بسم هللا الرحمن الرحيم

Water treatment for HD Unit

DR Samir Sally, MD

Consultant Internal Medicine & Nephrology,MUNC, Mansoura University, Egypt

•

1940 1960 today

THE UNDENIABLE TECHNOLOGICAL PROGRESS IN DIALYSIS

Mission

Vision

Goals

Our Mission

• To serve our community at all levels by providing health care services through a multidisciplinary team approach at highest international standards covering all aspects of Hemodialysis

Our Vision

• To be one of the best recognized Health Care providers not only at local or national level but internationally too

Our Core Values

• Focus on patient safety

• Focus on Staff safety

• More and more education for the patients

• More and more education for the staff

• Confidentiality & Respect to patients and staff alike

Manual of Hemodialysis

Policies and Procedures

Purpose

Policy Statement

Definition

Procedure

Forms/Attachments/Flowcharts

Material/Equipment

Review History

Reference

Approval

Manual of HD

• Policies and procedures (patient related)

1-Dialysis request and patient specific care

2-Assessment of medical status of patient

3-Iniating & discontinuing dialysis treatment

4-Nursing care during dialysis

5-Fluid management of dialysis

6-Intravenous drug administration

7-Anticoagulant regimens

Manual of HD

8-Diagnostic testing including frequency

9-Managing vascular access

10-Adequacy of dialysis

11-Code blue arrest protocols

12-Management of complications ( CPG)

13-Dialyzer selection and priming

14-Water treatment & monitoring of quality

15-preperation and monitoring of Dialyzate

Manual of HD

• Infection Control

1-immunization guidelines

2-Infection prevention:

A- Cleaning procedures

B-Hand Washing

C-Handling of infectious waste

D- Handling of infected/contagious patient

Manual of HD

• Equipment

1-Operating and service manual

2-Record of repair

Dress code in the treatment area

Manual of HD

• Safety

1-General safety

2-Infection Control

3-Storing & handling of hazardous wast

4-Electrical safety

5-Fire safety

6-Needle injury with contaminated item

7- Staff immuization

Manual of HD

• House keeping: Daily, weekly and monthly

1- Standard precautions

2-Transport of soiled materials

3-Soap/detergent/antiseptic use and dispensing

Regular investigations and action plan

• Monthly

Creatinine,BUN,URR,Na,K,Ca,Po4,ALT,Albumin,Glucose,CBC

• Every 3 months

Iron pannel

Viral screening

• Every 6 months

Lipid profile

PTH

Towards better quality of HD

Better quality of HD

We suggest that machines should be replaced after between seven and ten years’ service or after completing between 25,000 and 40,000 hours of use for haemodialysis, depending upon an assessment of machine condition. (2C)

Multidisciplinary Team

Pt. and Family Educator

1-Awarness about kidney failure

2-Choice of RRT ( HD,PD,TX)

3-Compliance with dietary and fluid instructions and restrictions

4-Compliance with medication instruction and dialysis treatment prescription and schedule

5- Significance of Lab test results

Pt. and Family Educator

6-Importance of caring vascular access

7-Importance of good hygiene and infection control

8-Awarness, prevention and management of HTN,renal bone disease, sexual and Psychological effects of RF on patients and their families

Social Worker

1-Discuss medical condition of the patient with doctors and nurses

2-Provide emotional and psychological support for new patients and families

3-Evaluate home situation

Renal Dietitian

1-Nutritional assessment and reassessment

2-Current malnutrition related to renal failure

3-Diet history and eating habits

4-Explain relation of lab values to the food

5-Review food and fluid intake

6-Educate medical staff on renal nutrition

7-Food drug interaction

Bio Med

1-Disinfection of water treatment unit and portable

RO

2-Daily TDS, conductivity and PH

3-Checking all machines maintenance and contact

with the manufacturing companies

4-Awarness of all AAMI standards

5-Check free chlorine or chloramine test

6- Daily percent rejection

Pharmacists

1-Chart review

2-Drug related problems

3-Contribute to resolution of drug related problems

4-Educate pt as needed

5-Review blood work

Vascular access

Vascular access

65% of all patients commencing haemodialysis should commence with an AV fistula

85% of all prevalent patients on HD should

receive dialysis via a functioning AVF

Vascular access planning should commence on CKD stage 4. (2C)

Vascular access

AVF should be placed as a minimum at three months prior to the commencement of haemodialysis and probably not more than one year from the expected date of dialysis.

