EffEctiveness of Prophylactic fOam dressings in the prevention of saCral pressure injuries in at-risk hospitalised patients: the EEPOC trial

BACKGROUND

Prophylactic dressings are increasingly used to prevent pressure injuries in hospitalised patients. However, evidence regarding the effectiveness of these dressings is still emerging. This trial aims to determine the clinical and cost-effectiveness of a prophylactic silicone foam border dressing in preventing sacral pressure injuries in medical-surgical patients.

METHODS

This is a multicentre, pragmatic, parallel group, randomised controlled trial. A sample size of 1320 was calculated to have >90% power to detect a 5% difference in the primary outcome at an alpha of 0.05. Adult patients admitted to participating medical-surgical wards are screened for eligibility: ≥18 years, admitted to hospital within the previous 36 h, expected length of stay of ≥24 h, and assessed high risk for hospital-acquired pressure injury. Consenting participants are randomly allocated to either prophylactic silicone foam dressing intervention or usual care without any dressing as the control group via a web-based randomisation service independent of the trial. Patients are enrolled across three Australian hospitals. The primary outcome is the cumulative incidence of patients who develop a sacral pressure injury. Secondary outcomes include the time to sacral pressure injury, incidence of severity (stage) of sacral pressure injury, cost-effectiveness of dressings, and process evaluation. Participant outcomes are assessed daily for up to 14 days by blinded independent outcome assessors using de-identified, digitally modified sacral photographs. Those who develop a sacral pressure injury are followed for an additional 14 days to estimate costs of pressure injury treatment. Analysis of clinical outcomes will be based on intention-to-treat, per-protocol, and sensitivity analyses.

DISCUSSION

This trial aims to provide definitive evidence on the effect prophylactic dressings have on the development of hospital-acquired sacral pressure injuries in medical-surgical patients. A parallel economic evaluation of pressure injury prevention and treatment will enable evidence-informed decisions and policy. The inclusion of a process evaluation will help to explain the contextual factors that may have a bearing on trial results including the acceptability of the dressings to patients and staff. The trial commenced 5 March 2020 and has been significantly delayed due to COVID-19.

TRIAL REGISTRATION

ANZCTR ACTRN12619000763145. Prospectively registered on 22 May 2019.

Process evaluation of an intervention to test the effectiveness of foam border dressings in preventing hospital-acquired sacral pressure injuries (the EEPOC trial): A protocol

BACKGROUND

Prophylactic foam border dressings are recommended for high-risk patients in addition to standard pressure injury prevention protocols despite limited high-quality evidence regarding their effectiveness. This protocol describes the process evaluation that will be undertaken alongside a multisite randomised controlled trial investigating the clinical and cost-effectiveness of these dressings in reducing hospital-acquired sacral pressure injury incidence.

METHODS

This theory informed parallel process evaluation using qualitative and quantitative methods will be undertaken in medical and surgical units. To evaluate fidelity, recruitment, reach, dose delivered and received, and context, process data will include: research nurses' self-reported adherence to intervention protocols; semi-structured interviews with participants and research nurses and focus groups with nursing staff; participants' satisfaction and comfort with the dressings and perceived level of participation in pressure injury prevention; and nurses' attitudes toward pressure injury prevention. The proportion of the target population recruited, participant characteristics, and adherence to intervention protocols will be reported using descriptive statistics. Chi square or t-tests will compare differences in demographic characteristics between groups, and non-participants, and multivariate modelling will investigate potential moderators on the trial outcomes. Analysis of qualitative data will be guided by the Framework Method, which provides a clear, systematic process for developing themes.

DISCUSSION

This process evaluation will provide valuable insights into mechanisms of impact and contextual and moderating factors influencing trial outcomes. Process data will enhance reproducibility of the intervention and trustworthiness of findings, and inform clinicians, researchers, and policy makers about the extent to which foam border dressings can be feasibly implemented in clinical practice.

TRIAL REGISTRATION

ACTRN12619000763145p.

