Safety and effectiveness of an antiseptic wound cleansing and irrigation solution containing polyhexamethylene biguanide

OBJECTIVE

There is currently a wide range of cleansing and irrigation solutions available for wounds, many of which contain antimicrobial agents. The aim of this study was to assess the safety of HydroClean Solution (HARTMANN, Germany), a polyhexamethylene biguanide (PHMB)-containing irrigation solution, in a standard cytotoxicity assay, and to assess its effect in a three-dimensional (3D) full-thickness model of human skin.

METHOD

A number of commercially available wound cleansing and irrigation solutions, including the PHMB-containing irrigation solution, were tested in a cytotoxicity assay using L929 mouse fibroblasts (ISO 10993-5:2009). The PHMB-containing irrigation solution was then assessed in an in vitro human keratinocyte-fibroblast 3D full-thickness wounded skin model to determine its effect on wound healing over six days. The effect of the PHMB-containing irrigation solution on tissue viability was measured using a lactate dehydrogenase (LDH) assay, and proinflammatory effects were measured using an interleukin-6 (IL-6) production assay.

RESULTS

The PHMB-containing irrigation solution was shown to be equivalent to other commercially available cleansing and irrigation solutions when tested in the L929 fibroblast cytotoxicity assay. When assessed in the in vitro 3D human full-thickness wound healing model, the PHMB-containing irrigation solution treatment resulted in no difference in levels of LDH or IL-6 when compared with levels produced in control Dulbecco's phosphate-buffered saline cultures. There was, however, a pronounced tissue thickening of the skin model in the periwound region.

CONCLUSION

The experimental data presented in this study support the conclusion that the PHMB-containing irrigation solution has a safety profile similar to other commercially available cleansing and irrigation solutions. Evidence also suggests that the PHMB-containing irrigation solution does not affect tissue viability or proinflammatory cytokine production, as evidenced by LDH levels or the production of IL-6 in a 3D human full-thickness wound healing model. The PHMB-containing irrigation solution stimulated new tissue growth in the periwound region of the skin model.

Artificial intelligence in wound care: diagnosis, assessment and treatment of hard-to-heal wounds: a narrative review

OBJECTIVE

The effective assessment of wounds, both acute and hard-to-heal, is an important component in the delivery by wound care practitioners of efficacious wound care for patients. Improved wound diagnosis, optimising wound treatment regimens, and enhanced prevention of wounds aid in providing patients with a better quality of life (QoL). There is significant potential for the use of artificial intelligence (AI) in health-related areas such as wound care. However, AI-based systems remain to be developed to a point where they can be used clinically to deliver high-quality wound care. We have carried out a narrative review of the development and use of AI in the diagnosis, assessment and treatment of hard-to-heal wounds. We retrieved 145 articles from several online databases and other online resources, and 81 of them were included in this narrative review. Our review shows that AI application in wound care offers benefits in the assessment/diagnosis, monitoring and treatment of acute and hard-to-heal wounds. As well as offering patients the potential of improved QoL, AI may also enable better use of healthcare resources.

Considerations for an ideal post-surgical wound dressing aligned with antimicrobial stewardship objectives: a scoping review

OBJECTIVE

Most surgical wounds heal by primary or secondary intention. Surgical wounds can present specific and unique challenges including wound dehiscence and surgical site infection (SSI), either of which can increase risk of morbidity and mortality. The use of antimicrobials to treat infection in these wounds is prevalent, but there is now an imperative to align treatment with reducing antimicrobial resistance and antimicrobial stewardship (AMS). The aim of this review was to explore the published evidence identifying general considerations/criteria for an ideal post-surgical wound dressing in terms of overcoming potential wound healing challenges (including infection) while supporting AMS objectives.

METHOD

A scoping review examining evidence published from 1954-2021, conducted by two authors acting independently. Results were synthesised narratively and have been reported in line with PRISMA Extension for Scoping Reviews.

RESULTS

A total of 819 articles were initially identified and subsequently filtered to 178 for inclusion in the assessment. The search highlighted six key outcomes of interest associated with post-surgical wound dressings: wound infection; wound healing; physical attributes related to comfort, conformability and flexibility; fluid handling (e.g., blood and exudate); pain; and skin damage.

CONCLUSION

There are several challenges that can be overcome when treating a post-surgical wound with a dressing, not least the prevention and treatment of SSIs. However, it is imperative that the use of antimicrobial wound dressings is aligned with AMS programmes and alternatives to active antimicrobials investigated.

