that mostly (19/27) have very low-certainty evidence concerning reduction of pressure ulcer risk. We included 40 studies (12,517 participants; 1298 participants with new ulcers) in a network meta-analysis involving 13 types of intervention. Data informing the network are sparse and this, together with the high risk of bias in most studies informing the network, means most network contrasts (64/78) yield evidence of very low certainty. There is low-certainty evidence that, compared with foam surfaces (reference treatment), reactive air surfaces (e.g. static air overlays) (risk ratio (RR) 0.46, 95% confidence interval (CI) 0.29 to 0.75), alternating pressure (active) air surfaces (e.g. alternating pressure air mattresses, large-celled ripple mattresses) (RR 0.63, 95% CI 0.42 to 0.93), and reactive gel surfaces (e.g. gel pads used on operating tables) (RR 0.47, 95% CI 0.22 to 1.01) may reduce pressure ulcer incidence. The ranking of treatments in terms of effectiveness is also of very low certainty for all interventions. It is unclear which treatment is best for preventing ulceration. (2) Time to pressure ulcer incidence: four reviews had direct evidence on this outcome for seven comparisons. We included 10 studies (7211 participants; 699 participants with new ulcers) evaluating six interventions in a network meta-analysis. Again, data from most network contrasts (13/15) are of very low certainty. There is low-certainty evidence that, compared with foam surfaces (reference treatment), reactive air surfaces may reduce the hazard of developing new pressure ulcers (hazard ratio (HR) 0.20, 95% CI 0.04 to 1.05). The ranking of all support surfaces for preventing pressure ulcers in terms of time to healing is uncertain. (3) Cost-effectiveness: this overview includes direct evidence for three comparisons. For preventing pressure ulcers, alternating pressure air surfaces are probably more cost-effective than foam surfaces (moderate-certainty evidence). Pressure ulcer treatment: two reviews (of 12 studies with 972 participants) report direct evidence for five comparisons on: complete pressure ulcer healing, time to complete pressure ulcer healing, patient comfort response, adverse event rates, and cost-effectiveness. Here we focus on outcomes with some evidence at a minimum of low certainty. (1) Complete pressure ulcer healing: our overview includes direct evidence for five comparisons. There is uncertainty about the relative effects of beds, overlays and mattresses on ulcer healing. The corresponding network meta-analysis (with four studies, 397 participants) had only three direct contrasts and a total of six network contrasts. Again, most network contrasts (5/6) have very low-certainty evidence. There was low-certainty evidence that more people with pressure ulcers may heal completely using reactive air surfaces than using foam surfaces (RR 1.32, 95% CI 0.96 to 1.80). We are uncertain which surfaces have the highest probability of being the most effective (all very low-certainty evidence). (2) Time to complete pressure ulcer healing: this overview includes direct evidence for one comparison: people using reactive air surfaces may be more likely to have healed pressure ulcers compared with those using foam surfaces in long-term care settings (HR 2.66, 95% CI 1.34 to 5.17; low-certainty evidence). (3) Cost-effectiveness: this overview includes direct evidence for one comparison: compared with foam surfaces, reactive air surfaces may cost an extra 26 US dollars for every ulcer-free day in the first year of use in long-term care settings (low-certainty evidence).

AUTHORS' CONCLUSIONS

Compared with foam surfaces, reactive air surfaces may reduce pressure ulcer risk and may increase complete ulcer healing. Compared with foam surfaces, alternating pressure air surfaces may reduce pressure ulcer risk and are probably more cost-effective in preventing pressure ulcers. Compared with foam surfaces, reactive gel surfaces may reduce pressure ulcer risk, particularly for people in operating rooms and long-term care settings. There are uncertainties for the relative effectiveness of other support surfaces for preventing and treating pressure ulcers, and their efficacy ranking. More high-quality research is required; for example, for the comparison of reactive air surfaces with alternating pressure air surfaces. Future studies should consider time-to-event outcomes and be designed to minimise any risk of bias.

Alternating pressure (active) air surfaces for preventing pressure ulcers

BACKGROUND

Pressure ulcers (also known as pressure injuries, pressure sores, decubitus ulcers and bed sores) are localised injuries to the skin or underlying soft tissue, or both, caused by unrelieved pressure, shear or friction. Alternating pressure (active) air surfaces are widely used with the aim of preventing pressure ulcers.

