Impact of pharmacist-led antimicrobial stewardship on antibiotic prescribing for pneumonia in the intensive care unit

Background:  Pharmacist-led antimicrobial stewardship strategies have been shown to be effective in optimizing antibiotic utilization in the intensive care unit (ICU). However, their impact on appropriate antibiotic selection and patient outcomes in the community hospital setting requires further evaluation. The purpose of this study was to determine the proportion of ICU patients receiving appropriate empiric antibiotic selection for healthcare-associated (HCAP) and community-acquired pneumonia (CAP) before and after implementation of a pharmacist-led antimicrobial stewardship program (ASP).

Methods:  This retrospective, quasi-experimental study evaluated CAP and HCAP patients admitted to a 350-bed community teaching hospital ICU between January 2011 and June 2012 (pre-ASP) as well as January 2014 and June 2015 (post-ASP). A pharmacist-led ASP was implemented in October 2013 with daily audit and feedback as well as guideline implementation. Study endpoints compared between the pre- and post-ASP groups included the proportion of patients who received appropriate antibiotic treatment based on institutional and national guidelines, time to de-escalation, duration of antibiotic therapy, and total length of ICU and hospital stay. Patient outcomes evaluated included 90-day readmission, in-hospital mortality, reintubation, and Clostridium difficile infection within 30 days.

Results: Compared to the pre-ASP group (n=100), the post-ASP group (n=84) received appropriate empiric antibiotic therapy more frequently (60% vs 86.9%, p<0.001; HCAP 53% vs 98%, p<0.001; CAP 67.3% vs 70.6%, p=0.754). The pre-ASP HCAP group received significantly more double coverage for Pseudomonas (45.1% vs 0%, p<0.001). Median time to de-escalation of antibiotics was shorter (71 hr vs. 60 hr, p=0.029) and de-escalation occurred more often (69% vs 86.9%, p=0.004) in the post-ASP group. There were no significant differences in 90-day readmission (p=0.091), in-hospital mortality (p=0.587), or ICU (p=0.118) and hospital length of stay (p=0.694).

Conclusion:  Implementation of a pharmacist-led ASP in a community hospital ICU resulted in improved empiric antibiotic selection, more timely de-escalation of antibiotics, and was not associated with adverse patient outcomes in patients treated for pneumonia.