An Investigation into the Ability of an Antimicrobial Dressing with Soft Silicone to Prevent Microbial Re-growth

Objective:

This poster reports on the results of a study that was undertaken to evaluate the antimicrobial activity of antimicrobial dressings against the native skin microflora.

Methods:

Chlorhexidine/silver-containing soft silicone adhesive film dressings, film dressings with a chlorhexidine gel pad and non-antimicrobial film dressings were applied to the skin on the backs of healthy human volunteers after a baseline antimicrobial prepping procedure. Dressings were removed 4 or 7 days after application. The bacterial populations underneath centre and off-centre sites were measured by quantitative cultures and compared with one another.

Results:

The mean log reductions (log₁₀ CFU/cm²) measured underneath the central portion of chlorhexidine/silver-containing dressings were 0.30 and -0.08 on days 4 and 7, respectively, compared with log reductions of 0.04 and -0.25 from underneath the centre of the chlorhexidine-containing pad/film dressings and -2.90 and -3.38 from underneath the centre of the control film dressings. Mean log reductions (log₁₀ CFU/cm²) for off-centre sites of chlorhexidine/silver-containing dressings were -0.20 and -0.68 on days 4 and 7, respectively, compared with log reductions of -1.76 and -1.99 from underneath the chlorhexidine-containing pad/film dressings and -2.81 and -3.40 from underneath the control film dressings. There was no significant difference on days 4 and 7 between the log reductions of the two antimicrobial dressings at central site, but the off-centre log reduction associated with the chlorhexidine/silver-containing dressing was significantly higher than that associated with the chlorhexidine-containing pad/film dressing.

Conclusion:

The incorporation of chlorhexidine and silver into the soft silicone adhesive layer of the antimicrobial dressing offers antimicrobial benefit across the entire surface of the dressing for up to 7 days whereas bacterial proliferation is seen under the chlorhexidine-containing pad/film dressing at the adhesive border from day 4.