The diagnosis of infection in chronic leg ulcers: A narrative review on clinical practice

Clinical performance and cost-effectiveness of a Silicone foam with 3DFit™ technology in chronic wounds compared with standard of care: An open randomised multicentre investigation

The objective of the study was to show the clinical performance and cost-effectiveness of a Silicone foam dressing with 3DFit™ Technology compared to current standard of care. This was an open-labelled, two-arm, randomised controlled multicentre study conducted from February to December 2023. One hundred and two participants with an exuding, non-infected and chronic ulcer were randomised in a 1:1 fashion and treated with either a Silicone foam with 3DFit™ Technology or standard of care (a filler combined with a secondary dressing), stratified by venous leg ulcers and diabetic foot ulcers. After a 4-week study period, wound size and total costs were evaluated. After 4 weeks of treatment, a comparable percentage in wound area reduction was observed in both treatment arms with mean and 95% confidence interval of 54.3% (37.1%; 71.5%) and 43.0% (26.5%; 59.6%) for the investigational and comparator dressing, respectively. This corresponded to a mean difference of 11.3% ([-10.22; 32.86], p = 0.299). Total mean estimated costs were significantly lower for the investigational dressing (£14.3, 95% confidence interval [£9.6; £19.0]) compared to the two-dressing regime (£21.4 [£16.9; £26.0]), corresponding to a 33% price reduction (p = 0.033) after 4 weeks of treatment. With this RCT, a conforming Silicone foam dressing with 3DFit™ Technology was shown to be clinically comparable and a cost-effective alternative to using a filler and a secondary dressing at a significantly lower cost in both venous leg ulcers and diabetic foot ulcers up to 2 cm in depth.

Biofilms and microbiome profiles in chronic wounds: links to antibiotic use and wound severity in a Sri Lankan cohort

AIMS

We have characterized the microbiome of infected chronic diabetic wounds (CDWs), exploring associations with antibiotic use and wound severity in a Sri Lankan cohort.

METHODS AND RESULTS

Fifty CDW patients were enrolled, 38 of whom received antibiotics. Tissue biopsies were analysed by microbiome profiling, and wounds were graded using the University of Texas Wound Grading System. Biofilm presence was assessed in 20 wounds. The microbiome was largely dominated by Enterobacteriaceae, Pseudomonadaceae, Streptococcaceae, and Corynebacteriaceae. Proteobacteria levels were significantly higher in antibiotic-treated wounds (P = .019), with increased Pseudomonas abundance. Wounds were categorized as grade 1 (10), grade 2 (29), and grade 3 (11). Alpha diversity varied by wound grade (P = .015), with grade 2 wounds showing the highest diversity and grade 3 the lowest. All 20 tested wounds were biofilm-positive, and community composition varied more in antibiotic-treated wounds (P = .004).

CONCLUSIONS

CDW microbiomes were dominated by Enterobacteriaceae and Pseudomonadaceae, with elevated Proteobacteria in antibiotic-treated wounds. Alpha diversity correlated with wound severity, peaking in grade 2 wounds. The high prevalence of biofilms in wounds underscores the need for management of CDWs that address microbial complexity.

Anti-infective management of infected skin ulcers

Infected skin ulcers represent a frequent and intricate clinical challenge, necessitating prompt and comprehensive multidisciplinary interventions to avert complications. Anti-infective therapy constitutes a cornerstone in the therapeutic paradigm. This manuscript delineates our approach to anti-infective management of infected ulcers, encompassing insights into clinical classifications, diagnostic features, exampless of early clinical decision-making in anti-infective treatment, comprehensive evaluation of infectious diseases encompassing host clinical considerations and potential interventions, determination of antibiotic therapy duration, methodologies for assessing clinical response, identification of potential causes for lack of clinical response, as well as strategies for outpatient parenteral antibiotic therapy and a diagnostic and therapeutic algorithm.

Improving wound infection management: education and evaluation of an infection management pathway

OBJECTIVE

To assess the clinical impact and acceptance of an infection management (IM) pathway, designed to improve the consistency of care of wound infection when introduced, and supported by an educational programme.

METHOD

An education and evaluation programme (T3 programme) was-conducted in Portugal, Spain and Italy. This consisted of a two-hour educational, virtual seminar, followed by a four-week evaluation of an IM pathway during which survey data were collected on the impact of this pathway on clinician-selected patients. Finally, all participants reconvened for a virtual meeting during which the combined results were disseminated. The pathway provided guidance to clinicians regarding the targeted use of antimicrobial wound dressings according to the presence and absence of signs and symptoms of wound infection.