In individuals in whom an AV graft is deemed to be the appropriate access, placement can be delayed until a time closer to the expected date of dialysis.

Vascular access

Tunneled catheters should be preferred in all patients..

We recommend that venous catheters should be removed in all seriously ill haemodialysispatients with catheter related bacteraemiaunless no alternative vascular access can be achieved. (1B)

Vascular access

Catheter related bacteraemia episodes are relatively common – the incidence is reported at between 1-10/1000 patient days

Higher rates of mortality and morbidity related to an increased incidence of metastatic infection (e.g. discitis, endocarditis).

Introduction

• Survival of HD patients is steadily improving

• Water treatment for preparation of dialysate is probably the most neglected area of RRT with dialysis

• Quality of water contributes very significantly in acute and long term morbidity and prognosis

Introduction

• Dialysis staff should have a fundamental understanding of water pre-treatment for haemodialysis

• Written policies, practices and procedures shall be in place for the safe operation of dialysis water pre-treatment systems

• All servicing, maintenance, interventions and changes to the water pre-treatment plant, as a minimum, shall be recorded in an on-site log book

Introduction

The worst way to hurt patients is through the water system, so it is expected that you know what is going on.

Exposure to Water and Contaminants

Average Population

• Drinks approximately 14 L/week (2L/day)

• Able to excrete toxic substances in urine

• Contaminants selectively absorbed in GI tract, indirectly exposed to blood

Hemodialysis Patient

• Exposed to approximately 360 L\w

• Kidneys unable to excrete toxic substances

• Contaminants directly exposed to blood via dialyzer membrane

Weekly Water Exposure

Water supply

There are 2 sources of municipal water:

• Surface water is generally more contaminated with organisms and microbes, industrial wastes, fertilizers, and sewage.

• Ground water is generally lower in organic materials but contains higher inorganic ions such as iron, ca, mg and sulfate

Toxic effects of water contaminants in HDContaminant Possible effects

Aluminum Dialysis encephalopathy, renal bone disease

Calcium, Magnesium Hard water syndrome, hypertension, hypotension

Chloramine Hemolysis, anemia, methameglobinemia

Copper Nausea, headache, liver damage, fatal hemolysis

Fluoride Osteomalacia, osteoporosis

Sodium Hypertension, pulmonary edema, confusion, headache, seizures, coma

Microbial Pyrexia reactions, chills, fever, shock

Nitrate Methmeglobinemia, hypotension, nausea

High iron Hemosiderosis

Sulfate Nausea, vomiting, metabolic acidosis

Zinc Anemia, vomiting, fever

Aromatic hydrocarbons Potential chemical carcinogens

Progressive Dialysis Encephalopathy from Dialysate AluminiumArch Intern Med V138, 1978

• 8 cases of fatal dialysis encephalopathy observed in 22 months (38% of all patients)

• Coincided with addition of Al SO4 and Na aluminate to city water resulting in dialysis fluid Al concentration of 200-1000 ug/l

• The outbreak ended after installation of deionizer that reduced dialysis fluid Al to < 1 ug/l

• “Philadelphia Incident” of 1987. Initially, a nurse in the facility noticed an unusually large number of hematocrit values that were lower than normal.

• Forty-four patients out of 107 required transfusions, and 10 were sent to the emergency department for additional treatment.

• Upon further investigation, The staff person monitoring the system recorded the chloramine levels accurately as they climbed to toxic levels (AAMI maximum level is 0.1 mg/L), but the staff member was not aware that this was a dangerous situation and did not report it to a supervisor.

• Further, no written policy was in place regarding the testing of total chlorine levelsThis incident illustrates the need for staff education

Arnow PM et al. An outbreak of fatal fluoride intoxication in a long-term hemodialysis unit. Ann Intern Med 1994;121:339-344.

• On 16 July 1993, 12 patients treated at a long-term HD unit in Chicago became ill during or soon after HD.

• The patients experienced symptoms of severe pruritus, headache, nausea, and chest or back pain.

• Three patients arrested and died due to ventricular fibrillation after completion of dialysis that day.

• Subsequent investigations found that fluoride was released from the deionization system after the ion exchange resin inside was exhausted.

• The investigator concluded that the incident was caused by errors in maintenance of the deionization system

• In February 1996, Caruaru,Brazil, 116 (89%) of 131 patients experienced visual disturbances, nausea, vomiting, and muscle weakness, following routine HD treatment. Subsequently, 100 patients developed acute liver failure. As of December 1996, 52 deaths occurred.