OBJECTIVES

To assess the effects of alternating pressure (active) air surfaces (beds, mattresses or overlays) compared with any support surface on the incidence of pressure ulcers in any population in any setting.

SEARCH METHODS

In November 2019, we searched the Cochrane Wounds Specialised Register; the Cochrane Central Register of Controlled Trials (CENTRAL); Ovid MEDLINE (including In-Process & Other Non-Indexed Citations); Ovid Embase and EBSCO CINAHL Plus. We also searched clinical trials registries for ongoing and unpublished studies, and scanned reference lists of relevant included studies as well as reviews, meta-analyses and health technology reports to identify additional studies. There were no restrictions with respect to language, date of publication or study setting.

SELECTION CRITERIA

We included randomised controlled trials that allocated participants of any age to alternating pressure (active) air beds, overlays or mattresses. Comparators were any beds, overlays or mattresses.

DATA COLLECTION AND ANALYSIS

At least two review authors independently assessed studies using predetermined inclusion criteria. We carried out data extraction, 'Risk of bias' assessment using the Cochrane 'Risk of bias' tool, and the certainty of the evidence assessment according to Grading of Recommendations, Assessment, Development and Evaluations methodology.

MAIN RESULTS

We included 32 studies (9058 participants) in the review. Most studies were small (median study sample size: 83 participants). The average age of participants ranged from 37.2 to 87.0 years (median: 69.1 years). Participants were largely from acute care settings (including accident and emergency departments). We synthesised data for six comparisons in the review: alternating pressure (active) air surfaces versus: foam surfaces, reactive air surfaces, reactive water surfaces, reactive fibre surfaces, reactive gel surfaces used in the operating room followed by foam surfaces used on the ward bed, and another type of alternating pressure air surface. Of the 32 included studies, 25 (78.1%) presented findings which were considered at high overall risk of bias.

PRIMARY OUTCOME

pressure ulcer incidence Alternating pressure (active) air surfaces may reduce the proportion of participants developing a new pressure ulcer compared with foam surfaces (risk ratio (RR) 0.63, 95% confidence interval (CI) 0.34 to 1.17; I² = 63%; 4 studies, 2247 participants; low-certainty evidence). Alternating pressure (active) air surfaces applied on both operating tables and hospital beds may reduce the proportion of people developing a new pressure ulcer compared with reactive gel surfaces used on operating tables followed by foam surfaces applied on hospital beds (RR 0.22, 95% CI 0.06 to 0.76; I² = 0%; 2 studies, 415 participants; low-certainty evidence). It is uncertain whether there is a difference in the proportion of people developing new pressure ulcers between alternating pressure (active) air surfaces and the following surfaces, as all these comparisons have very low-certainty evidence: (1) reactive water surfaces; (2) reactive fibre surfaces; and (3) reactive air surfaces. The comparisons between different types of alternating pressure air surfaces are presented narratively. Overall, all comparisons suggest little to no difference between these surfaces in pressure ulcer incidence (7 studies, 2833 participants; low-certainty evidence). Included studies have data on time to pressure ulcer incidence for three comparisons. When time to pressure ulcer development is considered using a hazard ratio (HR), it is uncertain whether there is a difference in the risk of developing new pressure ulcers, over 90 days' follow-up, between alternating pressure (active) air surfaces and foam surfaces (HR 0.41, 95% CI 0.10 to 1.64; I² = 86%; 2 studies, 2105 participants; very low-certainty evidence). For the comparison with reactive air surfaces, there is low-certainty evidence that people treated with alternating pressure (active) air surfaces may have a higher risk of developing an incident pressure ulcer than those treated with reactive air surfaces over 14 days' follow-up (HR 2.25, 95% CI 1.05 to 4.83; 1 study, 308 participants). Neither of the two studies with time to ulcer incidence data suggested a difference in the risk of developing an incident pressure ulcer over 60 days' follow-up between different types of alternating pressure air surfaces. Secondary outcomes The included studies have data on (1) support-surface-associated patient comfort for comparisons involving foam surfaces, reactive air surfaces, reactive fibre surfaces and alternating pressure (active) air surfaces; (2) adverse events for comparisons involving foam surfaces, reactive gel surfaces and alternating pressure (active) air surfaces; and (3) health-related quality of life outcomes for the comparison involving foam surfaces. However, all these outcomes and comparisons have low or very low-certainty evidence and it is uncertain whether there are any differences in these outcomes. Included studies have data on cost effectiveness for two comparisons. Moderate-certainty evidence suggests that alternating pressure (active) air surfaces are probably more cost-effective than foam surfaces (1 study, 2029 participants) and that alternating pressure (active) air mattresses are probably more cost-effective than overlay versions of this technology for people in acute care settings (1 study, 1971 participants).