Effectiveness of wound contact layers in enabling undisturbed wound management: a case series

OBJECTIVE

Wound contact layers (WCLs) are intended to protect and support wounds during the healing process. An open, non comparative, case series clinical evaluation was undertaken to assess the impact of these dressings on establishing an undisturbed wound environment that supports effective wound management, and to allow the establishment of limits of duration of the wear time for the experimental WCLs.

METHOD

The primary objectives of this clinical evaluation were to assess the ability of the WCLs to prevent tissue disturbance to the wound and surrounding skin and for the clinicians to have confidence to extend the wear time of the WCL dressings. For them to have confidence in leaving the dressings in place for extended periods, the assessment of the wound and periwound skin condition and an assessment of patient comfort was performed: assessment of wound and periwound condition in relation to tissue adherence of the dressing to the wound resulting in tissue damage/bleeding (to wound and/or periwound skin) and cellular infiltration into the WCL; assessment of patient wearing comfort and satisfaction; assessment of WCL wear time, relating to times between dressing changes as judged by the clinician.

RESULTS

Based upon five parameters used to assess the extent to which the WCLs Atrauman, Atrauman Silicone and Atrauman Ag (HARTMANN, Germany) disturbed the underlying tissues-bleeding, wound tissue damage, periwound skin damage, tissue ingrowth and dressing adherence-the majority (>95%) of assessments indicated low or no disturbance of tissue. Over the 14 days of study assessment, the mean (±standard deviation) wear time was 7.3±1.2 days for the Atrauman group, 9.9±2.8 days for the Atrauman Silicone group, and 5.8±1.0 days for the Atrauman Ag group. All dressings were well tolerated by patients and rated highly in terms of in-use dressing performance.

CONCLUSION

The results indicate that Atrauman WCLs are suitable for the management of a variety of wounds as they promote an undisturbed wound environment, including extended wear time.

Polyhexamethylene biguanide and its antimicrobial role in wound healing: a narrative review

A wound offers an ideal environment for the growth and proliferation of a variety of microorganisms which, in some cases, may lead to localised or even systemic infections that can be catastrophic for the patient; the development of biofilms exacerbates these infections. Over the past few decades, there has been a progressive development of antimicrobial resistance (AMR) in microorganisms across the board in healthcare sectors. Such resistant microorganisms have arisen primarily due to the misuse and overuse of antimicrobial treatments, and the subsequent ability of microorganisms to rapidly change and mutate as a defence mechanism against treatment (e.g., antibiotics). These resistant microorganisms are now at such a level that they are of grave concern to the World Health Organization (WHO), and are one of the leading causes of illness and mortality in the 21st century. Treatment of such infections becomes imperative but presents a significant challenge for the clinician in that treatment must be effective but not add to the development of new microbes with AMR. The strategy of antimicrobial stewardship (AMS) has stemmed from the need to counteract these resistant microorganisms and requires that current antimicrobial treatments be used wisely to prevent amplification of AMR. It also requires new, improved or alternative methods of treatment that will not worsen the situation. Thus, any antimicrobial treatment should be effective while not causing further development of resistance. Some antiseptics fall into this category and, in particular, polyhexamethylene hydrochloride biguanide (PHMB) has certain characteristics that make it an ideal solution to this problem of AMR, specifically within wound care applications. PHMB is a broad-spectrum antimicrobial that kills bacteria, fungi, parasites and certain viruses with a high therapeutic index, and is widely used in clinics, homes and industry. It has been used for many years and has not been shown to cause development of resistance; it is safe (non-cytotoxic), not causing damage to newly growing wound tissue. Importantly there is substantial evidence for its effective use in wound care applications, providing a sound basis for evidence-based practice. This review presents the evidence for the use of PHMB treatments in wound care and its alignment with AMS for the prevention and treatment of wound infection.

The importance of periwound skin in wound healing: an overview of the evidence

DECLARATION OF INTEREST

The authors have no conflicts of interest.

HydroTac-a hydro-responsive wound dressing: a review of the in vitro evidence

AIM

The aim of this review is to identify and summarise the key in vitro evidence available to support the use of HydroTac (HRWD-2) to address specific aspects associated with the treatment of both acute and hard-to-heal wounds.

BACKGROUND

The provision of a moist wound healing environment to support optimal wound healing has been a basic tenet in wound care since the pioneering work on the benefits of occlusion to support wound healing. Modern wound dressings have adopted the benefits of moist healing through their innovative development. HRWD-2 has been shown in clinical studies to enable and support good healing outcomes and the in vitro evidence in support of this dressing is presented in this article.

