Water Purification for Hemodialysis dialysis and Dialysis solutionYousaf khanRenal dialysis lecturerIPMS-KMU

Did You Know??• An Average Hemodialysis patient is exposed to approximately 560

liters of water through their weekly Dialysis Treatments. This is more water than most people in a lifetime

Water Treatment for Dialysis

Water Treatment• It is important to treat water so impurities and excess minerals

are removed. Minerals in the water can be toxic to patients and harmful to equipment.

• Elements in untreated water may be small enough to pass from the dialysate side of the membrane into the patient’s blood.

Water contaminants harmful for dialysis patient Sign or Symptom Possible Water Contamination-Related Cause• Anemia - Aluminum, chloramines, copper, zinc• Bone Disease - Aluminum, floride• Hemolysis - Aluminum, copper, nitrates, chloramines• Hypertension - Calcium, sodium• Hypotension - Bacteria, endotoxins, nitrates• Metabolic Acidosis - Low pH, sulfates• Muscle Weakness - Calcium, Magnesium• Nausea and Vomiting - Bacteria, calcium, copper, endotoxin, low pH,

magnesium, nitrates, sulfates, zinc• Neurological deterioration - Aluminum• Fever, chills - Bacteria, endotoxin, copper, zinc

Methods of purifying water for hemodialysis• Pre Treatment• Primary Purification• Distribution

Pre Treatment• Preliminary filtration• Softening• Adsorption with activated carbon

• This cascade is designed to prepare the water for optimal operation of the primary purification process.

• Correction of PH (HCL) – Correct excessive alkalinity which can impede functioning of carbon adsorption beds as well as RO membrane.

Water softener• Used to remove calcium and

magnesium from water by ionic exchange with sodium that has been affixed to a resin bed.

• Resin exchanges two Na+ ions for Ca++ and Mg++ as well as other cations such iron and manganese.

• Protect RO membrane.

Carbon adsorption• Activated carbon is utilized to

remove chlorine and chloramines which are not removed by reverse osmosis.

• Cause hemolytic anemia• Chloramines take longer time

to adsorbed by carbon than chlorine.

• Also removed organic compound

Primary purification process

Reverse osmosis:• Achieved by high pressure filtration of water (using powerful pump)

through semipermeable membrane that will hold back the dissolved solutes.

• Reverse osmosis will removed more than 95% of ionic contaminants and non ionic contaminants as small as glucose

• Provide effective barrier against bacteria and endotoxins

• RO provide water of sufficient quality for the preparation of dialysis solution with out further purification.

Primary purification process

Deionization:• Used as alternative to reverse osmosis. • But is more frequently used to further purify water• Deionizers do not remove nonionic contaminants bacteria or

endotoxins• Contain two beds ( one for the cationic resin and the other for

anionic resin)• Cationic resins contain sulfuric radicals and these exchange H ion for

other cation such as Na, Ca and aluminum• Anionic resins contain ammonium radicals which exchange hydroxyl

ion for other anions such as chloride, phosphate and fluoride.

Primary purification process

Water treatment for Hemodialysis

Distribution of purified water• Distribution of purified water must be free of contaminants

• Chemical contaminants must be avoided by using inert materials such as plastic for all components that contact the purified water and dialysis solution.

• Microbiologic contamination is avoided by using appropriately designed and constructed piping systems in combination with regular disinfection

Safety standards• Careful procedure and documentation of the functioning of each

part of the water supply system must be done.

• Both AAMI (Association for advancement of medical instrumentation ) and the European Best Practices Group have developed standards for equipment used to purify water for dialysis that are designed to maximized patient safety.

• These include chemical purity monitoring of water and dialysis solution

• Chloramines are checked for at least daily.

Thank you