ONLINE PREDILUTION HEMOFILTRATION VERSUS ULTRAPURE HIGH-FLUX HEMODIALYSIS - A MULTICENTER PROSPECTIVE-STUDY IN 23 PATIENTS

The aims of the present prospective multicenter study were to assess t he clinical tolerance and well being, the correlation between nPCr and Kt/V and the pretreatment beta(2)-microglobulin level in patients seq uentially treated with high-flux dialysis with ultrapure bicarbonate h emodialysis (HD; phase I) and predilution hemofiltration (HF) with on- line prepared bicarbonate substitution fluid (phase II). The same moni tor (Gambro AK 100 ULTRA(R)) and membrane (polyamide) were used. Twent y-three patients, all in a stable clinical condition, entered the stud y. The treatment was targeted to an equilibrated Kt/V (eqKt/V) of 1.4 for HD and 1.0 for HF. No mortality or relevant morbidity were observe d. The number of hypotensive episodes was 1.78 +/- 2.8 per patient and month during HD vs. 1.17 +/- 3.1 during HF (p = 0.003) and the number of the hypertensive episodes 1.28 +/- 2.8 during HD vs. 0.42 +/- 0.8 during HF (p = 0.04). Incidences of arrhythmia, muscular cramps and he adache were significantly less frequent during HF. Interdialytic cramp s, arthralgia and fatigue were also significantly less frequent during the HF period. The average beta(2)-microglobulin level was 27.1 +/- 1 4.7 mg/dl at the start of the study, 22.9 +/- 4.9 mg/dl at the beginni ng of phase II and 22.4 +/- 4 mg/dl at the end of phase II (p = 0.01 c ompared to the start). A significant linear correlation between the no rmalized protein catabolic rate and eqKt/V was obtained faster during HD than during HF (45 vs. 120 days) indicating that HF affects the nut ritional status with mechanisms different from HD. The present study i s in agreement with the hypothesis that HF gives an adequate nutrition al status with improved clinical stability and well being at a lower K t/V compared to HD. Both therapies were efficient in controlling the p retreatment beta(2)-microglobulin level.