METHOD

An online literature search (supplemented with a manual search of resources not available online) was conducted to identify articles and studies describing in vitro evidence in support of HRWD-2 in aspects important for promoting a healing response in the clinical environment.

RESULTS

In vitro studies showed that HRWD-2 contributes to balancing moisture levels and enhances the availability of growth factors known to be important for re-epithelialisation. Pre-clinical studies indicate that HRWD-2 enhances wound re-epithelialisation. Together these results suggest that HRWD-2 promotes a moist healing environment leading to the dressing supporting re-epithelialisation. In vitro data indicating an intrinsic lower in vitro adherence of HRWD-2 likely translate clinically to the benefits of an atraumatic wound dressing, including reduced pain (specifically at dressing change).

CONCLUSION

The in vitro evidence presented in this review supports the successful clinical results reported for HRWD-2 in terms of fluid management, wound healing and pain reduction at dressing change.

Implications of endotoxins in wound healing: a narrative review

Bacterial toxins are thought to play a role in delayed wound healing in critically colonised and infected wounds. Endotoxins are released from Gram-negative bacteria when they are lysed by host phagocytic cells during an immune response, or by antimicrobial agents, potentially leading to a detrimental effect on the host tissues. Endotoxins can affect all aspects of the wound healing process, leading to delayed healing and contributing to wound chronicity. Release of endotoxins by bacteria can also have serious systemic effects (for example, septic shock) that can lead to high levels of patient mortality. This review summarises the role and implications on wound healing of bacterial endotoxins, describing the impact of endotoxins on the various phases of the wound healing response. There is a paucity of in vivo/clinical evidence linking endotoxins attributed to a wound (via antibiotic treatment) or their release from infecting bacteria with parameters of delayed wound healing. Future work should investigate if this link is apparent and determine the mechanism(s) by which such detrimental effects occur, offering an opportunity to identify possible treatment pathways. This paper describes the phenomenon of antimicrobial-induced endotoxin release and summarises the use of wound dressings to reduce wound bioburden without inducing microbial death and subsequent release of endotoxins, thus limiting their detrimental effects.

Hydro-responsive wound dressings for treating hard-to-heal wounds: a narrative review of the clinical evidence—part 2

This narrative clinical review summarises the key evidence in support for the use of a hydro-responsive wound dressing, HydroTac (HRWD-2, PAUL HARTMANN AG, Germany) to address key aspects associated with the treatment of both acute and hard-to-heal wounds. This review demonstrates how HRWD-2 can be used in general to address the challenges presented by a wide range of wound types and skin injuries. It highlights the ability of HRWD-2 to regulate an optimal moist wound environment that promotes wound progression and healing. Key aspects covered in this review include the dressing's ability to: promote certain phases of the wound healing response (for example, re-epithelialisation) address the concepts and needs for wound progression as set out in the TIME wound management framework provide an optimal hydration level reduce tissue trauma and pain at dressing change.

The clinical impact of hydro-responsive dressings in dynamic wound healing: Part II

OBJECTIVE

Over the course of a wound's healing trajectory, whether the wound is acute or hard-to-heal, management is likely to involve the use of several different dressing types. Minimising the complexity of treatment (in terms of dressing usage) would aid clinicians in providing effective wound care but excellent clinical outcomes must remain the primary goal.

METHOD

This study was an open-labelled, non-comparative study assessing the clinical effectiveness of a coordinated wound dressing treatment regimen. After an initial phase of using a hydro-responsive wound dressing (HydroClean, HRWD-1, PAUL HARTMANN AG, Germany) to cleanse and debride hard-to-heal wounds, the wounds were subsequently treated with either HydroTac (HRWD-2, PAUL HARTMANN AG, Germany) (to maintain healing progression and re-epithelialisation) or RespoSorb (a superabsorbent dressing, PAUL HARTMANN AG, Germany) (to manage moderate-to-high levels of exudate). The Pressure Ulcer Scale for Healing (PUSH) assessment tool was used to measure the wound status over the course of the treatment period and to assess several wound status parameters (for example, wound area, exudate levels and wound characteristics such as level of re-epithelialisation).

RESULTS

The results from this study demonstrated that wounds treated with HRWD-2 showed a positive healing response when using the PUSH score assessment tool with a significant mean reduction (p<0.0001) in the PUSH score of wounds treated with HRWD-2, with >75% of wounds being closed by the end of the study. This result underlines the effectiveness of HRWD-2 in supporting healing progression.

CONCLUSION

The results from this study support the coordinated use of HRWDs for the effective management and treatment of a variety of hard-to-heal wounds.

