By Temple University School of Podiatric Medicine Journal Review Club

Editor's note: This post is part of the Temple University School of Podiatric Medicine (TUSPM) journal review club blog series. In each blog post, a TUSPM student will review a journal article relevant to wound management and related topics and provide their evaluation of the clinical research therein.

Article: Defying Hard-to-Heal Wounds With an Early Antibiofilm Intervention Strategy: Wound Hygiene

Authors: Murphy C, Atkin L, Swanson T, et al

Journal: J Wound Care. 2020;29(Suppl 3b):S1-S26

Reviewed by: Cindy H, Duong, class of 2021, Temple University School of Podiatric Medicine

Introduction

An appropriate timeline to initiate biofilm-based wound care (BBWC) has been in question since the incorporation of biofilm therapy was introduced. In hard-to-heal delayed wounds, it is largely agreed on that biofilms are a significant barrier to healing and that removal is essential. By definition, hard-to-heal wounds are wounds that have failed to respond to evidence-based standard of care and that contain biofilm. Biofilms are polymicrobial communities residing in an extracellular matrix produced by bacteria. This matrix is well hydrated and resistant to antimicrobial agents and host defenses. Biofilm can form within hours, can reach maturity within 48 to 72 hours, and has the ability to regrow within 24 to 48 hours.

Biofilm-Based Wound Care Consensus Document Development

A first critical step in BBWC is debridement, although it requires additional suppression methods, as well as consideration of a patient’s risk factors. Risk factors include peripheral vascular disease, infection, diabetes, and pressure offloading, which encourage biofilm development by delaying wound healing. Risks and costs of early BBWC are most likely lower than those associated with biofilm-related wound complications. Thus, in March 2019, a panel of nine experts met in London for an Advisory Board Meeting, where they developed solutions to barriers preventing early BBWC and methods of appropriate “wound hygiene” for all health professionals. These experts reconvened in the summer of 2019 to create a clinical consensus document published in the Journal of Wound Care and supported by ConvaTec Limited.

Wound Bed Preparation and Biofilm Management

Barriers to Adoption of Biofilm-Based Wound Care

Major barriers to early intervention of biofilm therapy include an inability of all clinical environments to detect the presence of biofilm accurately, different interpretations of the term “chronic” (such as a lack of urgency), poor practices of antibiotic stewardship, and the lack of training on the role of biofilm in delayed wound healing. Unclear terminology acts as a major barrier to understanding and adopting early intervention with BBWC.

Solutions to the major barriers include the following: improving access to a biofilm detection tool; replacing the term “chronic” with “hard-to-heal”; developing reliable diagnostic tools to identify the presence of infection and prevent inappropriate use of antibiotics; and educating providers about wound hygiene terminology, which describes optimal care and consistent wound decontamination for the reduction of bacterial burden. This terminology communicates that effective, repetitive “wound hygiene” to promote healthy healing environments should be a patient standard of care.

Stages of Wound Hygiene

The proposed stages of wound hygiene are demonstrated as follows: wound and periwound cleansing, debridement, refashioning of wound edges, and wound dressing. Skin and wound cleansing of the periwound skin and wound removes surface contaminants, loose debris, slough, excess exudate, and necrosis, which can promote biofilm formation. It also disrupts biofilm. The periwound is concentrated either in the area 10 to 20 cm away from the wound edges or in the area covered by the dressing. This cleansing step should be done with as much physical force as the patient can tolerate and performed at each dressing change and after debridement.

The panel encourages daily use of a surfactant-containing antiseptic or pH-balanced solution. To prevent cross-contamination, use different cleansing cloths for the wound and periwound. Wound debridement removes or minimizes any unwanted material by means of mechanical aids and progresses a wound not covered by granulation tissue into healing. This should be performed every time the wound is managed. Selection of the debridement method is based on the wound bed assessment, the periwound, and the patient’s tolerance levels. In combination with a surfactant or antimicrobial solution, mechanical force is effective in breaking up and clearing biofilm.

Be cautious about considering debriding lower extremity wounds in patients with poorly perfused limbs and autoimmune conditions (e.g., pyoderma gangrenosum). In addition, be cautious about mechanical debridement in patients with bleeding disorders, anticoagulation therapy, or intolerable pain. Topical anesthetic agents or surfactants may be used to ease the pain. After debridement, a culture may be taken if warranted, and then the wound and periwound should be rinsed with an antiseptic solution.

In full-thickness wounds, biofilm is most active at the wound edges, and this prevents epithelialization. This type of wound requires mechanical debridement of the wound edges to pinpoint bleeding. Refashioning the wound edges ensures the continuation of the skin edges with the wound bed to facilitate epithelial advancement and wound contraction. This step also includes removal of hyperkeratotic callus from the periwound. Wound bed fragility is not a common issue, and thus, removal of devitalized tissue from the wound edges should take priority because it will result in healthy tissue.

Undermining or tunneling should be addressed either by packing a dressing or refashioning the wound edges. Finally, dress the wound with antimicrobial dressings to address any residual biofilm. The skin should be clean and dry before application of a wound dressing. Topical antimicrobial and antibiofilm dispersal agents are used to penetrate and disrupt the biofilm and prevent its formation. These agents include enzymes, metal chelators, surfactants, and topical antiseptic dressings (e.g., polyhexamethylene biguanide, povidone iodine, silver). When choosing a wound dressing, the volume of wound exudate should be considered because exudate can promote biofilm formation. A step-up–step-down approach should be taken to ensure that the antimicrobial dressings are used only when required. Assess the wound every two to four weeks to determine whether it is necessary to step down to a non-antimicrobial dressing or another type of dressing.

Conclusion

By being able to disrupt and prevent biofilm formation, infection risk is reduced, which may lead to less antibiotic use in wound care. The concept of wound hygiene is consistent with previous studies demonstrating that repetitive, early intervention with multiple therapies provides an optimal healing environment for hard-to-heal wounds, as long as all underlying etiologic factors have been addressed. A holistic assessment is vital in identifying and treating all potential wound etiologies and patient comorbidities. BBWC should begin at the first referral and continue until full healing is achieved.

About The Author

Cindy H. Duong is a third-year podiatric medical student at Temple University School of Podiatric Medicine (TUSPM) in Philadelphia, Pennsylvania. Born in Philadelphia, she graduated from Central High School in 2013 and then graduated from Temple University (TU) in 2017 with a Bachelor of Science in Biology. At TU, Cindy was active with pre-medical organizations and leadership programs around the campus, where she held the Vice President positions for the Pre-Student Osteopathic Medical Association and Pre-Student National Podiatric Medical Association. While shadowing multiple podiatrists in the Philadelphia area and participating in TUSPM’s summer internship, Cindy chose to pursue a career in the podiatric medical field. She matriculated at TUSPM with a merit scholarship in the fall of 2017. Dr. James McGuire is the director of the Leonard S. Abrams Center for Advanced Wound Healing and an associate professor of the Department of Podiatric Medicine and Orthopedics at the Temple University School of Podiatric Medicine in Philadelphia.