RESULTS

Responses relating to 259 patients treated according to the IM pathway, 139 (53.7%) of whom had received previous antimicrobial treatment, were captured. Signs and symptoms of infection resolved within four weeks of treatment in >90% of patients. All 25 patients who had received prior antimicrobial treatment for ≥3 months experienced a resolution in the signs and symptoms of infection within four weeks. The majority of participating clinicians agreed that the IM pathway improved decision-making (94.9%) and confidence (97.3%), and helped to determine the correct antimicrobial treatment (91.4%) in the context of wound infection.

CONCLUSION

The T3 programme was an efficient way to deliver a structured educational programme. The use of the IM pathway resulted in >90% of patients achieving resolution of their signs and symptoms of wound infection.

Homocysteine and Inflammatory Cytokines in the Clinical Assessment of Infection in Venous Leg Ulcers

Inflammation and biofilm-associated infection are common in chronic venous leg ulcers (VU), causing deep pain and delayed healing. Albeit important, clinical markers and laboratory parameters for identifying and monitoring persistent VU infections are limited. This study analyzed 101 patients with infected (IVU) and noninfected VUs (NVU). Clinical data were collected in both groups. The serum homocysteine (Hcys) and inflammatory cytokines from the wound fluid were measured. In addition, microbial identification, antibiotic susceptibility, and biofilm production were examined. IVU were 56 (55.4%) while NVU were 45 (44.5%). IVUs showed a significant increase in the wound's size and depth compared to NVUs. In addition, significantly higher levels of interleukin (IL)-6, IL-10, IL17A, and tumor necrosis factor-alpha (TNF-α) were found in patients with IVUs compared to those with NVUs. Notably, hyperhomocysteinemia (HHcy) was significantly more common in patients with IVUs than NVUs. A total of 89 different pathogens were identified from 56 IVUs. Gram-negative bacteria were 51.7%, while the Gram-positives were 48.3%. At the species level, Staphylococcus aureus was the most common isolate (43.8%), followed by Pseudomonas aeruginosa (18.0%). Multidrug-resistant organisms (MDROs) accounted for 25.8% of the total isolates. Strong biofilm producers (SBPs) (70.8%) were significantly more abundant than weak biofilm producers (WBP) (29.2%) in IVUs. SBPs were present in 97.7% of the IVUs as single or multispecies infections. Specifically, SBPs were 94.9% for S. aureus, 87.5% for P. aeruginosa, and 28.6% for Escherichia coli. In IVU, the tissue microenvironment and biofilm production can support chronic microbial persistence and a most severe clinical outcome even in the presence of an intense immune response, as shown by the high levels of inflammatory molecules. The measurement of local cytokines in combination with systemic homocysteine may offer a novel set of biomarkers for the clinical assessment of IVUs caused by biofilm-producing bacteria.

Diagnosis and treatment of infected wounds: A multi-centre audit of current clinical practice across the UK, Ireland and Scandinavia

AIMS AND OBJECTIVES

Surveillance of wound infection including signs of infection alongside antimicrobial usage (types, duration, frequency) can highlight knowledge gaps and inconsistencies. This manuscript aims to highlight these, identify and inform opportunities for practice improvement and to show impact of infection management practice may be having on the issue of antimicrobial resistance.

BACKGROUND

Infected wounds pose challenges to healthcare professionals. Balancing risk of wound deterioration and progression to systemic infection with appropriate use of antimicrobials is necessary to minimise development of resistance.

METHODS

Analysis consisted of a practice survey of 9661 wounds across 70 community sites over a period of one week. Data were collected from projects between 2017 and 2020. The form was available to providers within the UK, Ireland, Norway, Denmark, Sweden and Finland. EQUATOR research guidelines were followed; STROBE checklist for observational research reporting was completed.

RESULTS

Infection rates of 8.9% were reported from wounds assessed. These data indicate inconsistencies with diagnosis across practice with non-specialists more likely to be unsure of wound infection. Greater confidence in infection identification was observed as number of signs increased. Inconsistencies were also observed in appropriate treatment; antimicrobials were used in 35% of wounds considered not infected and not used in 41% of wounds that were identified as infected.

CONCLUSIONS

This investigation of infection management practice of over 9000 wounds provides an insight into diagnosis and treatment of infection. Inconsistencies in diagnosis and treatment of wound infections reported highlight the need for increased education, awareness of diagnosis and treatment of infection.

RELEVANCE TO CLINICAL PRACTICE

Variability in management of infected wounds highlights opportunities to aid more effective diagnosis and treatment of infected wounds. Incorporation of support tools or evidence-based pathways into practice may enhance confidence in management of local infection, balanced with appropriate use, potentially minimising resistance and improving outcomes.