Hydro-responsive wound dressings for treating hard-to-heal wounds: a narrative review of the clinical evidence

A break in skin integrity must be repaired as quickly as possible to avoid excess blood and fluid loss, and to minimise the onset of infection. Hard-to-heal wounds, in which the progression of the wound healing response is compromised, present several challenges to healing (for example, the presence of devitalised tissue acting as a physical barrier to healing and as a focus for bacterial contamination with the potential for subsequent infection). The objective of this article is to present, as a narrative review, the clinical evidence supporting the use of a unique hydro-responsive wound dressing (HydroClean, HRWD1, PAUL HARTMANN AG, Germany). The dressing provides a simple treatment option to address a number of clinical challenges clinicians must overcome in order to facilitate wound healing progression. These studies demonstrated that this product supported successful debridement/cleansing of a wide variety of wounds, including hard-to-heal wounds, enabled wound bed preparation, and lead to positive healing outcomes, including in wounds that previously had failed to heal. The simplicity of using HRWD1 as a single dressing can help clinicians overcome a variety of challenges when treating both acute and hard-to-heal wounds, which, with the benefit of proven patient outcomes, could make it an ideal choice for a first-line treatment.

Estrategias de protección antimicrobiana en el cuidado de heridas: evidencia para el uso de apósitos recubiertos con DACC

BACKGROUND

Antimicrobial resistance (AMR) is one of the most serious health threats globally. The development of new antimicrobials is not keeping pace with the evolution of resistant microorganisms, and novel ways of tackling this problem are required. One of such initiatives has been the development of antimicrobial stewardship programmes (AMS). The use of wound dressings that employ a physical sequestration and retention approach to reduce bacterial burden offers a novel approach to support AMS. Bacterial-binding by dressings and their physical removal can minimise their damage and prevent the release of harmful endotoxins.

OBJECTIVE

To highlight AMS to promote the correct use of antimicrobials and to investigate how dialkylcarbamyl chloride (DACC)-coated dressings can support AMS.

METHOD

MEDLINE, Cochrane Database of Systematic Reviews, and Google Scholar were searched to identify articles relating to AMS, and the use of wound dressings in the prevention and treatment of wound infections. The evidence supporting alternative wound dressings that can reduce bioburden and prevent wound infection in a way that does not kill or damage the microorganisms were reviewed.

RESULTS

The evidence demonstrated that using bacterial-binding wound dressings that act in a physical manner (eg, DACC-coated dressings) to preventing infection in both acute and hard-to-heal wounds does not exacerbate AMR and supports AMS.

CONCLUSION

Some wound dressings work via a mechanism that promotes the binding and physical sequestration and removal of intact microorganisms from the wound bed (eg, a wound dressing that uses DACC technology to prevent/reduce infection). They provide a valuable tool that aligns with the requirements of AMS by effectively reducing wound bioburden without inducing/selecting for resistant bacteria.

Superabsorbent Wound Dressing for Management of Patients With Moderate-to-Highly Exuding Chronic Leg Ulcers: An Early Stage Model-Based Benefit-Harm Assessment

The aim of the research is to assess the benefit-harm of superabsorbent polymers wound dressings based on polyacrylate polymers (SAPs) compared with standard of care (SoC) dressing mix for patients with moderate-to-highly exuding hard-to-heal leg ulcers. The SoC dressings mix was composed of other superabsorbents in 29% of cases, antimicrobials 26%, foams 20%, alginates 5%, and other dressings 19% weighted according to their frequency. We have used the decision-analytic modeling method, Markov process, as an adequate analytical solution for medical prognosis. We have combined the systematic literature search to identify the most relevant inputs for the analysis, with available patient-level clinical data concerning benefits of superabsorbent to generate a robust prediction of patient-relevant outcomes, including healing rates and health-related quality of life. Besides, we have qualitatively described adverse events associated with those treatments. Our research indicates that SAPs when compared with SoC dressing mix in a patient with moderate-to-highly excluding leg ulcers are leading to an improved healing rate with an absolute risk difference of 2.20% in 6 months and a relative risk of 1.07 in favor of SAP dressings. The attributable fraction among those exposed to SAP dressings of 6.6%, meaning that 6.6% of the healed ulcers could be attributed to having had the SAP dressing treatment instead of the SoC dressing treatment. Besides, SAP dressings lead to improved quality of life measured as incremental quality-adjusted life weeks (QALWs) of 0.13 QALWs.

