Prontosan wound irrigation and gel: management of chronic wounds

Assessment between antiseptic and normal saline for negative pressure wound therapy with instillation and dwell time in diabetic foot infections

Negative pressure wound therapy with instillation and dwell time (NPWTi-d) is increasingly used for a diverse range of wounds. Meanwhile, the topical wound irrigation solution consisting of polyhexamethylene biguanide and betaine (PHMB-B) has shown efficacy in managing wound infections. However, the effectiveness of this solution as a topical instillation solution for NPWTi-d in patients with diabetic foot infections (DFIs) has not been thoroughly studied. The objective of this retrospective study was to evaluate the impact of using PHMB-B as the instillation solution during NPWTi-d on reducing bioburden and improving clinical outcomes in patients with DFIs. Between January 2017 and December 2022, a series of patients with DFIs received treatment with NPWTi-d, using either PHMB-B or normal saline as the instillation solution. Data collected retrospectively included demographic information, baseline wound characteristics, and treatment outcomes. The study included 61 patients in the PHMB-B group and 73 patients in the normal saline group, all diagnosed with DFIs. In comparison to patients treated with normal saline, patients with PHMB-B exhibited no significant differences in terms of wound bed preparation time (P = 0.5034), length of hospital stay (P = 0.6783), NPWTi-d application times (P = 0.1458), duration of systematic antimicrobial administration (P = 0.3567), or overall cost of hospitalization (P = 0.6713). The findings of the study suggest that the use of either PHMB-B or normal saline as an instillation solution in NPWTi-d for DFIs shows promise and effectiveness, yet no clinical distinction was observed between the two solutions.

Advances in Functional Hydrogel Wound Dressings: A Review

One of the most advanced, promising, and commercially viable research issues in the world of hydrogel dressing is gaining functionality to achieve improved therapeutic impact or even intelligent wound repair. In addition to the merits of ordinary hydrogel dressings, functional hydrogel dressings can adjust their chemical/physical properties to satisfy different wound types, carry out the corresponding reactions to actively create a healing environment conducive to wound repair, and can also control drug release to provide a long-lasting benefit. Although a lot of in-depth research has been conducted over the last few decades, very few studies have been properly summarized. In order to give researchers a basic blueprint for designing functional hydrogel dressings and to motivate them to develop ever-more intelligent wound dressings, we summarized the development of functional hydrogel dressings in recent years, as well as the current situation and future trends, in light of their preparation mechanisms and functional effects.

Polyhexamethylene biguanide and its antimicrobial role in wound healing: a narrative review

A wound offers an ideal environment for the growth and proliferation of a variety of microorganisms which, in some cases, may lead to localised or even systemic infections that can be catastrophic for the patient; the development of biofilms exacerbates these infections. Over the past few decades, there has been a progressive development of antimicrobial resistance (AMR) in microorganisms across the board in healthcare sectors. Such resistant microorganisms have arisen primarily due to the misuse and overuse of antimicrobial treatments, and the subsequent ability of microorganisms to rapidly change and mutate as a defence mechanism against treatment (e.g., antibiotics). These resistant microorganisms are now at such a level that they are of grave concern to the World Health Organization (WHO), and are one of the leading causes of illness and mortality in the 21st century. Treatment of such infections becomes imperative but presents a significant challenge for the clinician in that treatment must be effective but not add to the development of new microbes with AMR. The strategy of antimicrobial stewardship (AMS) has stemmed from the need to counteract these resistant microorganisms and requires that current antimicrobial treatments be used wisely to prevent amplification of AMR. It also requires new, improved or alternative methods of treatment that will not worsen the situation. Thus, any antimicrobial treatment should be effective while not causing further development of resistance. Some antiseptics fall into this category and, in particular, polyhexamethylene hydrochloride biguanide (PHMB) has certain characteristics that make it an ideal solution to this problem of AMR, specifically within wound care applications. PHMB is a broad-spectrum antimicrobial that kills bacteria, fungi, parasites and certain viruses with a high therapeutic index, and is widely used in clinics, homes and industry. It has been used for many years and has not been shown to cause development of resistance; it is safe (non-cytotoxic), not causing damage to newly growing wound tissue. Importantly there is substantial evidence for its effective use in wound care applications, providing a sound basis for evidence-based practice. This review presents the evidence for the use of PHMB treatments in wound care and its alignment with AMS for the prevention and treatment of wound infection.

Effect of the most common wound antiseptics on human skin fibroblasts

Background

Antiseptics are used for the cleansing of acute or chronic wounds to eliminate micro‐organisms from the wound bed. However, they have effects on the skin cells.