The aetiology of medical device-related pressure ulcers and how to prevent them

This article provides an introduction to the aetiology of medical device-related pressure ulcers (MDRPUs), describes the vicious cycle that leads to these injuries and highlights bioengineering methodologies and findings that connect the aetiology to the clinical practice of preventing MDRPUs. Specifically, the vicious cycle of MDRPUs is triggered by the sustained tissue deformations induced by a skin-contacting device. The primary, deformation-inflicted cell damage leads to a secondary inflammatory-oedema-related damage and then to tertiary ischaemic damage. Each of these three factors contributes to cumulative cell death and tissue damage under and near the applied device. The damage therefore develops in an escalated manner, as a result of the added contributions of the above three factors. This phenomenon is exemplified through two common clinical scenarios. First, through the use of continuous positive airway pressure (CPAP) masks, which are being applied extensively in the current COVID-19 pandemic, and, second, through the use of doughnut-shaped head positioners, which are applied to surgical patients and sometimes to bedridden individuals who receive intensive care in a supine position. These two medical devices cause intense, localised mechanical loads in the facial skin and underlying tissues (CPAP mask) and at the occipital scalp (doughnut-shaped positioner), where the soft tissues cannot swell in response to the inflammatory oedema as, in both cases, the tissues are sandwiched between the device and the skull. Accordingly, the two device types result in characteristic MDRPUs that are avoidable through appropriate prophylactic interventions, that is, preventive dressings under the CPAP mask and replacement of the doughnut device by a soft, shape-conforming support aid to alleviate and disperse the localised soft tissue deformations. Hence, understanding the aetiology of MDRPUs targets and focuses effective clinical interventions.

Physiological measurements of facial skin response under personal protective equipment

Medical device-related pressure ulcers (MDRPUs) were traditionally associated with skin-contacting medical devices applied to patients, eventually causing tissue damage. The coronavirus-2019 pandemic has brought a new variant of MDRPUs: facial skin irritation or damage associated with extended use of protective personal equipment (PPE), e.g. facemasks and respirators. In this context, we report here a comprehensive experimental evaluation including facial contact forces, skin temperatures and sub-epidermal moisture (SEM) measurements pre/post-PPE usage, to determine how these physiological parameters change under the effects of surgical facemasks and KN95 respirators and whether such potential changes can explain the commonly reported skin irritation or damage. We found that a surgical mask is potentially less irritating to facial skin than the KN95 respirator, as it applies lower forces and facilitates faster return of facial temperatures to their basal levels. Further, we demonstrated that use of dressing cuts for padding under a KN95 respirator considerably reduced localized forces and did not worsen the thermal and SEM readings at the skin-device contact sites. This study provides a basis for improvement of PPE designs, as it describes physiological measurement methodologies for quantitative comparisons of the effects of different PPE types on facial skin status.

The microclimate under dressings applied to intact weight-bearing skin: Infrared thermography studies

BACKGROUND

When a patient is lying in a hospital bed (e.g. supine or prone), bodyweight forces distort soft tissues by compression, tension and shear, and may lead to the onset of pressure ulcers in those who are stationary and insensate, especially at their pelvic region. Altered localized microclimate conditions, particularly elevated skin temperatures leading to perspiration and resulting in skin moisture or wetness, are known to further increase the risk for pressure ulcers, which is already high in immobile patients.

METHODS

We have used infrared thermography to measure local skin temperatures at the buttocks of supine healthy subjects, to quantitatively determine, for the first time in the literature, how skin microclimate conditions associated with a weight-bearing Fowler's position are affected by application of dressings. Our present methodology has been applied to compare a polymeric membrane dressing versus placebo foam, with a no-dressing case used as reference.

FINDINGS

One hour of lying in a Fowler's position was already enough to cause considerable heat trapping (~3 °C rise) between the weight-bearing body and the support surface. Analyses of normalized local skin temperatures and entropy of the temperature distributions indicated that the polymeric membrane dressing material allowed better and more homogenous clearance of locally accumulated body-heat with respect to simple foam.

INTERPRETATION

Infrared thermography is suitable for characterizing skin microclimate conditions under different dressings, and, accordingly, is effective in developing and evaluating pressure ulcer prevention and treatment strategies - both of which require adequate skin microclimate.

The contribution of a directional preference of stiffness to the efficacy of prophylactic sacral dressings in protecting healthy and diabetic tissues from pressure injury: computational modelling studies

