Water Quality for Hemodialysis

GMCT Guidelines for Water Management

• All servicing, maintenance, interventions, and changes to the water pre-treatment plant must be recorded in a dedicated water folder.
• Water quality and plant function should be reviewed bi-monthly by a multidisciplinary committee including senior nursing, medical, and technical staff.
• Minutes of these reviews must be circulated to appropriate health service authorities, including the Clinical Practice Improvement Unit (CPIU), Director of Renal Medicine, and Division of Medicine andCritical Care.
• Dialysis staff must be trained and deemed competent in water quality risk management, with annual education sessions.

Guideline Recommendations – CARI

AAMI Standards

• Water:
  • Bacterial count: 200 CFU/mL maximum; >50 CFU/mL warrants corrective action.
  • Endotoxin count: <2 IU/mL maximum; >1 IU/mL warrants corrective action.
• Dialysate:
  • Bacterial count: <200 CFU/mL; >50 CFU/mL warrants corrective action.
  • Ultrapure dialysate: <0.1 CFU/mL bacterial count; <0.03 IU/mL endotoxinfor high flux.
• Chemical: Listed in AAMI guidelines.

EBPG (European Best Practice Guidelines)

• Water:
  • Bacterial count: <100 CFU/mL; Ultrapure <0.1 CFU/mL for high flux.
  • Endotoxin count: <0.25 EU/mL; Ultrapure <0.03 EU/mL for high flux.
• Chemical: European Pharmacopoeia standards (equivalent to AAMI).

Comparison with Other Guidelines

• Kidney Disease Outcomes Quality Initiative: Generally uses AAMI recommendations.
  • Water: Bacterial count <200 CFU/mL, endotoxin count<2 IU/mL.
  • Dialysate: Regular as for water.
  • Ultrapure Water: Bacterial <0.1 CFU/mL, endotoxin 0.03 IU/mL.
  • Chemical contaminants: As listed in ANSI/AAMI RD62:2001.
• British Renal Association:
  • Adopts concentrate standard prEN 13867:2002 and water standard BS ISO 13959:2001.
  • For hemodiafiltration, water microbial count should not exceed 0 CFU/ml and endotoxin <0.015 IU/ml.
• European Best Practice Guidelines (EBPG):
  • Waterbacterial count: Regular <100 CFU/mL; Ultrapure <0.1 CFU/mL (for high flux or on-line fluid production).
  • Endotoxin count: Regular <0.25 EU/mL;Ultrapure <0.03 EU/mL.
  • Chemical: European Pharmacopoeia standards.
• International guidelines: No specific recommendation.
• CARI guidelines: Based on Level 1 or 2 evidence.
• Canadian Society of Nephrology: No specific recommendation.

Background (GMCT Home Haemo Supplement)

Water quality is paramount for safe and effective hemodialysis, as patients are exposed to over 300 liters of water weekly. Controlling and monitoring water quality is crucial to prevent harmful elements from reaching the patient.

The water pretreatment system includes components such as sediment filters, water softeners, carbon tanks, micro-filters, UV disinfection units, reverse osmosis (RO) units, ultrafilters, and storage tanks. Thesystem's configuration depends on feed water quality and its ability to consistently produce appropriate water quality.

Inadequate water quality can lead to severe patient harm or death. Symptoms of water contamination in hemodialysis patients are listed below:

NOTE: Revised from Food and Drug Administration (FDA). (1989). A manual on water treatment for haemodialysis.

What is the Evidence? (Based on CARI guidelines)

Chemical Contaminants

Themost important chemical contaminants toxic to hemodialysis patients include aluminium, chlorine compounds (e.g., chloramine), nitrates, sulphates, copper, and zinc. These can cause dementia, osteomalacia, hemolytic anemia, nausea, vomiting, and acidosis. Other contaminants like arsenic, chromium, lead,and selenium are typically not in excessive quantities in municipal water, and their limits are set at 10% of the U.S. Environmental Protection Agency Safe Drinking Water Act. Physiological substances like calcium, potassium, and sodium can also cause injury if present in excess. AAMI and EBPG standards are largely similar for these chemicals.

