Epidemiology of ICU-Onset Bloodstream Infection: Prevalence, Pathogens, and Risk Factors Among 150,948 ICU Patients at 85 US Hospitals

OBJECTIVES: Bloodstream infections (BSIs) acquired in the ICU represent a detrimental yet potentially preventable condition. We determined the prevalence of BSI acquired in the ICU (ICU-onset BSI), pathogen profile, and associated risk factors. DESIGN: Retrospective cohort study. DATA SOURCES: Eighty-five U.S. hospitals in the Cerner Healthfacts Database. PATIENT SELECTION: Adult hospitalizations between January 2009 and December 2015 including a (>= 3 d) ICU stay. DATA EXTRACTION AND DATA SYNTHESIS: Prevalence of ICU-onset BSI (between ICU Day 3 and ICU discharge) and associated pathogen and antibiotic resistance distributions were compared with BSI present on (ICU) admission (ICU-BSIPOA); and BSI present on ICU admission day or Day 2. Cox models identified risk factors for ICU-onset BSI among host, care setting, and treatment-related factors. Among 150,948 ICU patients, 5,600 (3.7%) had ICU-BSI(POA )and 1,306 (0.9%) had ICU-onset BSI. Of those with ICU-BSI(POA )4,359 (77.8%) were admitted to ICU at hospital admission day. Patients with ICU-onset BSI (vs ICU-BSIPOA) displayed higher crude mortality of 37.9% (vs 20.4%) (p < 0.001) and longer median (interquartile range) length of stay of 13 days (8-23 d) (vs 5 d [3-8 d]) (p < 0.001) (considering all ICU stay). Compared with ICU-BSIPOA, ICU-onset BSI displayed more Pseudomonas, Acinetobacter, Enterococcus, Candida, and Coagulase-negative Staphylococcus species, and more methicillin-resistant staphylococci, vancomycin-resistant enterococci, ceftriaxone-resistant Enterobacter, and carbapenem-resistant Enterobacterales and Acinetobacter species, respectively. Being younger, male, Black, Hispanic, having greater comorbidity burden, sepsis, trauma, acute pulmonary or gastrointestinal presentations, and pre-ICU exposure to antibacterial and antifungal agents was associated with greater ICU-onset BSI risk after adjusted analysis. Mixed ICUs (vs medical or surgical ICUs) and urban and small/medium rural hospitals were also associated with greater ICU-onset BSI risk. The associated risk of acquiring ICU-onset BSI manifested with any duration of mechanical ventilation and 7 days after insertion of central venous or arterial catheters. CONCLUSIONS: ICU-onset BSI is a serious condition that displays a unique pathogen and resistance profile compared with ICU-BSIPOA. Further scrutiny of modifiable risk factors for ICU-onset BSI may inform control strategies.

Automated summary

ICU-onset bloodstream infections (BSI) are a serious condition with unique pathogen and resistance profiles compared to infections acquired on ICU admission. Risk factors for ICU-onset BSI include being younger, male, Black, Hispanic, having higher comorbidity burden, certain diseases and treatments, and exposure to antibacterial and antifungal agents. Further investigation of modifiable risk factors may inform strategies for prevention and control of ICU-onset BSI.