Antimicrobial stewardship strategies in wound care: evidence to support the use of dialkylcarbamoyl chloride (DACC)- coated wound dressings

BACKGROUND

Traditionally, infections are treated with antimicrobials (for example, antibiotics, antiseptics, etc), but antimicrobial resistance (AMR) has become one of the most serious health threats of the 21st century (before the emergence of COVID-19). Wounds can be a source of infection by allowing unconstrained entry of microorganisms into the body, including antimicrobial-resistant bacteria. The development of new antimicrobials (particularly antibiotics) is not keeping pace with the evolution of resistant microorganisms and novel ways of addressing this problem are urgently required. One such initiative has been the development of antimicrobial stewardship (AMS) programmes, which educate healthcare workers, and control the prescribing and targeting of antimicrobials to reduce the likelihood of AMR. Of great importance has been the European Wound Management Association (EWMA) in supporting AMS by providing practical recommendations for optimising antimicrobial therapy for the treatment of wound infection. The use of wound dressings that use a physical sequestration and retention approach rather than antimicrobial agents to reduce bacterial burden offers a novel approach that supports AMS. Bacterial-binding by dressings and their physical removal, rather than active killing, minimises their damage and hence prevents the release of damaging endotoxins.

AIM

Our objective is to highlight AMS for the promotion of the judicious use of antimicrobials and to investigate how dialkylcarbamoyl chloride (DACC)-coated dressings can support AMS goals.

METHOD

MEDLINE, Cochrane Database of Systematic Reviews, and Google Scholar were searched to identify published articles describing data relating to AMS, and the use of a variety of wound dressings in the prevention and/or treatment of wound infections. The evidence supporting alternative wound dressings that can reduce bioburden and prevent and/or treat wound infection in a manner that does not kill or damage the microorganisms (for example, by actively binding and removing intact microorganisms from wounds) were then narratively reviewed.

RESULTS

The evidence reviewed here demonstrates that using bacterial-binding wound dressings that act in a physical manner (for example, DACC-coated dressings) as an alternative approach to preventing and/or treating infection in both acute and hard-to-heal wounds does not exacerbate AMR and supports AMS.

CONCLUSION

Some wound dressings work via a mechanism that promotes the binding and physical uptake, sequestration and removal of intact microorganisms from the wound bed (for example, a wound dressing that uses DACC technology to successfully prevent/reduce infection). They provide a valuable tool that aligns with the requirements of AMS (for example, reducing the use of antimicrobials in wound treatment regimens) by effectively reducing wound bioburden without inducing/selecting for resistant bacteria.

Cost-effectiveness of superabsorbent wound dressing versus standard of care in patients with moderate-to-highly exuding leg ulcers

OBJECTIVE

To determine the cost-effectiveness/utility of a superabsorbent wound dressing (Zetuvit Plus Silicone) versus the current standard of care (SoC) dressings, from the NHS perspective in England, in patients with moderate-to-high exudating leg ulcers.

METHOD

A model-based economic evaluation was conducted to analyse the cost-effectiveness/utility of a new intervention. We used a microsimulation state-transition model with a time horizon of six months and a cycle length of one week. The model uses a combination of incidence base and risk prediction approach to inform transition probabilities. All clinical efficiency, health-related quality of life (HRQoL), cost and resource use inputs were informed by conducting a systematic review of UK specific literature.

RESULTS

Treatment with the superabsorbent dressing leads to a total expected cost per patient for a six month period of £2887, associated with 15.933 expected quality adjusted life weeks and 10.9% healing rate. When treated with SoC, the total expected cost per patient for a six month period is £3109, 15.852 expected quality adjusted life weeks and 8% healing rate. Therefore, the superabsorbent dressing leads to an increase in quality-adjusted life weeks, an increase in healing rate by 2.9% and a cost-saving of £222 per single average patient over six months. Results of several scenario analyses, one-way deterministic sensitivity analysis, and probabilistic sensitivity analysis confirmed the robustness of base-case results. The probabilistic analysis confirmed that, in any combination of variable values, the superabsorbent dressing leads to cost saving results.

CONCLUSION

According to the model prediction, the superabsorbent dressing leads to an increase in health benefits and a decrease in associated costs of treatment.

Management of postoperative bleeding in surgically debrided wounds: topical haemostat versus electrocautery

OBJECTIVE

To compare the effectiveness of a temporary topical external haemostat (OMNI-STAT Granules, Omni-stat Medical Inc., US) versus the use of electrocautery for bleeding control in patients who have undergone surgical wound debridement. Time saved in the operating room (OR) was evaluated.

