Ultrashort hemodiafiltration: efficiency and hemodynamic tolerance

During hemodiafiltration, solutes are removed simultaneously by diffusion and convection. Increase of the fraction removed by diffusion, by using large surface area hemodiafilters, allows a further reduction of treatment time by hemodiafiltration. To assess the efficiency and biochemical safety of ultrashort treatment (mean duration 3 X 105 +/- 14 min/week) six patients (age 22-64) have been observed for six months. There were no differences in the clinical state or in the biochemical parameters compared to those found during the preceding hemodialysis period (3 X 240 min/week). In a second study, hemodynamic measurements in six individual patients aged 34-72 have been compared during a 90 min ultrashort hemodiafiltration (90 min) and during a 240 min hemodialysis. Circulatory stability was maintained during hemodiafiltration despite a rate of fluid removal that was 2.5 times that which occurred during hemodialysis. During both techniques there was a reduction of stroke volume and an adequate norepinephrine-induced rise of peripheral resistance. Plasma levels of vasopressin did not change during treatment. There were no differences in the frequency and quality of premature ventricular beats between the two treatments. The data from the two studies suggests that ultrashort hemodiafiltration (3 X 1.5-2 hr/week) provides biochemical safety as well as hemodynamic stability.