AUTHORS' CONCLUSIONS

Current evidence is uncertain about the difference in pressure ulcer incidence between using alternating pressure (active) air surfaces and other surfaces (reactive water surfaces, reactive fibre surfaces and reactive air surfaces). Alternating pressure (active) air surfaces may reduce pressure ulcer risk compared with foam surfaces and reactive gel surfaces used on operating tables followed by foam surfaces applied on hospital beds. People using alternating pressure (active) air surfaces may be more likely to develop new pressure ulcers over 14 days' follow-up than those treated with reactive air surfaces in the nursing home setting; but as the result is sensitive to the choice of outcome measure it should be interpreted cautiously. Alternating pressure (active) air surfaces are probably more cost-effective than reactive foam surfaces in preventing new pressure ulcers. Future studies should include time-to-event outcomes and assessment of adverse events and trial-level cost-effectiveness. Further review using network meta-analysis will add to the findings reported here.

Beds, overlays and mattresses for treating pressure ulcers

BACKGROUND

Pressure ulcers (also known as pressure injuries, pressure sores, decubitus ulcers and bed sores) are localised injuries to the skin or underlying soft tissue, or both, caused by unrelieved pressure, shear or friction. Beds, overlays or mattresses are widely used with the aim of treating pressure ulcers.

OBJECTIVES

To assess the effects of beds, overlays and mattresses on pressure ulcer healing in people with pressure ulcers of any stage, in any setting.

SEARCH METHODS

In November 2019, we searched the Cochrane Wounds Specialised Register; the Cochrane Central Register of Controlled Trials (CENTRAL); Ovid MEDLINE (including In-Process & Other Non-Indexed Citations); Ovid Embase and EBSCO CINAHL Plus. We also searched clinical trials registries for ongoing and unpublished studies, and scanned reference lists of relevant included studies as well as reviews, meta-analyses and health technology reports to identify additional studies. There were no restrictions with respect to language, date of publication or study setting.

SELECTION CRITERIA

We included randomised controlled trials that allocated participants of any age to pressure-redistributing beds, overlays or mattresses. Comparators were any beds, overlays or mattresses that were applied for treating pressure ulcers.

DATA COLLECTION AND ANALYSIS

At least two review authors independently assessed studies using predetermined inclusion criteria. We carried out data extraction, 'Risk of bias' assessment using the Cochrane 'Risk of bias' tool, and the certainty of the evidence assessment according to Grading of Recommendations, Assessment, Development and Evaluations methodology.

