A Diagnostic-Driven Prospective Clinical Study Evaluating the Combination of an Antibiofilm Agent and Negative Pressure Wound Therapy.

BACKGROUND: Each year, millions of Americans develop truncal pressure ulcers (PUs) which can persist for months, years, or until the end of life. Despite the negative impact on quality of life and escalating costs associated with PUs, there is sparse evidence supporting validated and efficacious treatment options. As a result, treatment is based on opinion and extrapolation from other wound etiologies. The ideal reconstructive plan maximizes the patient's nutritional status, incorporates the basic tenets of wound bed preparation (debridement, offloading, proper moisture balance, reduction of bacterial burden), and employs diagnostics to guide therapeutic intervention. The use of combination therapies can potentially overcome several of the barriers to wound healing. Negative pressure wound therapy (NPWT), a commonly used modality in the management of PUs, facilitates healing by stimulating the formation of granulation tissue and promoting wound contraction; however, NPWT alone is not always effective. Clinical studies examining microbial bioburden in PUs determined that most ulcers contain bacteria at levels that impede wound healing (>104 CFU/g). OBJECTIVE: Thus, we hypothesized that adding an anti-microbial agent to decrease both planktonic and biofilm bacteria in the wound would increase the efficacy of NPWT. METHOD: In this prospective study, twenty patients with recalcitrant PUs that previously failed NPWT were treated with a biofilm-disrupting agent (Blast-X, Next Science, Jacksonville, FL, USA) in combination with NPWT. Fluorescence imaging was used to follow bacterial burden and guide therapy. RESULTS: In total, 45% of the PUs reduced in size over the course of the four-week study, with a resolution of bacterial fluorescence in the NPWT dressing and wound bed seen in an average of three weeks. CONCLUSION: The combination of an antibiofilm agent and NPWT reduced bacterial levels and improved wound healing in recalcitrant PUs.

A double-blind trial comparing an antimicrobial combination to standard care in hard-to-heal wounds.

OBJECTIVE: Excessive numbers of bacteria in hard-to-heal wounds impede wound healing. Numerous topical antiseptics have demonstrated effectiveness in benchtop studies; however, few clinical studies have demonstrated efficacy in the target population: patients with hard-to-heal wounds. This study addressed the clinical efficacy of a novel antibiofilm cleanser and gel in reducing bacterial load and improving wound outcomes. METHOD: Hard-to-heal wounds were photographed, measured and evaluated for bacterial load using fluorescence imaging weekly for four weeks. The target ulcers were randomised to be cleaned and treated with either a synergistic antibiofilm cleanser and antibiofilm gel with standard of care (AMC-AMG + SoC) or normal saline wash and an amorphous gel with standard of care (NSS-HG + SoC). RESULTS: A Chi-squared test of independence determined that the relationship between the treatment and the patient reaching 40% percentage area reduction (PAR) in four weeks was not significant (χ2(1, n=54)=0.73; p=0.39 at a significance level of 0.05); however, there was a strong trend favouring the antibiofilm cleanser and gel. A significant reduction (p<0.05) in bacterial load was observed in the antibiofilm group. CONCLUSION: This randomised controlled double-blind proof-of-concept study suggests that the performance of antibiofilm agents in vivo is comparable to that in vitro studies.

Skin Pigmentation Impacts the Clinical Diagnosis of Wound Infection: Imaging of Bacterial Burden to Overcome Diagnostic Limitations.

