ACUTE SYMPTOMS DURING AND BETWEEN HEMODIALYSIS - THE RELATIVE ROLE OFSPEED, DURATION, AND BIOCOMPATIBILITY OF DIALYSIS

The relationship between hemodialysis (HD) symptoms and dialyzer membr ane composition and area, blood-flow, treatment duration, urea removal , ultrafiltration volume, leukocyte activation, and complement generat ion (C3a) was studied in 20 patients undergoing 234 HD treatments by 1 2 different modes in random order using Cuprophan, hemophane, or polya mide membranes with small or large membrane areas with high Qb (400 ml /min) and short duration (2 h) or low Qb (200 ml/min) and long duratio n (4 h). Fewer symptoms occurred during the 2-h HD at high Qb than dur ing the 4-h HD with low Qb (19% vs. 32%, p = 0.0351). No differences w ere observed between different dialyzer membranes or areas. More intra dialytic symptoms occurred when urea elimination was high than it was low (p = 0.0044). Leukocyte activation (leukocyte drop) after 15 min o f dialysis and complement generation did not influence symptom inciden ce. Blood pressure changes were mainly influenced by ultrafiltration v olume (p < 0.001). Symptoms between dialyses were determined by urea r emoval and ultrafiltration. Membrane, area, or Qb were of no importanc e. Thus, duration of dialysis, urea removal, and demand for ultrafiltr ation, but not membrane composition, area, or biocompatability, are im portant for the development of HD-related symptoms.