| [ Summary ] |
Chronically ill patients under treatment with hemodialysis (HD) are exposed to the equivalent of a 25-fold increase in drinking water in one hour' during HD. The substances in the water used for dialysate production are introduced into the patients directly through the dialysis membrane and accumulate in them. Very small amount's of the substances in the dialysate can easily cause acute or chronic intoxication in patients. Such conditions as hard water syndrome, fluoride and chloramine associated disorders, aluminum encepharopathy and aluminum-related bone disease. Therefore, guidelines for HD water quality are necessarily strict. They are issued by the AAMI/ASAIO and the Japanese Society of Dialysis Therapy etc. Furthermore, water processing must be adapted for each water source. There are different methods of water processing, such as 'filtration' to remove large particles or endotoxins, 'activated charcoal' to remove many kinds of organic compounds, 'water softening' to remove cations (calcium and magnesium etc.), "deionization" to remove both cations and anions, and "reverse osmosis" to remove microparticles, ions and endotoxins over a wide rang. Recently, 2 types of combined methods are popular for water processing. First one is the combination of an activated charcoal, microfilter, softening and reverse osmosis and another is one having activated charcoal, a microfilter, deionization and ultrafiltration. |