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 12.3 cm². At week 8, the bioburden had reduced to < 105 cfu/g in 54.2% of patients, with 41.7% achieving this reduction by week 2. At week 8, the median reduction was 0.7 log¹⁰ (p < 0.001). The median percentage reductions in bioburden were 50.5%, 56.8% and 80.4% at weeks 2, 4 and 8 respectively. Over the study period, 79.2% of the patients had > 75% 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.