Benjamin A. Lipsky, Anthony R. Berendt, Paul B. Cornia, James C. Pile, Edgar J. G. Peters, David G. Armstrong, H. Gunner Deery, John M. Embil, Warren S. Joseph, Adolf W. Karchmer, Michael S. Pinzur, and Eric Senneville
Foot infections are a common and serious problem in persons with diabetes. Diabetic foot infections (DFIs) typically begin in a wound, most often a neuropathic ulceration. While all wounds are colonized with microorganisms, the presence of infection is defined by ≥2 classic findings of inflammation or purulence. Infections are then classified into mild (superficial and limited in size and depth), moderate (deeper or more extensive), or severe (accompanied by systemic signs or metabolic perturbations). This classification system, along with a vascular assessment, helps determine which patients should be hospitalized, which may require special imaging procedures or surgical interventions, and which will require amputation. Most DFIs are polymicrobial, with aerobic gram-positive cocci (GPC), and especially staphylococci, the most common causative organisms. Aerobic gram-negative bacilli are frequently copathogens in infections that are chronic or follow antibiotic treatment, and obligate anaerobes may be copathogens in ischemic or necrotic wounds.
Wounds without evidence of soft tissue or bone infection do not require antibiotic therapy. For infected wounds, obtain a post-debridement specimen (preferably of tissue) for aerobic and anaerobic culture. Empiric antibiotic therapy can be narrowly targeted at GPC in many acutely infected patients, but those at risk for infection with antibiotic-resistant organisms or with chronic, previously treated, or severe infections usually require broader spectrum regimens. Imaging is helpful in most DFIs; plain radiographs may be sufficient, but magnetic resonance imaging is far more sensitive and specific. Osteomyelitis occurs in many diabetic patients with a foot wound and can be difficult to diagnose (optimally defined by bone culture and histology) and treat (often requiring surgical debridement or resection, and/or prolonged antibiotic therapy). Most DFIs require some surgical intervention, ranging from minor (debridement) to major (resection, amputation). Wounds must also be properly dressed and off-loaded of pressure, and patients need regular follow-up. An ischemic foot may require revascularization, and some nonresponding patients may benefit from selected adjunctive measures. Employing multidisciplinary foot teams improves outcomes. Clinicians and healthcare organizations should attempt to monitor, and thereby improve, their outcomes and processes in caring for DFIs.
BACKGROUND: Diabetic Foot Osteomyelitis (DFO) is a common infection where treatment involves multiple services including Infectious Disease (ID), Podiatry, and Pathology. Despite its ubiquity in the hospital, consensus on much of its management is lacking. METHODS: Representatives from ID, Podiatry, and Pathology interested in quality improvement (QI) developed multidisciplinary institutional recommendations culminating in an educational intervention describing optimal diagnostic and therapeutic approaches to DFO. Knowledge acquisition was assessed by pre- and post-intervention surveys. Inpatients with forefoot DFO were retrospectively reviewed pre- and post- intervention to assess frequency of recommended diagnostic and therapeutic maneuvers, including appropriate definition of surgical bone margins, definitive histopathology reports, and unnecessary intravenous antibiotics or prolonged antibiotic courses. RESULTS: A post-intervention survey revealed significant improvements in knowledge of antibiotic treatment duration and the role of oral antibiotics in managing DFO. There were 104 consecutive patients in the pre-intervention cohort (4/1/2018-4/1/2019) and 32 patients in the post-intervention cohort (11/5/2019-03/01/2020), the latter truncated by changes in hospital practice during the COVID-19 pandemic. Non-categorizable or equivocal pathology reports decreased from pre-intervention to post-intervention (27.0% vs 3.3%, respectively, P=0.006). We observed non-significant improvement in correct bone margin definition (74.0% vs 87.5%, p=0.11), unnecessary PICC line placement (18.3% vs 9.4%, p=0.23), and unnecessary prolonged antibiotics (21.9% vs 5.0%, p=0.10). Additionally, by working as an interdisciplinary group, many solvable misunderstandings were identified, and processes were adjusted to improve the quality of care provided to these patients. CONCLUSIONS: This QI initiative regarding management of DFO led to improved provider knowledge and collaborative competency between these three departments, improvements in definitive pathology reports, and non-significant improvement in several other clinical endpoints. Creating collaborative competency may be an effective local strategy to improve knowledge of diabetic foot infection and may generalize to other common multidisciplinary conditions.