METHOD

A prospective evaluation of use of a topical haemostat in an OR setting was compared with retrospective data collected using electrocautery to understand the time-saving benefits of using a topical haemostat versus electrocautery.

RESULTS

A total of 52 patients were treated with the topical haemostat, and 89 patients with electrocautery. The topical haemostat was shown to be as effective in achieving haemostasis post-surgical debridement as electrocautery, with the added benefits of significant time savings in the OR (reducing the mean total OR time by 19.1%). Additionally, preprocedure and surgical procedure times in patients treated with the topical haemostat were significantly reduced. The results showed that wounds treated with the topical haemostat demonstrated a more advanced stage of healing, which may be a result of the lack of tissue damage demonstrated with the topical haemostat compared with electrocautery.

CONCLUSION

This study found that the temporary topical haemostat was equally as effective as cauterisation in achieving haemostasis. In addition, significant saving in OR time was demonstrated relative to electrocautery. The improved OR times may translate into increased cost-effectiveness, relative to electrocautery, by increasing the number of surgical cases per day and/or using resources more effectively to treat more patients. It may also enable bleeding control in the outpatient clinic or at the bedside, freeing up costly OR time and enabling more effective management of healthcare resources.

Clinical evaluation of a superabsorbent polymer dressing in enabling self-care of wounds

Patient involvement in their own treatment can enable those with wounds in the community to play an active role in the management of their condition by, for example, completing dressing changes between health professional visits. The original primary study was undertaken to assess the clinical effectiveness of Zetuvit Plus Silicone Border (ZPSB) on exudate management. This retrospective sub-group analysis is aimed to demonstrate the effectiveness of a superabsorbent polymer (SAP) dressing (ZPSB) in enabling patients or their carers to undertake unsupervised dressing changes on their own. ZPSB was found to be clinically effective in this subgroup of patients, while also having additional features that enabled the patient to self-care. Overall, ZPSB enabled the patient to be part of their treatment plan and play an active role in the care of their wounds, thereby promoting self-care. This had a positive effect on nursing time saving and patient satisfaction.

Evaluation of a superabsorbent wound dressing, patient and clinician perspective: a case series

Objective:

The primary objective of this study was to evaluate the fluid management capabilities of a superabsorbent wound dressing (Zetuvit Plus Silicone), with secondary objectives related to parameters that support whether the dressing enables undisturbed healing.

Method:

This study was an open labelled non-comparative study. Patients included in the study were selected by the clinical investigator(s) according to whether the patient required a dressing for the management of moderately to highly exuding wounds.

Results:

A total of 50 patients were included in the study. Results related to the primary objective demonstrated that the superabsorbent wound dressing was able to absorb all levels of exudate across the range (low to high). At each assessment time point these results show that in 98% of assessments the superabsorbent dressing was rated as ‘very good’ (91%) or ‘good’ (7%) at exudate management. Secondary objectives relating to wound bed preparation, healing and management of pain were also positive. Additionally, at the end of each patient treatment, the dressing's fluid management capabilities were rated overall as ‘excellent’ (100% of cases). There was little pain associated with the wound or at dressing change throughout the study and its flexibility/conformability allowed for comfort and patient satisfaction aligned with increased quality of life. Additionally, inclusion of a silicone adhesive layer allowed painless and atraumatic removal of the dressing, increasing patient comfort, both during wear and at dressing removal, and supported the description of enabling undisturbed wound healing.

Conclusion:

The superabsorbent wound dressing achieved the primary objective relating to wound exudate management in all the assessments undertaken in this study. In addition, the silicone interface allowed for undisturbed healing as evidenced by little or no adherence of the dressing to underlying tissue, preventing damage to periwound skin. Overall, the superabsorbent wound dressing with the addition of the silicone interface could offer advantages over other superabsorbent polymer dressings (that might adhere to the wound surface) or silicone wound dressings (that might not have the absorbent properties of this type of dressing).

Treating drug-resistant wound pathogens with non-medicated dressings: an in vitro study

Objective:

To assess the in vitro antimicrobial performance of a non-medicated hydro-responsive wound dressing (HRWD) on the sequestration and killing of wound relevant microorganisms found on the World Health Organization (WHO) priority pathogens list.

Methods:

Suspensions of Pseudomonas aeruginosa, Acinetobacter baumannii and methicillin-resistant Staphylococcus aureus (MRSA) were placed on petri dishes. Dressings were each placed on top, incubated for 30 minutes and then removed from the inoculated petri dish. The surface of the dressings previously in contact with the bacterial suspensions were placed directly onto a tryptone soy agar (TSA) plate and incubated for 24 hours. Dressings were then removed from the TSA plate and the level of bacterial growth on the plates was assessed. Sequestered microorganism viability was assessed using LIVE/DEAD viability kits and visualisation by epifluorescence.