Aim

To determine the effects of hexetidine, povidone–iodine (PI), undecylenamidopropyl‐betaine/polyhexanide (UBP), chlorhexidine, disodium eosin and hydrogen peroxide on human skin fibroblasts.

Methods

CCD‐1064Sk cells were treated with hexetidine, PI, UBP, chlorhexidine, disodium eosin or hydrogen peroxide. Spectrophotometry was used to measure cell viability and flow cytometry was used to study apoptosis and necrosis after the treatment. In vitro wound scratch assays were performed to determine the gap closure.

Results

All antiseptics significantly reduced the viability of human skin fibroblasts compared with controls. The percentage wound closure was lower with hexetidine, PI and UBP. The scratch assay could not be measured after treatments with chlorhexidine, disodium eosin or hydrogen peroxide, owing to their cytotoxicity. The apoptosis/necrosis experiments evidenced a significant reduction in viable cells compared with controls. An increased percentage of apoptotic cells was observed after treatment with all antiseptics. Compared with controls, the percentage of necrotic cells was significantly increased with all antiseptics except for hexetidine.

Conclusion

The proliferation, migration and viability of human skin fibroblasts are reduced by treatment with hexetidine, PI, UBP, chlorhexidine, disodium eosin and hydrogen peroxide.

Rinse But Don't Repeat: Single Application V.A.C. VERAFLO Salvages Infected Breast Prostheses

Introduction

Existing salvage protocols for infected breast prostheses using negative pressure wound therapy with instillation and dwell (NPWTi-d) require multiple returns to the operating room and prolonged length of stay. We present our expedited salvage protocol and discuss outcomes and associated costs savings.

Methods

Using a retrospective review, we identified 25 consecutive patients (27 breasts) with peri-prosthetic breast infection. Nine patients (10 breasts) underwent removal of infected breast prostheses followed by autologous or staged implant-based reconstruction. Sixteen patients (17 breasts) underwent our single application salvage protocol. A cost analysis was performed comparing the two groups, and an economic model was used to project the cost savings associated with using single application NPWTi-d protocol.

Results

Fifteen of the 16 patients (94%) who underwent single application NPWTi-d had successful implant salvage. Average duration of NPWTi-d was 2 days, 7 hours, and average length of stay was 4.43 days. Compared to control, patients who received the single application protocol required significantly fewer hospitalizations and office visits. A total savings of $58,275 could have been achieved by using the single application NPWTi-d protocol in the patients who did not undergo NPWTi-d.

Conclusions

Single application of NPWTi-d is a simple, safe, and cost-effective technique for salvage of breast prostheses, with 94% success rate, even in immunocompromised patients and severe infection. Compared to previous protocols, ours requires fewer trips to the operating room, shorter length of stay, and more permanent implants placed during salvage. Our protocol is also associated with fewer office visits and fewer returns to the operating room.

Quaternary ammonium N,N,N-trimethyl chitosan derivative and povidone‑iodine complex as a potent antiseptic with enhanced wound healing property

The importance of developing more potent antimicrobials and robust infection prevention practices has been highlighted recently with the increase in reports of emerging bacterial resistance mechanisms and the development of antibiotic-resistant microbes. In this study, a quaternary ammonium chitosan derivative, N,N,N-trimethyl chitosan chloride (TMC) with inherent bactericidal property was synthesized and complexed with povidone‑iodine (PVP-I) to create a potentially more potent antiseptic solution that could also significantly enhance the wound healing process. TMC, a positively charged, water-soluble derivative of chitosan, formed stable solutions with PVP-I at 5% w/v TMC concentration (TMC5/PVP-I). TMC5/PVP-I was significantly effective against multidrug-resistant bacteria S. aureus compared with PVP-I alone. TMC/PVP-I solutions also showed fungicidal property against C. albicans, with no cytotoxic effects when tested against human fibroblast cells cultured in vitro. Wound healing assessment in vivo revealed early collagen formation and re-epithelialization for TMC5/PVP-I treated wounds in rats relative to control and PVP-I only. Formulation of TMC/PVP-I solutions presented in the study can be easily adapted in the existing production of commercial PVP-I creating a new product with more potent bactericidal and enhanced wound healing properties for optimal wound care.