Underrepresentation of diverse skin tones in medical education and providers' implicit racial bias drives inequities in wound care, such as disproportionally poor outcomes for Black patients. Diagnostic indicators (e.g., erythema) can present differently depending on skin pigmentation. This post hoc analysis of 350 chronic wounds from a prospective 14-site clinical trial aimed to determine how the perception of clinical signs and symptoms of infection (CSS) differs by patient skin tone and if fluorescence-imaging can offer a more objective diagnostic solution. Participants were grouped by skin tone (low, medium, high) as measured by the Fitzpatrick Skin Phototype Classification (FSPC) scale. CSS and total bacterial load (TBL) were compared across FSPC groups, along with sensitivity to detect TBL >104 CFU/g using CSS alone and combined with fluorescence-imaging. Erythema was reported less often with increasing FSPC score (p = 0.05), from 13.4% (low), to 7.2% (medium), to 2.3% (high), despite comparable bacterial loads (median = 1.8 × 106 CFU/g). CSS sensitivity in the high group (2.9%) was 4.8-fold to 8.4-fold lower than the low (p = 0.003) and medium groups (p = 0.04). Fluorescence-imaging significantly improved the detection of high bacterial load in each group, peaking in the high group at 12-fold over CSS alone. These findings underscore the threat of pervasive racialized health inequities in wound care, where missed diagnosis of pathogenic bacteria and infection could delay treatment, increasing the risk of complications and poor outcomes. Fluorescence-imaging is poised to fill this gap, at least in part, serving as a more objective and equitable indicator of wound bacteria. Clinicaltrials.gov #NCT03540004 registered 16-05-2018.

Proceedings of the Leaders in Wound Healing conference.

SerenaGroup Research Foundation, New Orleans, 17-19 April 2023.

Point-of-care fluorescence imaging reveals extent of bacterial load in diabetic foot ulcers.

Elevated levels of bacteria, including biofilm, increase the risk of chronic wound infection and inhibit healing. Addressing asymptomatic high bacterial loads is challenged by a lack of clinical terminology and diagnostic tools. This post-hoc multicenter clinical trial analysis of 138 diabetic foot ulcers investigates fluorescence (FL)-imaging role in detecting biofilm-encased and planktonic bacteria in wounds at high loads. The sensitivity and specificity of clinical assessment and FL-imaging were compared across bacterial loads of concern (104 -109 CFU/g). Quantitative tissue culture confirmed the total loads. Bacterial presence was confirmed in 131/138 ulcers. Of these, 93.9% had loads >104 CFU/g. In those wounds, symptoms of infection were largely absent and did not correlate with, or increase proportionately with, bacterial loads at any threshold. FL-imaging increased sensitivity for the detection of bacteria across loads 104 -109 (P < .0001), peaking at 92.6% for >108 CFU/g. Imaging further showed that 84.2% of ulcers contained high loads in the periwound region. New terminology, chronic inhibitory bacterial load (CIBL), describes frequently asymptomatic, high bacterial loads in diabetic ulcers and periwound tissues, which require clinical intervention to prevent sequelae of infection. We anticipate this will spark a paradigm shift in assessment and management, enabling earlier intervention along the bacterial-infection continuum and supporting improved wound outcomes.

Efficacy of Topical Wound Oxygen Therapy in Healing Chronic Diabetic Foot Ulcers: Systematic Review and Meta-Analysis.

Objective: To conduct a systematic review and meta-analysis of recently published randomized controlled trials (RCTs) that employed the use of topical oxygen therapy (TOT) as an adjunct therapy in the treatment of Wagner 1 and 2 diabetic foot ulcers. Approach: Following a literature search of eligible studies from 2010 onward, four RCTs were included. Studies were analyzed for patient and wound characteristics, outcomes, risk of bias, and quality of the evidence assessed using the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) methodology. A random-effects meta-analysis for complete wound healing was carried out due to statistical heterogeneity of included studies. Results: Risk of bias judgment (RoB2 analysis) resulted in one low-risk trial and three trials with some risk. One study was determined to be the origin of the statistical heterogeneity. Pooled results showed statistical significance with a risk ratio (RR) of 1.59 (95% confidence interval [CI]: 1.07-2.37; p = 0.021). Sensitivity analysis, based on imputed values for missing outcomes, demonstrated that both the RR and 95% CIs changed little. The GRADE ratings for each domain were as follows: (a) risk of bias: moderate (3); (b) imprecision: moderate (2), high (1); (c) inconsistency: low (2), high (1); (d) indirectness: moderate (2), high (1); and (e) publication bias: moderate (1), high (2). Overall, the evidence was moderate. Innovation: Our study shows that TOT is a viable diabetic foot ulcer therapy. Conclusions: These data support the use of TOT for the treatment of chronic Wagner 1 or 2 diabetic foot ulcers in the absence of infection and ischemia.

