WATER PREPARATION FOR DIALYSIS

Transcription

1 In the name of God WATER PREPARATION FOR DIALYSIS Behnam Hoshyari

2 Ultrafiltration: The process by which plasma water is removed due to a pressure gradient between the blood and dialysate compartments Diffusion: solute exchange between two solutions separated by a semipermiable membrane. Molecules move from a region of higher solute concentration to a region of lower solute concentrations

3 Water significance for the patient Needed by a human being app cc per min or 120 liter per treatment Dialysis patients need app. 20 m 3 /yr

4 How do impurities get into water Water is a complexnand incompletely understood chemical compound. The purest form of water is freshly formed rain as it leaves the cloud. Inthejourneyfromraincloudtoearth,waterabsorbs a lot of polutions such as carbon dioxide, sulfur dioxide, Upon hitting the ground, this water encouters limestone and other minerals to form calcium bicarbonate and sulfate, magnesium carbonate and other salts. Calcium carbonate is the most impurity in tap water and is named water hardness

5 Kinds of contaminations in water Two categories of contaminating substances can cause patient injury: Organic pollutants particles, colloids, bacteria, pyrogens, chloramines, pesticides Inorganic pollutants monovalent/ polyvalent ions, especially calcium, sodium, magnesium, nitrate, copper, aluminium etc.

6 Chloramines :Haemolysis, Methemoglobinemia in hemodialysis patients Fluoride :Nausea, Cardiac arrest in high concentrations, bone disease,chest pain, pruritis Copper :Nausea, Chills,Haemolysis, fatal in high concentrations Lead : Abdominal pain, muscle weakness

7 Zinc :Anemia Sodium:Hypertension Sulfate :Nausea, Vomiting Magnesium: Nausea, Vomiting, Muscle weakness Nitrate: Nausea, Vomiting, Methemoglobinemia Calcium: Nausea, Vomiting, Hypertension, Muscle weakness

8 Bacteria and Endotoxin Shaking chills, hypotension, and fever can be occered by bacteria Maximum level for bacteria of 200 colony forming units (CFU)/mL and a maximum endotoxin concentration of 2 EU/mL

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10 Installation of water pre-treatment and RO system

11 pretreatment

12 1-Sand filter filled with sand with different grains 1 st layer biggest grains 2 nd layer middle grains 3 rd layer smallest grains Water pressure min. 1,8 bar, max. 8,5 bar Electrical connection: 230 V/ 50 Hz/ 5 W Water temperature not under 4 C and not over 43 C

13 2-Activated carbon filter filled with gravel and activated carbon: 1 st layer gravel 2 nd layer activated carbon Pressure, electrical connection, temperature- the same like sand filter Needed for adsorption Change the content of the filters regular (sand and carbon filter) Recommend once a year (depend of the pollution of the raw water)

14 2-Activated carbon filter for adsorption principle: *van der Waals forces *high specific surface (100g act. carbon ca m 2 ) remove chlorine from drinking water

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16 3-Softener/ double softener To reduce the water hardness or to remove the Ca ++ Vessel is filled with negative charged resin During regeneration many Na +- ions remain hanging on the resin (electrical bonding) During the work, Na + -ions are displaced by the Ca ++ -ions For each Ca ++ - ion two Na + - ions are released That s why electrical conductivity from the soft water is higher than from the hard water!

17 Structure of double Softener control unit with solenoid valve, µp double vessel filled with resin Salt tank with salt for regeneration

18 SOFTENER

19 What happens in the softener? Ca ++ /Mg ++ Ca ++ /Mg ++ Ca ++ /Mg ++ Na + / Cl - Resin Resin Resin Resin Na + Na + Na + Na + Ca ++ / Mg ++ Ca ++ / Mg ++ Cl - Softener is in operation Capacity is exhausted in regeneration

20 Reverse Osmosis State of Art to produce pure water in the dialyses osmosis is a well known principle in the nature prerequisite is a semipermeable membrane with very small pores, high pressure, high flow over the membrane (cross flow membranes)

21 Principle of Osmosis Osmotic pressure clear water saline solution semipermeable membrane

22 Principle of Reverse Osmosis pressure clear water saline solution semipermeable membrane

23 Reverse osmosis apparatus

24 Technical details of the Reverse Osmosis pressure: 2 to 15 bar rejection: % of the all salt ions >99 % substances with molecular weight >100 D Reduction of the TOC < 100 ppb Module types: Spiral wound- Module Hollow fibre- Module

25 MICROBIOLOGICAL QUESTIONS OF WATER QUALITY IN HEMODIALYSIS

26 Microbiological contamination in purified water 1. Contamination with pathogenic microorganism gram-negative and gram-positive bacteria spore-form bacteria virus fungi, yeasts 2. Formation of a biofilm 3. Contamination with products of a biofilm parts of biofilm cells pyrogens (can pass the dialyzer)