Quality of life and therapeutic regimen management in onychomycosis patients and in vitro study of antiseptic solutions

Onychomycosis or tinea unguium (EE12.1) and Onychomycosis due to non-dermatophyte moulds (1F2D.5) (OM) is a fungal infection of the nail plates with a high prevalence that often affects vulnerable people with co-existing health problems. Gold standard pharmacological treatments for onychomycosis have been associated with low success rates and increasing antifungal resistance, suggesting that treatment outcome is dependent on multiple variables. Here, the prevalence of OM and quality of life were characterized in two vulnerable populations—Hospital patients and Homeless people. Comparing both groups, the most prevalent fungal species were identified in Hospital patients. Then, the in vitro fungicidal properties of the antiseptics povidone-iodine, polyhexamethylene biguanide-betaine, octenidine dihydrochloride, and a super-oxidized solution against two ATCC strains (Candida albicans and Aspergillus niger) and three clinical fungal isolates from Hospital patients (Candida parapsilosis, Trichophyton interdigitale, and Trichophyton rubrum) were tested. OM prevalence was high in both patient groups studied, who also reported a reduction in quality of life and concerns about the state of their feet. In addition, Hospital patients had a non-negligent therapeutic regimen management style. Antiseptics tested in vitro revealed antifungal properties. As antiseptics are low-cost and easy to apply and have few iatrogenic effects, the demonstration of fungicidal properties of these solutions suggests that they may constitute potential supportive therapeutics for OM.

Surgical Strategies to Promote Cutaneous Healing

Usually, cutaneous wound healing does not get impeded and processes uneventfully, reaching wound closure easily. The goal of this repair process is to restore the integrity of the body surface by creating a resilient and stable scar. Surgical practice and strategies have an impact on the course of wound healing and the later appearance of the scar. By considering elementary surgical principles, such as the appropriate suture material, suture technique, and timing, optimal conditions for wound healing can be created. Wounds can be differentiated into clean wounds, clean–contaminated wounds, contaminated, and infected/dirty wounds, based on the degree of colonization or infection. Furthermore, a distinction is made between acute and chronic wounds. The latter are wounds that persist for longer than 4–6 weeks. Care should be taken to avoid surgical site infections in the management of wounds by maintaining sterile working conditions, using antimicrobial working techniques, and implementing the principles of preoperative antibiotics. Successful wound closure is influenced by wound debridement. Wound debridement removes necrotic tissue, senescent and non-migratory cells, bacteria, and foreign bodies that impede wound healing. Additionally, the reconstructive ladder is a viable and partially overlapping treatment algorithm in plastic surgery to achieve successful wound closure.

Development of an Experimental Ex Vivo Wound Model to Evaluate Antimicrobial Efficacy of Topical Formulations

Wound infections are considered a major cause for wound-associated morbidity. There is a high demand for alternative, robust, and affordable methods that can provide relatable and reproducible results when testing topical treatments, both in research and in the pharmaceutical industry. Here we present an ex vivo wound infection model using porcine skin and a burn wounding method, allowing for the efficacy evaluation of topical antimicrobial formulations. Utilizing this model, we demonstrate the potential of topical treatments after infecting the wounds with clinically significant bacteria, P. aeruginosa and S. aureus. We show that the method is compatible with several analytical tools used to analyze infection and antimicrobial effects. Both bacterial strains successfully infected the wound surface, as well as deeper regions of the tissue. Quantification of viable bacteria on the wound surface and in the tissue, longitudinal measurements of bioluminescence, fluorescence microscopy, and scanning electron microscopy were used to confirm the effects of antibacterial treatments. Furthermore, we show that biofilms are formed on the wound surface, indicating that the demonstrated method mirrors typical in vivo infections.

In Vitro Efficacy of Bacterial Cellulose Dressings Chemisorbed with Antiseptics against Biofilm Formed by Pathogens Isolated from Chronic Wounds

Local administration of antiseptics is required to prevent and fight against biofilm-based infections of chronic wounds. One of the methods used for delivering antiseptics to infected wounds is the application of dressings chemisorbed with antimicrobials. Dressings made of bacterial cellulose (BC) display several features, making them suitable for such a purpose. This work aimed to compare the activity of commonly used antiseptic molecules: octenidine, polyhexanide, povidone-iodine, chlorhexidine, ethacridine lactate, and hypochlorous solutions and to evaluate their usefulness as active substances of BC dressings against 48 bacterial strains (8 species) and 6 yeast strains (1 species). A silver dressing was applied as a control material of proven antimicrobial activity. The methodology applied included the assessment of minimal inhibitory concentrations (MIC) and minimal biofilm eradication concentration (MBEC), the modified disc-diffusion method, and the modified antibiofilm dressing activity measurement (A.D.A.M.) method. While in 96-well plate-based methods (MIC and MBEC assessment), the highest antimicrobial activity was recorded for chlorhexidine, in the modified disc-diffusion method and in the modified A.D.A.M test, povidone-iodine performed the best. In an in vitro setting simulating chronic wound conditions, BC dressings chemisorbed with polyhexanide, octenidine, or povidone-iodine displayed a similar or even higher antibiofilm activity than the control dressing containing silver molecules. If translated into clinical conditions, the obtained results suggest high applicability of BC dressings chemisorbed with antiseptics to eradicate biofilm from chronic wounds.

