Abstract: Incidence of Pathogens in First Episode of Diabetic Foot Infections and Frequency of Empiric Coverage of Pathogens in Emergency Department and on Hospital Admission: A Retrospective Cohort Study.
Diabetic foot infections (DFIs) are a common complication of diabetes mellitus and a leading cause of hospitalization. Due to the polymicrobial nature of these infections and delays in aerobic and anaerobic culture results, patients are often started on broad-spectrum antibiotics, which may lead to unnecessary antimicrobial use. The purpose of this study was to assess the incidence of methicillin-resistant Staphylococcus aureus (MRSA), Pseudomonas aeruginosa, and anaerobic organisms in DFIs. Secondary endpoints evaluated the frequency of empiric antibiotic coverage for these organisms in both the emergency department (ED) and on initial hospital admission.
This single-center retrospective study reviewed medical records over a five-year period for patients admitted with an initial DFI. The incidence of positive cultures for MRSA, Pseudomonas, and anaerobic organisms was compared with the frequency of empiric antimicrobial coverage for each. The incidence of these organisms was also compared between patients with and without hospitalization within the prior 90 days.
Of the 184 patients in the study, 102 patients (55.43%) had cultures positive for one or more of the following: MRSA (17.0%), Pseudomonas (5.40%), and/or anaerobic organisms (45.10%). In the ED, 117 patients (63.59%) were treated empirically for MRSA, 111 patients (60.30%) were treated empirically for Pseudomonas, and 82 patients (44.60%) were treated empirically for anaerobes. On admission, 164 patients (89.10%) were treated empirically for MRSA, 140 patients (76.10%) were treated empirically for Pseudomonas, and 115 patients (62.50%) were treated empirically for anaerobes.
The study demonstrated rates of MRSA and Pseudomonas consistent with prior literature. However, rates of anaerobic organisms, which have historically been less studied in DFIs, were prominent. Despite this, empiric antimicrobial coverage for anaerobes was lowest among the organisms studied. This study may help guide clinicians in considering organism incidence and in selecting empiric parenteral antibiotic therapy.
This single-center retrospective study reviewed medical records over a five-year period for patients admitted with an initial DFI. The incidence of positive cultures for MRSA, Pseudomonas, and anaerobic organisms was compared with the frequency of empiric antimicrobial coverage for each. The incidence of these organisms was also compared between patients with and without hospitalization within the prior 90 days.
Of the 184 patients in the study, 102 patients (55.43%) had cultures positive for one or more of the following: MRSA (17.0%), Pseudomonas (5.40%), and/or anaerobic organisms (45.10%). In the ED, 117 patients (63.59%) were treated empirically for MRSA, 111 patients (60.30%) were treated empirically for Pseudomonas, and 82 patients (44.60%) were treated empirically for anaerobes. On admission, 164 patients (89.10%) were treated empirically for MRSA, 140 patients (76.10%) were treated empirically for Pseudomonas, and 115 patients (62.50%) were treated empirically for anaerobes.
The study demonstrated rates of MRSA and Pseudomonas consistent with prior literature. However, rates of anaerobic organisms, which have historically been less studied in DFIs, were prominent. Despite this, empiric antimicrobial coverage for anaerobes was lowest among the organisms studied. This study may help guide clinicians in considering organism incidence and in selecting empiric parenteral antibiotic therapy.