Catheter-related bloodstream infections in hemodialysis: microbiology, antimicrobial resistance, complications and predictors of mortality.

backgroundCatheter-related bloodstream infections (CRBSI) remain a major clinical problem in hemodialysis patients and are associated with substantial morbidity, mortality, and healthcare costs. Understanding local epidemiology, causative microorganisms, resistance patterns, and predictors of adverse outcomes is essential for optimizing management strategies.

methodsThis retrospective study included adult hemodialysis patients diagnosed with CRBSI between January 2016 and December 2022. Diagnostic criteria were based on the 2009 IDSA guidelines. Demographic characteristics, comorbidities, clinical and laboratory findings, microbiological results, antimicrobial treatments, complications, and in-hospital mortality were analyzed. Differential time to positivity, catheter tip cultures, and antimicrobial susceptibility profiles were evaluated. Factors associated with complications and mortality were assessed using appropriate statistical tests.

resultsA total of 191 patients were included (median age: 69 years; 49.2% female). Gram-positive microorganisms accounted for 68.6% of isolates, predominantly coagulase-negative staphylococci (35.8%) and Staphylococcus aureus (23%). Methicillin resistance was detected in 83.5% of coagulase-negative staphylococci and 34% of S. aureus isolates. Gram-negative bacteria constituted 29.4% of isolates, with notable resistance to cephalosporins and piperacillin–tazobactam. Complications occurred in 17.2% of patients, most commonly endocarditis (11%) and spondylodiscitis (4.2%). Staphylococcus aureus was the most common pathogen in patients who developed endocarditis (38.1%), whereas coagulase-negative staphylococci predominated among patients with spondylodiscitis. In-hospital mortality was 11%. Diabetes mellitus, higher Charlson comorbidity index, and elevated CRP, WBC, and neutrophil levels were significantly associated with mortality. The presence of complications increased the risk of mortality, particularly endocarditis, suppurative thrombophlebitis, cerebrovascular events, and abscess formation. The duration of hemodialysis was not associated with mortality, although higher hemodialysis frequency was observed among deceased patients. Neither empirical therapy, antimicrobial de-escalation/escalation, antibiotic lock therapy, nor catheter removal showed a significant impact on mortality.

conclusionsCRBSI in hemodialysis patients is predominantly caused by Gram-positive organisms and carries a considerable risk of severe complications and mortality. Early diagnosis, targeted antimicrobial therapy, and appropriate catheter management are crucial for improving clinical outcomes. Local epidemiological data should guide empirical treatment decisions, particularly in settings with high antimicrobial resistance.