4CPS-194 Analysis of interventions implemented in an antimicrobial stewardship program in a surgical critical care unit

<h3>Background and Importance</h3> The appropriate use of antimicrobials remains a major challenge in critical care units, and antimicrobial stewardship programs (ASP) are essential to improve clinical outcomes and reduce antimicrobial resistance. The involvement of the clinical pharmacist plays a key role in promoting the rational use of these agents. <h3>Aim and Objectives</h3> To describe and analyze the interventions carried out within the ASP in the surgical intensive care unit (SICU) and post-anaesthesia recovery unit (PACU) of a tertiary hospital during 2023 and 2024. <h3>Material and Methods</h3> A multidisciplinary ASP team was established in the SICU and PACU, comprising anaesthesiologists, an infectious disease specialist, and a clinical pharmacist. All ongoing antimicrobial treatments in the SICU and PACU were reviewed once a week, and those identified as candidates for intervention or optimisation were discussed with the prescribing physician, according to the empirical infection treatment protocol implemented in the hospital in 2024. All interventions recorded during 2023 and 2024 were included in this study. <h3>Results</h3> In 2023, 38 meetings were held, reviewing 177 treatments. A total of 101 interventions were performed, the most frequent being treatment discontinuation (50 cases, 49.5%), therapeutic de-escalation (21 cases, 20.7%), and therapeutic escalation (15 cases, 14.8%). The most frequently prescribed antimicrobials were piperacillin/tazobactam (18%), meropenem (16.8%), and metronidazole (12.4%), followed by ceftriaxone (9.1%). In 2024, 44 meetings were held, reviewing 185 treatments. A total of 115 interventions were performed, the most frequent being therapeutic de-escalation (38 cases, 33%), treatment discontinuation (27 cases, 23.5%), and therapeutic escalation (25 cases, 21.7%). The most commonly prescribed antimicrobials were meropenem (16.6%), piperacillin/tazobactam (14.6%), and vancomycin (12.9%), followed by metronidazole (7.8%). <h3>Conclusion and Relevance</h3> A change in the antibiotic prescribing pattern was observed between 2023 and 2024. In 2023, the most frequent intervention was treatment discontinuation, likely due to a higher initial prescription of narrow-spectrum antibiotics. In contrast, in 2024, therapeutic de-escalation predominated, associated with increased initial use of broad-spectrum antibiotics such as vancomycin, probably related to its prioritisation in the new empirical infection treatment protocol. These findings highlight the crucial role of the clinical pharmacist in the ASP team, both in detecting opportunities for intervention and in ensuring the appropriate use of antimicrobials. <h3>Conflict of Interest</h3> No conflict of interest