SYSTEMIC INFECTION WITH SINGLE OR MULTI-ORGAN DAMAGE CAUSED BY INADEQUATELY MANAGED CHRONIC WOUNDS: A CASE SERIES

Chronic wounds are often underestimated condition with increasingly growing inpatient and outpatient treatment costs. Since the patient population affected by chronic wounds is heterogeneous and includes diabetes, chronic venous insufficiency and peripheral artery disease patients, with additional differences in gender, age, previous medical history, treatment of chronic wounds is highly personalized and dependent on a variety of factors. This paper aims to highlight the problems that the chronic wound patient population is facing during the COVID-19 pandemic: from higher probability of an undesirable disease outcome to the fact that many of them have limited access to primary care providers and to the regular and continuous care that their condition demands. This paper describe three patients with chronic wounds. Each of the patients had a significant worsening of their chronic wounds during the COVID-19 pandemic: either following an active SARS-CoV-2 infection or due to the limited access to primary care. The cases described here highlight the necessity of providing proper and regular care for all patients during the COVID-19 pandemic, regardless of the current state of the healthcare system and the adversities and hurdles it currently faces, to prevent the pandemic from becoming a syndemic.

Microbiological Status of Venous Leg Ulcers and Its Predictors: A Single-Center Cross-Sectional Study

Venous leg ulcers are frequently colonized by microbes. This can be particularly devastating if the ulcer is infected with alert pathogens, i.e., highly virulent microorganisms with well-developed mechanisms of antibiotic resistance. We analyzed the microbiological status of venous leg ulcers and identified the clinicodemographic predictors of culture-positive ulcers, especially in ulcers with colonization by alert pathogens.

METHODS

This study included 754 patients with chronic venous leg ulcers. Material for microbiological analysis was collected by swabbing only from patients who did not receive any antibiotic treatment.

RESULTS

A total of 636 (84.3%) patients presented with culture-positive ulcers. Alert pathogens, primarily Pseudomonas aeruginosa, were detected in 28.6% of the positive cultures. In a logistic regression model, culture-positive ulcers were predicted independently by age > 65 years, current ulcer duration > 12 months, and ulceration area greater than 8.25 cm². Two of these factors, duration of current ulcer > 12 months and ulceration area > 8.25 cm², were also identified as the independent predictors of colonization by alert pathogens.

CONCLUSIONS

Colonization/infection is particularly likely in older persons with chronic and/or large ulcers. Concomitant atherosclerosis was an independent predictor of culture-negative ulcers.

Recent Progress in Intelligent Wearable Sensors for Health Monitoring and Wound Healing Based on Biofluids

The intelligent wearable sensors promote the transformation of the health care from a traditional hospital-centered model to a personal portable device-centered model. There is an urgent need of real-time, multi-functional, and personalized monitoring of various biochemical target substances and signals based on the intelligent wearable sensors for health monitoring, especially wound healing. Under this background, this review article first reviews the outstanding progress in the development of intelligent, wearable sensors designed for continuous, real-time analysis, and monitoring of sweat, blood, interstitial fluid, tears, wound fluid, etc. Second, this paper reports the advanced status of intelligent wound monitoring sensors designed for wound diagnosis and treatment. The paper highlights some smart sensors to monitor target analytes in various wounds. Finally, this paper makes conservative recommendations regarding future development of intelligent wearable sensors.

Therapeutic index for local infections score (TILI): a new diagnostic tool

OBJECTIVE

Local wound infections are a major challenge for patients and health professionals. Various diagnostic and therapeutic options are available. However, a generally accepted standard is still lacking in Europe. The aim was to develop an easy-to-use clinical score for the early detection of local wound infections, as a basis for decision-making on antiseptic therapy or decolonisation.

METHOD

An interdisciplinary and interprofessional panel of experts from seven European countries was brought together to discuss the various aspects of diagnosing local wound infections.

RESULTS

The result was the adoption of the Therapeutic Index for Local Infections (TILI) score, developed in Germany by Initiative Chronische Wunden e.V., specifically for health professionals not specialised in wound care. Available in six European languages, the TILI score could also be adapted for different European countries, depending on their specific national healthcare requirements. The six clinical criteria for local wound infection are erythema to surrounding skin; heat; oedema, induration or swelling; spontaneous pain or pressure pain; stalled wound healing; and increase and/or change in colour or smell of exudate. Meeting all criteria indicates that antiseptic wound therapy could be started. Regardless of these unspecific clinical signs, there are also health conditions for the clinical situation which are a direct indication for antimicrobial wound therapy. These include the presence of wound pathogens, such as meticillin-resistant Staphylococcus aureus, septic surgical wound or the presence of free pus.