MAIN RESULTS

We included 13 studies (972 participants) in the review. Most studies were small (median study sample size: 72 participants). The average age of participants ranged from 64.0 to 86.5 years (median: 82.7 years) and all studies recruited people with existing pressure ulcers (the baseline ulcer area size ranging from 4.2 to 18.6 cm²,median 6.6 cm²). Participants were recruited from acute care settings (six studies) and community and long-term care settings (seven studies). Of the 13 studies, three (224 participants) involved surfaces that were not well described and therefore could not be classified. Additionally, six (46.2%) of the 13 studies presented findings which were considered at high overall risk of bias. We synthesised data for four comparisons in the review: alternating pressure (active) air surfaces versus foam surfaces; reactive air surfaces versus foam surfaces; reactive water surfaces versus foam surfaces, and a comparison between two types of alternating pressure (active) air surfaces. We summarise key findings for these four comparisons below. (1) Alternating pressure (active) air surfaces versus foam surfaces: we are uncertain if there is a difference between alternating pressure (active) air surfaces and foam surfaces in the proportion of participants whose pressure ulcers completely healed (two studies with 132 participants; the reported risk ratio (RR) in one study was 0.97, 95% confidence interval (CI) 0.26 to 3.58). There is also uncertainty for the outcomes of patient comfort (one study with 83 participants) and adverse events (one study with 49 participants). These outcomes have very low-certainty evidence. Included studies did not report time to complete ulcer healing, health-related quality of life, or cost effectiveness. (2) Reactive air surfaces versus foam surfaces: it is uncertain if there is a difference in the proportion of participants with completely healed pressure ulcers between reactive air surfaces and foam surfaces (RR 1.32, 95% CI 0.96 to 1.80; I² = 0%; 2 studies, 156 participants; low-certainty evidence). When time to complete pressure ulcer healing is considered using a hazard ratio, data from one small study (84 participants) suggests a greater hazard for complete ulcer healing on reactive air surfaces (hazard ratio 2.66, 95% CI 1.34 to 5.17; low-certainty evidence). These results are sensitive to the choice of outcome measure so should be interpreted as uncertain. We are also uncertain whether there is any difference between these surfaces in patient comfort responses (1 study, 72 participants; very low-certainty evidence) and in adverse events (2 studies, 156 participants; low-certainty evidence). There is low-certainty evidence that reactive air surfaces may cost an extra 26 US dollars for every ulcer-free day in the first year of use (1 study, 87 participants). Included studies did not report health-related quality of life. (3) Reactive water surfaces versus foam surfaces: it is uncertain if there is a difference between reactive water surfaces and foam surfaces in the proportion of participants with healed pressure ulcers (RR 1.07, 95% CI 0.70 to 1.63; 1 study, 101 participants) and in adverse events (1 study, 120 participants). All these have very low-certainty evidence. Included studies did not report time to complete ulcer healing, patient comfort, health-related quality of life, or cost effectiveness. (4) Comparison between two types of alternating pressure (active) air surfaces: it is uncertain if there is a difference between Nimbus and Pegasus alternating pressure (active) air surfaces in the proportion of participants with healed pressure ulcers, in patient comfort responses and in adverse events: each of these outcomes had four studies (256 participants) but very low-certainty evidence. Included studies did not report time to complete ulcer healing, health-related quality of life, or cost effectiveness.

AUTHORS' CONCLUSIONS

We are uncertain about the relative effects of most different pressure-redistributing surfaces for pressure ulcer healing (types directly compared are alternating pressure air surfaces versus foam surfaces, reactive air surfaces versus foam surfaces, reactive water surfaces versus foam surfaces, and Nimbus versus Pegasus alternating pressure (active) air surfaces). There is also uncertainty regarding the effects of these different surfaces on the outcomes of comfort and adverse events. However, people using reactive air surfaces may be more likely to have pressure ulcers completely healed than those using foam surfaces over 37.5 days' follow-up, and reactive air surfaces may cost more for each ulcer-free day than foam surfaces. Future research in this area could consider the evaluation of alternating pressure air surfaces versus foam surfaces as a high priority. Time-to-event outcomes, careful assessment of adverse events and trial-level cost-effectiveness evaluation should be considered in future studies. Further review using network meta-analysis will add to the findings reported here.

Reactive air surfaces for preventing pressure ulcers

BACKGROUND

Pressure ulcers (also known as pressure injuries, pressure sores, decubitus ulcers and bed sores) are localised injuries to the skin or underlying soft tissue, or both, caused by unrelieved pressure, shear or friction. Reactive air surfaces (beds, mattresses or overlays) can be used for preventing pressure ulcers.

OBJECTIVES

To assess the effects of reactive air beds, mattresses or overlays compared with any support surface on the incidence of pressure ulcers in any population in any setting.

SEARCH METHODS

In November 2019, we searched the Cochrane Wounds Specialised Register; the Cochrane Central Register of Controlled Trials (CENTRAL); Ovid MEDLINE (including In-Process & Other Non-Indexed Citations); Ovid Embase and EBSCO CINAHL Plus. We also searched clinical trials registries for ongoing and unpublished studies, and scanned reference lists of relevant included studies as well as reviews, meta-analyses and health technology reports to identify additional studies. There were no restrictions with respect to language, date of publication or study setting.