Wound cleansing for treating venous leg ulcers

BACKGROUND

Leg ulcers are open skin wounds that occur below the knee but above the foot. The majority of leg ulcers are venous in origin, occurring as a result of venous insufficiency, where the flow of blood through the veins is impaired; they commonly arise due to blood clots and varicose veins. Compression therapy, using bandages or stockings, is the primary treatment for venous leg ulcers. Wound cleansing can be used to remove surface contaminants, bacteria, dead tissue and excess wound fluid from the wound bed and surrounding skin, however, there is uncertainty regarding the effectiveness of cleansing and the best method or solution to use.

OBJECTIVES

To assess the effects of wound cleansing, wound cleansing solutions and wound cleansing techniques for treating venous leg ulcers.

SEARCH METHODS

In September 2019 we searched the Cochrane Wounds Specialised Register; the Cochrane Central Register of Controlled Trials (CENTRAL); Ovid MEDLINE (including In-Process & Other Non-Indexed Citations); Ovid Embase and EBSCO CINAHL Plus. We also searched clinical trials registries for ongoing and unpublished studies, and scanned reference lists of relevant included studies as well as reviews, meta-analyses and health technology reports to identify additional studies. There were no restrictions with respect to language, date of publication or study setting.

SELECTION CRITERIA

We considered randomised controlled trials (RCTs) comparing wound cleansing with no wound cleansing, or RCTs comparing different wound cleansing solutions, or different wound cleansing techniques.

DATA COLLECTION AND ANALYSIS

We screened studies for their appropriateness for inclusion, assessed their risk of bias using the Cochrane 'Risk of bias' tool, and used GRADE methodology to determine the certainty of evidence. Two review authors undertook these tasks independently, using predetermined criteria. We contacted study authors for missing data where possible.

MAIN RESULTS

We included four studies with a total of 254 participants. All studies included comparisons between different types of cleansing solutions, and three of these reported our primary outcomes of complete wound healing or change in ulcer size over time, or both. Two studies reported the secondary outcome, pain. One study (27 participants), which compared polyhexamethylene biguanide (PHMB) solution with saline solution for cleansing venous leg ulcers, did not report any of the review's primary or secondary outcomes. We did not identify any studies that compared cleansing with no cleansing, or that explored comparisons between different cleansing techniques. One study (61 participants) compared aqueous oxygen peroxide with sterile water. We are uncertain whether aqueous oxygen peroxide makes any difference to the number of wounds completely healed after 12 months of follow-up (risk ratio (RR) 1.88, 95% confidence interval (CI) 1.10 to 3.20). Similarly, we are uncertain whether aqueous oxygen peroxide makes any difference to change in ulcer size after eight weeks of follow-up (mean difference (MD) -1.38 cm², 95% CI -4.35 to 1.59 cm²). Finally, we are uncertain whether aqueous oxygen peroxide makes any difference to pain reduction, assessed after eight weeks of follow-up using a 0 to 100 pain rating, (MD 3.80, 95% CI -10.83 to 18.43). The evidence for these outcomes is of very low certainty (we downgraded for study limitations and imprecision; for the pain outcome we also downgraded for indirectness). Another study (40 participants) compared propyl betaine and polihexanide with a saline solution. The authors did not present the raw data in the study report so we were unable to conduct independent statistical analysis of the data. We are uncertain whether propyl betaine and polihexanide make any difference to the number of wounds completely healed, change in ulcer size over time, or wound pain reduction. The evidence is of very low certainty (we downgraded for study limitations and imprecision). The final study (126 participants) compared octenidine dihydrochloride/phenoxyethanol (OHP) with Ringer's solution. We are uncertain whether OHP makes any difference to the number of wounds healed (RR 0.96, 95% CI 0.53 to 1.72) or to the change in ulcer size over time (we were unable to conduct independent statistical analysis of available data). The evidence is of very low certainty (we downgraded for study limitations and imprecision). None of the studies reported patient preference, ease of use of the method of cleansing, cost or health-related quality of life. In one study comparing propyl betaine and polihexanide with saline solution the authors do not report any adverse events occurring. We are uncertain whether OHP makes any difference to the number of adverse events compared with Ringer's solution (RR 0.58, 95% CI 0.29 to 1.14). The evidence is of very low certainty (we downgraded for study limitations and imprecision).

