SLR - December 2023 - Hobbs
Title: Empirical Antibiotic Therapy in Diabetic Foot Ulcer Infection Increases HospitalizationReference: Schmidt BM, Kaye KS, Armstrong DG, Pop-Busui R. Empirical Antibiotic Therapy in Diabetic Foot Ulcer Infection Increases Hospitalization. Open Forum Infect Dis. 2023 Oct 5;10(10)
Level of Evidence: Level III
Reviewed By: Madeline Hobbs, DPM
Residency Program: John Peter Smith Hospital, Forth Worth, TX
Podiatric Relevance: Diabetic foot ulcer (DFU) infections are a common occurrence in both out- and inpatient podiatric settings. There is often an urge to treat such infections with broad spectrum antibiotics and forego cultures, particularly with mild foot infections that may be without purulent drainage. In addition, recent IDSA recommendations have stated that culturing mild DFU infections may not be necessary. The authors of this article have highlighted that the previous recommendations may have been made on low-quality evidence, and call for the need to provide data on the effects of treating DFU infections with empirical versus culture-guided antibiotics.
Methods: A level III retrospective cohort study was performed from January-December 2019 in adults diagnosed with acute DFU infection in a clinic setting. DFU infections were categorized by the IDSA Diabetic Foot Infection guidelines as mild, moderate, or severe. A total of 116 patients were included, 39 of which were treated with empiric antibiotics (not based on microbiological cultures results), and 77 that received culture-guided antibiotics (based on tissue culture data including gram stain). The primary outcome measured was 30-day hospitalization rates after initial DFU infection diagnosis. Secondary outcomes measured included rates of lower extremity amputation, as well as rates of death 1 year after initial diagnosis.
Results: Of the 116 individuals with a new diagnosis of DFU infection, 68% had IDSA-mild infection, 26% IDSA-moderate, and 6% IDSA-severe infection. Without analyzing the DFU infections based on infection classification, there was no significant difference seen with rates of hospitalization between the empiric vs. culture-guided antibiotic therapies (51% and 38% hospitalized, respectively). When stratified based on IDSA severity, there was a significant difference seen with the IDSA-mild group, in which 52% of those empirically treated were hospitalized within 30 days, whereas 28% with culture-guided therapy were. There was no significant difference in hospitalization rates for moderate and severe DFU infections. There was no significant difference in rates of lower extremity amputations (total 24%) or death within 1 year of diagnosis (total 7%) within the treatment groups.
Conclusions: Individuals with mild DFU infections treated with empirical antibiotics are at 1.87 higher risk of being hospitalized within 30 days compared to those treated with culture-guided antibiotics. Data found suggests use of tissue culture-guided antibiotic therapy can reduce risk of hospitalization for individuals with acute, IDSA-mild DFU infection treated in outpatient setting. Study limitations include research being done at one single academic facility, small sample size, and researchers did not account for decision-making process for patient admission to hospital. Future research is warranted on the topic with special attention paid to method of culture collection (swab versus deep tissue), specific antibiotics used, and level of soft tissue infection involvement with rates of hospitalization after diagnosis of acute DFU infection.