Systematics, diagnosis and treatment of wound infections in chronic wounds: A position paper from WundDACH

Wound infections are still an interdisciplinary and interprofessional challenge, because of numerous complications, particularly in people with chronic wounds. There are many different concepts and approaches in this field today. Therefore, WundDACH, the umbrella organization of the German-speaking wound healing societies, wrote a position paper on this important topic. An interdisciplinary and interprofessional group of experts from German-speaking countries developed definitions and procedures for nomenclature, diagnosis and treatment of wound infections in people with chronic wounds in a modified Delphi process. The importance of correctly diagnosing wound infections is emphasized so that adequate treatment can be carried out as early and specifically as possible. For a differentiated assessment, a simplified continuum of wound infection with contamination, colonization, local and systemic infection and the corresponding therapeutic consequences was described. Most bacteria in wounds can be removed by repeated wound-irrigation and debridement. Local wound infections are diagnosed based on clinical signs of infection and TILI score. Treatment is then usually exclusively local, for example with modern antiseptics such as polyhexanide. Systemic antibiotics should mostly be considered when signs of systemic infections appear. The indication for antimicrobial wound therapy should be critically reviewed after 10-14 days at the latest.

Wnt/β-catenin and notch signaling pathways in cardiovascular disease: Mechanisms and therapeutics approaches

Wnt and Notch signaling pathways play crucial roles in the development and homeostasis of the cardiovascular system. These pathways regulate important cellular processes in cardiomyocytes, endothelial cells, and smooth muscle cells, which are the key cell types involved in the structure and function of the heart and vasculature. During embryonic development, Wnt and Notch signaling coordinate cell fate specification, proliferation, differentiation, and morphogenesis of the heart and blood vessels. In the adult cardiovascular system, these pathways continue to maintain tissue homeostasis and arrange adaptive responses to various physiological and pathological stimuli. Dysregulation of Wnt and Notch signaling has been involved in the pathogenesis of numerous cardiovascular diseases, including atherosclerosis, hypertension, myocardial infarction, and heart failure. Abnormal activation or suppression of these pathways in specific cell types can contribute to endothelial dysfunction, vascular remodeling, cardiomyocyte hypertrophy, impaired cardiac contractility and dead. Understanding the complex interplay between Wnt and Notch signaling in the cardiovascular system has led to the investigation of these pathways as potential therapeutic targets in clinical trials. In conclusion, this review summarizes the current knowledge on the roles of Wnt and Notch signaling in the development and homeostasis of cardiomyocytes, endothelial cells, and smooth muscle cells. It further discusses the dysregulation of these pathways in the context of major cardiovascular diseases and the ongoing clinical investigations targeting Wnt and Notch signaling for therapeutic intervention.

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

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.

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.

Antimicrobial stewardship in wound care

Strategies to tackle the global crisis of antimicrobial resistance include implementing antimicrobial stewardship across the healthcare and agricultural sectors. Many clinical specialities have developed policies to advise practitioners on how to prescribe antibiotics more effectively, but there is still a lack of data on the impact of this change. Overuse and misuse of antibiotics have been commonplace since their introduction 70 years ago, and have contributed to the development of the resistance seen today. There is a dearth of new antibiotics and, if nothing is done to restrict the use of those that remain effective, there is a risk of returning to the pre-antibiotic era where simple infections could result in death. In wound care, it is essential that antibiotic treatment is appropriate to reduce infections. Many medical conditions predispose people to wounds that are difficult to heal and become chronic unless the underlying causes are addressed. Most wound infections are caused by bacteria, which are becoming increasingly resistant to commonly used antibiotics. This necessitates strict regimens for managing infection, which include prescribing antibiotics only when they are essential. Antimicrobial stewardship is undertaken in all UK healthcare facilities, and local advisory committees oversee the prudent use of antibiotics and other antimicrobial agents to try to prevent further increases in resistance. National guidance has been produced but whether full compliance has been followed has yet to be established and the impact of implementation needs to be analysed.

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.

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.