Technical evaluation of dialysate flow in a hollow-fiber dialyzer

 In a hollow-fiber dialyzer, uremic toxins are removed by diffusion and convection, which are influenced by the dialysate flow patterns in the dialyzer. Recently available high-performance dialyzers have complicated dialysate flow patterns, because both positive filtration and negative filtration occur. The objective of the present study was to evaluate dialysate flow in high-performance dialyzers experimentally. Glass-coated 0.1 mmφ platinum electrodes were used for the electrode counter and the working electrode. A counter electrode was placed at the inlet of the dialyzer, and working electrodes were placed at 20 different positions. A voltage of 0.5 V was applied between the counter and the working electrodes with a potentiostat, and after the dialyzer was filled with water purified by reverse osmosis, 0.9% NaCl solution was caused to flow. The time at which the 0.9% NaCl solution reached each working electrode from the counter electrode was then measured at a dialysate-side flow rate of 300 ml/min and blood-side flow rates of 0 and 200 ml/min. It was found that in dialyzers with high permeability to pure water, dialysate flow was affected by both positive and negative filtration. A comparison was then made between the experimental results and the results of simulation by the finite element method; at positions at which positive and negative filtration occurred, good agreement was obtained. This method makes possible the experimental evaluation of dialysate flow in a high-performance dialyzer in which positive and negative filtration occur. Received: April 18, 2002 / Accepted: July 22, 2002 Correspondence to:K. Sakai     

Effects of vitamin E-coated dialyzer on oxidative stress and inflammation status in hemodialysis patients: a systematic review and meta-analysis

Background: Vitamin E-coated dialyzer may have an effect on oxidative stress and inflammation status in hemodialysis (HD) patients. Therefore, we performed a systematic review to assess the anti-oxidation and anti-inflammatory effects of vitamin E-coated dialyzer in HD patients. Methods: The randomized controlled trials (RCTs) and quasi-RCTs of vitamin E-coated dialyzer versus conventional dialyzer for HD patients were searched from multiple databases. We screened relevant studies according to predefined inclusion criteria and performed meta-analyses using RevMan 5.1 software. Results: Meta-analysis showed vitamin E-coated dialyzer therapy could significantly decrease the serum thiobarbituric acid reacting substances (TBARS) (SMD, ?0.95; 95% CI, ?1.28 to ?0.61; p?p?=?0.005), interleukin-6 (IL-6) (SMD, ?0.65; 95% CI, ?0.97 to ?0.32; p?p?=?0.03) compared with that of the control group. However, vitamin E-coated dialyzer did not result in increasing the total antioxidant status (TAS) (SMD, 0.23; 95% CI, ?0.16 to 0.61; p?=?0.25) and the fractional clearance of urea index (Kt/v) levels (MD, ?0.07; 95% CI, ?0.14 to 0.00; p?=?0.06), in addition, there was no significant difference in plasma superoxide dismutase (SOD) level compared with that of the conventional dialyzer &; oral vitamin E group (SMD, 0.28; 95% CI, ?0.20 to 0.75; p?=?0.26). Conclusions: Vitamin E-coated dialyzer can reduce the oxidative stress and inflammation status reflected by the decreasing of serum TBARS, oxLDL, CRP, and IL-6 levels, and this new dialyzer does not affect the dialysis adequacy.     

Clinical performance comparison of two medium cut-off dialyzers

Introduction

Medium-cut-off (MCO) dialyzers may beneficially impact outcomes in patients on hemodialysis.

Methods

In a randomized, controlled trial in maintenance hemodialysis patients, the new Nipro ELISIO-17HX MCO dialyzer was compared to the Baxter Theranova 400 filter regarding middle molecule removal. Furthermore, the suitability of two assays for free lambda-light chain (λFLC) detection (Freelite vs. N-Latex) was verified.

Results

ELISIO-HX achieved slightly lower reduction ratios for β₂-microglobulin (71.8 ± 6.0 vs. 75.3 ± 5.8%; p = 0.001), myoglobin (54.7 ± 8.6 vs. 64.9 ± 8.7%; p < 0.001), and kappa-FLC (62.1 ± 8.8 vs. 56.3 ± 7.7%; p = 0.021). λFLC reduction ratios were more conclusive with the Freelite assay and not different between ELISIO-HX and Theranova (28.4 ± 3.9 vs. 38.7 ± 13.4%; p = 0.069). The albumin loss of Theranova was considerably higher (2.14 ± 0.45 vs. 0.77 ± 0.25 g; p = 0.001) and the Global Removal Score_{Loss alb} largely inferior (30.6 ± 7.4 vs. 82.4 ± 29.2%/g; p = 0.006) to ELISIO-HX.

Conclusions

The new ELISIO-HX expands the choice of dialyzers for MCO hemodialysis.