Can dressings soaked with polyhexanide reduce bacterial loads in full-thickness skin grafting? A randomized controlled trial

Clinical use of 0.1% polyhexanide and propylbetaine on acute and hard-to-heal wounds: a literature review

OBJECTIVE

To summarise the findings on the effect of the clinical use of 0.1% polyhexanide-propylbetaine (PHMB/betaine) solution/gel on acute and hard-to-heal (chronic) wound healing.

METHOD

A literature search was conducted in MEDLINE, CINAHL, Embase, Scopus and the CENTRAL Trials Registry of the Cochrane Collaboration. Paired reviewers conducted title and abstract screening and full-text screening to identify experimental, quasi-experimental and observational studies. Study quality and risk of bias were not formally evaluated.

RESULTS

A total of 17 studies met the eligibility criteria. The findings from 12 studies indicated that the use of 0.1% PHMB/betaine solution/gel had: a low risk of contact sensitivity; could help debridement during wound cleansing; aided effective wound bed preparation; reduced wound size, odour and exudate; improved pain control; reduced microbial load; and enhanced wound healing. The results of three studies indicated that both 0.1% PHMB and saline solution were effective in reducing bacterial load, while another showed that adding 0.1% PHMB to tie-over dressings had no effect on reducing bacterial loads in wounds. Another study concluded that disinfection and granulation of pressure ulcers with hydrobalance dressing with 0.3% PHMB was faster and more effective than using 0.1% PHMB/betaine.

CONCLUSION

The findings of this literature review showed that 0.1% PHMB/betaine solution/gel appeared to be useful and safe for wound cleansing, was effective in removing soft debris and slough from the wound bed, and created a wound environment optimal for healing. Although these actions cannot be attributed solely to this treatment modality, these results do highlight the unique action of this combined product. However, more robust studies are needed to confirm these results.

Efficacy of Polyhexamethylene Biguanide in Reducing Post-Operative Infections: A Systematic Review and Meta-Analysis

Background: Post-operative infections are a substantial cause of morbidity and mortality worldwide. Polyhexamethylene biguanide (PHMB) is an antimicrobial agent that has been used in various surgical settings to prevent infections. However, the literature on its efficacy in reducing post-operative infections remains unclear. Materials and Methods: We conducted a systematic review and meta-analysis of randomized controlled trials (RCTs) to evaluate the efficacy of PHMB in reducing post-operative infections. The risk of bias and methodologic quality of the included studies were also assessed. Results: The systematic review included nine RCTs, and eight were included in the meta-analysis that showed that the use of PHMB was associated with a reduction in the rate of post-operative infections. The overall effect size was statistically significant, with moderate heterogeneity across the included studies (log Peto's odds ratio [OR], -0.890; 95% confidence interval [CI], -1.411 to -0.369; I2 = 41.89%). However, the diversity in the application of PHMB and the potential influence of other factors, such as adherence to infection prevention protocols and organizational-level variables, underscore the need for further primary studies. Conclusions: Polyhexamethylene biguanide appears to be a promising intervention for reducing post-operative infections. However, more high-quality, well-designed RCTs are needed to confirm these findings and to explore the most effective ways to use PHMB within specific infection prevention bundles. Future research should also aim to control for potential confounding factors to provide a more comprehensive understanding of the efficacy of PHMB in reducing post-operative infections.

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.

Biofilm reduction potential of 0.02% polyhexanide irrigation solution in several types of urethral catheters

Background

Long-term use of urethral catheters is associated with high risk of urinary tract infection (UTI) and blockage. Microbial biofilms are a common cause of catheter blockage, reducing their lifetime and significantly increasing morbidity of UTIs. A 0.02% polyhexanide irrigation solution developed for routine mechanical rinsing shows potential for bacterial decolonization of urethral catheters and has the potential to reduce or prevent biofilm formation.

Methods

Using an in vitro assay with standard market-leading types of catheters artificially contaminated with clinically relevant bacteria, assays were carried out to evaluate the biofilm reduction and prevention potential of a 0.02% polyhexanide solution versus no intervention (standard approach) and irrigation with saline solution (NaCl 0.9%). The efficiency of decolonization was measured through microbial plate count and membrane filtration.

Results

Irrigation using a 0.02% polyhexanide solution is suitable for the decolonization of a variety of transurethral catheters. The effect observed is significant compared to irrigation with 0.9% saline solution (p = 0.002) or no treatment (p = 0.011). No significant difference was found between irrigation with 0.9% saline solution and no treatment (p = 0.74).

