Importance of water quality

The chemical and microbiological contamination of dialysis fluids are serious problems in haemodialysis therapy and one of the cause might be the water used for the preparation of dialysis fluid.
During haemodialysis each patient is exposed to approximately 320 to 360 litres of water per week and hence, each patient is exposed to the potential risk of chemical or microbiological contamination.
If water purity is inadequate toxins may diffuse nonselectively across the dialysis membrane directly into the blood stream of the dialysis patient.
Moreover, end stage renal disease patients are no longer able to excrete distinct toxins via their kidneys.
The extent of exposure together with the nonselective absorption and incapability of urinary excretion places the dialysis patient at much higher risk to water-borne contamination than the healthy population.
Therefore, the chemical and microbiological quality of the water used for dialysis is essential if an additional health risk to those patients is to be avoided.

The most important chemical contaminants can be divided into five groups:
1. Ions found in standard dialysis fluids (Ca, K, Na, Mg,)
2. Trace elements (aluminium, copper, silver, zinc, cadmium, arsenic, mercury, lead, silver, iron, selenium, chromium, silicon, barium),
3. Organic substances (pesticides and aromatic hydrocompounds such as benzene)
4. Disinfectants and preservatives (formaldehyde, sodium hypochlorite, hydrogen peroxide,chloramines, free chlorine, peracetic acid),
5. Group of N-compounds (nitrate, nitrite, nitrosamines), sulphates and fluorides

Effect of water contamination
• High magnesium and calcium content:
  hard water syndrome , nausea,hypertension, headache, confusion, seizure or progressive lethargy.
• Heavy metals:
  haemolysis or nervous system disorders.
• Aluminium overload for instance may cause anaemia, encephalopathy and osteopathy.
• Microbiological Contaminants
  The most important pyrogen in dialysis is the cell-wall component of gram-negative bacteria called endotoxin or lipopolysaccharide (LPS), which is released during bacterial lysis lead to pyrogenic reaction accompanied by fever, chills, nausea, vomiting, hypotension, myalgias and headache
• Permanent microbiological contamination leads to various chronic complications such as dialysis-related amyloidosis, muscle wasting, progressive loss of bone mass, immunodysfunction, and cardiovascular disease