Various outcomes of mortality, medical costs, and antimicrobial usage result from antimicrobial stewardship (AS) programmes. Here, we clarified the effects of AS implementation by a well-trained pharmacist in an open intensive care unit (open ICU) through a retrospective, comparative study of 5123 open ICU patients of Tokai University Hospital. The 12 months before and after AS implementation were considered the control and study periods, respectively. After AS implementation, the number of AS cases increased significantly. The period until the implementation of therapeutic drug monitoring was significantly shortened, and antimicrobial drug usage increased significantly. The methicillin-resistant Staphylococcus aureus (MRSA) detection rate decreased significantly. Earlier and more frequent AS implementation could enhance treatment effects, possibly decreasing the MRSA incidence. Despite active AS implementation, antimicrobial drug usage did not necessarily decrease. ICU pharmacists with experience in AS should take on leadership roles and implement active AS strategies in open ICU settings.
Keywords: MRSA; antimicrobial drug usage; antimicrobial stewardship; drug-resistant bacteria; open ICU; pharmacist; strategy.