Optimization of the antibiotic management of diabetic foot infections: protocol for two randomized controlled trials

BACKGROUND: Few studies have addressed the appropriate duration of antibiotic therapy for diabetic foot infections (DFI) with or without amputation. We will perform two randomized clinical trials (RCTs) to reduce the antibiotic use and associated adverse events in DFI. METHODS: We hypothesize that shorter durations of postdebridement systemic antibiotic therapy are noninferior (10% margin, 80% power, alpha 5%) to existing (long) durations and we will perform two unblinded RCTs with a total of 400 DFI episodes (randomization 1:1) from 2019 to 2022. The primary outcome for both RCTs is remission of infection after a minimal follow-up of 2 months. The secondary outcomes for both RCTs are the incidence of adverse events and the overall treatment costs. The first RCT will allocate the total therapeutic amputations in two arms of 50 patients each: 1 versus 3 weeks of antibiotic therapy for residual osteomyelitis (positive microbiological samples of the residual bone stump); or 1 versus 4 days for remaining soft tissue infection. The second RCT will randomize the conservative approach (only surgical debridement without in toto amputation) in two arms with 50 patients each: 10 versus 20 days of antibiotic therapy for soft tissue infections; and 3 versus 6 weeks for osteomyelitis. All participants will have professional wound debridement, adequate off-loading, angiology evaluation, and a concomitant surgical, re-educational, podiatric, internist and infectiology care. During the surgeries, we will collect tissues for BioBanking and future laboratory studies. DISCUSSION: Both parallel RCTs will respond to frequent questions regarding the duration of antibiotic use in the both major subsets of DFIs, to ensure the quality of care, and to avoid unnecessary excesses in terms of surgery and antibiotic use. TRIAL REGISTRATION: ClinicalTrials.gov, NCT04081792. Registered on 4 September 2019.