The effect of pharmacist-led antimicrobial stewardship on antimicrobial use in an intensive care unit: a single-center, retrospective, observational study.

PURPOSE: We investigated the long-term impact of an antimicrobial stewardship program (ASP) led by a dedicated intensive care unit (ICU) pharmacist belonging to an antimicrobial stewardship team (AST) on trends in antimicrobial use and patient outcomes.

METHODS

This was a single-center, retrospective study of patients admitted in an open ICU. Days of therapy (DOT) and number of patients receiving antimicrobial drug (NAD) of carbapenems, anti-pseudomonal β-lactams and non-anti-pseudomonal β-lactams, and all-cause mortality at 28 days were compared between the pre-ASP period (April 2012 to March 2016) and post-ASP period (April 2016 to March 2024). We divided patients into the sepsis, non-sepsis, and non-infection groups and compared outcomes. De-escalation rates and number of days until de-escalation of carbapenems and anti-pseudomonal β-lactams were investigated in sepsis and non-sepsis cases.

RESULTS

DOT decreased significantly for carbapenems, anti-pseudomonal and non-anti-pseudomonal β-lactams post-ASP. In sepsis cases, the number of days until de-escalation of carbapenems and anti-pseudomonal β-lactams significantly decreased post-ASP; the ICU pharmacist intervened in all cases for sepsis and non-sepsis post-ASP. DOT of carbapenems and anti-pseudomonal β-lactams decreased significantly in non-sepsis and non-infection cases post-ASP. NAD significantly decreased in patients treated with carbapenems, anti-pseudomonal β-lactams and non-anti-pseudomonal β-lactams post-ASP. In non-infection cases, NAD significantly decreased in patients treated with carbapenems, anti-pseudomonal β-lactams post-ASP. No significant difference occurred in all-cause mortality rate between groups.

CONCLUSION

ASP led by a pharmacist belonging to an AST in the open ICU contributed to long-term appropriate antimicrobial use of carbapenems and anti-pseudomonal β-lactams, and DOT for non-pseudomonal β-lactams.