RISK FACTORS FOR CATHETER RELATED BLOOD STREAM INFECTION IN HEMODIALYSIS PATIENTS

The main complication in hemodialysis (HD) patients with central venous catheter (CVC) is catheter related bloodstream infection (CRBSI), that is associated with increased morbidity and mortality. The aim of the study was to evaluate the incidence, bacteria types, and risk factors for CRBSI.

In this multicenter prospective cohort study data were collected over a period of the last year. CRBSI was determined using positive blood culture. The CRBSI rate was estimated as infection count per 1000 catheter-days and it was compared in HD patients with permanent CVC (PCVC) and temporary CVC (TCVC). The CVC days from the start of the study until CRBSI event were registered. The parameters considered as predictors for CRBSI were: age, gender, HD vintage, diabetes mellitus (DM), CVC type (temporary or permanent), CVC site (jugular, subclavian or femoral), serum albumin, C-reactive protein (CRP), and hemoglobin level. According to serum albumin (<35 or ≥35 g/L), CRP (<6 or ≥6 mg/L) and hemoglobin level (<100 or ≥100 g/L) subgroups of patients were formed for analysis of risk factors for CRBSI. Statistical analysis was performed using SPSS software, for comparisons of means and frequencies analysis of variance and chi square test, but for evaluation of risk factors for CRBSI Cox proportional hazards regression analysis were performed.

The study encompassed 578 incident HD patients (346M and 232F) with the average age 63,4±12,0 years and the average HD vintage 73,54±68,97 months, but 187 patients (96M and 91F) or 32,3% were with CVC as vascular access for hemodialysis. Over the observed period 43 CRBSIs were registered, 32 in 118 patients with TCVC (14465 catheter-days) and 11 in 69 patients with PCVC (17820 catheter-days), but 11 patients had multiple CRBSIs. There was statistically significant difference of CRBSI rate between patients with TCVC and PCVC (2,212 vs 0,617 CRBSI/1000 catheter-days respectively, Chi square 15,267, p<0.001). Femoral site was in 60,5%, subclavian in 20,9% and jugular in 18,6% of patients with CRBSI. The prevalent bacteria determined were Staphylococcus coagulase negative in 27,9%, Staphylococcus aureus in 16,3% and Methicillin resistant staphylococcus aureus-MRSA in 11,6% of CRBSIs. Patients with CRBSI in comparison to patients without CRBSI had statistically significant lower mean serum albumin (32,93±5,02 vs 37,09±3,61 g/L, p<0.001), hemoglobin (94,69±14,87 vs 116,73±12,78 g/L, p<0.001) and higher CRP (39,29±43,39 vs 11,94±25,58 mg/L, p<0.001). Cox regression analysis showed that the model was statistically significant (Chi square 96,54; df=6; p<0.001) and statistically significant risk factors for CRBSI were TCVC type in comparison to PCVC (OR=7,57; 95% CI=2,86-20,0; p<0.001), hemoglobin <100 g/L in comparison to Hgb ≥100 g/L (OR=6,75; 95% CI=3,45-13,15; p<0.001), serum albumin <35 g/L in comparison to albumin ≥35 g/L (OR= 2,48; 95% CI=1,30-4,74; p=0.006), and CRP ≥6 mg/L in comparison to CRP <6 mg/L (OR=5,14; 95% CI=1,55-17,07; p=0.007). Age, gender, HD duration, DM, and CVC site were not significant risk factors for CRBSI.

The study showed that the CRBSI rate was significantly higher in HD patients with TCVC compared to PCVC. Temporary CVC, serum albumin below 35 g/L, hemoglobin below 100 g/L, and CRP over 6 mg/L were statistically significant risk factors for CRBSI.