2025 Southeastern Residency Conference

Title: Carbapenem Stewardship: Reducing Overuse in Empiric Treatment Strategies

Authors: Reshma Patel, Kristina Nakhla, Michael Saxon, Melissa Letzin 

Objective: This study aims to retrospectively evaluate carbapenem utilization across Northside Hospital’s five campuses to assess adherence to current Northside Hospital defined criteria, refine prescribing practices and reduce carbapenem overutilization.

Background: Carbapenems, a broad-spectrum class of antibiotics, are often overutilized in inpatient settings. While carbapenems are effective as a primary treatment option for infections caused by extended spectrum β-lactamase (ESBL)-producing bacteria, their overuse has raised concerns about developing carbapenem-resistant organisms. Establishing and adhering to appropriate carbapenem prescribing criteria is necessary to support effective stewardship.

Methods: This multi-center, randomized, retrospective chart review included patients 18 years or older, admitted to the inpatient medical-surgical floor at Northside Hospital campuses and received more than one dose of empiric carbapenem therapy from July 2023 through July 2024. Patients who received a single carbapenem dose in the emergency department, admitted to the intensive care unit (ICU), or on bone marrow transplant (BMT) service were excluded. The primary objective was to assess the appropriateness of carbapenem therapy based on current Northside Hospital defined criteria. Secondary objectives included evaluating average days of therapy for carbapenems, average days of therapy for total antibiotics, percentage of patients with confirmed ESBL isolates, and percentage of patients with confirmed multi-drug-resistant organism (MDRO) infections. 

Results: The retrospective review of 150 eligible patients indicated significant overutilization of carbapenems across all Northside Hospital campuses. The study population consisted of 57% (86/150) females and 43% (64/150) males. Only 48% (72/150) of patients met the appropriate criteria for carbapenem therapy. 52% (78/150) of patients did not meet the appropriate criteria for carbapenem therapy. The most commonly treated infections in the patients that met appropriate criteria for carbapenem prescribing were urinary tract infections (35%), intra-abdominal infections (24%), empiric coverage for sepsis (11%). The most commonly treated infections in the patients that did not meet appropriate criteria for carbapenem prescribing were urinary tract infections (36%), intra-abdominal infections (35%), and bacteremia (25%). The average duration of carbapenem therapy was 6.5 days, while the average duration for total antibiotic therapy was 7.6 days in patients with confirmed ESBL/MDRO infections. The average duration of carbapenem therapy was 5.8 days, while the average duration for total antibiotic therapy was 7.9 days in patients with no ESBL/MDRO infection or negative culture. Confirmed ESBL isolates were identified in 6% (9/150) of patients. Confirmed MDRO were identified in 5% (7/150).

Conclusion: This study highlights overutilization of carbapenem therapy across Northside Hospital campuses outside of the ICU, BMT service and single doses in the emergency department. With 48% of patients meeting appropriate criteria for its use, the findings suggest opportunities to optimize prescribing practices when initiating antimicrobial therapy. A majority of carbapenems were ordered without meeting clinical indications. Implementing standardized protocols and reinforcing antimicrobial stewardship across all campuses could enhance the appropriate use of carbapenems while reducing the risk of resistance and improving patient outcomes.