Effectiveness of an enhanced silver-containing dressing in hard-to-heal venous leg ulcers: a randomised controlled trial

OBJECTIVE

To assess the efficacy and safety of a carboxymethylcellulose dressing containing ionic silver, ethylenediaminetetraacetic acid and benzethonium chloride (CISEB) versus a dialkylcarbamoyl chloride-coated dressing (DACC) in hard-to-heal venous leg ulcers (VLUs).

METHOD

In a multinational, multicentre, randomised controlled trial, patients with hard-to-heal VLUs were randomised 1:1 to receive CISEB (n=100) or DACC (n=103) for up to four weeks. VLUs that were not healed by week 4 were managed with standard of care for up to 12 weeks or until healed (whichever was sooner). The primary endpoint was complete wound closure at week 12. Additional endpoints included time to complete wound closure and incidence of adverse events (AEs).

RESULTS

The trial cohort included 203 patients. CISEB achieved a higher rate of complete wound closure by week 12 compared to DACC (74.8% versus 55.6%, respectively; p<0.0031), and was associated with a 35% increased likelihood of healing (risk ratio, 1.35; 95% confidence interval: 1.10-1.65). Median time to complete wound closure was shorter in the CISEB arm (56 days) compared to the DACC arm (70 days; p<0.0272). A smaller proportion of patients experienced an AE with CISEB compared to DACC (5.0% versus 17.6%, respectively).

CONCLUSION

Management of hard-to-heal VLUs with CISEB was associated with improved healing outcomes compared to DACC, without additional safety concerns. CISEB is a gelling fibre dressing with antimicrobial, metal-chelating and surfactant components that may promote an optimal healing environment to address the challenge of hard-to-heal wounds.

Improving outcomes for patients with hard-to-heal wounds following adoption of the Wound Hygiene Protocol: real-world evidence

OBJECTIVE

To evaluate the impact of a four-step biofilm-based wound care strategy, Wound Hygiene Protocol (WHP: cleanse, debride, refashion, and dress), on hard-to-heal wounds.

METHOD

This was a prospective, real-world analysis of hard-to-heal wounds managed with the WHP that incorporated Aquacel Ag+ (Convatec Ltd., UK) dressings. Data were captured electronically between April 2021 and December 2022. The primary endpoint was change in wound volume from baseline to final assessment.

RESULTS

A total of 693 wounds in 669 patients (median patient age: 74 years) were included in the analysis with a median treatment time of 31 days. Most health professionals were general nurses (50%) or nurse practitioners (38%). Patient homes (27%) and community clinics (27%) were the most common clinical settings. Venous leg ulcers (26%) and pressure ulcers/injuries (17%) were the most common wound type. Duration was >12 months in 21% of wounds. At baseline, the mean wound volume was 57.8cm3. At the final assessment, mean wound volume was 17.2cm3, corresponding to an 80% reduction from baseline; p<0.001). At baseline, 66% of wounds were static or deteriorating. At final assessment, this had decreased to 5%, and 94% had improved or healed. Exudate levels were moderate or high in 69% of wounds at baseline which decreased to 25% at final assessment (p<0.001). Suspected biofilm and local wound infection decreased from 79% and 43%, respectively, at baseline, to 18% and 3%, respectively, at final assessment (p<0.001 for both).

CONCLUSION

The WHP is a new proposed standard of care that successfully treated hard-to-heal wounds by addressing the key local barriers to wound healing.

Advancements in Managing Wound Biofilm: A Systematic Review and Meta-analysis of Randomized Controlled Trials on Topical Modalities

Despite numerous available agents claiming anti-biofilm properties on wounds, the substantiating evidence remains inconclusive. This study aimed to assess the immediate impact of topical wound treatments on wound biofilm and healing outcomes in acute and chronic ulcers. We comprehensively searched PubMed, ClinicalTrials.gov, and Google Scholar. In addition, eligible gray literature was incorporated. English-language randomized controlled trials (RCTs), observational, cohort, and case-control studies targeting biofilm prevention, inhibition, or elimination across diverse wound types were included. Primary outcomes included biofilm presence and elimination, supplemented by secondary outcomes encompassing reduced wound size, complete closure, and diminished infection indicators. Bacterial load reduction and biofilm presence were also assessed. Twenty-eight articles met the inclusion criteria. Various modalities were identified, including biofilm-visualization techniques, such as wound blotting and handheld autofluorescence imaging. Pooled analysis for the primary outcomes was infeasible due to limited eligible studies and data-reporting challenges. As for the secondary outcomes, the pooled analysis for complete surgical wound closure (2 RCTs, yielding n=284) and presence of surgical site infections/inflammation (2 RCTs, yielding n=284) showed no significant difference, with a log odds ratio (LOD) of 0.58 (95% confidence interval [CI]: -.33, 1.50) and LOD -0.95 (95% CI: -3.54, 1.64; τ2 = 2.32, Q = 2.71, P = .10), respectively. Our findings suggest insufficient evidence to support anti-biofilm claims of topical modalities. Clinicians' skill appears to play a pivotal role in biofilm elimination and wound healing enhancement, with potential optimization through visual-guided techniques, such as wound blotting and autofluorescence imaging. More rigorous clinical trials are warranted to ascertain the efficacy of these techniques.Level of Evidence: Therapeutic, 1A.