SELECTION CRITERIA

We included randomised controlled trials that allocated participants of any age to reactive air beds, overlays or mattresses. Comparators were any beds, overlays or mattresses that were applied for preventing pressure ulcers.

DATA COLLECTION AND ANALYSIS

At least two review authors independently assessed studies using predetermined inclusion criteria. We carried out data extraction, 'Risk of bias' assessment using the Cochrane 'Risk of bias' tool, and the certainty of the evidence assessment according to Grading of Recommendations, Assessment, Development and Evaluations methodology. If a reactive air surface was compared with surfaces that were not clearly specified, then we recorded and described the concerned study but did not included it in further data analyses.

MAIN RESULTS

We included 17 studies (2604 participants) in this review. Most studies were small (median study sample size: 83 participants). The average participant age ranged from 56 to 87 years (median: 72 years). Participants were recruited from a wide range of care settings with the majority being acute care settings. Almost all studies were conducted in the regions of Europe and America. Of the 17 included studies, two (223 participants) compared reactive air surfaces with surfaces that were not well described and therefore could not be classified. We analysed data for five comparisons: reactive air surfaces compared with (1) alternating pressure (active) air surfaces (seven studies with 1728 participants), (2) foam surfaces (four studies with 229 participants), (3) reactive water surfaces (one study with 37 participants), (4) reactive gel surfaces (one study with 66 participants), and (5) another type of reactive air surface (two studies with 223 participants). Of the 17 studies, seven (41.2%) presented findings which were considered at high overall risk of bias.

PRIMARY OUTCOME

Pressure ulcer incidence Reactive air surfaces may reduce the proportion of participants developing a new pressure ulcer compared with foam surfaces (risk ratio (RR) 0.42; 95% confidence interval (CI) 0.18 to 0.96; I² = 25%; 4 studies, 229 participants; low-certainty evidence). It is uncertain if there is a difference in the proportions of participants developing a new pressure ulcer on reactive air surfaces compared with: alternating pressure (active) air surfaces (6 studies, 1648 participants); reactive water surfaces (1 study, 37 participants); reactive gel surfaces (1 study, 66 participants), or another type of reactive air surface (2 studies, 223 participants). Evidence for all these comparisons is of very low certainty. Included studies have data on time to pressure ulcer incidence for two comparisons. When time to pressure ulcer incidence is considered using a hazard ratio (HR), low-certainty evidence suggests that in the nursing home setting, people on reactive air surfaces may be less likely to develop a new pressure ulcer over 14 days' of follow-up than people on alternating pressure (active) air surfaces (HR 0.44; 95% CI 0.21 to 0.96; 1 study, 308 participants). It is uncertain if there is a difference in the hazard of developing new pressure ulcers between two types of reactive air surfaces (1 study, 123 participants; very low-certainty evidence). Secondary outcomes Support-surface-associated patient comfort: the included studies have data on this outcome for three comparisons. We could not pool any data as comfort outcome measures differed between included studies; therefore a narrative summary is provided. It is uncertain if there is a difference in patient comfort responses between reactive air surfaces and foam surfaces over the top of an alternating pressure (active) air surfaces (1 study, 72 participants), and between those using reactive air surfaces and those using alternating pressure (active) air surfaces (4 studies, 1364 participants). Evidence for these two comparisons is of very low certainty. It is also uncertain if there is a difference in patient comfort responses between two types of reactive air surfaces (1 study, 84 participants; low-certainty evidence). All reported adverse events: there were data on this outcome for one comparison: it is uncertain if there is a difference in adverse events between reactive air surfaces and foam surfaces (1 study, 72 participants; very low-certainty evidence). The included studies have no data for health-related quality of life and cost-effectiveness for all five comparisons.