Results:

Our results indicated that HRWDs sequester and retain Pseudomonas aeruginosa, Acinetobacter baumannii and MRSA within the dressing. Non-medicated HRWDs containing bound PHMB (polyhexamethylene biguanide, HRWD+PHMB) killed the microorganisms sequestered within the dressing matrix.

Conclusion:

These data suggest that non-medicated HRWD+PHMB is an effective against WHO priority pathogens and promoting goal of antimicrobial stewardship in wound care.

A multicentre, clinical evaluation of a hydro-responsive wound dressing: the Glasgow experience

OBJECTIVE

Our aim was to assess the effectiveness of hydro-responsive wound dressing (HRWD) in debridement and wound bed preparation of a variety of acute and chronic wounds that presented with devitalised tissue needing removal so that healing may proceed.

METHOD

This was a non-comparative evaluation of acute and chronic wounds that required debridement as part of their normal treatment regimen. Clinicians recorded wound changes including a subjective assessment level of devitalised tissue and wound bed preparation, presence of pain, wound status (e.g., wound size) and periwound skin condition. Data was also collected from clinicians and patients to provide information on clinical performance of the dressing.

RESULTS

We recruited 100 patients with a variety of wound types into the study. Over 90% of the clinicians reported removal of devitalised tissue to enable a healing response in both chronic and acute wounds. Specifically, over the course of the evaluation period, levels of devitalised tissue (necrosis and slough) reduced from 85.5% to 26.3%, and this was accompanied by an increase in wound bed granulation from 12.0% to 33.7%. Correspondingly, there was a 40% reduction in wound area, hence a clinically relevant healing response was seen upon treatment with HRWD. It is also noteworthy that this patient population included a significant proportion of chronic wounds (51.4%) that showed no signs of wound progression within <4 weeks before study inclusion. Of these chronic wounds, 93% demonstrated wound progression upon treatment with HRWD. Despite reported pain levels being low pre- and post-dressing change, overall wound pain improved (reduced) in 48% of patients. Periwound skin condition showed a tendency towards improvement, and the fluid management capabilities of the HRWD was reported as good to excellent in the majority of cases. Wound infections were reduced by at least 60% over the evaluation period. A simple cost-effective analysis demonstrated significant savings using HRWD (£6.33) over current standard practice regimens of a four-step debridement process (£8.05), larval therapy (£306.39) and mechanical pad debridement (£11.46).

CONCLUSION

HRWD was well tolerated and was demonstrated to be an efficient debridement tool providing rapid, effective and pain free debridement in a variety of wound types.

An in vitro assessment of bacterial transfer by products used in debridement

OBJECTIVE

The aim of this in vitro study was to investigate the transfer of viable Pseudomonas aeruginosa biofilm microorganisms following treatment with debridement tools.

METHOD

The level of viable biofilm microorganisms transferred by debridement tools was compared following treatment that reflected the clinical practice of each product.

RESULTS

A significant level of microorganism transfer was seen in response to the mechanical debridement tool. Minimal transfer of microorganisms was seen when in vitro-established biofilms were treated with hydroresponsive wound dressing + polyhexamethylene biguanide (HRWD+PHMB, HydroClean plus). Less Pseudomonas aeruginosa was recovered from explants exposed to dressings compared with those exposed to debridement tools suggesting that there was less transfer of bacteria by dressings.

CONCLUSION

The reduced transfer of viable microorganisms by HRWD+PHMB may be the result of significant binding and retention of microbes by the superabsorbent polymer within the dressing, together with enhanced sequestered bacterial killing within the dressing by polymer-bound PHMB. The high levels of microbial transfer/transmission seen for debridement tools suggests that, in the clinical setting, a significant level of bacterial spread over the wound surface and/or surrounding skin by these cleansing tools is likely.

Hydro-responsive wound dressings simplify T.I.M.E. wound management framework

The development of wound management protocols and guidelines such as the T.I.M.E. acronym are useful tools to aid wound care practitioners deliver effective wound care. The tissue, infection/inflammation, moisture balance and edge of wound (T.I.M.E.) framework provides a systematic approach for the assessment and management of the majority of acute and chronic wounds. The debridement of devitalised tissue from the wound bed, the reduction in wound bioburden and effective management of wound exudate - i.e., wound bed preparation - are barriers to wound healing progression that are targeted by T.I.M.E. There are a large number of wound dressings available to experienced wound care practitioners to aid in their goal of healing wounds. Despite the systematic approach of T.I.M.E., the large number of wound dressings available can introduce a level of confusion when dressing choices need to be made. Any simplification in dressing choice, for example by choosing a dressing system comprising of a limited number of dressings that are able to address all aspects of T.I.M.E., would be a valuable resource for delivering effective wound care. This article briefly reviews the principles of T.I.M.E. and describes the evidence for the use of a two-dressing, moisture balance-oriented, dressing-based wound management system.

