HOW DOES DRINKING WATER COMPARE TO KIDNEY DIALYSIS WATER STANDARDS?

While the water in your home might be safe to drink, and in general it is extremely safe, but it is not safe to use for hemodialysis treatments. For this reason, people who use home dialysis systems must have a water purification system either built into their home dialysis equipment or in addition to a home dialysis equipment so that the water they use for their dialysis treatments is ultra pure.

Companies who sell water purification systems are regulated by the Food and Drug Administration (FDA). Water systems along with dialysis machines, are mandated as Class II medical devices by the FDA. Class II devices require diligent tracking of critical components and a complaint investigation system in place. Class I devices include loosely regulated items such as tongue depressors and band-aids, while Class III stringently regulates devices like high-flux hemodialyzers and implantable pace makers and requires tracking of all parts (even nuts and bolts).

There are many opportunities for water to pick up environmental substances starting when rain drops fall down to earth. Gases such as carbon dioxide can be picked up by the rain, dissolve and make acid rain. Once water seeps down into the earth, it can pick up numerous minerals including calcium from limestone, metals such as lead and copper and even poisons such as arsenic. There are man-made impurities that can contaminate the water such as pesticides and fertilizers. Well water often contains a large amount of salt, while water from reservoirs usually harbors bacteria, viruses and algae. And finally, city water suppliers add chemicals to water to destroy bacteria, fluorides to prevent tooth decay, and aluminum to make the water clear.

Unlike your drinking water that contains chloramines for disinfection purposes, dialysis centers must remove this before treating its patients. Dialysis centers and hospitals are notified before a water system converts to chloramine. Like chlorine, chloramine residuals need to be removed from water that is used for dialysis machines. As part of their standard test procedures, technicians check for total chlorine residuals (due to chloramine) to ensure the residual is zero. Some machines may need modifications depending on the method of chlorine removal that is currently used. A change in the disinfectant used to treat the water should not impact or require any change in the normal operation of dialysis machines.

Why does the water I use for my dialysis treatments have to be ultra pure? The thin, hair-like threads inside your dialyzer are hollow. The walls of these fibers are made of a semipermeable material which acts like a filter. During your dialysis treatment, your blood flows inside these hollow fibers, while the outside of the fibers is bathed in dialysate. Dialysate is a cleansing solution which is a mixture of water and chemicals that pulls the wastes and extra fluid through the fibers and out of your blood. However, because the fibers are semipermeable, if the water used to make the dialysate is not completely pure, impurities from the water in the dialysate can get into your blood. Many of these impurities can cause you serious harm. If anything less than ultra pure water is used during your dialysis treatment, a variety of things could happen:

• Too much calcium or magnesium can cause nausea, vomiting, muscle weakness, severe headaches, skin flushing and low or high blood pressure.
• Metals can cause a variety of symptoms including liver damage, inflammation of the pancreas, destruction of red blood cells, seizures, brain damage and even death.
• Pesticides and fertilizers can cause headaches, dizziness, convulsions and heart and liver damage.
• The chemicals added to destroy bacteria will destroy red blood cells if they enter the blood stream.
• Bacteria and endotoxin can cause infections and fever.
• Overexposure to fluoride can cause abnormal hardening of bones, as well as nausea and vomiting, muscle twitching, low blood pressure and seizures.

Turning tap water into ultra pure water for dialysis treatments is essential to protect dialysis patients from harm or injury. A dialysis center’s biomedical technicians will ensure that your dialysis equipment functions properly and are well trained to operate the system and perform required safety tests. Contact your health care team to assist you with questions or concerns you may have.