Conclusions

A 0.02% polyhexanide solution is able to reduce bacterial biofilm from catheters artificially contaminated with clinically relevant bacteria in vitro. The data shows a reduction of the viability of thick bacterial biofilms in a variety of commercially available urinary catheters made from silicone, latex-free silicone, hydrogel-coated silicone and PVC. Further research is required to evaluate the long-term tolerability and efficacy of polyhexanide in clinical practice.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12894-021-00826-3.

Nasal decolonization of Staphylococcus aureus and the risk of surgical site infection after surgery: a meta-analysis

Aim

To assess the effects of nasal decontamination on preventing surgical site infections (SSIs) in people who are Staphylococcus aureus carriers undergoing different types of surgeries and diverse measures of decolonization.

Methods

Relevant randomized controlled trials (RCTs) were identified through systematic searches of the PubMed, Embase, Web of science, and the Cochrane Library databases. The risk ratios (RRs) and 95% confidence intervals (CIs) were calculated and the effects model was chosen according to the heterogeneity. Subgroup analyses were performed according to different types of surgeries and measures of decolonization that Staphylococcus aureus carriers were applied.

Results

Twenty RCTs published between 1996 and 2019 involving 10,526 patients were included. Pooled results showed that the overall SSIs and pulmonary surgery SSIs presented with a statistical difference in measures of nasal decontamination (RR = 0.59 and 0.47, respectively, both p < 0.01). However, the associations between nasal decolonization and increased risks of SSIs in orthopedics surgery or cardiovascular surgery remained insignificant in studies. As for the diverse measures of nasal decontamination, 50% used mupirocin, 15% used chlorhexidine, 30% used different types of antimicrobial drugs, and 5% use others. The SSIs rate were decreased after chlorhexidine (RR = 0.474, 95% CI 0.259–0.864), while no significant difference was shown in the use of mupirocin (RR = 0.871, 95% CI 0.544–1.394).

Conclusion

It seems that nasal decolonization of Staphylococcus aureus may be associated with a reduction of SSIs in these patients, especially in patients who have been administered by pulmonary surgeries or treated with chlorhexidine.

Full-thickness Skin Graft Fixation Techniques: A Review of the Literature

Multiple techniques for skin graft fixation have been proposed, but the evidence underlying these techniques is unclear. This study aimed to review the literature for full-thickness graft fixation techniques. PubMed was electronically searched to identify relevant studies. The search strategy identified 91 relevant articles. These consisted of 2 randomised controlled trials (RCTs), 10 observational cohort studies (8 retrospective, 2 prospective), and 79 descriptive studies (case series, case reports, or expert opinion articles). Both identified RCTs compared the tie-over dressing against a modified tie-over dressing. The tie-over dressing was also included in all identified observational studies, and comparisons were made against quilting/mattress suturing (4 studies, 181 grafts in total), simple pressure dressings (3 studies, 528 grafts), non-tie-over dressings non-specifically (1 study, 71 grafts), hydrocolloid dressings (1 study, 62 grafts), and double-tie over dressings (1 study, 43 grafts). No significant differences were found between fixation methods for graft take, haematoma rate, and infection rate. No studies have found a significant difference between tie-over dressings and alternative graft fixation technique, with the most evidence for simple pressure dressings and quilting/mattress suturing. However, the evidence base consists mostly of small, retrospective observational studies. This article describes the current evidence base and this should be considered when planning future reports in the field.

Considerations and Caveats in Combating ESKAPE Pathogens against Nosocomial Infections

ESKAPE pathogens (Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter species) are among the most common opportunistic pathogens in nosocomial infections. ESKAPE pathogens distinguish themselves from normal ones by developing a high level of antibiotic resistance that involves multiple mechanisms. Contemporary therapeutic strategies which are potential options in combating ESKAPE bacteria need further investigation. Herein, a broad overview of the antimicrobial research on ESKAPE pathogens over the past five years is provided with prospective clinical applications.

