L G Burdiel | Search PubMed

PubMed1989

Factors affecting beta 2-microglobulin plasma concentration during hemodialysis.

We studied ten patients on hemodialysis (HD) treated in sequence with cuprophan (CU), ethylenevinylalcohol (EVAL), polyacrylonitrile (A-69) and polysulphone (PSP) membrane dialyzers. beta 2-microglobulin (beta 2m) was measured by radioimmunoassay in plasma and dialysate samples. Plasma concentrations were corrected for changes in extracellular volume (ECV). We also studied adsorption in vitro by incubating the above membranes with I-125-labelled beta 2m. There were no changes in beta 2m plasma concentration after HD with CU dialyzers, but a significant decrease was observed with the other membranes tested. Filtration of beta 2m across the dialyzer was absent with CU and minimal with EVAL. However, large amounts were recovered from dialysate with the high-permeability dialyzers, AN-69 and PSP. In vitro studies showed that maximal adsorption capacity was obtained with AN-69 (13%) compared to 9% with CU, 4% with EVAL and 7% with PSP. In summary, beta 2m clearance with PSP is achieved through greater removal of this protein by mass transport across the membrane. The mechanism by which beta 2m is removed from blood during AN-69 dialysis seems to include both adsorption to and filtration by the membrane itself.

Adolescent↗

PubMed1985

Sequential hypertonic dialysis.

We have investigated the usefulness and practicability of the so-called sequential hypertonic dialysis in 2 selected patients with severe hemodialysis-induced hypotension; 190 mmol/l of sodium dialysate during the 1st and 3rd h and 132 mmol/l throughout the 2nd and 4th h were used, with a Drake-Willock-Bi proportionating unit, which was electronically modified for the purpose of the study. Crossover was made, patients serving as their own controls in two consecutive cycles: 3 weeks conventional hemodialysis followed by 4 weeks sequential hypertonic dialysis, using high-flux dialyzers. At the end of sequential hypertonic dialysis a greater weight loss was achieved (p less than 0.001) with absolute stability of blood pressure. There were no significant changes in plasma osmolality and plasma volume during sequential hypertonic dialysis when compared with conventional hemodialysis. Dialysis symptoms and complications were less frequently recorded during sequential hypertonic dialysis (p less than 0.001). At the end of each sequential hypertonic dialysis period, hemoglobin, potassium, and phosphate plasma levels improved significantly and plasma sodium concentrations remained within the normal range. We conclude that sequential hypertonic dialysis is an easy and routine feasible procedure with our methodology. It is possible to achieve the ideal dry weight with no symptomatic hypotension. Sequential hypertonic dialysis constitutes an alternative to sequential ultrafiltration in selected patients, as it minimizes the falloff in plasma volume and osmolality observed during conventional hemodialysis.

Adult↗