Hemodialysis patients are particularly vulnerable to contaminants in the water used to prepare concentrate and dialysate, or in water used for reprocessing dialyzers. Compared with healthy individuals, hemodialysis patients are exposed to extremely large volumes of water, have inadequate barriers to such toxins, and cannot easily eliminate contaminants:
●The estimated water intake of a healthy individual is 2 liters per day or 14 liters per week. By comparison, a hemodialysis patient may be exposed to 350 to 500 liters of water per week, depending upon their treatment time and dialysate flow rate.
●With normal individuals, the gastrointestinal tract separates blood from contaminants in the water. By comparison, the barrier between blood and water in hemodialysis patients is a thin membrane through which transfer of contaminants is limited only by the size of the contaminant.
●When dialyzers are reused, water is introduced into the blood compartment of the dialyzer during reprocessing. Contaminants in this water may be trapped in the blood compartment and the patient directly exposed to them during the next dialysis treatment.
●Hemodialysis patients are unable to renally excrete any contaminants taken up from the dialysate.