High-flux hemodiafiltration: 5 years experience.

The introduction of hemodiafiltration in the substitutive treatment of chronic renal failure has arisen from the need to find new techniques that could improve the efficiency of the traditional systems and, therefore, to treat adequately chronic uremia in the shortest possible time. 61 months of experience at our institution have shown that such a goal can be achieved, offering also practical advantages such as a better quality of life for the patients as well as the possibility to treat a greater number of them.

Clinical experience with a new hemodiafiltration (HDF) system.

Purity of reinfusion fluid and dialysate is mandatory in high flux, high efficiency substitutive treatments for chronic uremia, particularly when using bicarbonate concentrates. Bags of sterile and pyrogen free substitution fluid are in part responsible for the high costs of these treatments. In order to overcome these problems, the authors tested a new monitoring system (MPS-10, Gambro) for high efficiency hemodiafiltration (HDF) in which the reinfusion fluid was prepared from bicarbonate dialysate by filtration. During 5 months time, 96 on-line HDF treatments were performed in five chronic uremic patients. We found the infusion fluid and dialysate containing bicarbonate free from bacteria and endotoxins, with a correct weight balance obtained by the monitoring system. The authors believe that MPS-10 is a safe and adequate system for the production of sterile, pyrogen free dialysate and reinfusion fluid for on-line HDF, hemodialysis (HD), and hemofiltration (HF).

Soft and hard hemodiafiltration (HDF).

Soft and Hard Hemodiafiltration (HDF). A 32-month study was made to assess efficiency and clinical tolerance in a comparison between "soft" and "hard" HDF. Soft HDF was performed in 18 patients using a polyacrylonitrile AN 69 S 1.2m2 membrane and hard HDF in 12 patients using a polyacrylonitrile hollow-fibre 1.8m2 membrane. Different technical parameters were used for each of the two methods. Biochemical data registered during a single session showed the efficiency of both kinds of treatment and in this study clinical tolerance and patient well-being were significantly better than with hemodialysis. Hard HDF permits considerable shortening of treatment time.

beta 2-Microglobulin and other low molecular weight proteins in haemodiafiltrates and in haemofiltrates.

Uraemic patients underwent haemodialysis by cuprophan membrane, or haemodiafiltration by polyacrylonitrile membrane, or haemofiltration by acetate cellulose membrane. Plasma samples drawn before and after treatment with the dialyser were gel-filtered on Sephadex G-75. A comparison of the chromatograms showed that the treatment causes a removal of middle molecules, which is more consistent when haemodiafiltration and haemofiltration are used. Protein removal was examined in the fluids from the three dialysers. It was observed that proteins (300 +/- 45 mg and 410 +/- 60 mg respectively) were removed when polyacrylonitrile and acetate cellulose membranes were used, but not in the case of cuprophan membrane. beta 2-Microglobulin was the protein lost in the greatest amount.

[Investigation on the renal clearance of metylglucamine diatrizoate and of sodium and metylglucamine diatrizoate (author's transl)]. / Studio delle clearance renali del diatrizoato di metilglucamina e del diatrizoato di sodio e metilglucamina.

In 14 patients the kinetics has been studied of two contrast media labelled with 131I, and namely of MGM diatrizoate and of diatrizoate of sodium and MGM. The clearance was determined both at basal concentrations and in double concentration by means of external counting. The results were statistically studied by means of the linear regression method. The authors conclude that the MGM diatrizoate is exclusively eliminated through the glomeruli both in basal and double concentration. The diatrizoate of sodium and MGM is eliminated in low concentration through the glomeruli, while in double concentration it is partially eliminated through the tubuli.