INTRODUCTION AND BACKGROUND
Water is required for hemodialysis. Hemodialysis patients are vulnerable to contaminants in the water used to prepare concentrate and dialysis fluid, or in water used for reprocessing dialyzers. This vulnerability is due to the following:
●Hemodialysis patients are exposed to extremely large volumes of water. The estimated water intake of a healthy individual is 2 L per day or 14 L per week. By comparison, during a single dialysis treatment lasting four hours, performed at a dialysis fluid flow rate of 800 mL/min, a hemodialysis patient is exposed to 192 L of water or to 576 L per week, if treated three times weekly.
●Hemodialysis patients have inadequate barriers to waterborne contaminants. In healthy individuals who are not on dialysis, the gastrointestinal tract separates blood from contaminants in the water. By comparison, the barrier between blood and water in hemodialysis patients is the membrane within the hemodialyzer through which transfer of contaminants is limited only by the size of the contaminant.
●Hemodialysis patients are unable to renally excrete any contaminants taken up from the dialysate.
No municipal water can be considered safe for use in hemodialysis applications in the absence of a treatment system. All dialysis facilities therefore require a properly designed and maintained water treatment system to safeguard patients .