Background:

The use of biocompatible high-flux membranes is more efficient than low-flux membranes in controlling a number of hemodialysis-related diseases. The aim of this cooperative study was to evaluate the 6-month effect of a switch from low- to high-flux dialysers on patients treated in 39 Spanish dialysis centres.

Methods:

The clinical data used in this analysis were prospectively collected by the EuCliD^® database, developed to monitor the quality of treatment delivered in a large network of European Dialysis Centres. Inclusion criteria for the study were the condition of end-stage renal disease (ESRD) on chronic hemodialysis and low-flux dialysis for at least six months before the switch to high-flux dialysis. Of 1,543 patients enrolled in the study between 2000 and 2001, 1,046 patients were considered for the analysis. 497 patients were excluded because they did not complete the follow-up. Outcome measures were the reduction of pre-dialysis beta-2 microglobulin, the improvement of anemia or reduction in rHu-EPO dose required to maintain best correction of anemia, reduction of inflammatory parameters (CRP), improvement in lipid profile (Total and HDL cholesterol, tryglycerides), maintenance of nutritional status. Albumin and “dry” (post-hemodialysis) body weight were both evaluated as nutritional indexes.

Results:

During the six months of high-flux hemodialysis, there was a significant increase in hemoglobin (from 11.55±1.41 to 11.88±1.43 g/L; p<0.001). Considering the temporarily untreated patients on a 0 U/week dose, erythropoietin remained stable (from 5,670±4,199 to 5,657±4,411 U/week). During the second part of the follow-up, the lipid profile significantly improved (Fig. 3). Total cholesterol and triglycerides decreased significantly (p<0.001), while HDL cholesterol increased (p=0.006). Calculated levels of LDL cholesterol also significantly decreased (p=0.001). Dry body weight remained stable (64.7±11.9 vs. 64.7±12.0 kg) as well as in albumin levels (3.93±0.43 vs. 3.94±0.43 g/dL) between the two modalities of treatment. The level of ß2-microglobulin significantly decreased during high-flux dialysis (33.5±14.4 vs. 26.3±8.6 mg/dL, p<0.001).

Conclusion:

All above mentioned results may have as a common denominator an improved blood purification from uremic toxins and a reduced level of chronic sub-clinical inflammation. All together, these results seem to confirm the superiority of high-flux dialysis in terms of clinical and physiological outcomes.