AUTHORS' CONCLUSIONS

There is currently a lack of RCT evidence to guide decision making about the effectiveness of wound cleansing compared with no cleansing and the optimal approaches to cleansing of venous leg ulcers. From the four studies identified, there is insufficient evidence to demonstrate whether the use of PHMB solution compared with saline solution; aqueous oxygen peroxide compared with sterile water; propyl betaine and polihexanide compared with a saline solution; or OHP compared with Ringer's solution makes any difference in the treatment of venous leg ulcers. Evidence from three of the studies is of very low certainty, due to study limitations and imprecision. One study did not present data for the primary or secondary outcomes. Further well-designed studies that address important clinical, quality of life and economic outcomes may be important, based on the clinical and patient priority of this uncertainty.

Nanodefensin-encased hydrogel with dual bactericidal and pro-regenerative functions for advanced wound therapy

Background: Host defense peptides (HDPs) have emerged as a novel therapeutic paradigm for wound management; however, their clinical applications remain a challenge owing to their poor pharmacological properties and lack of suitable pharmaceutical formulations. Nanodefensin (ND), a nanoengineered human α-defensin 5 (HD5), has shown improved pharmacological properties relative to the parent compound. In this study, we engineered a nanodefensin-encased hydrogel (NDEFgel), investigated the effects of NDEFgel on wound healing, and elucidated underlying mechanisms. Method: ND was chemically synthesized and tested functions by in vitro antimicrobial and scratch assays and western blotting. Different NDEFgels were evaluated by in vitro characterizations including degradation, drug release and antimicrobial activity. In full-thickness excisional murine models, the optimal NDEFgel was directly applied onto wound sites, and the efficacy was assessed. Moreover, the underlying mechanisms of pro-regenerative effect developed by NDEFgel were also explored. Results: Apart from bactericidal effects, ND modulated fibroblast behaviors by promoting migration and differentiation. Among the tested hydrogels, the Pluronic F127 (Plu) hydrogel represented the most desirable carrier for ND delivery owing to its favorable controlled release and compatibility with ND. Local treatment of NDEFgel on the wound bed resulted in accelerated wound regeneration and attenuated bacterial burden. We further demonstrated that NDEFgel therapy significantly upregulated genes related to collagen deposition and fibroblasts, and increased the expression of myofibroblasts and Rac1. We therefore found that Rac1 is a critical factor in the ND-induced modulation of fibroblast behaviors in vitro through a Rac1-dependent cytoskeletal rearrangement. Conclusion: Our results indicate that NDEFgel may be a promising dual-action therapeutic option for advanced wound management in the future.

Effect of Polyhexamethylene Biguanide in Combination with Undecylenamidopropyl Betaine or PslG on Biofilm Clearance

Hospital-acquired infection is a great challenge for clinical treatment due to pathogens’ biofilm formation and their antibiotic resistance. Here, we investigate the effect of antiseptic agent polyhexamethylene biguanide (PHMB) and undecylenamidopropyl betaine (UB) against biofilms of four pathogens that are often found in hospitals, including Gram-negative bacteria Pseudomonas aeruginosa and Escherichia coli, Gram-positive bacteria Staphylococcus aureus, and pathogenic fungus, Candida albicans. We show that 0.02% PHMB, which is 10-fold lower than the concentration of commercial products, has a strong inhibitory effect on the growth, initial attachment, and biofilm formation of all tested pathogens. PHMB can also disrupt the preformed biofilms of these pathogens. In contrast, 0.1% UB exhibits a mild inhibitory effect on biofilm formation of the four pathogens. This concentration inhibits the growth of S. aureus and C. albicans yet has no growth effect on P. aeruginosa or E. coli. UB only slightly enhances the anti-biofilm efficacy of PHMB on P. aeruginosa biofilms. However, pretreatment with PslG, a glycosyl hydrolase that can efficiently inhibit and disrupt P. aeruginosa biofilm, highly enhances the clearance effect of PHMB on P. aeruginosa biofilms. Meanwhile, PslG can also disassemble the preformed biofilms of the other three pathogens within 30 min to a similar extent as UB treatment for 24 h.

Wound bed preparation: a case series using polyhexanide and betaine solution and gel-a UK perspective

OBJECTIVE

The burden of wound care within the NHS is estimated at a cost of £5.3 billion per year and is set to rise annually by 30%. This case series describes the results of using polyhexanide (PHMB) and betaine wound irrigation solution and gels (Prontosan, B.Braun Medical Ltd., UK) across the UK in hard-to-heal (also described as chronic) wounds up to 20 years' duration, with an observation period of greater than one month. Over half of the hard-to-heal wounds were healed and vast improvements to all other wounds were observed. Improvements to wound bed condition were reported as early as two days after commencing initial treatment, with decreases in malodour, exudate, slough and pain reported across the case series. In addition to wound bed improvements, a reduction in dressing change frequency of 55% was observed in hard-to-heal wounds under the new treatment regime.