A prospective clinical pilot study comparing two post-operative dressings in the treatment of surgical incisions in volunteers.

OBJECTIVE: Surgical site infections (SSIs) are one of the leading causes of post-operative morbidity and mortality worldwide. The original post-operative dressing, gauze taped in place, did not protect the incision from contamination. A recent clinical trial demonstrated that transparent films were superior to gauze in reducing SSIs. Transparent films are semi-occlusive (semi-permeable, transparent). They protect the incision from contamination; however, one of the drawbacks of current films is that they may become dislodged during daily activities, such as showering. Patients may not realise that the integrity of the dressing has been compromised, leading to soiling of the incision and possible infection. DrySee (DrySee Inc., US) is a novel film dressing with a colorimetric indicator that alerts the patient when the dressing has been compromised. METHOD: This trial compared the film dressing with the indicator (DSD) to a commonly used post-operative dressing comparator (Tegaderm + Pad; 3M, US). A 1.5cm incision was made in the volar forearm of volunteers. The incisions were randomly treated with the DSD or comparator dressing. RESULTS: A cohort of 20 volunteer patients was recruited. The DSD had a greater wear time and patients reported that the DSD dressing stayed in place better during activities compared to the comparator. CONCLUSION: Overall, 75% of patients preferred DSD and 25% preferred the comparator.

A Multicenter, Randomized, Controlled, Clinical Trial Evaluating Dehydrated Human Amniotic Membrane in the Treatment of Venous Leg Ulcers.

BACKGROUND: This randomized controlled trial evaluated the safety and effectiveness of weekly and biweekly applications of dehydrated human amnion and chorion allograft (dHACA) plus standard of care compared to standard of care alone on chronic venous leg ulcers. METHODS: This open-label randomized controlled trial included patients with chronic venous leg ulcers at eight wound care centers across the United States. The primary endpoint was the proportion of healed ulcers at 12 weeks. Secondary endpoints included the proportion of ulcers achieving 40 percent closure at 4 weeks and the incidence of adverse events. RESULTS: Among 101 patients screened for eligibility, 60 were eligible and enrolled. At 12 weeks, significantly more venous leg ulcers healed in the two dHACA-treated groups (75 percent) than in the standard-of-care group (30 percent) ( p = 0.001) even after adjustment for wound area ( p = 0.002), with an odds ratio of 8.7 (95 percent CI, 2.2 to 33.6). There were no significant differences in the proportion of wounds with percentage area reduction greater than or equal to 40 percent at 4 weeks among all groups. The adverse event rate was 63.5 percent. Among the 38 adverse events, none were graft or procedure related, and all were resolved with appropriate treatment. CONCLUSIONS: dHACA and standard of care, either applied weekly or biweekly, significantly healed more venous leg ulcers than standard of care alone, suggesting that the use of aseptically processed dHACA is advantageous and a safe and effective treatment option in the healing of chronic venous leg ulcers. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, I.

A multicenter clinical trial evaluating the durability of diabetic foot ulcer healing in ulcers treated with topical oxygen and standard of care versus standard of care alone 1 year post healing.

Multiple clinical trials and real-world studies have demonstrated accelerated healing in diabetic foot ulcers (DFU) treated with advanced modalities, such as topical oxygen therapy (TOT). In addition to healing, the durability of wound closure is a crucial long-term endpoint for DFU clinical trials: an advanced treatment that does not confer a reasonable ulcer-free period will have limited clinical benefit and modest economic value. Preclinical studies suggest that DFUs receiving topical oxygen therapy will experience improved quality of healing: increased collagen deposition and angiogenesis. It is postulated that these changes will translate into a more long-lasting closure for ulcers treated with TOT and SOC compared to ulcers treated with SOC alone. At the conclusion of a recently completed randomised controlled DFU clinical trial evaluating the efficacy of TOT and SOC compared to SOC alone, patients with healed ulcers were asked to enrol in a long-term follow-up study. Healed patients completed four questionnaires through text messages or phone calls within 1-year post completion of the trial. Twenty-nine patients consented to participate in the long-term follow-up trial (17 TOT/SOC and 12 SOC). Only seven subjects were lost to follow up (5 TOT and 2 SOC). This is a surprisingly low number when factoring in the disruption caused by the COVID-19 pandemic that continued throughout the entire follow-up period. In the remaining patients, 85% of the TOT patients and 60% of the SOC remained healed at 1 year. There was one major amputation, which occurred in an SOC-treated patient. The numbers in the long-term follow-up were too small to reach statistical significance; however, there is a strong trend toward more durable closure in ulcers treated with TOT.