The sacral region is the most common site for pressure injuries (PIs) associated with lying in bed, and such sacral PIs often commence as deep tissue injuries (DTIs) that later present as open wounds. In complex patients, diabetes is common. Because, among other factors, diabetes affects connective tissue stiffness properties, making these tissues less able to dissipate mechanical loads through physiological deformations, diabetes is an additional biomechanical risk factor for PIs and DTIs. A preventive measure with established successful clinical outcomes is the use of sacral prophylactic dressings. The objective of this study has been to expand our previous work regarding the modes of action and biomechanical efficacy of prophylactic dressings in protecting the soft tissues adjacent to the sacrum by specifically examining the role of a directional stiffness preference (anisotropy) of the dressing while further accounting for diabetic tissue conditions. Multiple three-dimensional anatomically detailed finite element (FE) model variants representing diabetic tissue conditions were used, and tissue loading state data were compared with healthy tissue simulations. We specifically compared soft tissue exposures to elevated internal shear stresses and strain energy densities (SED) near the sacrum during supine weight bearing on a standard (foam) hospital mattress without a dressing, with a prophylactic dressing lacking directional stiffness preferences and with an anisotropic dressing. Our results have clearly shown that an anisotropic dressing design reduces the peak tissue stresses and exposure to sustained tissue deformations in both healthy and diabetic cases. The present study provides additional important insights regarding the optimal structural and material design of prophylactic dressings, which in turn, informs clinicians and decision makers regarding beneficial features.

The biomechanical efficacy of dressings in preventing heel ulcers

The heels are the most common site for facility-acquired pressure ulcers (PUs), and are also the most susceptible location for deep tissue injuries. The use of multilayer prophylactic dressings to prevent heel PUs is a relatively new prevention concept, generally aimed at minimizing the risk for heel ulcers (HUs) through mechanical cushioning and reduction of friction at the dressing-support interface. We used 9 finite element model variants of the posterior heel in order to evaluate the biomechanical performance of a multilayer dressing in prevention of HUs during supine lying. We compared volumetric exposures of the loaded soft tissues to effective and maximal shear strains, as well as peak stresses in the Achilles tendon, without any dressing and with a single-layer or a multilayer dressing (Mepilex(®) Border Heel-type), on supports with different stiffnesses. The use of the multilayer dressing consistently and considerably reduced soft tissue exposures to elevated strains at the posterior heel, on all of the tested support surfaces and when loaded with either pure compression or combined compression and shear. The aforementioned multilayer design showed (i) clear benefit over a single-layer dressing in terms of dissipating tissue strains, by promoting internal shear in the dressing which diverts loads from tissues; (ii) a protective effect that was consistent on supports with different stiffnesses. Recent randomized controlled trials confirmed the efficacy of the simulated multilayer dressing, and so, taken together with this modeling work, the use of a prophylactic multilayer dressing indicates a great promise in taking this route for prevention.

Systematic review of the use of prophylactic dressings in the prevention of pressure ulcers

This systematic review considers the evidence supporting the use of prophylactic dressings for the prevention of pressure ulcer. Electronic database searches were conducted on 25 July 2013. The searches found 3026 titles and after removal of duplicate records 2819 titles were scanned against the inclusion and exclusion criteria. Of these, 2777 were excluded based on their title and abstract primarily because they discussed pressure ulcer healing, the prevention and treatment of other chronic and acute wounds or where the intervention was not a prophylactic dressing (e.g. underpads, heel protectors and cushions). Finally, the full text of 42 papers were retrieved. When these 42 papers were reviewed, 21 were excluded and 21 were included in the review. The single high-quality randomised controlled trial (RCT) and the growing number of cohort, weak RCT and case series all suggest that the introduction of a dressing as part of pressure ulcer prevention may help reduce pressure ulcer incidence associated with medical devices especially in immobile intensive care unit patients. There is no firm clinical evidence at this time to suggest that one dressing type is more effective than other dressings.

The cost-benefit of using soft silicone multilayered foam dressings to prevent sacral and heel pressure ulcers in trauma and critically ill patients: a within-trial analysis of the Border Trial

Little is known about the cost-benefit of soft silicone foam dressings in pressure ulcer (PU) prevention among critically ill patients in the emergency department (ED) and intensive care unit (ICU). A randomised controlled trial to assess the efficacy of soft silicone foam dressings in preventing sacral and heel PUs was undertaken among 440 critically ill patients in an acute care hospital. Participants were randomly allocated either to an intervention group with prophylactic dressings applied to the sacrum and heels in the ED and changed every 3 days in the ICU or to a control group with standard PU prevention care provided during their ED and ICU stay. The results showed a significant reduction of PU incidence rates in the intervention group (P = 0·001). The intervention cost was estimated to be AU$36·61 per person based on an intention-to-treat analysis, but this was offset by lower downstream costs associated with PU treatment (AU$1103·52). Therefore, the average net cost of the intervention was lower than that of the control (AU$70·82 versus AU$144·56). We conclude that the use of soft silicone multilayered foam dressings to prevent sacral and heel PUs among critically ill patients results in cost savings in the acute care hospital.