Management of wounds in the community: five principles

The care of any wound in the community requires multidisciplinary working between healthcare professionals. In this article, the authors offer five generalisable principles that colleagues providing community care can apply in order to achieve timely wound healing: (1) assessment and exclusion of disease processes; (2) wound cleansing; (3) timely dressing change; (4) appropriate (dressing choice; and (5) considered antibiotic prescription. High-quality wound care is an essential aspect of healthcare practice but lacks an evidence base and standardised practice at present. The practice and teaching of wound care should be more greatly emphasised in healthcare training for all disciplines.

In vitro activity of a polyhexanide-betaine solution against high-risk clones of multidrug-resistant nosocomial pathogens

OBJECTIVE

To determine the in vitro activity of a polyhexanide-betaine solution against collection strains and multidrug-resistant (MDR) nosocomial isolates, including high-risk clones.

METHODS

We studied of 8 ATCC and 21 MDR clinical strains of Staphylococcus aureus, Enterococcus faecium, Enterococcus faecalis, Escherichia coli, Enterobacter cloacae, Klebsiella pneumoniae, Acinetobacter baumannii, and Pseudomonas aeruginosa, including the multiresistant high-risk clones. The MICs and MBCs of a 0.1% polyhexanide-0.1% betaine solution were determined by microdilution. For each species, strains with the highest MICs were selected for further experiments. The dilution-neutralization test (PrEN 12054) was performed by incubating bacterial inocula of 10⁶CFU/mL for 1min with undiluted 0.1% polyhexanide-betaine solution. The CFUs were counted after neutralization. Growth curves and time-kill curves at concentrations of 0.25, 1, 4, and 8×MIC, were performed. MICs of recovered strains were determined when regrowth was observed in time-kill studies after 24h of incubation. Strains with reduced susceptibility were selected by serial passage on plates with increasing concentrations of polyhexanide-betaine, and MICs were determined.

RESULTS

Polyhexanide-betaine MIC range was 0.5-8mg/L. MBCs equalled or were 1 dilution higher than MICs. The dilution-neutralization method showed total inoculum clearance of all strains. In time-kill curves, no regrowth was observed at 4×MIC, except for S. aureus (8×MIC). Increased MICs were not observed in time-kill curves, or after serial passages after exposure to polyhexanide-betaine.

CONCLUSIONS

Polyhexanide-betaine presented bactericidal activity against all MDR clinical isolates tested, including high-risk clones, at significantly lower concentrations and time of activity than those commercially used.

[Randomised clinical trial to compare two tracheotomy care methods in an Intensive Care Unit]

INTRODUCTION

Tracheotomy is a common technique in Intensive Care Units (ICU). It is known that nursing care during and after that procedure is directly related to its success, by reducing the possible complications to a minimum, such as the stoma infection, and contributing to a favourable outcome in critical patients.

OBJECTIVES

To compare the use of polyhexanide (PLX) versus saline+povidone iodine (PY) as antiseptics and infection incidence in tracheostomies performed in Intensive Care Units.

MATERIAL AND METHOD

A 2-year, experimental, randomised, open-label trial carried out in a multidiscipline ICU with 32 beds. The study was approved by the Research Ethics Committee of Principality of Asturias.

RESULTS

The overall infection rate observed for every hundred patients was 1.34 (95% CI; 0.81-2.01), with 1.46 when using PLX and 1.21 for PY (P=.685).

CONCLUSIONS

In spite of the experimental treatment (PLX) was shown to be effective in other types of wounds in our study. No significant differences were found between this technique and the standard one. Since there is no national registry of tracheotomy- associated infections, it is not possible to know whether the rate observed is within the usual parameters.

Efficacy of 1% acetic acid in the treatment of chronic wounds infected with Pseudomonas aeruginosa: prospective randomised controlled clinical trial

Chronic wounds are those wounds that are persistent and do not respond to any sort of treatment. The concept of using topical antiseptics on open wounds is to prevent and treat infections. They also help to shorten the time taken to heal the wounds. The use of topical agents on wounds to prevent infection is a minimal ability to develop resistance to the microorganisms. Pseudomonas aeruginosa is a Gram-negative opportunistic pathogen with innate resistance to many antibiotics. In places that are economically backward, these problems get compounded by the inability of patients to afford newer expensive drugs. Topically applied dilute acetic acid, which is cheap and easily available, has been found to be effective in such chronic wounds. In the present study, an attempt has been made to use 1% acetic acid as the sole antimicrobial agent for the treatment of pseudomonal wound infections. A control limb was used in which the wounds were treated with normal saline. Our objective was to evaluate the efficacy of acetic acid in low concentration of 1% in chronic wounds infected with P. aeruginosa. This was a prospective study conducted over a period of 6 months.

