Abstract
Greater than 100 L of tap water is used for a conventional hemodialysis (HD) session as 4 hours of dialysis time and 500 ml/min. of dialysis fluid flow rate. It means that a dialysis patient receiving 3 HD sessions per week could be exposed to 15,000 L of water per year. Therefore, we should recognize how easily affected by the water quality chronic dialysis patients are. We have to purify the dialysis water and dialysis fluid as clean as possible because we usually use high flux membranes in which dialysis fluid could pass into the blood site. Some International Standards (IS) have been established for dialysis water quality as IS 13959 and dialysis fluid quality as ISO 11663. The contaminations of dialysis water was categorized into chemical contamination and microbial contamination, contaminants, 4 electorates normally included dialysis fluid and 10 trace elements. Some of them cause serious or life threatening adverse effects if they were not sufficiently removed in the water treatment process. The carbon filters and the reverse osmosis (RO) system are tools for removing these chemical contaminants and the mal-function of these system occasionally lead to such accidents known as aluminum intoxication and hemolytic anemia by chlorine.
The microbial contaminations of dialysis water system easily occur because residual chlorine in tap water for disinfection is removed at charcoal filter in the water treatment system for avoiding hemolytic anemia. Furthermore the dialysis fluid delivery system is not a closed circuit and the drained dialysate is rich for glucose, phosphate and protein which is a good environment for bacterial growth. Gram negative rods are one of the major isolated bacteria and they have lipopolysaccharides on their cell membrane which is well known as endotoxin, a strong bioactive substance. The microbiological water quality should be cautiously monitored by bacterial counts and endotoxin level of dialysis water and dialysis fluid.
