Recherche de publication

Antibacterial activity of dressings containing antimicrobials is mostly evaluated using in vitro tests. However, the various methods available differ significantly in their properties and results obtained are influenced by the method selected, micro-organisms used, and extraction method, the degree of solubility or the diffusability of the test-compounds. Here, results on antimicrobial activity of silver-containing dressings obtained by agar diffusion test (ADT), challenge tests (JIS L 1902, AATCC 100), and extraction-based methods (microplate laser nephelometry (MLN), luminescent quantification of bacterial ATP (LQbATP)) using Staphylococcus aureus and Pseudomonas aeruginosa were evaluated. Furthermore, the effect of the pH on antibacterial efficacy of these dressings was investigated. All silver-containing dressings exerted antimicrobial activity in all in vitro tests and results correlated considerably well. Differences were observed testing the agent-free basic materials. They did not exhibit any antimicrobial effects in the ADT, MLN or LQbATP, since these methods depend on diffusion/extraction of an active agent. However, they showed a strong antimicrobial effect in the challenge tests as they possess a high absorptive capacity, and are able to bind and sequester micro-organisms present. Therefore, it seems recommendable to choose several tests to distinguish whether a material conveys an active effect or a passive mechanism. In addition, it could be shown that release of silver and its antimicrobial efficacy is partially pH-dependent, and that dressings themselves affect the pH. It can further be speculated that dressings' effects on pH and release of silver ions act synergistically for antimicrobial efficacy.

This document is a practical guide to the management of hyperkeratosis of the lower limb for all healthcare professionals involved in the care of patients with hyperkeratosis or those who are at risk of developing the condition, such as specialist nurses, district nurses, practice nurses, GPs, and podiatrists.

It offers pragmatic clinical recommendations for all aspects of care and introduces a novel, stepped approach to management, covering assessment, treatment and management of patients with hyperkeratosis, prevention of recurrence, and prophylactic measures for patients who may be at risk of developing the condition. The document also presents outcome measures that can be used to assess the efficacy of prevention and treatment interventions.

There is currently no standardised strategy or evidence-based national guideline for the management of hyperkeratosis and the condition is poorly represented generally in the medical literature. This document is therefore based on the best available evidence, supported by the consensus opinion of an expert working group of key opinion leaders from a wide range of disciplines, including lymphoedema, wound care, diabetes, dermatology and general practice. It aims to build on the success of the All Wales guidance on hyperkeratosis, which drew largely from the experience of its Tissue Viability Nurse Forum (AWTVNF, 2014).

In producing consensus recommendations, the expert working group recognises the many challenges facing healthcare professionals in this field, such as time constraints hindering a holistic approach, lack of cohesive national or local strategies for managing hyperkeratosis, and limited experience with newer, more efficacious technologies.

With these issues in mind, this document seeks to improve understanding of hyperkeratosis and equip healthcare professionals with the knowledge and skills necessary to recognise and treat this chronic condition effectively.

Caroline Dowsett, Chair

Aim:

Debridement and removal of biofilm is a major challenge in treatment of patients with chronic wounds. Surgical debridement requires trained personal, operation theatre and is often associated with pain but conventional methods relaying on cotton gauze may not be enough. A monofilament debrider* consisting of polyester fibres presents a fast and almost painless option for debridement. Hence, we have investigated the capacity of this monofilament debrider* to remove biofilm in vitro and compared it to cotton gauze**.

Methods:

For the wound debridement model, a S.aureus biofilm is cultivated on glass plates. The monofilament debrider* and conventional cotton gauze** were used to debride/clean the glass plates under standardized conditions (p=0.067N/cm2, v=1.6cm/s). Afterwards, the glass plates were stained with crystal violet to visualize the bacteria residuals. Plate images were obtained and all images were processed using ImageJ 1.45m.

Results:

Monofilament debrider* and cotton gauze** initially exhibited a comparable cleansing performance. However, the monofilament debrider* demonstrated a significantly higher cleansing capacity. While the monofilament debrider’ was able to achieve a retained high reduction of the biofilm over wiping several plates, gauze** quickly lost its efficacy.

Conclusions: The reduction of biofilm achieved using the monofilament debrider* is significantly higher than that of cotton gauze**. Moreover, it presents a non-invasive and therefore almost painless alternative to other. Hence, this technique should provide a valuable tool in the treatment of patients with chronic wounds to improve the quality of life as well as to safe costs.