Bacterial Distribution and Risk Factors of Nosocomial Blood Stream Infection in Neurologic Patients in the Intensive Care Unit

Objective: To investigate the risk factors and analyze the distribution of pathogens to provide a basis for the prevention of nosocomial blood stream infections (BSI) and reduce the incidence and mortality of nosocomial BSI in neurologic patients. Patients and Methods: A retrospective chart review of neurologic patients admitted to an adult intensive care unit from January 2012 to December 2017 was conducted. Every positive blood culture, clinical demographic, microbiologic and laboratory result, as well as 28-day outcome data, were compiled on a data collection sheet. The clinical significance of each isolate was determined; in addition, the antimicrobial susceptibilities of causative pathogens and the most likely source were recorded. Results: During the five-year study period, there were 121 nosocomial BSI yielding 151 isolates in 404 neurologic patients. Eighty-one percent of nosocomial BSI were monomicrobial. Gram-positive organisms caused 67.9% of these BSI, gram-negative organisms caused 32.1%, and fungi caused 0.8%. The crude incidence rate was approximately 29.9%, and the mortality of nosocomial BSI was as high as 29.8%. Intravascular lines were the most common source of nosocomial BSI (79.3%). The most common organisms causing BSI were coagulase-negative staphylococci (CoNS; 44.6% of isolates), Staphylococcus aureus (17.4%), Klebsiella species (11.5%), and Acinetobacter spp. (11.5%). Multivariable regression analysis revealed that the use of antibiotic agents in the 90 days prior (odds ratio [OR], 5.81; 95% confidence interval [CI], 3.18-10.62; p=0.001), brain trauma (OR, 0.28; 95% CI, 0.15-0.51; p=0.001), and transfusion (OR, 3.02; 95% CI, 1.45-6.29; p=0.001) were significant predictors of nosocomial BSI. Conclusions: The incidence and mortality of nosocomial BSI were high in our neurologic patients. Strictly aseptic operations, hand hygiene, and reasonable use of transfusions and antibiotic agents are effective measures to prevent nosocomial BSI.