Background:The purpose of the study was to investigate the amounts of albumin lost in the dialysate in a dialysis session using either a high-flux (on-line hemodiafiltration (HDF)) or a low-flux filter (conventional hemodialysis (HD)). Methods:The loss of albumin was studied in 10 hemodialyzed patients, with on-line HDF (pre-and post-dilution) and with conventional HD. We determined the albumin loss in the total ultrafiltrate for four different dialysis models. Results:No change was found in serum albumin levels when switching from conventional HD to on-line HDF. The loss of albumin in online HDF post-dilution, with a high-flux filter of 2.5 m 2 (group A) was marginally significantly greater than the loss with the same filter with a surface area of 2.1 m 2 (group B) (P = 0.05). However, there was no difference in albumin loss when comparing groups A and B with group C (conventional HD) (P = NS). Albumin loss was significantly less in group D (pre-dilution on-line HDF, with filter 2.5 m 2 surface area) compared to groups A (P < 0.01), B (P < 0.01) and C (P < 0.03). The urea reduction ratio in each case (groups A, B, C and D) was, on average, > 73.5%, but in group C, it was significantly lower than in groups A and B (P < 0.05). Transmembrane pressure in group D was clearly lower than in groups A and B. Conclusion:The polyethersulfone filters (polynephron) used in the on-line HDF lost very little albumin in a session (more with postdilution), but this increased when their surface area and the transmembrane pressure increased. The urea reduction ratio was above the desired target in each model of dialysis using this filter, including both surface areas.

Introduction: β 2 -microglobulin and prolactin are medium-molecular-weight toxins. We believe that the rate of removal of these molecules, using filters with two different surfaces, in post-and pre-dilution haemodiafiltration, will be of interest to the literature. Methods: We studied, in 12 haemodialyzed patients, the removal of those, with filter with surface of 2.5 m 2 (Group A) or 2.1 m 2 (Group B) with post-dilution haemodiafiltration, and with a filter with surface 2.5 m 2 with pre-dilution (Group C). Results: Satisfactory removal of β 2 -microglobulin (best with post-dilution) was found, and a good rate of removal of prolactin without the filter surface played a role in both cases. Conclusion: The elimination of β 2 -microglobulin in post-dilution is not affected by the filter surface area. Pre-dilution achieves removal of β 2 -microglobulin, less than that of post-dilution. Prolactin was removed satisfactorily regardless of the filter surface in post-dilution, and its removal appears to be less than that of β 2 -microglobulin.

Introduction: Over the past 20 years, extensive research has been conducted on blood transfusion and the hazards arising from them, as well as on safest maximum storage duration for blood derivatives. Blood transfusion rates in patients with and-stage renal disease may have declined markedly after the discovery and use of erythropoietin in the mid-1980s, but is still remains a standard of care. Since several biochemical changes take place in stored blood, physicians should be alert when transfusing blood in end-stage renal disease patients,who are,theoretically at least,at higher risk of complications. Methods and Results: This study were designed to investigate changes in storer blood over time (every 10 days from 0 to 40 days). Changes in sodium, potassium, chloride, total calcium, lactate, pH, partial pressure of carbon dioxide, bicarbonate and hematocrit,as well as the degree of hemolysis,were recorded.The findings show a significant increase in potassium,lactate,partial pressure of carbon dioxide and hematocrit and a reduction in chloride,pH and bicarbonate. The serum levels of sodium initially increased (up to day 20) and then declined. Conclusions: In conclusion, stored blood undergoes significant changes, which can be life-threatening, especially + when the transfusions are massive or in patients with end-stage renal disease,who are more sensitive to significant K or acid overload.