A dual-action peptide-containing hydrogel targets wound infection and inflammation

There is a clinical need for improved wound treatments that prevent both infection and excessive inflammation. TCP-25, a thrombin-derived peptide, is antibacterial and scavenges pathogen-associated molecular patterns (PAMPs), such as lipopolysaccharide, thereby preventing CD14 interaction and Toll-like receptor dimerization, leading to reduced downstream immune activation. Here, we describe the development of a hydrogel formulation that was functionalized with TCP-25 to target bacteria and associated PAMP-induced inflammation. In vitro studies determined the polymer prerequisites for such TCP-25–mediated dual action, favoring the use of noncharged hydrophilic hydrogels, which enabled peptide conformational changes and LPS binding. The TCP-25–functionalized hydrogels killed Gram-positive Staphylococcus aureus and Gram-negative Pseudomonas aeruginosa bacteria in vitro, as well as in experimental mouse models of subcutaneous infection. The TCP-25 hydrogel also mediated reduction of LPS-induced local inflammatory responses, as demonstrated by analysis of local cytokine production and in vivo bioimaging using nuclear factor κB (NF-κB) reporter mice. In porcine partial thickness wound models, TCP-25 prevented infection with S. aureus and reduced concentrations of proinflammatory cytokines. Proteolytic fragmentation of TCP-25 in vitro yielded a series of bioactive TCP fragments that were identical or similar to those present in wounds in vivo. Together, the results demonstrate the therapeutic potential of TCP-25 hydrogel, a wound treatment based on the body’s peptide defense, for prevention of both bacterial infection and the accompanying inflammation.

Re-evaluation of polihexanide use in wound antisepsis in order to clarify ambiguities of two animal studies

OBJECTIVE

Due to classification of the agent polihexanide (PHMB) in category 2 'may cause cancer' by the Committee for Risk Assessment of the European Chemicals Agency in 2011, the users of wound antiseptics may be highly confused. In 2017, this statement was updated, defining PHMB up to 0.1% as a preservative safe in all cosmetic products. In the interest of patient safety, a scientific clarification of the potential carcinogenicity of PHMB is necessary.

METHODS

A multidisciplinary team (MDT) of microbiologists, surgeons, dermatologists and biochemists conducted a benefit-risk assessment to clarify the hazard of antiseptic use of PHMB.

RESULTS

In two animal studies, from which the assessment of a carcinogenic risk was derived, PHMB was administered orally over two years in extremely high concentrations far above the NO(A)EL (no-observed-(adverse-) effect level) in rats and mice. Feeding in the NO(A)EL range resulted in no abnormal effects. In one male in the highest dose group of 4000ppm PHMB, an adenocarcinoma was found, which the author attributed to chronic inflammation of the colon with systemic atypical exposure. The increasing incidence of hemangiosarcomas highly probably resulted from increased endothelial proliferation, triggered by the exceedingly high dosage fed, because PHMB is not genotoxic and there is no evidence for epigenetic effects.

DISCUSSION

It is well known that PHMB is not absorbed when applied topically. Considering the absence of genotoxicity and epigenetic effects together with the interpretation of the animal studies, it is the consensus of the multidisciplinary experts that a carcinogenic risk from PHMB-use for wound antisepsis can be ruled out.

CONCLUSION

On this basis and considering their effectiveness, tolerability and clinical evidence, the indications for PHMB based wound antiseptics are justified.

Inflammation Biomarkers and Correlation to Wound Status After Full-Thickness Skin Grafting

Background: A surgical site infection (SSI) is believed to be the result of an exaggerated inflammatory response. Objective: Examine the relationship between clinical status and inflammation biomarkers in full-thickness skin grafting wounds. Methods: Twenty patients planned for facial full-thickness skin grafting were enrolled. A week after surgery, all graft wounds were clinically assessed using a 3-step scale for inflammation (low, moderate, high). All wounds were swabbed for routine microbiological analysis and assessment of numbers of aerobic bacteria. Tie-over dressings from all patients were collected and used for wound fluid extraction and subsequent analysis of MMPs, cytokines, and NF-κB inducing activity. Results: Wounds with a high degree of inflammation contained increased total MMP activity (P ≤ 0.05) in their corresponding fluids. Likewise, the level of the cytokines IL-1ß, IL-8, IL-6, TNF-α was analyzed, and particularly IL-1ß was discriminatory for highly inflamed wounds (P ≤ 0.01). Moreover, bacterial loads were increased in highly inflamed wounds compared to wounds with a low degree of inflammation (P ≤ 0.01). NF-κB activation in the monocytic cell line THP-1 was significantly higher when these cells were stimulated by wound fluids with a high degree of inflammation (P ≤ 0.01). Growth of S. aureus in wounds did not vary between wounds with different degrees of inflammation (chi-square 3.8, P = 0.144). Conclusion: Biomarkers analyzed from tie-over dressings correlated to clinical wound healing in full-thickness skin grafting.

