Title: Evaluation of the impact of lower extremity wound order set revision
Authors: Katie Hindman, Adesuwa Utomwen, Dustin Zeigler, Jeremy Frens
Objective: Discuss the utilization of an updated lower extremity wound order set
Self-Assessment Question:
- True or False: The updated lower extremity wound order set had numerically increased adherence compared to the prior order set.
Background: Diabetic foot infections (DFIs) pose a significant threat to quality of life, being a leading cause of non-traumatic lower extremity amputations. Therefore, it is essential to utilize effective antibiotics to treat these infections. The International Working Group on the Diabetic Foot (IWGDF) and Infectious Diseases Society of America (IDSA) published updated guidelines in 2023, advising that empiric coverage for
Pseudomonas aeruginosa is not necessary in Western countries and temperate climates. A prior systematic review on the epidemiology of
P. aeruginosa in DFIs found a global prevalence of 16.6%, with the lowest prevalence of 11.1% being in Western countries. A review of patients at our institution, Cone Health, with toe and/or foot amputation(s), supported these findings with only 1.7% of cultures identifying
P. aeruginosa. The most isolated pathogens were
Staphylococcus aureus and coagulase-negative Staphylococcus species. The lower extremity wound order set at Cone Health was modified, removing empiric
P. aeruginosa coverage due to its low incidence. The purpose of this study is to evaluate prescriber compliance with the updated order set and assess microbiological concordance between prescribed empiric therapy and cultured pathogens following the modifications.
Methods: This was an IRB approved, determined exempt, retrospective cohort analysis of individuals with diabetic foot infections at a single health system encompassing four community hospitals. The revised order set went live in February 2025. The review spanned a pre-intervention cohort from June to December 2024 and a post-intervention cohort from June to November 2025. Adults aged 18 years or older with confirmed DFI with or without osteomyelitis were included in this study. Those individuals admitted to the intensive care unit or with the presence of chronic foot ulceration were excluded. Infection-related information collected included wound classification, utilization of order set, inpatient antibiotics utilized, duration of antibiotics, type of amputation, culture results, pathology results and discharge antibiotics. The primary outcome of this study is adherence to order set recommendations, defined as aligning with the antibiotic recommendations per infection severity. Secondary outcomes include proportion of patients with microbiological match to empiric antibiotics, 30-day mortality rate and 30-day readmission rate.
Results: The post-intervention cohort demonstrated a modest increase in adherence to lower extremity wound order set recommendations compared to the pre-intervention cohort (34% vs 30%, p=0.55). Among patients with available culture data, all 17 individuals in the pre-intervention cohort received empiric antibiotics concordant with culture results compared to 26 of 30 patients (87%) in the post-cohort (p=0.075).
Streptococcus species were the most commonly isolated gram-positive organisms in both cohorts (10 cases in the pre-cohort and 11 in the post-cohort). There was a higher prevalence of
Proteus mirabilis and
Enterobacter cloacae in the post-cohort, but these organisms demonstrated minimal resistance to penicillins and cephalosporins. The use of vancomycin and cefepime decreased from the pre- to post-intervention period, while utilization of linezolid and ampicillin/sulbactam increased.
Conclusion: The revised lower extremity wound order set was associated with a numerically higher rate of adherence compared to the prior version, with approximately half of providers in each cohort utilizing the order set. Empiric antibiotics demonstrated microbiological match in most cases. The organisms cultured in this study align with those typically observed in DFIs in the United States. The updated order set represents an advancement in antimicrobial stewardship in DFIs through the inclusion of preferred alternatives. Limitations of this study include variability in obtainment of pathology and cultures between providers as well as a small sample size. Future directions include reinforcing appropriate utilization of the DFI order set and evaluating discharge antibiotic therapy to assess the potential benefit of creating standardized recommendations.