Bacterial protease activity: a prognostic biomarker of early wound infection.

OBJECTIVE: High bacterial burden is one of several reasons that wounds fail to heal. At present, clinicians rely primarily on clinical signs and symptoms (CSS) to diagnose infection in hard-to-heal wounds; however, studies have demonstrated that CSS can be unreliable. This is especially true in the early stages of bacterial infection. Bacteria release proteases, virulence factors that promote invasive infection. This clinical trial evaluated the use of bacterial protease activity (BPA) as a biomarker to detect whether a wound was in the period of pathogenicity, prior to overt clinical signs. METHOD: Participants were drawn from six US wound centres and had their wounds assessed clinically for infection. In addition, wound fluid swabs were collected and analysed for BPA, inflammatory cytokines (interleukin-1ß (IL-1ß), interleukin-6 (IL-6) and tumour necrosis factor-α (TNF-α)), and cultured for quantitative microbiology. RESULTS: A total of 366 patients were recruited. The median BPA level increased with the increasing number of signs of infection. The majority of wounds tested positive for elevated BPA prior to exhibiting at least three CSS of infection, the level at which the criteria for infection are met. BPA tended to increase with the bioburden (colony forming unit (CFU)/ml) although some wounds with high bioburden were negative for BPA, and others with low bioburden were positive for BPA. The mean levels of IL-1ß and TNF-α were significantly higher in BPA-positive wounds (p<0.0001 and p=0.0002, respectively). CONCLUSION: The results of this clinical trial suggest that measuring BPA can lead to the early detection of pathogenic bacteria in the wound that impede wound healing and may progress to invasive infection. In a large percentage of cases, BPA detected virulent bacteria in the absence of CSS of infection. As a biomarker, BPA has an advantage over measuring bacterial load-hard-to-heal wounds are often colonised with non-pathogenic bacteria that do not inhibit wound healing and, conversely, a low number of highly virulent species could disrupt the healing process.

Guidelines for the use of topical oxygen therapy in the treatment of hard-to-heal wounds based on a Delphi consensus.

A growing body of evidence supports the use of topical oxygen therapy (TOT) in the treatment of diabetic foot ulcers (DFUs). In addition, anecdotal evidence suggests that topical oxygen may be effective in the treatment of other wound types. In May 2021, experts in the field of wound healing from across the US assembled in New Orleans for the inaugural Leaders in Wound Healing conference. In an interactive session dedicated to TOT, several physicians presented and debated the evidence for TOT. Experts in the audience also shared their experiences in treating patients with TOT. The consensus of the experts recommended the use of TOT in DFUs and supported payer reimbursement for the modality. However, they stressed the need for a guidance document on the use of TOT in patients with hard-to-heal wounds. Following the conference, a Delphi method was employed to establish consensus guidelines for prescribing TOT. A multidisciplinary panel of 24 wound experts (15 wound specialists, six vascular surgeons, one plastic surgeon, one critical care provider and one PhD researcher) participated in two rounds of questionnaires. The Delphi survey questions focused on the indications for topical oxygen, when to prescribe the therapy, pretreatment work-up, visit frequency and length of therapy. A clinical workflow algorithm was also included as part of the Delphi. After two rounds, the Delphi participants were able to reach consensus of >77% on when to prescribe topical oxygen, the wound types that may benefit from the therapy, pretreatment wound preparation and work-up and length of therapy. The goal of the guidelines is to standardise the use of topical oxygen and inform further research efforts.

The efficacy of sodium hypochlorite antiseptic: a double-blind, randomised controlled pilot study.

