Antimicrobial use and mortality among intensive care unit patients with bloodstream infections: implications for stewardship programs.

Background: Bloodstream infections (BSIs) are one of the most critical illnesses requiring intensive care unit (ICU) admission. Antimicrobial therapy (AMT) is one of the vital management strategies for the treatment of BSIs; it should be chosen appropriately to reduce mortality.

Objectives: This is the first study to investigate the types of antimicrobial agents administered in the ICU setting and the predictor variables associated with mortality.

Methods: This retrospective study was conducted at King Abdullah University Hospital (KAUH). All hospitalized patients admitted to the ICU and received at least one antimicrobial agent over 3 years period (January 1, 2017, to December 31, 2019) were included in the study. Electronic patients' medical records were used to collect patients' demographic and clinical characteristics, patient general health status, events that occurred during hospitalization, and events after obtaining the blood culture. Descriptive analysis was done to identify the types of antimicrobials used and the distribution of the microorganisms among the study participants. The susceptibility test of the bloodstream culture was checked for each patient Moreover, crude mortality and its associated factors were investigated.

Results: A total of 1051 patients were enrolled in the study, where 650 patients (61.84%) were treated with three or more antimicrobial agents. The most frequent antimicrobials used were piperacillin/tazobactam followed by teicoplanin, meropenem, and levofloxacin. About half of the patients died within 30-days of BSI, which was associated with several factors including advanced age, presence of co-morbidities, nosocomial infections or healthcare-associated infections, length of ICU stay, respiratory tract infections, receiving vasopressor during the hospital stay, concurrent positive culture other than blood with BSI, receiving combination antimicrobial therapy, those who were complicated with septic shock or renal failure, receiving total parenteral protein (TPN) nutrition, and inappropriate empiric antimicrobial therapy.

Conclusion: In conclusion, the administration of the antimicrobials among ICU patients was highly based on a combination of three or more agents covering a broad spectrum of microorganisms. The mortality rate was high among patients which were associated with inappropriate empirical therapy. Therefore, the antimicrobial stewardship (ASP) protocol has to be evaluated in the hospital for ICU patients. Moreover, we suggest recommending that hospital policies should apply the ASP protocol, infection control, implement the antimicrobial de-escalation protocol, and do best controlling on the co-morbid conditions, especially for ages 65 years or more to reduce the mortality rate in the ICU.