Analysis of risk factors for catheter-related bacteremia in 2000 permanent dual catheters for hemodialysis

Background: Infection constitutes a leading cause of morbidity and mortality in hemodialysis (HD) patients. The type of vascular access is an important determinant of the risk of infection. Therefore, identification of risk factors leading to catheter-related bacteremia (CRB) is strongly required. The aim of this prospective large cohort study of HD patients using only catheters as vascular access was to isolate risk factors for CRB.

Methods: 2,230 permanent silicone dual catheters implanted in 1,749 patients between November 1982 and November 2005 were studied. The following data were collected at the time of catheter implantation: presence of hypertension, diabetes mellitus, obesity, atherosclerosis, immunodepression, Wright-Khan index, site and side of catheter insertion, and history of bacteremia.

Results: The site of catheter insertion was internal jugular (n = 2,133), subclavian (n = 79) and femoral (n = 17). Duration of catheter use was as follows: 30-90 days (n = 1,607) and >90 days (n = 1,054); 226 episodes of bacteremia occurred in 197 catheters. Microorganisms responsible were mainly Staphylococcus aureus, coagulase-negative staphylococci, Enterobacter spp. and Pseudomonas aeruginosa. The overall incidence of bacteremic episodes was 0.514/1,000 catheter days. Hypertension, atherosclerosis, diabetes mellitus, site of catheter implantation, duration of catheter use, Wright-Khan comorbidity index and previous history of CRB were significant risk factors associated with bacteremia in univariate analysis. Multivariate analysis revealed that a previous history of a bacteremic episode (odds ratio, OR = 2.70, 95% confidence interval, CI = 1.56-4.68), diabetes mellitus (OR = 2.37, 95% CI = 1.65-3.39), duration of catheter use >90 days (OR = 1.85, 95% CI = 1.35-2.55) and hypertension (OR = 1.49, 95% CI = 1.08-2.04) were still significant factors associated with bacteremia.

Conclusion: Reducing CRB is still a challenge for nephrologists to reduce patient morbidity and mortality. Our study could demonstrate that diabetes, previous history of CRB, site of catheter implantation and duration of catheter use were the most important risk factors for bacteremia. Therefore, to prevent CRB, particular attention should be paid to patients with diabetes and a previous history of bacteremia following strict hygienic and aseptic rules for catheter handling associated with the regular use of antiseptic lock solutions.