Epidemiological Trends of Bloodstream Infections and Risk Factors for MDRO Bloodstream Infections in Critically Ill Patients: An Eight-Year Single-Center Data Analysis

Background: The epidemiological characteristics, pathogen distribution, drug resistance patterns, and their temporal trends in bloodstream infections (BSI), along with the risk factors for BSI caused by multidrug-resistant organisms (MDRO) in critically ill patients, remain unclear. Methods: This single-center retrospective observational study included adult patients with BSI admitted to the Intensive Care Unit (ICU) from January 2013 to December 2020. Clinical data were collected through the hospital’s electronic medical record system. We analyzed the incidence and mortality rates of BSI, the distribution of pathogens and resistance patterns, and their temporal trends in critically ill patients. Risk factors for BSI caused by MDRO were also analyzed. Results: BSI had a 9.32% (955/10249) incidence. The 28-day and ICU mortality rates were 27.9% (266/955) and 26.8% (256/955), respectively, both showing a gradual declining trend. Gram-negative bacteria (GNB) were the predominant pathogens (63.2%, 604/955), followed by Gram-positive bacteria (GPB) (26.1%, 249/955). The distribution of pathogens did not show significant changes over time. Antibiotic exposure (Odds Ratio [OR]: 1.49, 95% Confidence Interval [CI]: 1.05-2.11) and ICU-acquired BSI (OR: 1.72, 95%CI: 1.08-2.73) were independent risk factors, and catheter-related BSI (OR: 0.66, 95%CI: 0.45-0.97) and early appropriate antimicrobial therapy (OR: 0.24, 95%CI: 0.17-0.33) were independent protective factors for BSI caused by MDRO. Conclusions: BSI in critically ill patients has high incidence and mortality rates, primarily caused by GNB and with no significant temporal change. Antibiotic exposure and ICU-acquired BSI are linked to an increased risk, while catheter-related BSI and early appropriate antimicrobial therapy are associated with a reduced risk of BSI caused by MDRO.