OBJECTIVE: According to a recent clinical trial, 82% of hard-to-heal wounds harbour levels of bacteria that impede healing. A follow-up analysis of trial data revealed that the use of antiseptic cleansers did not correlate with bacterial burden. At a minimum, these findings suggest the need for clinical research into the efficacy of antiseptics in reducing bacterial burden. Evidence supporting the bacterial killing ability of antiseptics is largely derived from preclinical and laboratory studies. Few clinical trials have examined bacterial levels and healing rates in hard-to-heal wounds. Fortunately, the advent of fluorescence imaging to detect bacterial burden has simplified the conduct of clinical research examining the effectiveness of antiseptics in the clinic setting. The aim of this study was to evaluate the efficacy of a modified sodium hypochlorite (NaOCl) solution in reducing wound size and bacterial load in hard-to-heal wounds. METHOD: In this randomised, double-blind pilot study, patients were randomised to one of two groups: daily wound cleansing with either normal saline solution (NSS) or NaOCl. Patients and investigators were blinded to the allocation. All wound types were included. RESULTS: A total of 16 patients consented to participate. At the initial visit, the target ulcer was measured and a fluorescence image to evaluate bacterial load obtained. The wound was then cleansed with either NSS or NaOCl and fluorescence imaging repeated. Patients cleansed the wound daily in accordance with the randomisation schedule. They returned to the clinic weekly for four weeks, and on each visit the wound was measured and a fluorescence image captured. Patients receiving NaOCl had a greater percent reduction in wound area versus NSS; although the first phase of the study was not powered for statistical significance, there was a strong trend favouring NaOCl. In addition, there was greater bacterial reduction in the NaOCl group. CONCLUSION: Based on the results of this pilot study, enrolment has continued in order to increase the study's power. This pilot study suggests that sodium hypochlorite is efficacious in reducing bacterial burden and promoting healing.

The CALCIPHYX study: a randomized, double-blind, placebo-controlled, Phase 3 clinical trial of SNF472 for the treatment of calciphylaxis.

BACKGROUND: Calcific uraemic arteriolopathy (CUA; calciphylaxis) is a rare disease seen predominantly in patients receiving dialysis. Calciphylaxis is characterized by poorly healing or non-healing wounds, and is associated with mortality, substantial morbidity related to infection and typically severe pain. In an open-label Phase 2 clinical trial, SNF472, a selective inhibitor of vascular calcification, was well-tolerated and associated with improvement in wound healing, reduction of wound-related pain and improvement in wound-related quality of life (QoL). Those results informed the design of the CALCIPHYX trial, an ongoing, randomized, placebo-controlled, Phase 3 trial of SNF472 for treatment of calciphylaxis. METHODS: In CALCIPHYX, 66 patients receiving haemodialysis who have an ulcerated calciphylaxis lesion will be randomized 1:1 to double-blind SNF472 (7 mg/kg intravenously) or placebo three times weekly for 12 weeks (Part 1), then receive open-label SNF472 for 12 weeks (Part 2). All patients will receive stable background care, which may include pain medications and sodium thiosulphate, in accordance with the clinical practices of each site. A statistically significant difference between the SNF472 and placebo groups for improvement of either primary endpoint at Week 12 will demonstrate efficacy of SNF472: change in Bates-Jensen Wound Assessment Tool-CUA (a quantitative wound assessment tool for evaluating calciphylaxis lesions) or change in pain visual analogue scale score. Additional endpoints will address wound-related QoL, qualitative changes in wounds, wound size, analgesic use and safety. CONCLUSIONS: This randomized, placebo-controlled Phase 3 clinical trial will examine the efficacy and safety of SNF472 in patients who have ulcerated calciphylaxis lesions. Patient recruitment is ongoing.

Antimicrobial stewardship: a JWC Masterclass.

This paper presents an overview of a Journal of Wound Care (JWC) webinar 'Antimicrobial Stewardship Masterclass' which took place on 17 June 2021, bringing together international experts in the field of wound care. The webinar was undertaken to provide an educational platform elucidating the basis of an effective antimicrobial strategy in wound care, and to demonstrate how it impacts on wound care clinicians and their day-to-day practice, using examples of 'real-life' patient outcomes.