27 1. Contamination with pathogenic microorganism Retroactive contamination permeate connecting hoses on the dialysis machine contaminated inlets of the dialysis machine maintenance and service Micro organism passing through the RO membrane

28 1-Preventive measure ofmicroorganism enterance Maintenance and service working only with gloves heat- or chemical disinfection from the entire system after the repair Microorganism passing through the RO membrane periodical check of the permeate conductivity on the reverse osmosis (conductivity is an indicator for the quality of the membrane) quick reaction after increase of conductivity (cleaning / exchanging the defect module)

29 1-Contamination with pathogenic microorganism 2-Biofilm 3-Pyrogen

30 What is a biofilm? one of the most persistent problems in dialysis units form easily in any crevice, corner or inner surface of containers, pipes, treatment devices, storage tanks and dialysis machines produced when bacterial cells adhere to a surface, replicate, and produce extracellular polysaccharides

31 Development of a biofilm Adhesion from single bacteria on the surface Growth and formation of a protective polysaccharides film Manifestation and increase

32 Effects of a biofilm increase contamination with microorganism by biofilm expansion contamination of permeate with living and dead bacteria contamination with microbiological degradation and metabolism products (pyrogens)

33 Measures against the formation of a biofilm 1. Periodical heat-disinfection to prevent or eliminate the biofilm 2. Permanent ultrafiltration of the permeate to eliminate pyrogenic substances (endotoxins, exotoxins) to eliminate fragments of a biofilm

34 1-Contamination with pathogenic microorganism 2-Biofilm 3-Pyrogen

35 3- Pyrogens (heat resistant) Acute consequences fever, chills, nausea, headache hypotension lungs oedema... Chronic acute phase responses (micro inflammation) release from inflammation transmitters atherosclerosis immunodeficiency state ß2-microglobulin amyloidosis...

36 Atherosclerosis - risk factors Study:Arici M, Alls J; End-stage renal disease, atherosclerosis and cardiovascular mortality: is C-reactive protein the missing link? Kidney Int 2001; 59(2): kinds of atherosclerosis risk factors classic risk factors e.g. smoking risk factors through uremia risk factors through dialysis e.g. pyrogens and bacteria in the permeate

37 Impact of ultrapure dialysate on CRP Wiemer et al.: Impact of ultrapure dialysate on CRP and erythropoietin response in hemodialysis patients. Kidney Blood Press Res 2001; 24: 297 CRP [mg/decilitres] 1,2 1,0 0,8 0,6 0,4 start after 15 months number of patients = 55 number of patients = 33 0,2 0,0 Ultrapure dialysis fluid < 0,1 CFU/ml < 0,03 IU/ml Standard dialysis fluid < 100 CFU/ml < 0,25 IU/ml

38 Bacteria- and pyrogen free at the point of use What means Point of use? point of use

39 Bacteria- and pyrogen free at the point of use Permeate loop bacteria / endotoxins endotoxins bacteria Microbiological contamination of permeate systems

40 Bacteria- and pyrogen free at the point of use Permeate loop - with heat-disinfection from the loop, the tube to the dialysis machine and the inlet of the dialysis machine bacteria / endotoxins endotoxins bacteria Microbiological contamination of permeate systems

41 Bacteria- and pyrogen free at the point of use Permeate loop - with deadleg free heat-disinfection into the dialysis machine and permanent ultrafiltration bacteria / endotoxins endotoxins bacteria Microbiological contamination of permeate systems

42 Dialysis solution is prepared from Purified water + Concentrate

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44 Bicarbonate Concentrate NaHCO3 Acid Concentrate (acetic acid, citric acid, Na, K, Mg, Cl, dextrose HCO3 + H+ = H2CO3 PH: 7-7.4

45 Conductivity Setting ms/cm mmol/l Generally: Na total = Na Bic + Na acidic LF total = LF Bi + LF acidic 14.3 ms/cm = 3.0 ms/cm ms/cm = 1/resistanceconductivity = 1/1000 1mS 14 ms/cm 140 mmol/l Na because all ions contribute to conductivity 11/06/2015

46 Correlation between Ratio and ph 1L Acid + ( L NaHCO L H 2 O ) = to 2.4 ph to 8.2 ph + osmosis water ~ 7.4 ph 11/06/2015

47 A Standard HD Delivery System Informational Display PT = Pressure Transducer Saline Anticoagulant PT Blood from Patient Blood Leak Detector Dialysate / UF Out (green / yellow) PT Conductivity Meter Dialysate In Mixing System PT Drip Chamber Air Detector Pre-mixed or sorbent Water, Acid regenerated Concentrate, dialysate Bicarbonate Concentrate In Venous clamp Blood return to Patient

48 Thank you for your Attention!