Vancomycin-soaked wrapping of harvested hamstring tendons during anterior cruciate ligament reconstruction. A review of the 'vancomycin wrap'

The practice of 'vancomycin wrapping' of harvested hamstring autografts during Anterior Cruciate Ligament Reconstruction (ACLR) surgery has gathered recent interest. This practice involves the wrapping of harvested grafts in a vancomycin-soaked swab during the preparatory phase. Different techniques are observed, and a small number of studies have shown that pre-soaking hamstring ACLR grafts in this manner dramatically reduces the post-surgical infection rate compared with standard intravenous antibiotic prophylaxis alone. However, the literature surrounding this practice is surprisingly limited and thus the basis and rationale of the 'vancomycin wrap' has established itself largely without question. The exact popularity of this practice is difficult to establish but there has been increasing disclosure of its efficacy in reducing post-operative infection in ACLR since 2012. We provide a synopsis of the current literature surrounding vancomycin and its use in 'wraps' in ACLR to help apprise the surgeon of the nature of infection in ACLR, the rationale for vancomycin, whilst considering evidence to support alternatives and discussing potential ramifications for future practice.

Variability in the diagnosis of surgical-site infections after full-thickness skin grafting: an international survey

BACKGROUND

Diagnosis of a surgical-site infection (SSI) in dermatological surgery can be based entirely on a subjective assessment, according to the fourth criterion of the most common definition of an SSI, which was established by the US Centers for Disease Control and Prevention.

OBJECTIVES

To investigate the interobserver agreement between dermatologists in their diagnosis of SSI of dermatosurgical wounds.

METHODS

An international electronic photographic survey with eight photographs of wounds 1 week after full-thickness skin grafting (FTSG) was sent to dermatologists. All wounds were assessed in terms of visual criteria beforehand. Data collected from respondents included physician characteristics and experience, and SSI assessments of all wounds.

RESULTS

In total, 393 dermatologists from 27 countries enrolled. Most respondents were from the U.S.A. (25%), followed by Sweden (24%) and the U.K. (13%). There was only a slight interobserver agreement on SSI suspicion (κ = 0·19). SSI suspicion was lower for male physicians (P = 0·03), board-certified dermatologists (P = 0·001), physicians regularly assessing surgical wounds (P = 0·03) and physicians performing FTSG (P < 0·001). Swedish physicians diagnosed more SSIs than U.S. physicians (P = 0·002). Erythema was more common in cases with higher SSI suspicion.

CONCLUSIONS

This study reveals broad inter-rater variability in the diagnosis of SSI, illustrating the need for novel objective diagnostic methods that can better capture the variables that constitute an SSI.

Efficacy of Conventional and Liposomal Povidone-Iodine in Infected Mesh Skin Grafts: An Exploratory Study

Introduction

Infection is a major threat to wound healing and a leading cause of graft loss in patients undergoing meshed skin grafts (MSGs). Therefore, topical antisepsis is important in the overall treatment scheme.

Methods

An exploratory satellite group of 14 patients with infected MSGs were enrolled as part of a prospective, randomized, controlled, parallel-group, open-label, pilot Phase II study that investigated the efficacy and tolerability of 3% liposomal povidone–iodine hydrogel (PVP–ILH, Repithel^®; RepiGel^®) versus chlorhexidine gauze in non-infected MSGs. The satellite group included both patients with infected wound beds prior to grafting and patients with infection of a previously placed graft, with MSG sizes ranging from 50 to 1000 cm², who were randomized to treatment with (PVP–ILH) or 10% povidone–iodine ointment (Betaisodona^®; BETADINE^®). Medication was applied in a 2-mm layer and dressing changes with identical application of study medication took place daily. Wounds were evaluated by photoplanimetry, microbiologically and subjectively by patients and physicians.

Results

The results for the main study group have been reported previously. In the satellite group, both PVP–ILH and povidone–iodine ointment performed remarkably well with respect to lowering the bacterial count and restoring wound healing, with different emphasis. Povidone–iodine ointment showed excellent antibacterial efficacy with no detectable microorganisms by Day 10, and rapid re-epithelialization (mean 90% by Day 6). PVP–ILH also demonstrated rapid re-epithelialization (mean 72% by Day 6) with a trend towards improved subjective measures of wound healing quality. Four patients (40%) receiving PVP–ILH experienced partial graft loss (10–15% of total MSG area); no patients in the povidone–iodine ointment group experienced graft loss.

Conclusion

Our results suggest that povidone–iodine ointment has a strong role in managing infected wounds, especially when a high concentration of povidone–iodine may be warranted, while PVP–ILH indicated similar beneficial results on markers of wound healing quality in larger infected wounds.

Trial Registration

The trial was conducted prior to mandatory registration of drug products, PVP–ILH represents a medicated device in the EU and many other countries.

Funding

Mundipharma Research GmbH & Co. KG.