Hemodialysis: Chapter 5, Dialyzers Overview - Dr.Gawad

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1. Mohammed Abdel Gawad MD/PhD Neph, ESENeph
Nephrology Unit, School of Medicine, NewGiza University
Nephrology Consultant, Alexandria
Founder of NephroTube.com
Chair of AFRAN Web/Media Committee
ISN Education SoMe Team Member
Chapter 5
Dialyzers Overview
You can get this book free from www.NephroTube.com

2. Watch the video recording of this lecture
on NephroTube YouTube channel
www.YouTube.com/NephroTube

3. Visit
www.NephroTube.com
to get more Nephrology lectures
(pdf and video recordings)

4. Dialyzer
Blood
compartment
Dialysate
compartment
Semipermeable membrane
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5. NephroTube Synopsis of Conventional Hemodialysis, First Edition, 2024
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Parallel plate dialyzer
https://homedialysis.org/home-dialysis-
basics/machines-and-supplies/dialysis-museum

6. Talk Outline: Chapter 5 :Dialyzers Overview
•Dialyzer structure
•The flow direction of blood and dialysate: Counter-current flow
•Materials of the dialyzer membranes
•Physical properties of the dialyzer
•Dialyzer sterilization
•Dialyzer reuse
•Dialyzer efficiency and flux:
•Extraction ratio (ER)
•Dialyzer efficiency:
•Dialyzer clearance (KD or K)
•Mass transfer-area coefficient (KoA)
•Dialyzer flux:
•Ultrafiltration coefficient (KUF)
•β2-microglobulin clearance, β2-microglobulin sieving
coefficient, or membrane pore size
•Available evidence comparing the use of low- versus
high-flux membranes
•Interrelation between dialyzer efficiency and dialyzer flux
•Expanded hemodialysis (HDx): Medium cut-off
(MCO) membrane
•Albumin and amino acids loss during
hemodialysis
•Dialyzer monitoring and related alarms:
•I. Transmembrane pressure (TMP)
monitoring
•II. Blood leak detector
•III. Pressure monitors
NephroTube Synopsis of Conventional Hemodialysis, First Edition, 2024
You can get this book free from www.NephroTube.com

7. Talk Outline: Chapter 5 :Dialyzers Overview
•Dialyzer structure
•The flow direction of blood and dialysate: Counter-current flow
•Materials of the dialyzer membranes
•Physical properties of the dialyzer
•Dialyzer sterilization
•Dialyzer reuse
•Dialyzer efficiency and flux:
•Extraction ratio (ER)
•Dialyzer efficiency:
•Dialyzer clearance (KD or K)
•Mass transfer-area coefficient (KoA)
•Dialyzer flux:
•Ultrafiltration coefficient (KUF)
•β2-microglobulin clearance, β2-microglobulin sieving
coefficient, or membrane pore size
•Available evidence comparing the use of low- versus
high-flux membranes
•Interrelation between dialyzer efficiency and dialyzer flux
•Expanded hemodialysis (HDx): Medium cut-off
(MCO) membrane
•Albumin and amino acids loss during
hemodialysis
•Dialyzer monitoring and related alarms:
•I. Transmembrane pressure (TMP)
monitoring
•II. Blood leak detector
•III. Pressure monitors
NephroTube Synopsis of Conventional Hemodialysis, First Edition, 2024
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8. NephroTube Synopsis of Conventional Hemodialysis, First Edition, 2024
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Arterial blood port
(Blood inlet)
Venous blood port
(Blood outlet)
Dialysate inlet port
Dialysate outlet port
Header space
Potting material
Blood compartment
Dialysate compartment
Capillary hollow fibers

