In vivo effect of sustained-release silver sulphadiazine foam on bioburden and wound closure in infected venous leg ulcers

Objective: To determine the in vivo effect of a sustained-release silver sulphadiazine powder foam dressing on the bacterial burden of venous leg ulcers (VLUs), with a view to correlating the wound closure rate with the degree of bioburden and to assess other markers of its progression towards healing. Method: Patients attending a tertiary care wound practice were screened for a VLU bacterial count of >105 colony forming units (cfu/g) per gram of tissue. Patients were treated with the above topical dressing plus multilayer compression bandaging for 12 weeks. Quantitative cultures were taken at weeks 0, 2, 4 and 8. Wounds were assessed at each weekly visit using photography and planimetry. Results: Twenty-four of the 33 screened patients met the inclusion criteria. The average baseline wound size was 12.3cm2. At week 8, the bioburden had reduced to 5cfu/g in 54.2% of patients, with 41.7% achieving this reduction by week 2. At week 8, the median reduction was 0.7log10 (p75% wound area reduction and 45.8% achieved ulcer closure in a median of 80.5 days. Conclusion: Although the wound size and bacterial counts reduced significantly, there was no statistical correlation between the two. Nevertheless, the in vivo data show that this active antimicrobial dressing was associated with a very high healing rate in these hard-to-heal wounds. Conflict of interest: This research was supported by a grant from Smith & Nephew, Hull, UK. In addition, the principal investigator receives other grants from Smith & Nephew, Hull, UK.