A randomised, double-blinded, placebo-controlled trial is being conducted in Tropical North Queensland, Australia, to evaluate the effectiveness of oral clindamycin and bacterial load reduction as prophylactic measures against surgical site infections (SSI) following skin cancer excisions below the knee. The study addresses the high incidence of SSI in this region, particularly in complex flap and graft surgeries, despite current Australian guidelines not recommending routine antibiotic prophylaxis.
Study Design and Interventions
The trial, registered with the Australian New Zealand Clinical Trials Registry (ACTRN12624000076572), involves 155 participants aged over 18 years undergoing surgical management of skin cancer below the knee requiring flap or graft repair. Participants are randomised into one of three arms:
- Bacterial Load Reduction: Nasal screening for Staphylococcus aureus carriage, followed by nasal mupirocin ointment for positive cases, and all-over chlorhexidine body wash preoperatively, plus placebo antibiotics.
- Clindamycin: 450 mg oral clindamycin administered 30–60 minutes preoperatively and again six hours postoperatively, along with placebo bacterial load reduction.
- Control: Placebo oral capsules, placebo wash, and placebo ointment, mimicking the timing of active treatments in the other arms.
Methodology and Outcome Measures
Patients are excluded if they have allergies to clindamycin, chlorhexidine, or mupirocin, existing skin infections, peripheral vascular disease, diabetes, current antibiotic use, or clinical indications for antibiotic treatment. The primary outcome is the incidence of postoperative SSI, determined according to a modified version of the CDC definition, assessed at suture removal (day 14) and via follow-up telephone call at 28 days. Secondary outcomes include adverse reactions to the interventions, microbiology of infected wounds, patterns of antibiotic resistance, and cost-effectiveness.
Data Analysis and Ethical Considerations
Data collected includes patient demographics, surgical details, and any complications. Statistical analysis will involve chi-squared testing and multiple logistic regression to compare infection incidence between groups, accounting for clinic and surgeon variations. The study has been approved by the Queensland Health Human Research Ethics Committee (approval number 50257), ensuring participant privacy and confidentiality.
Significance and Potential Impact
Given the global health priority of antibiotic resistance and Australia's relatively high antibiotic consumption, this trial seeks to reduce antibiotic prescribing through innovative bacterial load reduction strategies. If either intervention proves successful, it could lead to changes in clinical practice, reducing patient morbidity and promoting antibiotic stewardship. The trial's pragmatic design allows for immediate translation of findings into clinical practice, potentially benefiting a wide range of settings beyond the tropical rural environment where the study is conducted.