Comparative study of the efficacy of Ionic Silver Solution and Super Oxidized Solution in the management of chronic wounds

Background

Chronic wounds are of many etiologies and difficult to treat. Many commercial products to manage such wounds are available, which claim to have good outcomes. Aim of this study was to compare the efficacy of Ionic Silver Solution and Super Oxidized Solution in the management of chronic wounds.

Methods

Patients with chronic wounds were randomly placed in two groups-Group A (Ionic Silver Solution) and Group B (Super Oxidized Solution) with 30 patients each. The dressings were continued until the wound healed completely or the wound was ready for a definitive procedure. Wound parameters were recorded as per Bates Jensen Wound Assessment Tool (BJWAT) Score.

Results

FIfty patients completed the study. The scores were compared at the initiation and endpoint of treatment. The pretreatment total for BJWAT was 916 and 924 in group A and group B respectively, which was not statistically significant. Post-treatment improvement was noticed in both the groups and the score decreased to 510 and 675 in group A and group B respectively (p = 0.001). Ionic Silver Solution and Super Oxidized Solution both were found to be effective in improving the overall wound condition. However, Ionic Silver Solution was found to be more effective than Super Oxidized Solution in the healing of chronic wounds. Complete healing was noticed in a small number (6%) of patients. These agents can therefore best prepare the wounds for early surgical intervention.

Conclusion

Both the agents were found to be safe and useful in the management of chronic wounds. However, Ionic Silver Solution was found to be more effective than the super oxidized solution in this study.

An observational study of wounds treated with hydro-responsive wound dressings

OBJECTIVE

Acute and hard-to-heal wounds are a significant burden to both a patient's quality of life and resources in healthcare systems. Here, we evaluate the outcomes of a non-comparative case series study in which Ringer's solution-preactivated polyacrylate dressings were used to treat acute and hard-to-heal wounds (the presence of Ringer's solution provides a wound dressing that allows, upon application, the immediate hydration of the underlying wound tissue).

METHOD

Patients with acute and hard-to-heal wounds were enrolled into an open-labelled, non-comparative observational study. Patients were treated with Ringer's solution-preactivated polyacrylate dressings to enable wound debridement and wound cleansing for up to 12 weeks.

RESULTS

A total of 303 patients were enrolled in the study and 278 were included in the analysis. Wound size decreased, from a median of 3.6cm² (interquartile range (IQR): 1.2-9.3] at baseline to a median of 2.6cm² (IQR: 1.1-7.8] at 84 days. Relative wound area reduction (WAR) was 43.1% at 84 days and estimated probability of achievement of a WAR of ≥40% and ≥60% was 68.7% and 53.4%, respectively. Median time to achieve a WAR of ≥40% and ≥60% was 54 days and 75 days, respectively. The median percentage of wound area covered by fibrin had decreased from 50.0% to 10% and granulation tissue had increased from 25% to 50% after 84 days. In addition, periwound skin condition, local signs of infection and pain all showed improvement. The majority of the wounds were assessed as 'healed' or 'better' at the conclusion of the evaluation period.

CONCLUSION

Based on the findings of this study, the use of Ringer's solution-preactivated polyacrylate dressings in daily practice has the potential to improve clinical outcomes, including healing, in patients with acute and hard-to-heal wounds.

Evaluating polymeric biomaterials to improve next generation wound dressing design

Wound healing is a dynamic series of interconnected events with the ultimate goal of promoting neotissue formation and restoration of anatomical function. Yet, the complexity of wound healing can often result in development of complex, chronic wounds, which currently results in a significant strain and burden to our healthcare system. The advancement of new and effective wound care therapies remains a critical issue, with the current therapeutic modalities often remaining inadequate. Notably, the field of tissue engineering has grown significantly in the last several years, in part, due to the diverse properties and applications of polymeric biomaterials. The interdisciplinary cohesion of the chemical, biological, physical, and material sciences is pertinent to advancing our current understanding of biomaterials and generating new wound care modalities. However, there is still room for closing the gap between the clinical and material science realms in order to more effectively develop novel wound care therapies that aid in the treatment of complex wounds. Thus, in this review, we discuss key material science principles in the context of polymeric biomaterials, provide a clinical breadth to discuss how these properties affect wound dressing design, and the role of polymeric biomaterials in the innovation and design of the next generation of wound dressings.

