Water treatment in domiciliary hemodialysis equipment: ultraviolet irradiation and Sartobind membrane.

Water is a fundamental element in any hemodialysis device. It must be safe, free not only of micro-organisms but also of any organic or inorganic chemical contaminant. Up to now ion exchanger, reverse osmosis, activate carbon and chlorine are generally used for this purpose. The results are not satisfactory. Microbial contaminants survive and at some points multiply. Pyrogens and endotoxins are not completely eliminated. Chlorine itself adds more risk factors because of the compounds deriving from its interaction with organic molecules. A system to obtain safe water in hemodialysis equipment is described. It is based on the use of ultraviolet irradiation to eliminate any microbial contaminant and on Sartobind membranes to eliminate pyrogens, endotoxins, proteins and other unwanted molecules. Mobile domiciliary hemodialysis equipment was used. Ultraviolet lamps (30 mW/cm2) were applied at two points: after the ion exchange and after the reverse osmosis. Three Q100 Sartobind membranes were positioned immediately before the monitor. The values of cfu/mL counted in the water after the ion exchange ranged from 450 to 1,990, whereas before the monitor they dropped from 0.01 to 0.09 cfu/mL. The LAL test, positive before the Sartobind membrane, was negative thereafter. The system proposed has shown to be effective in guaranteeing safe water free of micro-organisms and endotoxins.