• Chlorine and Chloramine Toxicity: A well-established phenomenon leading to hemolytic anemia and potentially fatal hyperkalemia. Resistance to erythropoietic agents has been reported with chloramine levels of 0.1-0.2 mg/L. Free chlorine can damage reverseosmosis membranes.
• Aluminium Removal: Requires reverse osmosis; pretreatment water softening may help. Deionizers are less effective if aluminium is in colloidal form at neutral pH.
• Chlorine Product Removal: Requires carbon adsorption, especially with high natural levels of N-chloramines or highpH. Chloramines require 4-5 times longer than free chlorine to be adsorbed.

Microbiological Contaminants

• Bacterial Contamination: Pyrogenic reactions have been linked to bacterial contamination of dialysate exceeding 2000 CFU/mL. Water-based organisms (e.g., Gram-negative Pseudomonads) can cause clinical and subclinical consequences.
• Endotoxins: Pyrogenic reactions due to exo/endotoxins are associated with excessive microbial levels in the dialysate system.
• Ultrapure Water: Definedas bacterial count <0.1 CFU/mL and endotoxin <0.03 EU/mL, recommended by both European and American guidelines for high-flux dialyzers.
• Sterile Fluid: For on-line replacement during hemodiafiltration, requires 0 CFU/100L and endotoxin <0.03 EU/mL. This standard is supported by AAMI and EBPG, and required by Pharmacopeia regulations.

Testing frequency for water purity should be more intense during initiation phases or afterany break in the closed circuit (e.g., for repair or maintenance).

Water system design should minimize microbial growth and chemical contamination, incorporating excess capacity or fail-safe mechanisms to prevent unsafe patient treatment due to equipment failure.

Suggestions for Clinical Care (CARI)

(Suggestions based on Level III and IV evidence)

• Ensure regular testing and auditing of water treatment systems and the quality of water produced for dialysis.
• Infusion fluid for hemodiafiltrationmust be produced following the manufacturer's validated process, with final filtration guaranteeing a 7 log reduction in bacterial count of ultrapure fluid.
• Ultrapure water may reduce the long-term risk of accelerated vascular damage, improve response to erythropoietic agents, and mitigate catabolic nutritional states.
• European Best Practice Guidelines (EBPG) should serve as the foundation for optimal dialysate production.
• Familiarize oneself with local municipal water treatment practices and testing procedures.

WATER TESTING

The purity of water for hemodialysis is critical becausethe dialyzer membrane cannot selectively absorb or reject ions, leading to potential toxic levels in dialysis patients.

QUALITY CONTROL

Every hemodialysis unit must have written policies and procedures for the safe operation of water pretreatment systems. These include education policies, procedures for obtaining and testing water samples, recording and trending results, identifying trends, taking actionfor high test results, and adhering to Occupational Health and Safety (OH&S) principles. Currently, Gambro is responsible for water testing, and St George and Sutherland sites review and act on results. Medical, nursing, and technical staff share responsibility for safe operation and participate in regular committee meetings. Dialysis nurses must participate inaudits and ongoing training.

Audits, Training, and Continuing Education

• The operation of water pretreatment systems and ongoing staff training should be audited annually and reported to the Nurse Unit Manager of St George and Sutherland sites.
• Audit reports and recommendations are to be reviewed and managed by thesite committee and resolved with the contracted company, Gambro Pty Ltd.

POLICIES AND PROCEDURES

Education

• Dialysis nursing staff should be educated on overall water management and know who manages water quality (currently Gambro and hospital engineers).
• Personnelinvolved in the water pretreatment system must be trained in their area of responsibility, with records maintained by Engineering & Gambro.

Operation of the Water Pre-treatment Systems

• Only trained and accredited persons should operate the water pretreatment system.
• Records of whois responsible for operating parts of the system must be maintained in the dialysis unit.
• Sutherland staff are trained in bypassing the RO under strict Gambro Pty Ltd guidance, whereas St George nursing staff do not perform this task due to geographical barriers and OH&S concerns.