INCLUSION CRITERIA

All patients with chronic wounds infected with P. aeruginosa.

EXCLUSION CRITERIA

Wounds due to massive burns, suspected malignancy, immunocompromised individuals and individuals with sepsis. A total of 32 patients enrolled in the study. Subjects were randomised equally to the 1% acetic acid group and saline dressing group. None of the patients received any systemic antibiotics during the study period and received twice daily dressings. The endpoint of the treatment was wounds free of P. aeruginosa. The duration of treatment required to eliminate the Pseudomonas from the wounds in the acetic acid group was on an average 7 days less than that required by the saline group. P value was <0·001. In the 1% acetic acid group irrespective of the sensitivity of the organism to antibiotics, Pseudomonas organisms were eliminated within the same time period - 4·5 days. In the saline group, susceptible organisms were eliminated within 11·5 days and multidrug-resistant organisms were eliminated by 15·5 days. 1% acetic acid is a simple, safe and effective topical antiseptic that can be used in the elimination of P. aeruginosa from chronic infected wounds.

Increased peritoneal dialysis exit site infections using topical antiseptic polyhexamethylene biguanide compared to mupirocin: results of a safety interim analysis of an open-label prospective randomized study

Prophylactic mupirocin for peritoneal catheter exit sites reduces exit site infection (ESI) risk but engenders antibiotic resistance. We present early interim safety analysis of an open-label randomized study comparing polyhexamethylene biguanide (PHMB) and mupirocin. A total of 106 patients randomized to 53 in each group were followed up for a mean of 12.68 months per patient. On safety analysis, the PHMB group had a significantly greater ESI rate than the mupirocin group (odds ratio [OR], 0.26; 95% confidence interval [CI], 0.09 to 0.80), leading to discontinuation of the trial.

Clinical evaluation of gauze-based negative pressure wound therapy in challenging wounds

The aim of this randomised clinical study was to evaluate the effectiveness and safety of gauze-based negative pressure wound therapy (NPWT) in patients with challenging wounds. A total of 50 consecutive patients who had wound drainage for more than 5 days, required open wound management and had existence of culture positive infection were included the study. In this study, gauze-based NPWT was compared with conventional dressing therapy in the treatment of patients with difficult-to-heal wounds. The patients were randomly divided into two groups. Group I (n = 25) was followed by conventional antiseptic (polyhexanide solution) dressings, and group II (n = 25) was treated with saline-soaked antibacterial gauze-based NPWT. The wounds' sizes, number of debridement, bacteriology and recurrence were compared between group I and group II. The mean age of the patients was 59·50 years (range 23-97). In group I, average wound sizes of pre- and post-treatment periods were 50·60 ± 55·35 and 42·50 ± 47·92 cm(2), respectively (P < 0·001). Average duration of treatment was 25·52 ± 16·99 days, and average wound size reduction following the treatment was 19·99% in this group. In group II, the wounds displayed considerable shrinkage, accelerated granulation tissue formation, decreased and cleared away exudate. The average wound sizes in the pre- and post-treatment periods were 98·44 ± 100·88 and 72·08 ± 75·78 cm(2) , respectively (P < 0·001). Average duration of treatment was 11·96 ± 2·48 days, and average wound size reduction following the treatment was 32·34%. The patients treated with antibacterial gauze-based NPWT had a significantly reduced recurrence (2 wounds versus 14 wounds, P = 0·001), and increased number of the culture-negative cases (22 wounds versus 16 wounds, P < 0·047) in a follow-up period of 12 months. There was a statistically significant difference between two groups in all measurements. As a result, we can say that the gauze-based NPWT is a safe and effective method in the treatment of challenging infective wounds when compared with conventional wound management.

Effects of biofilm treatments on the multi-species Lubbock chronic wound biofilm model

OBJECTIVE

To evaluate the efficacy of several biofilm effectors in inhibiting biofilm formation in an in vitro multi-species chronic wound biofilm model.

METHOD

The Lubbock Chronic Wound Biofilm (LCWB) model has been described in detail elsewhere. Pathogens used in the model are Pseudomonas aeruginosa, Enterococcus faecalis and Staphylococcus aureus. These are three of the most important species associated with biofilms. Here, the model was exposed to the following biofilm effectors: xylitol, salicylic acid, farnesol, erythritol and two proprietary, semi-solid, wound-dressing formulations currently under development (Sanguitec gels).