Uncovering the high prevalence of bacterial burden in surgical site wounds with point-of-care fluorescence imaging.

Detection of bacterial burden within or near surgical wounds is critical to reducing the occurrence of surgical site infection (SSI). A distinct lack of reliable methods to identify postoperative bioburden has forced reliance on clinical signs and symptoms of infection (CSS). As a result, infection management has been reactive, rather than proactive. Fluorescence imaging of bacterial burden (FL) is positioned to potentially flip that paradigm. This post hoc analysis evaluated 58 imaged and biopsied surgical site wounds from the multi-centre fluorescence imaging assessment and guidance clinical trial. Diagnostic accuracy measures of CSS and FL were evaluated. A reader study investigated the impact of advanced image interpretation experience on imaging sensitivity. Forty-four of fifty-eight surgical site wounds (75.8%) had bacterial loads >104  CFU/g (median = 3.11 × 105  CFU/g); however, only 3 of 44 were CSS positive (sensitivity of 6.8%). FL improved sensitivity of bacterial detection by 5.7-fold compared with CSS alone (P = .0005). Sensitivity improved by 11.3-fold over CSS among clinicians highly experienced with FL interpretation (P < .0001). Surgical sites that reach the stage of referral to a wound specialist frequently harbour asymptomatic high bacterial loads that delay healing and increase infection risk. Advanced imaging of pathological bacterial burden improves surgical site monitoring and may reduce the rate of SSIs.

A prospective clinical trial evaluating changes in the wound microenvironment in patients with chronic venous leg ulcers treated with a hypothermically stored amniotic membrane.

Amniotic tissues have been long utilised to treat chronic wounds; however, there are few studies evaluating how the wound microenvironment responds to these therapies. The goal of this study was to evaluate the changes in wounds treated with a hypothermically stored amniotic membrane (HSAM). In this prospective single-arm study, 15 female patients with venous leg ulcers were treated with HSAM from male donors and standard of care for 12 weeks. Over the course of the study, wound exudate was collected and evaluated using proteomic microarrays. Biopsies were collected during the course of treatment to detect the presence of HSAM tissue. By 4 weeks, 60% of subjects achieved 50% or greater reduction in wound size, and by 12 weeks, 53% of subjects achieved 100% re-epithelialization. HSAM DNA was detected in 20% of biopsies as determined by the detection TSPY4, indicating HSAM was no longer present within the wound bed approximately 7 days from the last treatment for the majority of wounds. Proteomic analysis of wound exudate found that wounds on a healing trajectory had significantly higher levels of MMP-10, MMP-7, and TIMP-4 and significantly lower levels of CX3CL1, FLT-3 L, IL-1ra, IL-1a, IL-9, IL-2, IL-3, MCP-1, and TNF-b compared with other wounds.

Reliance on Clinical Signs and Symptoms Assessment Leads to Misuse of Antimicrobials: Post hoc Analysis of 350 Chronic Wounds.

Objectives: Bacteria frequently impede wound healing and cause infection. Clinicians rely on clinical signs and symptoms (CSS) to assess for bacteria at the point of care, and inform prescription of antibiotics and other antimicrobials. Yet, robust evidence suggests that CSS has poor sensitivity for detection of problematic bacterial burden and infection, hindering antimicrobial stewardship efforts. This study evaluated CSS-based antimicrobial prescribing practices across 14 wound care centers. Approach: Data were analyzed from the fluorescence assessment and guidance (FLAAG) trial, a study of 350 chronic wounds across 20 clinicians. Clinicians reviewed patient history and assessed for CSS using the International Wound Infection Institute infection checklist. Wounds with >3 criteria or any overwhelming symptom were considered CSS+. Bacterial levels were confirmed with quantitative tissue culture of wound biopsies. Results: Antimicrobials (including dressings, topicals, and systemic antibiotics) were prescribed at a similar rate for wounds identified as CSS+ (75.0%) and CSS- (72.8%, p = 0.76). Antimicrobial dressings, the most frequently prescribed antimicrobial, were prescribed at a similar rate for CSS+ (83.3%) and CSS- (89.5%, p = 0.27) wounds. In 33.3% of patients prescribed systemic antibiotics, no CSS were present. Prescribing patterns did not correlate with bacterial load. Innovation: This study is the first to evaluate antimicrobial prescribing trends in a large, multisite cohort of chronic wound patients. Conclusions: Reliance on CSS to diagnose clinically significant bacterial burden in chronic wounds leads to the haphazard use of antimicrobials. Improved methods of identifying bacterial burden and infection are needed to enhance antimicrobial stewardship efforts in wound care. Clinicaltrials.gov ID. NCT03540004.