Obtaining Suitable Water Samples

• Water samples should be obtained from appropriate locations as detailed in operational policies, including guidance on collection method, location, container, and maintenance until testing.
• This responsibility currently lies with Gambro Pty Ltd as part of their Price Per Treatment (PPT) agreement.

Testing of Samples

• Testing must be carried out by trained and accredited personnel or laboratories.
• Records must be maintained within the dialysis unit, managed by Gambro Pty Ltd, and kept in dialysis facilities.

Recording and Trending Results

• All water test resultsshould be recorded and trended over time (e.g., using graphs showing averages).
• Trending helps identify subtle changes in results.
• Test results and trending graphs must be maintained in a Quality folder. Trends are reported biannually to the Renal Department.

Identifying Trends inResults

• Trended water test results should be regularly reviewed by an approved staff member to identify any trends requiring intervention before contaminated products reach hemodialysis equipment.
• Individual sites review water results and liaise with Gambro Pty Ltd for deviations to ensure corrective action is taken.

ActionWhen High Test Results Are Obtained

• Each dialysis unit must have policies detailing required actions for high test results.
• High results must be promptly communicated to responsible senior staff.
• Gambro is responsible for retesting abnormal results and communicating changes until levels return to acceptable standards.

Occupational Health and Safety Principles

• Every dialysis unit should have safe work practice statements for all procedures on the water pretreatment system, developed through risk management.
• These statements (currently attended by StG engineers and ECO Water) must be followed by all personnel working on the system and alsofor those collecting and testing water samples (Responsibility of contractor: Gambro Pty Ltd).
• All contractors must complete a site induction and a written risk management procedure before working on the system.
• Records of risk management procedures, safe work method statements, and contractor inductions mustbe maintained by Gambro and the Engineering Department.

Committee Meetings

• Bi-monthly, water quality and system functioning reports should be presented to a multidisciplinary committee (senior nursing, medical, and technical staff, and other stakeholders).
• Issues should be resolved, and minutes keptand circulated to relevant health service authorities to confirm safe operation of the dialysis unit and water pretreatment plant.

WATER UTILITY COMMUNICATIONS

• NSW Health recommends water utilities communicate with hospitals and dialysis units about planned or unplanned water supply interruptions or changes in water quality (e.g., chlorine, chloramine concentrations exceeding agreed maximums).

Acceptable Levels of Chlorine and Chloramine

• AAMI maximum level for chlorine is 0.5mg/L, and for chloramine is 0.1mg/L.
• If using an on-line chlorine meter, the maximum acceptable level for total chlorine is 0.1mg/L.
• If trending results show increased chlorine, carbon filters must be replaced earlier than twelve monthly.

Bacteria and Endotoxin Testing

• Bacterial levels should be tested monthlyat connection points for hemodialysis equipment (post RO, post water loop), including dialysis machines and bicarbonate filling stations.
• Bacteria levels must not exceed 200 CFU/ml, with an action level of 50 CFU/ml.
• Endotoxins should be measured six-monthly. AAMI requires endotoxin content in product water not to exceed 2 IU/ml; a stricter requirement of 1 IU/ml applies at the outlet of water treatment (post RO). Current Gambro Pty Ltd recommendation is once annually for endotoxin level.
• Testingapplies to sampling at the point of delivery to hemodialysis equipment. When monitoring equipment, rotation ensures each machine is tested within several months.
• The Limulus Amoebocyte Lysate (LAL) assay can test for endotoxins.

EBPG criteria are stricterthan AAMI and are increasingly adopted by Australian dialysis units.

Figure 1. St George Dialysis Units Water TreatmentSystem Diagram

References

• CARI Guidelines: http://www.cari.org.au/DIALYSIS adequacy published/water_quality_for_haemodialysis_july_2005.pdf
• Levy, J., J. Morgan, Eds. (2004). Water Purification. Oxford Handbook of Dialysis. Oxford, Oxford University Press.
• Greater Metropolitan Committee Taskforce: Dialysis Water Pre-treatment for In-Centre and Satellite Haemodialysis Units in NSW: A set of guidelines, 2008.
• Greater Metropolitan Committee Taskforce: Water Pre-treatment Standards for Home Haemodialysis, supplement: A set of guidelines and standards, 2009.