• Two groups of hepatotoxic cyanotoxins were idnetified: microcystins, specifically microcystin-YR, -LR and -AR.

• The outbreak occurred in one of two HD units using same water source

Water treatment system

1.Feed Water Components: (Back-flow preventer, Temperature blending valve, booster pump and raw water tank, ±acid feed pump )

2.Pre-treatment section: (filters, activated carbon and softner).

3.Treatment section: (reverse osmosis).

4.Post-treatment section: (microbial and UV filters or/and deionization)

5.the distribution system: piping, valves, pumps, ±storage tanks

• An indication of mineral deposits forming on the membrane will be high readings of total dissolved solids (TDS), percent rejection and conductivity (or low resistivity).

• In feed water classified as being very hard, damage to the RO membrane may occur extremely rapidly, even within hours, with irreversible membrane damage

• So the softener is placed before the reverse osmosis (RO) unit to protect the RO membrane.

• Analysis of the level of calcium carbonate (CaCO3) in the feed water is important for determining the size of the softener.

Schematic diagram example of a water treatment system for hemodialysis

Back flow preventer: inhibits flow

back of treated water into

municipal water

Temperature blending valve:

brings water to a standard

temperature of 25 oC for

proper function of RO system

Booster pump: maintains adequate

flow and pressure of water

so the system operates

successfully.

Acid feed pump

• By increasing the pH of the city water supply using lime softening agents or Ca CO3 prevent leaching of lead, copper from the piping system

• For proper function of RO and carbon tanks, incoming water pH should be between 5-8.5

• A pH higher than 8.5 with chloramines present will cause the carbon to be less adsorptive and the RO membrane performance to degrade, resulting in poor water quality.

Purification Processes

Process Contaminant

Carbon Adsorption Chloramine, organics

Softener Calcium, Mg

Reverse osmosis Inoic contaminants, bacteria, endotoxin

Deionization Ionic contaminants

Ultrafiltration Bacteria, endotoxin

Multimedia depth filter

• Large particulates of >10 microns such as dirt, are removed by a multimedia depth filter.

• Floculants can clog the carbon and softener tanks, destroy the RO pump, and foul the RO membrane

• Contain multiple layers of various sized rocks that trap the large particles as the water filtered downward

Carbon Tank

• Removes chlorine and chloramine

• These are high level oxidative chemicals. They are added to municipal water systems to kill bacteria, but they also cause hemolysis

Carbon filter

•As the input water flows down through the granular activated carbon (GAC), solutes diffuse from the water into the pores of the carbon and become attached to the structure.

•A 10-minute exposure time of the water through the carbon tanks to reduce chlorine to at least 0.5 mg/L and the chloramine to be adsorbed to at least 0.1 mg/L.

A wide variety of naturally occurring and synthetic organic compounds, such as herbicides, pesticides, and industrial solvents, will be adsorbed as well

Water Softener• Water containing Ca and Mg

form deposits on RO membrane

• Softeners work on ion exchange basis. The resin beads within the tank have a high affinity for the cations Ca and Mg (divalents) present in the source water and release 2 sodium ions (monovalent) for one Ca or Mg captured

Hardness of water

• Calcium carbonate Classification

• 0–60 mg/L Soft

• 61–120 mg/L Moderately hard

• 121–180 mg/L Hard

• Greater than 180 mg/L Very hard

Water Softener

• The softener needs regenerating on a routine basis with concentrated NaCl solution (brine) before the resin capacity is used up

• The resin is backwashed to loosen the media and clean any particulates from the tank. After the backwashing step, the brine solution is drawn into the tank

Reverse Osmosis system

• RO overcomes natural osmosis by forcing feed water under pressure thru a semi-permeable membrane leaving contaminants behind (ions, organics)

Reverse osmosis

•Reverse osmosis (RO) uses high pressure to force water across a semipermeable membrane, thereby rejecting

90 to 99 percent of ionic compounds and

>95 percent of nonionic contaminants,

also it is an effective barrier against microbiological contaminants, including bacteria, viruses, and endotoxin.

Ion exchange deionizers (DI)

DI use a two-stage process to remove virtually all ionic material remaining in pretreated water.

Two types of synthetic resins are used; one to remove positively charged ions (cations) and another to remove negatively charged ions (anions).

