Rationalization of Carbapenem Use and Reduction of Bacterial Resistance: Impact of a Stewardship Program in an Intensive Care Unit

The emergence of carbapenemase-producing Enterobacterales (CPE) represents a growing challenge in hospital settings, exacerbated by inappropriate antimicrobial use and failures in preventive measures. Stewardship programs have proven effective strategies for rationalizing antibiotic use and containing bacterial resistance. This study evaluated the effectiveness of a stewardship program initiated in 2022, focusing on meropenem consumption and its association with CPE identification in blood cultures from ICU patients between 2022 and 2025. A retrospective observational study conducted in a private hospital in São Paulo. The program was implemented in a multidisciplinary manner, involving the Hospital Infection Control Service (SCIH), medical staff, clinical pharmacy, and microbiology, with institutional support. Prospective monthly audits were conducted for critical antimicrobials, and retrospective audits for meropenem, among others. Consumption was monitored by DDD and DOT. Average duration of use was tracked, with SCIH alerts for prescriptions exceeding 10 days. Escalation and de-escalation adequacy based on cultures and infectious disease review were also assessed. Between 2022 and 2025, ICU meropenem consumption decreased by approximately 41% (from 185.34 to 110.03 DDD). Since 2023, average duration of antimicrobial use has remained below 10 days. Appropriateness of meropenem escalation based on collected cultures exceeded 90%, while de-escalation adequacy remained above 85%. These data were periodically presented to the care team in SCIH meetings, promoting engagement and adherence to the program. Reduced meropenem use coincided with decreased CPE identification in ICU blood cultures. Additionally, reduced consumption of amphotericin and linezolid was observed, as well as more judicious prescribing of high-cost antimicrobials such as ceftazidime–avibactam and ceftolozane–tazobactam. Implementation of a continuous stewardship program with systematic audits and interprofessional communication was effective in reducing carbapenem use and CPE incidence in the ICU. Results highlight the value of collaborative strategies to optimize antimicrobial use, contain bacterial resistance, and strengthen sustainability.