9. NephroTube Synopsis of Conventional Hemodialysis, First Edition, 2024
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10. Talk Outline: Chapter 5 :Dialyzers Overview
•Dialyzer structure
•The flow direction of blood and dialysate: Counter-current flow
•Materials of the dialyzer membranes
•Physical properties of the dialyzer
•Dialyzer sterilization
•Dialyzer reuse
•Dialyzer efficiency and flux:
•Extraction ratio (ER)
•Dialyzer efficiency:
•Dialyzer clearance (KD or K)
•Mass transfer-area coefficient (KoA)
•Dialyzer flux:
•Ultrafiltration coefficient (KUF)
•β2-microglobulin clearance, β2-microglobulin sieving
coefficient, or membrane pore size
•Available evidence comparing the use of low- versus
high-flux membranes
•Interrelation between dialyzer efficiency and dialyzer flux
•Expanded hemodialysis (HDx): Medium cut-off
(MCO) membrane
•Albumin and amino acids loss during
hemodialysis
•Dialyzer monitoring and related alarms:
•I. Transmembrane pressure (TMP)
monitoring
•II. Blood leak detector
•III. Pressure monitors
NephroTube Synopsis of Conventional Hemodialysis, First Edition, 2024
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11. NephroTube Synopsis of Conventional Hemodialysis, First Edition, 2024
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Arterial blood port
(Blood inlet)
Venous blood port
(Blood outlet)
Dialysate inlet port
Dialysate outlet port
Header space
Potting material
Blood compartment
Dialysate compartment
Capillary hollow fibers

12. Talk Outline: Chapter 5 :Dialyzers Overview
•Dialyzer structure
•The flow direction of blood and dialysate: Counter-current flow
•Materials of the dialyzer membranes
•Physical properties of the dialyzer
•Dialyzer sterilization
•Dialyzer reuse
•Dialyzer efficiency and flux:
•Extraction ratio (ER)
•Dialyzer efficiency:
•Dialyzer clearance (KD or K)
•Mass transfer-area coefficient (KoA)
•Dialyzer flux:
•Ultrafiltration coefficient (KUF)
•β2-microglobulin clearance, β2-microglobulin sieving
coefficient, or membrane pore size
•Available evidence comparing the use of low- versus
high-flux membranes
•Interrelation between dialyzer efficiency and dialyzer flux
•Expanded hemodialysis (HDx): Medium cut-off
(MCO) membrane
•Albumin and amino acids loss during
hemodialysis
•Dialyzer monitoring and related alarms:
•I. Transmembrane pressure (TMP)
monitoring
•II. Blood leak detector
•III. Pressure monitors
NephroTube Synopsis of Conventional Hemodialysis, First Edition, 2024
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13. NephroTube Synopsis of Conventional Hemodialysis, First Edition, 2024
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14. Talk Outline: Chapter 5 :Dialyzers Overview
•Dialyzer structure
•The flow direction of blood and dialysate: Counter-current flow
•Materials of the dialyzer membranes
•Physical properties of the dialyzer
•Dialyzer sterilization
•Dialyzer reuse
•Dialyzer efficiency and flux:
•Extraction ratio (ER)
•Dialyzer efficiency:
•Dialyzer clearance (KD or K)
•Mass transfer-area coefficient (KoA)
•Dialyzer flux:
•Ultrafiltration coefficient (KUF)
•β2-microglobulin clearance, β2-microglobulin sieving
coefficient, or membrane pore size
•Available evidence comparing the use of low- versus
high-flux membranes
•Interrelation between dialyzer efficiency and dialyzer flux
•Expanded hemodialysis (HDx): Medium cut-off
(MCO) membrane
•Albumin and amino acids loss during
hemodialysis
•Dialyzer monitoring and related alarms:
•I. Transmembrane pressure (TMP)
monitoring
•II. Blood leak detector
•III. Pressure monitors
NephroTube Synopsis of Conventional Hemodialysis, First Edition, 2024
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15. NephroTube Synopsis of Conventional Hemodialysis, First Edition, 2024
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Physical
properties of
the dialyzer
Dialyzer
surface area
0.8 to 2.5m2
the surface area of the dialyzer membrane
could be roughly equivalent to the patient's
body surface area
Dialyzer
priming
volume
60 to 120 mL