The importance of hydration in wound healing: reinvigorating the clinical perspective

Balancing skin hydration levels is important as any disruption in skin integrity will result in disturbance of the dermal water balance. The discovery that a moist environment actively supports the healing response when compared with a dry environment highlights the importance of water and good hydration levels for optimal healing. The benefits of 'wet' or 'hyper-hydrated' wound healing appear similar to those offered by moist over a dry environment. This suggests that the presence of free water may not be detrimental to healing, but any adverse effects of wound fluid on tissues is more likely related to the biological components contained within chronic wound exudate, for example elevated protease levels. Appropriate dressings applied to wounds must not only be able to absorb the exudate, but also retain this excess fluid together with its protease solutes, while concurrently preventing desiccation. This is particularly important in the case of chronic wounds where peri-wound skin barrier properties are compromised and there is increased permeation across the injured skin. This review discusses the importance of appropriate levels of hydration in skin, with a particular focus on the need for optimal hydration levels for effective healing. Declaration of interest: This paper was supported by Paul Hartmann Ltd. The authors have provided consultative services to Paul Hartmann Ltd.

Adsorption of serum-derived proteins by primary dressings: implications for dressing adhesion to wounds

Using an in vitro immunolocalization technique, an exploratory study was carried out into the serum-derived protein adsorption capacity and the cell adherence of a traditional gauze dressing versus a new gelling fibre gauze dressing. We found that the traditional gauze dressing adsorbed protein more readily than the new dressing. The findings indicate that reduced binding of serum proteins to the surface of the gelling fibre dressing may help reduce the adherence characteristics for this type of dressing, minimising trauma and possibly reducing the acute pain experienced during dressing changes.

Application of an in vitro model to evaluate bioadhesion of fibroblasts and epithelial cells to two different dressings

The cellular component of a healing wound consists of many cell types and the environment in which these cells grow is important to the rate and quality of healing which can be influenced by the type of dressing used. The most commonly used dressings are traditional gauze-type dressings. In many cases these dressings may adhere to the wound surface, and subsequent removal is often traumatic, causing pain and tissue reinjury. Some modern gelling dressings have been developed to overcome this adherence problem. In order to evaluate in more detail cell-dressing interactions, an in vitro model has been developed utilising wound fibroblasts and epithelial cells. Quantitative evaluation of adherence of cells cultured with a traditional gauze or a new gelling dressing has been undertaken using radiolabel and manual counting techniques. Scanning electron microscopy has been used to visualise the cells adherent to dressings allowing evaluation of their adhesion-morphology. The results show differential attachment of cells to viscose and gelling fibres of the dressings; considerably reduced cell adhesion to the gelling fibre was evident, and it was apparent that cells adhered predominantly to the viscose component of the dressing. This model can be used to investigate and compare the adhesion of cells to different dressings and their components.

In vitro model(s) for the percutaneous delivery of active tissue repair agents

There is a need to evaluate the permeability of human ulcerated tissue and periulcer tissue in order to assess the possible treatment of such a localized pathological lesion with a topical therapy. In vitro percutaneous absorption studies were undertaken to evaluate an animal model that may mimic this clinical situation. Porcine skin from three anatomical sites, the ear, abdomen, and dorsum; ischaemic skin (porcine and guinea pig); porcine wounds; and human skin (including periulcer and ulcerated tissue) were investigated, utilizing both whole skin and dermal membranes. Dermal membranes were chosen as representative of ulcerated tissue, as there would be no epidermal barrier present, and the thickness of the dermal membrane was not expected to offer any diffusional resistance to topically applied active agents. A range of chemicals with differing physicochemical properties was investigated using a Franz type diffusion cell. For all tissues a permeability coefficient (kp with units of cm h-1) was measured, along with skin thickness and tissue partition coefficient measurements. Under these experimental conditions and for the range of compounds tested, the results suggest that porcine skin, whole skin, and dermal membranes should be considered as good representative in vitro models for the topical delivery of compounds to human skin and ulcerated tissue, respectively.