RESULTS

Biofilm formation was completely inhibited in the LCWB model following treatment with 20% xylitol, 10% erythritol, 1,000 microg/ml farnesol, 20mM salicylic acid or 0.1% of either of the two Sanguitec gel formulations. Salicylic acid specifically inhibited S. aureus (p<0.01) at 10mM and 20mM, consequently increasing the ratios of P. aeruginosa and E. faecalis within the biofilm. Xylitol had an increasing inhibitory effect on P. aeruginosa (p<0.01) at all concentrations evaluated. Erythritol had an inhibitory effect on P. aeruginosa and S. aureus growth (p<0.01) at over 5% concentrations. The inhibitory effect of both Sanguitec gel formulations was more broadly effective, with an increasingly inhibitory effect on all LCWB species (p<0.01).

CONCLUSION

The LCWB model provides a multi-species format with which to evaluate the effect of biofilm effectors on wound flora in a biofilm phenotype. These results suggest that different treatments can target specific populations within a biofilm. Salicylic acid preferentially targeted S. aureus, xylitol preferentially targeted P. aeruginosa, while erythritol preferentially targeted both P. aeruginosa and S. aureus. In contrast, the two Sanguitec gel formulations provided a broad, less preferential, inhibition of biofilm development.

DECLARATION OF INTEREST

Research and Testing Laboratory is a for-profit enterprise that develops molecular methods and performs service research work on biofilms. Sanguitec gel was developed by JPK and CEJ.

Wound cleansing, topical antiseptics and wound healing

Quality of care is a critical requirement for wound healing and 'good' care of wounds has been synonymous with topical prevention and management of microbial contamination. Topical antiseptics are antimicrobial agents that kill, inhibit or reduce the number of microorganisms and are thought to be essential for wounds infection control. However, they have long and commonly been used on wounds to prevent or treat infection, the merits of antiseptic fluid irrigation have received little scientific study. Unlike antibiotics that act selectively on a specific target, antiseptics have multiple targets and a broader spectrum of activity, which include bacteria, fungi, viruses, protozoa and even prions. Although certain skin and wound cleansers are designed as topical solutions with varying degrees of antimicrobial activity, concerns have been raised. Wound cleansers may affect normal human cells and may be antimitotic adversely affecting normal tissue repair. Repeated and excessive treatment of wounds with antiseptics without proper indications may have negative outcomes or promote a microenvironment similar to those found in chronic wounds. However, when applied at the proper times and concentrations, some classes of antiseptics may provide a tool for the clinician to drive the wound bed in desired directions. The present review summarises the various antiseptics in use and their negative impact on the wound healing mechanisms. It is clear that the role of antiseptics on wounds and their role in wound care management need to be reconsidered.

Survey of bacterial diversity in chronic wounds using pyrosequencing, DGGE, and full ribosome shotgun sequencing

BACKGROUND

Chronic wound pathogenic biofilms are host-pathogen environments that colonize and exist as a cohabitation of many bacterial species. These bacterial populations cooperate to promote their own survival and the chronic nature of the infection. Few studies have performed extensive surveys of the bacterial populations that occur within different types of chronic wound biofilms. The use of 3 separate16S-based molecular amplifications followed by pyrosequencing, shotgun Sanger sequencing, and denaturing gradient gel electrophoresis were utilized to survey the major populations of bacteria that occur in the pathogenic biofilms of three types of chronic wound types: diabetic foot ulcers (D), venous leg ulcers (V), and pressure ulcers (P).

RESULTS

There are specific major populations of bacteria that were evident in the biofilms of all chronic wound types, including Staphylococcus, Pseudomonas, Peptoniphilus, Enterobacter, Stenotrophomonas, Finegoldia, and Serratia spp. Each of the wound types reveals marked differences in bacterial populations, such as pressure ulcers in which 62% of the populations were identified as obligate anaerobes. There were also populations of bacteria that were identified but not recognized as wound pathogens, such as Abiotrophia para-adiacens and Rhodopseudomonas spp. Results of molecular analyses were also compared to those obtained using traditional culture-based diagnostics. Only in one wound type did culture methods correctly identify the primary bacterial population indicating the need for improved diagnostic methods.

CONCLUSION

If clinicians can gain a better understanding of the wound's microbiota, it will give them a greater understanding of the wound's ecology and will allow them to better manage healing of the wound improving the prognosis of patients. This research highlights the necessity to begin evaluating, studying, and treating chronic wound pathogenic biofilms as multi-species entities in order to improve the outcomes of patients. This survey will also foster the pioneering and development of new molecular diagnostic tools, which can be used to identify the community compositions of chronic wound pathogenic biofilms and other medical biofilm infections.