AUTHORS' CONCLUSIONS

Current evidence is uncertain regarding any differences in the relative effects of reactive air surfaces on ulcer incidence and patient comfort, when compared with reactive water surfaces, reactive gel surfaces, or another type of reactive air surface. Using reactive air surfaces may reduce the risk of developing new pressure ulcers compared with using foam surfaces. Also, using reactive air surfaces may reduce the risk of developing new pressure ulcers within 14 days compared with alternating pressure (active) air surfaces in people in a nursing home setting. Future research in this area should consider evaluation of the most important support surfaces from the perspective of decision-makers. Time-to-event outcomes, careful assessment of adverse events and trial-level cost-effectiveness evaluation should be considered in future studies. Trials should be designed to minimise the risk of detection bias; for example, by using digital photography and adjudicators of the photographs being blinded to group allocation. Further review using network meta-analysis will add to the findings reported here.

Alternative reactive support surfaces (non-foam and non-air-filled) for preventing pressure ulcers

BACKGROUND

Pressure ulcers (also known as injuries, pressure sores, decubitus ulcers and bed sores) are localised injuries to the skin or underlying soft tissue, or both, caused by unrelieved pressure, shear or friction. Reactive surfaces that are not made of foam or air cells can be used for preventing pressure ulcers.

OBJECTIVES

To assess the effects of non-foam and non-air-filled reactive beds, mattresses or overlays compared with any other support surface on the incidence of pressure ulcers in any population in any setting.

SEARCH METHODS

In November 2019, we searched the Cochrane Wounds Specialised Register; the Cochrane Central Register of Controlled Trials (CENTRAL); Ovid MEDLINE (including In-Process & Other Non-Indexed Citations); Ovid Embase and EBSCO CINAHL Plus. We also searched clinical trials registries for ongoing and unpublished studies, and scanned reference lists of relevant included studies as well as reviews, meta-analyses and health technology reports to identify additional studies. There were no restrictions with respect to language, date of publication or study setting.

SELECTION CRITERIA

We included randomised controlled trials that allocated participants of any age to non-foam or non-air-filled reactive beds, overlays or mattresses. Comparators were any beds, overlays or mattresses used.

DATA COLLECTION AND ANALYSIS

At least two review authors independently assessed studies using predetermined inclusion criteria. We carried out data extraction, 'Risk of bias' assessment using the Cochrane 'Risk of bias' tool, and the certainty of the evidence assessment according to Grading of Recommendations, Assessment, Development and Evaluations methodology. If a non-foam or non-air-filled surface was compared with surfaces that were not clearly specified, then the included study was recorded and described but not considered further in any data analyses.

MAIN RESULTS

We included 20 studies (4653 participants) in this review. Most studies were small (median study sample size: 198 participants). The average participant age ranged from 37.2 to 85.4 years (median: 72.5 years). Participants were recruited from a wide range of care settings but were mainly from acute care settings. Almost all studies were conducted in Europe and America. Of the 20 studies, 11 (2826 participants) included surfaces that were not well described and therefore could not be fully classified. We synthesised data for the following 12 comparisons: (1) reactive water surfaces versus alternating pressure (active) air surfaces (three studies with 414 participants), (2) reactive water surfaces versus foam surfaces (one study with 117 participants), (3) reactive water surfaces versus reactive air surfaces (one study with 37 participants), (4) reactive water surfaces versus reactive fibre surfaces (one study with 87 participants), (5) reactive fibre surfaces versus alternating pressure (active) air surfaces (four studies with 384 participants), (6) reactive fibre surfaces versus foam surfaces (two studies with 228 participants), (7) reactive gel surfaces on operating tables followed by foam surfaces on ward beds versus alternating pressure (active) air surfaces on operating tables and subsequently on ward beds (two studies with 415 participants), (8) reactive gel surfaces versus reactive air surfaces (one study with 74 participants), (9) reactive gel surfaces versus foam surfaces (one study with 135 participants), (10) reactive gel surfaces versus reactive gel surfaces (one study with 113 participants), (11) reactive foam and gel surfaces versus reactive gel surfaces (one study with 166 participants) and (12) reactive foam and gel surfaces versus foam surfaces (one study with 91 participants). Of the 20 studies, 16 (80%) presented findings which were considered to be at high overall risk of bias.

