2025 Southeastern Residency Conference

Title: Impact of Oral Antibiotics on Length of Stay in Patients with Gram-Negative Rod Bacteremia
 
Authors: Katlyn Womble, Marcus Mize, Serina Tart


Objective: To compare the length of hospital stay (LOS) in days in patients with gram-negative rod (GNR) bacteremia who are transitioned to oral antibiotics to complete treatment versus patients who receive intravenous (IV) antibiotics for the duration of therapy.


Methods: Eligible patients were those aged ≥18 years old, admitted to a hospital within the health system from January 2023 – December 2023 with documented GNR bacteremia, and received antibiotic therapy for ≥48 hours. Patients with polymicrobial infections, multi-drug resistant (MDR) or extended-spectrum beta-lactamase (ESBL) organisms, were unable to tolerate oral medications, had an infection or predisposing condition that would require IV therapy, or received >14 days of IV therapy were excluded. Data was collected through chart review on the electronic health record system. The primary outcome was the difference in LOS between patients who were transitioned to oral therapy compared to those who remained on IV therapy for the duration of treatment. Secondary outcomes included percentage of treatment failure in each group, the difference in total duration of antibiotic therapy between groups, and the difference in LOS between patients who were transitioned to oral therapy early (defined as ≤4 days from start of appropriate antibiotics) compared to those who were transitioned to oral therapy late.


Results: Of the 388 patients reviewed, 176 patients were excluded with the most common reason being polymicrobial infection. A total of 208 patients were included, with 168 being transitioned to oral antibiotics and 40 receiving IV antibiotics for the duration of therapy. Of those included, 65.4% were female and the average age was 64.9 years in the oral group, compared to 71.5 years in the IV group. Of those in the oral group, 11.9% had an indwelling device and 6% were immunocompromised, compared to 15% and 10% in the IV group, respectively. The majority of patients had a urinary infection source, with the most common isolated organism being Escherichia coli. The most common parenteral antibiotic administered was ceftriaxone, with most patients in the oral group being transitioned to cefdinir. The average length of stay was 18.7 (±17.3) days in the IV group, compared to 6.3 (±12.0) days in the oral group (95% CI -18.2 to -6.6, p < 0.0001). Average duration of therapy in the IV group was 11.4 (±3.0) days, compared to 13.0 (±3.0) days in the oral group (95% CI 0.53 to 2.65, p=0.0039). Among patients in the oral group, the average length of stay was 5.6 (±17.8) days in those transitioned to oral therapy early, compared to 6.9 (±4.0) days in those who were not (95% CI -5.6 to 3.0, p =0.5606).  Treatment failure was low in both groups, occurring in 4.2% patients in the oral group versus 10% in the full IV group (p = 0.1708).


Conclusions: Among patients with GNR bacteremia, those who were transitioned to oral antibiotics had a significantly shorter LOS compared to those remaining on IV therapy, although duration of therapy was significantly longer. Within the oral therapy group, LOS was significantly shorter in those transitioned to oral antibiotics early. Although the results of this study are descriptive, it further supports current evidence demonstrating that oral antibiotics may be effective in patients with uncomplicated GNR bacteremia and may shorten hospital LOS. Limitations of this study include the small number of patients who were immunocompromised or had indwelling devices, limiting application to these populations, and the small rate of treatment failure which prevents the outcome from being analyzed for statistical significance. More studies should be conducted to include broader patient populations and further analyze the effect that transitioning to oral antibiotics may have on treatment failure rates.