CONCLUSION

The development of the new internationally adapted TILI score, which could also be used by any caregiver in daily practice to diagnose local infections in acute and hard-to-heal wounds, is the result of expert consensus. However, the score system has to be validated through a clinical evaluation. This is to be performed in expert centres throughout Europe.

Therapeutic Index for Local Infections score validity: a retrospective European analysis

OBJECTIVE

A score to identify local wound infections was developed by a panel of experts from seven European countries. The Therapeutic Index for Local Infections (TILI) score was designed for health professionals who are not specialised in wound care. This study was carried out to test the validity of the TILI score in everyday practice.

METHOD

Content validity was analysed by means of evaluation by a panel of experts, individually and face-to-face, followed by a European multicentred, retrospective, observational study. Participating clinicians sent anonymised copies of completed TILI scores for patients with leg ulcers along with a photograph of the wound for analysis by two blinded reviewers. Concordance (Kappa index) and convergent criterion validity (sensitivity, specificity, accuracy, Youden's J Index and receiver operator characteristic (ROC) or area under the curve (AUC) curve) were calculated to construct validity and reliability.

RESULTS

A total of 307 patients with leg ulcers from seven institutions in five European countries were included in this retrospective analysis. It was shown that the diagnosis of local wound infection could be documented well with five of the six clinical criteria included in the TILI score. By summing up these facultative criteria in comparison with any direct criteria that may be present, there would have been an indication for local antiseptic wound therapy in 22% of patients examined.

CONCLUSIONS

The results show that the TILI score is concordant with the expert assessment of patients and with good diagnostic characteristics. Thus, the easy-to-use TILI score can now be used in the daily routine practice of health professionals to diagnose local wound infections.

Patient Explanation of Adherence and Non-Adherence to Venous Leg Ulcer Treatment: A Qualitative Study

The aim of this study was to understand which factors influence patients’ adherence to venous leg ulcer treatment recommendations in primary care. We adopted a qualitative study design, conducting phone interviews with 31 people with venous leg ulcers in Melbourne, Australia. We conducted 31 semi-structured phone interviews between October and December 2019 with patients with clinically diagnosed venous leg ulcers. Participants recruited to the Aspirin in Venous Leg Ulcer Randomized Control Trial and Cohort study were invited to participate in a qualitative study, which was nested under this trial. We applied the Theoretical Domains Framework to guide the data analysis. The following factors influenced patients’ adherence to venous leg ulcer treatment: understanding the management plan and rationale behind treatment (Knowledge Domain); compression-related body image issues (Social Influences); understanding consequences of not wearing compression (Beliefs about Consequences); feeling overwhelmed because it’s not getting better (Emotions); hot weather and discomfort when wearing compression (Environmental Context and Resources); cost of compression (Environmental Context and Resources); ability to wear compression (Beliefs about Capabilities); patience and persistence (Behavioral Regulation); and remembering self-care instructions (Memory, Attention and Decision Making). The Theoretical Domains Framework was useful for identifying factors that influence patients’ adherence to treatment recommendations for venous leg ulcers management. These factors may inform development of novel interventions to optimize shared decision making and self-care to improve healing outcomes. The findings from this article will be relevant to clinicians involved in management of patients with venous leg ulcers, as their support is crucial to patients’ treatment adherence. Consultation with patients about VLU treatment adherence is an opportunity for clinical practice to be targeted and collaborative. This process may inform guideline development.

Photodynamic Therapy for the Treatment of Infected Leg Ulcers-A Pilot Study

Chronic and infected leg ulcers (LUs) are painful, debilitating, resistant to antibiotics, and immensely reduce a patient’s quality of life. The purpose of our study was to demonstrate the efficacy of photodynamic therapy (PDT) for the treatment of infected chronic LUs. Patients were randomized into two experimental groups: the first group received 5-aminolevulinic acid photodynamic therapy (ALA-PDT) (10 patients), and the second group of 10 patients received local octenidine dihydrochloride (Octenilin gel) exposed to a placebo light source with an inserted filter that mimiced red light. In the PDT group, we used 20% ALA topically applied for 4 hrs and irradiation from a Diomed laser source with a wavelength of 630 nm at a fluency of 80 J/cm². ALA-PDT was performed 10 times during a 14-day hospitalization in 10 patients of both sexes aged 40–85 years with chronic leg ulcers. Treatments were carried out at 3-week intervals for 3–5 cycles. At 8-month follow-up with the PDT group, complete remission (CR) was obtained in four patients (40%), partial response (>50% reduction in ulcer diameter) in four patients (40%), and no response in two patients (20%) who additionally developed deterioration of the local condition with swelling, erythema, and inflammation. To assess the degree of pain during the trials, we used a numeric rating scale (NRS). From the preliminary results obtained, we concluded that PDT can be used to treat leg ulcers as a minimally invasive and effective method with no serious side effects, although further studies on a larger group of patients with LUs are warranted.