PRIMARY OUTCOME

Pressure ulcer incidence We did not find analysable data for two comparisons: reactive water surfaces versus foam surfaces, and reactive water surfaces versus reactive fibre surfaces. Reactive gel surfaces used on operating tables followed by foam surfaces applied on hospital beds (14/205 (6.8%)) may increase the proportion of people developing a new pressure ulcer compared with alternating pressure (active) air surfaces applied on both operating tables and hospital beds (3/210 (1.4%) (risk ratio 4.53, 95% confidence interval 1.31 to 15.65; 2 studies, 415 participants; I² = 0%; low-certainty evidence). For all other comparisons, it is uncertain whether there is a difference in the proportion of participants developing new pressure ulcers as all data were of very low certainty. Included studies did not report time to pressure ulcer incidence for any comparison in this review. Secondary outcomes Support-surface-associated patient comfort: the included studies provide data on this outcome for one comparison. It is uncertain if there is a difference in patient comfort between alternating pressure (active) air surfaces and reactive fibre surfaces (one study with 187 participants; very low-certainty evidence). All reported adverse events: there is evidence on this outcome for one comparison. It is uncertain if there is a difference in adverse events between reactive gel surfaces followed by foam surfaces and alternating pressure (active) air surfaces applied on both operating tables and hospital beds (one study with 198 participants; very low-certainty evidence). We did not find any health-related quality of life or cost-effectiveness evidence for any comparison in this review.

AUTHORS' CONCLUSIONS

Current evidence is generally uncertain about the differences between non-foam and non-air-filled reactive surfaces and other surfaces in terms of pressure ulcer incidence, patient comfort, adverse effects, health-related quality of life and cost-effectiveness. Reactive gel surfaces used on operating tables followed by foam surfaces applied on hospital beds may increase the risk of having new pressure ulcers compared with alternating pressure (active) air surfaces applied on both operating tables and hospital beds. Future research in this area should consider evaluation of the most important support surfaces from the perspective of decision-makers. Time-to-event outcomes, careful assessment of adverse events and trial-level cost-effectiveness evaluation should be considered in future studies. Trials should be designed to minimise the risk of detection bias; for example, by using digital photography and adjudicators of the photographs being blinded to group allocation. Further review using network meta-analysis will add to the findings reported here.

Foam surfaces for preventing pressure ulcers

BACKGROUND

Pressure ulcers (also known as pressure injuries) are localised injuries to the skin or underlying soft tissue, or both, caused by unrelieved pressure, shear or friction. Foam surfaces (beds, mattresses or overlays) are widely used with the aim of preventing pressure ulcers.

OBJECTIVES

To assess the effects of foam beds, mattresses or overlays compared with any support surface on the incidence of pressure ulcers in any population in any setting.

SEARCH METHODS

In November 2019, we searched the Cochrane Wounds Specialised Register; the Cochrane Central Register of Controlled Trials (CENTRAL); Ovid MEDLINE (including In-Process & Other Non-Indexed Citations); Ovid Embase and EBSCO CINAHL Plus. We also searched clinical trials registries for ongoing and unpublished studies, and scanned reference lists of relevant included studies as well as reviews, meta-analyses and health technology reports to identify additional studies. There were no restrictions with respect to language, date of publication or study setting.

SELECTION CRITERIA

We included randomised controlled trials that allocated participants of any age to foam beds, mattresses or overlays. Comparators were any beds, mattresses or overlays.

DATA COLLECTION AND ANALYSIS

At least two review authors independently assessed studies using predetermined inclusion criteria. We carried out data extraction, 'Risk of bias' assessment using the Cochrane 'Risk of bias' tool, and the certainty of the evidence assessment according to Grading of Recommendations, Assessment, Development and Evaluations methodology. If a foam surface was compared with surfaces that were not clearly specified, then the included study was recorded and described but not considered further in any data analyses.

MAIN RESULTS

We included 29 studies (9566 participants) in the review. Most studies were small (median study sample size: 101 participants). The average age of participants ranged from 47.0 to 85.3 years (median: 76.0 years). Participants were mainly from acute care settings. We analysed data for seven comparisons in the review: foam surfaces compared with: (1) alternating pressure air surfaces, (2) reactive air surfaces, (3) reactive fibre surfaces, (4) reactive gel surfaces, (5) reactive foam and gel surfaces, (6) reactive water surfaces, and (7) another type of foam surface. Of the 29 included studies, 17 (58.6%) presented findings which were considered at high overall risk of bias.

