Impact of switch of vascular access type on key clinical and laboratory parameters in chronic haemodialysis patients

BACKGROUND: Observational studies demonstrate poor clinical outcomes in chronic haemodialysis patients with venous catheters as vascular access. This longitudinal study examines the impact of vascular access change on key clinical and laboratory parameters. METHODS: We studied 2616 haemodialysis patients who had no or one vascular access change between January 2002 and June 2003. Two hundred and seventy-one patients switched from a catheter to an arteriovenous (AV) access (AV fistula or graft) and 69 patients from an AV access to a catheter. Accesses remained unchanged in 430 patients with catheters, and in 1846 patients with an AV access, who served as controls. Levels of serum albumin, white blood cell count (WBC), enPCR, eKdrt/V, blood haemoglobin and erythropoietin dosage were obtained monthly. Data were averaged over 6 months preceding (pre) and 6 months following the access change (post). Differences between post- and pre-access change were compared to changes in respective parameters between the last and first 6 months of the study period in controls. RESULTS: The change from a catheter to an AV access was associated with a rise of serum albumin (+0.12 g/dL; P < 0.001), enPCR (+0.05 g/kg body weight/day; P = 0.001) and haemoglobin (+0.41 g/dL; P < 0.001) and a decrease in WBC (-370/microL; P = 0.048). Conversely, switching from an AV access to a catheter was followed by a significant fall in albumin (-0.11 g/dL; P = 0.035), enPCR (-0.07 g/ kg body weight/day; P = 0.001) and eKdrt/V (-0.09; P < 0.001) and a rise in erythropoietin dosage (+89 IU/kg body weight/week; P = 0.002), as compared to controls. CONCLUSION: Change from a catheter to an AV access seems to alleviate malnutrition, inflammation and anaemia. Efforts to replace catheters with fistulae or grafts should be intensified.