Use of fluorescence imaging to optimize location of tissue sampling in hard-to-heal wounds.

Introduction: Wound microflora in hard-to-heal wounds is invariably complex and diverse. Determining the interfering organisms(s) is therefore challenging. Tissue sampling, particularly in large wounds, is subjective and, when performed, might involve swabbing or biopsy of several locations. Fluorescence (FL) imaging of bacterial loads is a rapid, non-invasive method to objectively locate microbial hotspots (loads >104 CFU/gr). When sampling is deemed clinically necessary, imaging may indicate an optimal site for tissue biopsy. This study aimed to investigate the microbiology of wound tissue incisional biopsies taken from sites identified by FL imaging compared with sites selected by clinical judgment. Methods: A post hoc analysis of the 350-patient FLAAG wound trial was conducted; 78 wounds were included in the present study. All 78 wounds were biopsied at two sites: one at the center of the wound per standard of care (SoC) and one site guided by FL-imaging findings, allowing for comparison of total bacterial load (TBL) and species present. Results: The comparison between the two biopsy sites revealed that clinical uncertainty was higher as wound surface area increased. The sensitivity of a FL-informed biopsy was 98.7% for accurately finding any bacterial loads >104 CFU/g, compared to 87.2% for SoC (p=0.0059; McNemar test). Regarding species detected, FL-informed biopsies detected an average of 3 bacterial species per biopsy versus 2.2 species with SoC (p < 0.001; t-test). Microbial hotspots with a higher number of pathogens also included the CDC's pathogens of interest. Conclusions & perspective: FL imaging provides a more accurate and relevant microbiological profile that guides optimal wound sampling compared to clinical judgment. This is particularly interesting in large, complex wounds, as evidenced in the wounds studied in this post hoc analysis. In addition, fluorescence imaging enables earlier bacterial detection and intervention, guiding early and appropriate wound hygiene and potentially reducing the need for antibiotic use. When indicated, this diagnostic partnership with antibiotic stewardship initiatives is key to ameliorating the continuing threat of antibiotic resistance.

Guidelines for Point-of-Care Fluorescence Imaging for Detection of Wound Bacterial Burden Based on Delphi Consensus.

Excessive levels of bacteria impede wound healing and can lead to infectious complications. Unfortunately, clinical signs and symptoms of elevated bacterial burden are often unreliable. As a result, point--of--care fluorescence imaging, used to detect critical bacterial burden in wounds, is becoming widely recognized and adopted by clinicians across the globe as an accepted and added component of wound assessment protocol. A Delphi method was employed to establish consensus guidelines describing fluorescence imaging use. A multidisciplinary panel of 32 wound experts (56% MD, 22% podiatrist, 12.5% nurses/nurse practitioners) representing multiple sites of service (e.g., hospital outpatient, inpatient, private office, long-term care) completed two rounds of online questionnaires. The Delphi included key topics, including competencies required to perform imaging, clinical indications for imaging (e.g., signs/symptoms present, procedures warranting imaging), frequency of imaging, and a clinical workflow algorithm. Describing their clinical experiences of imaging impact, >80% reported changes in treatment plans, 96% reported that imaging-informed treatment plans led to improved wound healing, 78% reported reduced rates of amputations, and 83% reported reduced rates of microbiological sampling. The guidelines provided here will help to standardize use of fluorescence imaging among wound care providers and enhance the quality of patient care.