PRIMARY OUTCOME

pressure ulcer incidence Low-certainty evidence suggests that foam surfaces may increase the risk of developing new pressure ulcers compared with (1) alternating pressure (active) air surfaces (risk ratio (RR) 1.59, 95% confidence interval (CI) 0.86 to 2.95; I2 = 63%; 4 studies, 2247 participants), and (2) reactive air surfaces (RR 2.40, 95% CI 1.04 to 5.54; I2 = 25%; 4 studies, 229 participants). We are uncertain regarding the difference in pressure ulcer incidence in people treated with foam surfaces and the following surfaces: (1) reactive fibre surfaces (1 study, 68 participants); (2) reactive gel surfaces (1 study, 135 participants); (3) reactive gel and foam surfaces (1 study, 91 participants); and (4) another type of foam surface (6 studies, 733 participants). These had very low-certainty evidence. Included studies have data on time to pressure ulcer development for two comparisons. When time to ulcer development is considered using hazard ratios, the difference in the risk of having new pressure ulcers, over 90 days' follow-up, between foam surfaces and alternating pressure air surfaces is uncertain (2 studies, 2105 participants; very low-certainty evidence). Two further studies comparing different types of foam surfaces also reported time-to-event data, suggesting that viscoelastic foam surfaces with a density of 40 to 60 kg/m3 may decrease the risk of having new pressure ulcers over 11.5 days' follow-up compared with foam surfaces with a density of 33 kg/m3 (1 study, 62 participants); and solid foam surfaces may decrease the risk of having new pressure ulcers over one month's follow-up compared with convoluted foam surfaces (1 study, 84 participants). Both had low-certainty evidence. There was no analysable data for the comparison of foam surfaces with reactive water surfaces (one study with 117 participants). Secondary outcomes Support-surface-associated patient comfort: the review contains data for three comparisons for this outcome. It is uncertain if there is a difference in patient comfort measure between foam surfaces and alternating pressure air surfaces (1 study, 76 participants; very low-certainty evidence); foam surfaces and reactive air surfaces (1 study, 72 participants; very low-certainty evidence); and different types of foam surfaces (4 studies, 669 participants; very low-certainty evidence). All reported adverse events: the review contains data for two comparisons for this outcome. We are uncertain about differences in adverse effects between foam surfaces and alternating pressure (active) air surfaces (3 studies, 2181 participants; very low-certainty evidence), and between foam surfaces and reactive air surfaces (1 study, 72 participants; very low-certainty evidence). Health-related quality of life: only one study reported data on this outcome. It is uncertain if there is a difference (low-certainty evidence) between foam surfaces and alternating pressure (active) air surfaces in health-related quality of life measured with two different questionnaires, the EQ-5D-5L (267 participants) and the PU-QoL-UI (233 participants). Cost-effectiveness: one study reported trial-based cost-effectiveness evaluations. Alternating pressure (active) air surfaces are probably more cost-effective than foam surfaces in preventing pressure ulcer incidence (2029 participants; moderate-certainty evidence).

AUTHORS' CONCLUSIONS

Current evidence suggests uncertainty about the differences in pressure ulcer incidence, patient comfort, adverse events and health-related quality of life between using foam surfaces and other surfaces (reactive fibre surfaces, reactive gel surfaces, reactive foam and gel surfaces, or reactive water surfaces). Foam surfaces may increase pressure ulcer incidence compared with alternating pressure (active) air surfaces and reactive air surfaces. Alternating pressure (active) air surfaces are probably more cost-effective than foam surfaces in preventing new pressure ulcers. Future research in this area should consider evaluation of the most important support surfaces from the perspective of decision-makers. Time-to-event outcomes, careful assessment of adverse events and trial-level cost-effectiveness evaluation should be considered in future studies. Trials should be designed to minimise the risk of detection bias; for example, by using digital photography and by blinding adjudicators of the photographs to group allocation. Further review using network meta-analysis will add to the findings reported here.