•Although deionizers produce water of very high purity with respect to ionic contaminants, they do not remove microbiological contaminants.

•Therefore, it is necessary to incorporate bacterial control equipment after the application of a deionizer.

Ultraviolet filter

The mechanism of microorganism destruction is currently believed to be that ultraviolet causes molecular rearrangements in DNA and RNA, which in turn blocks replication.

•As the UV kills the bacteria, it may increase the level of endotoxinas a result of the destruction of the gram-negative bacteria (endotoxin producing) cell wall

Bacterial filters

Distribution system• RO distribution systems: direct feed and

indirect feed

• Direct feed: directly delivers the product water from the RO unit to the loop for distribution

• Indirect feed: involves a storage tank that accumulates the product water and delivers to the distribution loop

• Unused portions are recirculated back into the storage tank

Microbiological aspects of fluid system design

• use of a recirculation-type system,

• avoidance of dead ends and dead space areas,

• use of materials compatible with the planned methods of disinfection

• avoidance of storage tanks. If a storage tank is necessary it should be cleaned and disinfected.

• The disinfection program could prevent the formation of biofilm, which can become difficult to eradicate.

Ultrapure dialysis solution

• Decreases CRP and IL-6

• Improves response to EPO

• Promotes better nutrition

• Reduces plasma levels of ß-2-microglobulin

• Slows loss of residual renal function

• Lowers cardiovascular morbidity

• Bacteria level below 0.1 cfu/ml and endotoxin level below 0.03 EU/ml

Susantitaphong P et al. Effect of ultrapure dialysate on markers of inflammation, oxidative stress, nutrition and anemia parameters: a meta-analysis. NDT (2013) 28: 438-446

Water treatment unit

TDS, and conductivity daily

Microbiological culture and endotoxin assay. Monthly

Chemical assay every 6 months

Water treatment unit

• There is no limit for RO product TDS/conductivity.

• Values that are acceptable in one location may not be acceptable in another location.

• TDS in some areas of 50 ppm is acceptable and other areas where 10 ppm is NOT acceptable. It all depends on your raw water.

• A slight change in the amount of Fluoride injected into the water can cause the RO product water to go less than a 1 ppm TDS increase.

Bacteriological Monitoring:

• The maximum level of bacteria in water used to prepare dialysis fluid must not exceed the AAMI standard of 100 CFU. The AAMI action level is 50 CFU

• An action level is defined as a point when measures must be taken to correct the potential source to remain in compliance with AAMI standards

Endotoxin standard

• The maximum level of endotoxin in water used to prepare dialysis fluid must not exceed the AAMI standard of 0.25 Endotoxin Units/ ml (EU/ml)

• The action level of endotoxin is 0.125 EU/ml

Contaminant Maximum

Concentration mg/L

Test Methodology

Calcium 2 (0.1 mEq/L) EDTA or Atomic Absorption

Magnesium 4 (0.3 mEq/L) Atomic Absorption

Potassium 8 (0.2 mEq/L) Atomic Absorption, or Flame Photometri

Sodium 70 (3.0 mEq/L) Atomic Absorption or Flame Photometric

Antimony 0.006 Atomic Absorption (platform)

Arsenic 0.005 Atomic Absorption (gaseous hydride)

Barium 0.10 Atomic Absorption (electrothermal)

Beryllium 0.0004 Atomic Absorption (platform)

Cadmium 0.001 Atomic Absorption (electrothermal)

Chromium 0.014 Atomic Absorption (electrothermal)

Lead 0.005 Atomic Absorption (electrothermal)

Mercury 0.0002 Flameless Cold Vapor (Atomic

Absorption)

Contaminant Maximum Concentration

mg/L

Test Methodology

Selenium 0.09 Atomic Absorption (gaseous, or

electrothermal)

Silver 0.005 Atomic Absorption (electrothermal)

Aluminum 0.01 Atomic Absorption (electrothermal)

Chloramines 0.10 DPD Ferrous Titrimetric Method

Total chlorine 0.50 DPD Ferrous Titrimetric Method

Copper 0.10 Atomic Absorption (direct aspiration)

Fluoride 0.20 Ion Selective Electrode Method

Nitrate (as N) 2.00 Cadmium Reduction Method

Sulfate 100.00 Turbidimetric Method

Thallium 0.002 Atomic Absorption (platform)

Zinc 0.10 Atomic Absorption (direct aspiration)

Association for the Advancement of Medical Instrumentation. Dialysate for hemodialysis (ANSI/AAMI RD52:2004).Arlington (VA). American National Standard. 2004

Water treatment unit

A programme of improvement should begin immediately if routine monitoring demonstrates that concentrations of chemical contaminants exceed the maximum allowable limits of AAMI. (1B)

Disinfection

General

• Disinfection schedules should be designed to prevent bacterial proliferation, rather than being designed to eliminate bacteria once they have proliferated to an unacceptable level (i.e. above the action level).

