Comparative assessment of commercially available wound gels in ex vivo human skin reveals major differences in immune response-modulatory effects.

Wound healing is a crucial process for maintaining the function of human skin as a protective barrier to pathogens and other external stress factors. Hydrogels-in combination with antimicrobials-are often used, as moist wound care has been widely accepted as standard therapy. Recently, we reported about immune response-modulatory effects of an octenidine-based hydrogel, however little is known about the mechanism of action of other hydrogels including antiseptic molecules or chlorine-based and chlorine-releasing agents, respectively. The aim of this study was the comparative assessment of commercially available wound gels (octenilin®, Prontosan®, Lavanid®, Betadona®, ActiMaris®, Microdacyn60®, VeriforteTMmed) with regard to their effects on the secretion of distinct cytokines (IL-6, IL-8, IL-10), matrix-metalloproteinases as well as their potential to cause alterations in skin structure and apoptosis. Hence, tape-stripped human ex vivo skin biopsies were treated topically with wound gels and cultured for 48 h. Enzyme-linked immunosorbent assays and an enzyme activity assay of culture supernatants revealed that octenilin® demonstrates significantly broader anti-inflammatory and protease-inhibitory capacities than other wound gels. Further, haematoxylin & eosin as well as caspase-3 staining of treated biopsies showed that octenilin® does not alter skin morphology and shows the least interfering effect on human epidermal cells compared to untreated controls. Overall, this study clearly demonstrates totally different effects for several commercially available hydrogels in our wound model, which gives also new insight into their tissue compatibility and mode of action.

A survey on current knowledge, practice and beliefs related to preoperative antimicrobial decolonization regimens for prevention of surgical site infections among Austrian surgeons.

BACKGROUND: Various measures are considered to reduce the risk of surgical site infection (SSI), including preoperative decolonization. Details of preoperative decolonization practices in surgical departments have not been investigated in Austria. AIM: To analyse the current situation of pre-surgical patient decolonization in national hospitals and to assess the current knowledge on this procedure among surgeons of different surgical disciplines. METHODS: A 12-point structured questionnaire was distributed to all Austrian hospitals with at least one surgical department. FINDINGS: Two-thirds (103/158; 65%) of responding surgeons stated that any type of preoperative decolonization is implemented in their surgical department. There was heterogeneity of different protocols, ranging from decolonization of only known S. aureus carriers, of a subgroup of patients, or universal decolonization of all patients before elective surgery. Octenidine was the most frequently used antimicrobial compound (60.2%), followed by mupirocin (38.8%), triclosan (14.6%), polyhexanide (12.6%), chlorhexidine (11.7%), and didecyldimonium chloride (7.8%). CONCLUSION: Preoperative decolonization seems to be performed in Austrian hospitals on a routine basis. However, this measure is implemented using a variety of modalities, antimicrobial compounds, and staff. Since our survey also demonstrated that those who are better informed about preoperative decolonization are also those who are more convinced of the usefulness of the preventive measure, future activities should not only focus on generating more comparable studies in this field, but should also include targeted education.

The effect of negative pressure wound therapy with antibacterial dressings or antiseptics on an in vitro wound model.

OBJECTIVE: The aim of this study was to investigate the bacterial bioburden in experimental in vitro wounds during the application of conventional negative pressure wound therapy (NPWT), with and without antimicrobial dressings (polyhexanide, silver), against NPWT instillation of octenidine. METHOD: Experimental wounds produced in an in vitro porcine wound model were homogenously contaminated with bacterial suspension and treated with NPWT and different options. Group A: non-antimicrobial polyurethane foam dressing; group B: antimicrobial polyurethane foam dressing containing silver; group C: antimicrobial gauze dressing containing polyhexanide; group D: non-antimicrobial polyurethane foam dressing intermittently irrigated with octenidine; group E: negative control (non-antimicrobial polyurethane foam dressing without NPWT). Standard biopsies were harvested after 24 and 28 hours. RESULTS: This study demonstrated that the use of NPWT with intermitted instillation of octenidine (group D) or application of silver-based polyurethane foam dressings (group B) is significantly superior against Staphylococcus aureus colonisation in experimental wounds compared with non-antimicrobial polyurethane foam dressing (group A) after 48 hours. Surprisingly, the polyhexanide-based dressing (group C) used in this model showed no statistical significant effect compared with the control group (group E) after 24 or 48 hours of treatment. CONCLUSION: Both intermitted instillation of octenidine and silver-based dressings in standard NPWT were significantly superior compared with non-antimicrobial polyurethane foam dressings or PHMB coated gauze dressing after 48 hours.