Rapid Detection of Pathogens in Wound Exudate via Nucleic Acid Lateral Flow Immunoassay

The rapid detection of pathogens in infected wounds can significantly improve the clinical outcome. Wound exudate, which can be collected in a non-invasive way, offers an attractive sample material for the detection of pathogens at the point-of-care (POC). Here, we report the development of a nucleic acid lateral flow immunoassay for direct detection of isothermally amplified DNA combined with fast sample preparation. The streamlined protocol was evaluated using human wound exudate spiked with the opportunistic pathogen Pseudomonas aeruginosa that cause severe health issues upon wound colonization. A detection limit of 2.1 × 10⁵ CFU per mL of wound fluid was achieved, and no cross-reaction with other pathogens was observed. Furthermore, we integrated an internal amplification control that excludes false negative results and, in combination with the flow control, ensures the validity of the test result. The paper-based approach with only three simple hands-on steps has a turn-around time of less than 30 min and covers the complete analytical process chain from sample to answer. This newly developed workflow for wound fluid diagnostics has tremendous potential for reliable pathogen POC testing and subsequent target-oriented therapy.

Efficacy of topical cadexomer iodine treatment in chronic wounds: Systematic review and meta-analysis of comparative clinical trials

The aim of this study was to summarise the clinical evidence supporting almost 40 years of topical cadexomer iodine (CIOD) use in wound bed preparation by removing barriers to healing such as exudate, slough, bioburden, and infection and allowing chronic wound progression. A systematic review was conducted (Embase/PubMed, November 2020) to identify relevant comparative studies meeting inclusion criteria. Meta‐analyses were performed using a fixed‐effects (I² < 50%) or random‐effects model (I² ≥ 50%) depending on statistical heterogeneity. Dichotomous outcomes were reported as relative risk (RR) and continuous outcomes as mean difference (MD), with 95% confidence intervals. In total, 436 publications were identified of which 13 were comparative trials including outcomes of interest. Significant reductions in exudate, pus/debris, slough, bioburden, and infection were reported in chronic wounds treated with CIOD, compared with standard of care (SOC). Meta‐analyses highlighted the positive impact of CIOD on mean wound area reduction (MD = 2.35 cm², 95% CI = 0.34–4.36, P = .0219) after eight weeks treatment and overall wound healing events compared to SOC; wounds including venous leg ulcers, diabetic foot ulcers, and pressure ulcers treated with CIOD were more than twice as likely to heal than those receiving SOC (RR = 2.30, 95% CI = 1.54–3.45, P < .0001). This meta‐analysis demonstrates the efficacy of CIOD on chronic wounds through removal of barriers to healing. CIOD should be considered in wound bed preparation and treatment protocols.

The diagnosis of infection in chronic leg ulcers: A narrative review on clinical practice

This literature review aimed to provide a narrative review of evidence on validity of clinical and microbial indicators of infection and to gain insights into the diagnosis of infection in chronic leg ulcers (CLUs). A search was conducted in Cinahl, Medline, the Cochrane Library databases, Embase, Web of Science, ScienceDirect, Pubmed, PsycINFO, ProQuest dissertations, and Google Scholar from January 1990 to July 2017. The inclusion criteria were original studies, systematic reviews, and consensus documents focused on "infection" in CLUs, English language, clinical and community settings, and human. The reviewed studies were inconsistent in criteria for infection between investigated wound types and lack of specificity regarding wound types. There were few studies investigating the criteria for diagnosis of infection in leg ulcers. The identification of leg ulcer infection still remains problematic and relies on out-of-date and not uniform evidence. Literature in this area was mostly limited to level III and IV evidence based on The Australian National Health and Medical Research Council Levels of Evidence, or expert opinion. This literature review showed seven clinical signs and symptoms that could be diagnostic for infection in CLUs, including: new, increased, or altered ulcer pain; malodour; increased ulcer area; wound breakdown, delayed or non-healing; and erythema and increased local temperature, whilst the microbial indicators used to diagnose infected leg ulcers were varied and regarded as less important.