• A proper disinfection strategy is to be preventive and this should be applied from the start of operation.

Disinfection

• Disinfection of the distribution piping systems.

• 1- Chemical disinfection

• 2- Hot water disinfection When used to control bacterial proliferation (minimum distribution loop temp 60 oC).

• Heat disinfection will not remove established biofilms, but is convenient, requires little rinse time and can thus be used more often to prevent biofilm formation. An occasional chemical disinfection might still be necessary.

Testing of samples

• Testing of water samples shall be carried out by trained and accredited persons or accredited laboratories.

• The dialysis unit shall maintain records of persons who have been trained and accredited and full details of accredited laboratories.

• The records shall be maintained within the dialysis unit.

Sample collection

• Water sample sites

• Samples are to be taken at outlets of the water distribution system.

• Prior to sampling, the inside of the outlet can be disinfected, especially if no hemodialysis machine is attached. The reason for such disinfection is that, over time, residual water in an outlet will support microbial growth. The disinfection can be made by flushing the inside of the outlet with 70 % ethanol or iso-propanol. A sterile cotton swab wetted with alcohol can also be used. Exposure time is to be >15 s.

• It is sufficient to let out enough water to rinse off the alcohol (200 ml to 500 ml) prior to sampling.

• Alternatively, hoses can be disconnected from the tap and the taps opened and allowed to flush for 2 min to 3 min before aseptically collecting a sample.

• Sample for cultivation and endotoxin analysis: Sample volume 5 ml to 1,000 ml or volume as specified by the laboratory..

Sample collection

• Dialysis fluid samples

• Dialysis fluid samples should be collected from a sampling port prior to the dialyzer. The sample port should be designed to minimize the likelihood of contaminating the sample and should be capable of being effectively disinfected.

• Many dialysis machines are equipped with dialysis fluid sample ports that can be accessed using a syringe. These sample ports may be disinfected with 70 % ethanol or iso-propanol and allowed to air dry.

• A sterile syringe (20 ml or larger) should then be used to aspirate dialysis fluid out of and into the port before filling the syringe. The filled syringe should then be discarded and a fresh sample of dialysis fluid collected using a new sterile syringe.

• Sample for cultivation and endotoxin analysis: Sample volume 5 ml to 1,000 ml or a volume as specified by the laboratory. Containers for samples to be cultured should be sterile and containers for samples to be tested for endotoxins should be sterile and endotoxin-free.

Storage of samples

• Heterotrophic plate count

• Storage of samples

• Microbial analysis of water and dialysis fluid samples should be conducted as soon as possible after collection to avoid unpredictable changes in the microbial population. If samples cannot be analyzed within 4 h of collection, follow the laboratory's instructions for shipping. Samples intended for colony counts should not be frozen.

• Storage of samples for endotoxin analysis may be different from what is given above, provided the complete procedure follows the manufacturer's instructions for use of the LAL assay.

Conclusion

• Water treatment is a generally neglected area of dialysis therapy

• Quality of water contributes very significantly in acute and long term morbidity and prognosis

• Due to increased survival of dialysis patients, increased use of bicarbonate dialysate and high flux membranes, water treatment has become essential

• It is worthwhile achieving the goal of sterile, pyrogen free and chemically pure water for dialysis

Conclusion• Written policies, practices and procedures shall be in place

• AAMI standards are the accepted minimum standards for water pre-treatment for haemodialysis.

Each unit should have standard operating procedures in place for sampling, monitoring and recording of feed and product water quality

• All servicing, maintenance, interventions and changes to the water pre-treatment plant shall be recorded.

.

Conclusion

• Medical directors who learn, know, and embrace the requirements for providing high-quality dialysis water will be most successful in this task.

• Medical, nursing and technical staff working in dialysis units share responsibility for the safe operation of the water pre-treatment plant and shall participate together in regular multidisciplinary committee meetings to review the safe operation of the water pre-treatment plant and RO water plant.