Outcomes for split-thickness skin transplantation in high-risk patients using octenidine.

Skin transplantation is a commonly used surgical technique; however, the complication rate, including postoperative infection and delayed wound healing due to inefficient perfusion, is significantly higher in patients suffering from comorbidities. Hence, a subsequent repeat procedure is often necessary. In this report, two case studies are presented in which an octenidine-based antiseptic is used with a tie-over dressing (TOD) instead of povidone iodine (PVP-iodine), following a split-thickness skin graft. The two patients selected were deemed to be at high risk of impaired wound healing due to comorbidities. The first patient, a confirmed smoker with diabetes, presented with a nodular melanoma that was resected and covered with a split-thickness skin graft. After 5 days of negative pressure wound therapy as a TOD, in combination with PVP-iodine, the graft became necrotic. A second split-thickness skin graft was performed and an antiseptic regimen with octenidine in combination with the same TOD resulted in a completely healed transplant. The second patient, also a confirmed smoker with diabetes and receiving oral corticosteroid treatment, was diagnosed with a skin necrosis on her leg. Following the split-thickness skin graft, octenidine and TOD were applied. The patient's skin graft completely healed without any adverse events. These two case studies indicate that the combination of octenidine and TOD following split-thickness skin transplantation is safe, well-tolerated and appears to have positive benefits in the reconstruction of defects in patients with impaired wound healing.

The combined use of NPWT and instillation using an octenidine based wound rinsing solution: a case study.

Effective wound bed preparation is an essential element in the healing of chronic wounds, including pressure ulcers (PUs). Negative pressure wound therapy (NPWT) reduces oedema, stimulates the formation of granulation tissue and helps remove wound exudate. This helps prepare the wound bed for secondary healing, skin grafting or coverage with flaps. Combining NPWT with an instillation phase using an antiseptic (octenidine based) irrigation solution is a novel approach to PU management. Three patients with Category 4 gluteal PUs were treated with NPWT and instillation fluid, following surgical debridement of necrotic tissue. The aim was to achieve optimal wound bed preparation prior to wound closure by local fasciocutaneous flap. The antiseptic efficacy of octenilin wound irrigation solution in microorganism eradication was quantified by in vitro tests simulating real conditions using leg ulcer vacuum exudates. All wounds completely healed after four weeks, and no adverse incidents occurred due to instillation of octenidine. No recurrence of the PU occurred during a one year follow-up.

Hypersensitivity for capsaicin in patients with functional dyspepsia.

The pathophysiology of functional dyspepsia is poorly understood, thus diagnostic and therapeutic options for this disease are limited. We assessed the relevance of a simple test for chemical hypersensitivity by applying an oral capsaicin load. After a preliminary dose-finding study, 61 healthy controls and 54 functional dyspepsia patients swallowed a capsule containing 0.75 mg capsaicin. A graded questionnaire evaluated severity of symptoms before and after capsule ingestion; an aggregate symptom score was calculated by adding all symptom scores. Controls developed moderate symptoms (symptom score: 6.0+/-4.1; median: 5.0). The 75% quartile (9.0) was considered the upper limit of normal. Functional dyspepsia patients had significantly higher symptom scores (10.0+/-6.5) than controls. About 54% of functional dyspepsia patients tested positive; clinically this group was not different from the group testing negative besides being on average younger and suffering more from bloating. In additional 13 patients with functional dyspepsia who tested positive (symptom score: 15.8+/-0.9), symptom response to placebo capsules (1.9+/-0.6) was similar to controls. In reliability testing, the Cronbach alpha-value of the capsaicin test was 0.86. The capsaicin test is a simple and non-invasive method to detect a subgroup of functional dyspepsia with chemical hypersensitivity.