Pharmaceutical strategies for the treatment of bacterial biofilms in chronic wounds

Biofilms are sessile communities of microorganisms, mainly bacteria, that grow on biotic and abiotic surfaces. These microorganisms are embedded within an extracellular polymeric substance that provides enhanced protection from antimicrobials. Chronic wounds provide an ideal habitat for biofilm formation. Bacteria can easily attach to wound debris and can infect the wound due to an impaired host immune response. This review highlights the mechanism of biofilm formation and the role of biofilms in the pathophysiology of chronic wounds. Our major focus is on various formulation strategies and delivery systems that are employed to eradicate or disperse biofilms, thereby effectively managing acute and chronic wounds. We also discuss clinical research that has studied or is studying the treatment of biofilm-infected chronic wounds. Teaser: Innovative pharmaceutical strategies such as hydrogels, nanofibers, films and various nanoscale materials can provide promising approaches for the treatment of biofilm-mediated chronic wound infections, offering the potential to improve therapeutic outcomes.

Implementation of Wound Hygiene in clinical practice: early use of an antibiofilm strategy promotes positive patient outcomes

Non-healing wounds are devastating for patients, potentially causing long-term morbidity and an impaired quality of life. They also incur a huge health economic burden for health-care services. Understanding of the causes of non-healing wounds has increased significantly. While the need to address the underlying aetiology has always been acknowledged, the role of biofilm in delaying or preventing healing is now accepted. There is a consensus on the need to debride the wound to remove biofilm and then prevent its reformation, to kickstart healing. The potential benefits of incorporating an antibiofilm component within the wound bed preparation framework are clear. However, such a strategy needs to be flexible enough so that it can be implemented by all practitioners, regardless of their expertise or specialty. Wound Hygiene does this. This supplement describes the Wound Hygiene protocol, and includes a selection of case studies on different wound types, demonstrating its ease of use and effectiveness in clinical practice.

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.

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.

Biofilm exacerbates antibiotic resistance: Is this a current oversight in antimicrobial stewardship?

Objective

To raise awareness of the role of environmental biofilm in the emergence and spread of antibiotic resistance and its consideration in antimicrobial stewardship.

Background

Antibiotic resistance is a major threat to public health. Overuse of antibiotics, increased international travel, and genetic promiscuity amongst bacteria have contributed to antibiotic resistance, and global containment efforts have so far met with limited success. Antibiotic resistance is a natural mechanism by which bacteria have adapted to environmental threats over billions of years and is caused either by genetic mutations or by horizontal gene transfer. Another ancient survival strategy involves bacteria existing within a self-produced polymeric matrix, which today is termed biofilm. Biofilm similarly enables bacterial tolerance to environmental threats, and also encourages the transfer of antibiotic resistance genes between bacterial species. This natural and ubiquitous mode of bacterial life has not been considered amongst strategies to tackle antibiotic resistance in healthcare facilities, despite its ability to significantly enhance bacterial survival and persistence, and to encourage antibiotic resistance.

Conclusion

Biofilm must be considered synonymously with antibiotic resistance because of its proficiency in transferring resistance genes as well as its innate phenotypic tolerance to antibiotics. Although biofilm falls outside of the current definition of antimicrobial stewardship, greater awareness of the existence, ubiquity, and consequences of environmental biofilm amongst healthcare practitioners is crucial to improving hygiene practices and controlling the emergence and spread of antibiotic resistance in healthcare facilities.

Use of internally validated in vitro biofilm models to assess antibiofilm performance of silver-containing gelling fibre dressings

Objective:

To assess the efficacy of five silver-containing gelling fibre wound dressings against single-species and multispecies biofilms using internally validated, UKAS-accredited in vitro test models.

Method:

Staphylococcus aureus, Pseudomonas aeruginosa and Candida albicans single- and multispecies biofilms were cultured using Centres for Disease Control (CDC) biofilm reactors and colony drip flow reactors (CDFR). Following a 72 hour incubation period, the substrates on which biofilms were grown were rinsed to remove planktonic microorganisms and then challenged with fully hydrated silver-containing gelling fibre wound dressings. Following dressing application for 24 or 72 hours, remaining viable organisms from the treated biofilms were quantified.

Results:

In single-species in vitro models, all five antimicrobial dressings were effective in eradicating Staphylococcus aureus and Pseudomonas aeruginosa biofilm bacteria. However, only one of the five dressings (Hydrofiber technology with combination antibiofilm/antimicrobial technology) was able to eradicate the more tolerant single-species Candida albicans biofilm. In a more complex and stringent CDFR biofilm model, the hydrofiber dressing with combined antibiofilm/antimicrobial technology was the only dressing that was able to eradicate multispecies biofilms such that no viable organisms were recovered.

Conclusion:

Given the detrimental effects of biofilm on wound healing, stringent in vitro biofilm models are increasingly required to investigate the efficacy of antimicrobial dressings. Using accredited in vitro biofilm models of increasing complexity, differentiation in the performance of dressings with combined antibiofilm/antimicrobial technology against those with antimicrobial properties alone, was demonstrated.

Clinical and in vitro performance of an antibiofilm Hydrofiber wound dressing

OBJECTIVE

To compare the clinical and in vitro performance of a next-generation antibiofilm silver dressing (NGAD) with an established antimicrobial dressing technology that was developed before the recognition of wound biofilm as a clinical challenge.

METHOD

Real-life evaluations of challenging wounds managed previously with cadexomer iodine (CI) dressings followed by switching to NGAD were evaluated alongside electron, confocal and light microscopy images from a challenging, in vitro, exuding chronic wound model. Clinical case studies on the use of CI and NGAD dressings are presented to further explore the real-life evidence and in vitro findings.

RESULTS

We assessed 13 non-healing wounds that had been managed with protocols including CI dressings. After a median of four weeks, switching to the NGAD as primary dressing resulted in improvements in nine wounds and healing in two wounds, with associated improvements in wound bed appearance, while dressing usage was the same as or lower than before. The NGAD was observed to prevent the development of Staphylococcus aureus- Pseudomonas aeruginosa biofilm over three days, in contrast to the CI dressing, which appeared to support biofilm development once the active antimicrobial was exhausted from its carrier material. Clinical case studies exhibited this exhaustion as 'whiting out' of the dressing, with wound biofilm observed from samples taken following dressing use. Positive wound and patient outcomes were observed in two cases following the switch from a CI primary dressing to the NGAD, in highly exuding and infected wounds.

CONCLUSION

Antimicrobial dressings may be effective against biofilm in some laboratory models, but their effectiveness as a wound dressings in protocols of care must be verified clinically.

Cadexomer iodine effectively reduces bacterial biofilm in porcine wounds ex vivo and in vivo

Biofilms are prevalent in non-healing chronic wounds and implicated in delayed healing. Tolerance to antimicrobial treatments and the host's immune system leave clinicians with limited interventions against biofilm populations. It is therefore essential that effective treatments be rigorously tested and demonstrate an impact on biofilm across multiple experimental models to guide clinical investigations and protocols. Cadexomer iodine has previously been shown to be effective against biofilm in various in vitro models, against methicillin-resistant Staphylococcus aureus biofilm in mouse wounds, and clinically in diabetic foot ulcers complicated by biofilm. Similarities between porcine and human skin make the pig a favoured model for cutaneous wound studies. Two antiseptic dressings and a gauze control were assessed against mature biofilm grown on ex vivo pig skin and in a pig wound model. Significant reductions in biofilm were observed following treatment with cadexomer iodine across both biofilm models. In contrast, silver carboxymethylcellulose dressings had minimal impact on biofilm in the models, with similar results to the control in the ex vivo model. Microscopy and histopathology indicate that the depth of organisms in wound tissue may impact treatment effectiveness. Further work on the promising biofilm efficacy of cadexomer iodine is needed to determine optimal treatment durations against biofilm.

The wound-healing effects of a next-generation anti-biofilm silver Hydrofiber wound dressing on deep partial-thickness wounds using a porcine model

Topical antimicrobials are widely used to control wound bioburden and facilitate wound healing; however, the fine balance between antimicrobial efficacy and non-toxicity must be achieved. This study evaluated whether an anti-biofilm silver-containing wound dressing interfered with the normal healing process in non-contaminated deep partial thickness wounds. In an in-vivo porcine wound model using 2 pigs, 96 wounds were randomly assigned to 1 of 3 dressing groups: anti-biofilm silver Hydrofiber dressing (test), silver Hydrofiber dressing (control), or polyurethane film dressing (control). Wounds were investigated for 8 days, and wound biopsies (n = 4) were taken from each dressing group, per animal, on days 2, 4, 6, and 8 after wounding and evaluated using light microscopy. No statistically significant differences were observed in the rate of reepithelialisation, white blood cell infiltration, angiogenesis, or granulation tissue formation following application of the anti-biofilm silver Hydrofiber dressing versus the 2 control dressings. Overall, epithelial thickness was similar between groups. Some differences in infiltration of specific cell types were observed between groups. There were no signs of tissue necrosis, fibrosis, or fatty infiltration in any group. An anti-biofilm silver Hydrofiber wound dressing did not cause any notable interference with normal healing processes.