16. Talk Outline: Chapter 5 :Dialyzers Overview
•Dialyzer structure
•The flow direction of blood and dialysate: Counter-current flow
•Materials of the dialyzer membranes
•Physical properties of the dialyzer
•Dialyzer sterilization
•Dialyzer reuse
•Dialyzer efficiency and flux:
•Extraction ratio (ER)
•Dialyzer efficiency:
•Dialyzer clearance (KD or K)
•Mass transfer-area coefficient (KoA)
•Dialyzer flux:
•Ultrafiltration coefficient (KUF)
•β2-microglobulin clearance, β2-microglobulin sieving
coefficient, or membrane pore size
•Available evidence comparing the use of low- versus
high-flux membranes
•Interrelation between dialyzer efficiency and dialyzer flux
•Expanded hemodialysis (HDx): Medium cut-off
(MCO) membrane
•Albumin and amino acids loss during
hemodialysis
•Dialyzer monitoring and related alarms:
•I. Transmembrane pressure (TMP)
monitoring
•II. Blood leak detector
•III. Pressure monitors
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17. Dialyzer sterilization
•1. Ethelyne oxide (Eto):
•It is the most frequently used.
•It is crucial to eliminate Eto completely before using the dialyzer by
conducting a thorough rinsing.
•Type A dialyzer reaction.
•2. Other sterilization methods are gamma radiation, steam
autoclaving, and electron beam.
NephroTube Synopsis of Conventional Hemodialysis, First Edition, 2024
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18. Talk Outline: Chapter 5 :Dialyzers Overview
•Dialyzer structure
•The flow direction of blood and dialysate: Counter-current flow
•Materials of the dialyzer membranes
•Physical properties of the dialyzer
•Dialyzer sterilization
•Dialyzer reuse
•Dialyzer efficiency and flux:
•Extraction ratio (ER)
•Dialyzer efficiency:
•Dialyzer clearance (KD or K)
•Mass transfer-area coefficient (KoA)
•Dialyzer flux:
•Ultrafiltration coefficient (KUF)
•β2-microglobulin clearance, β2-microglobulin sieving
coefficient, or membrane pore size
•Available evidence comparing the use of low- versus
high-flux membranes
•Interrelation between dialyzer efficiency and dialyzer flux
•Expanded hemodialysis (HDx): Medium cut-off
(MCO) membrane
•Albumin and amino acids loss during
hemodialysis
•Dialyzer monitoring and related alarms:
•I. Transmembrane pressure (TMP)
monitoring
•II. Blood leak detector
•III. Pressure monitors
NephroTube Synopsis of Conventional Hemodialysis, First Edition, 2024
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19. Dialyzer reuse
•The rising cost of dialysis supplies without reuse??
•The environmental impact of increased contaminated waste??
•However, there has now been a shift in focus from reuse to no reuse.
NephroTube Synopsis of Conventional Hemodialysis, First Edition, 2024
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20. Talk Outline: Chapter 5 :Dialyzers Overview
•Dialyzer structure
•The flow direction of blood and dialysate: Counter-current flow
•Materials of the dialyzer membranes
•Physical properties of the dialyzer
•Dialyzer sterilization
•Dialyzer reuse
•Dialyzer efficiency and flux:
•Extraction ratio (ER)
•Dialyzer efficiency:
•Dialyzer clearance (KD or K)
•Mass transfer-area coefficient (KoA)
•Dialyzer flux:
•Ultrafiltration coefficient (KUF)
•β2-microglobulin clearance, β2-microglobulin sieving
coefficient, or membrane pore size
•Available evidence comparing the use of low- versus
high-flux membranes
•Interrelation between dialyzer efficiency and dialyzer flux
•Expanded hemodialysis (HDx): Medium cut-off
(MCO) membrane
•Albumin and amino acids loss during
hemodialysis
•Dialyzer monitoring and related alarms:
•I. Transmembrane pressure (TMP)
monitoring
•II. Blood leak detector
•III. Pressure monitors
NephroTube Synopsis of Conventional Hemodialysis, First Edition, 2024
You can get this book free from www.NephroTube.com

21. Talk Outline: Chapter 5 :Dialyzers Overview
•Dialyzer structure
•The flow direction of blood and dialysate: Counter-current flow
•Materials of the dialyzer membranes
•Physical properties of the dialyzer
•Dialyzer sterilization
•Dialyzer reuse
•Dialyzer efficiency and flux:
•Extraction ratio (ER)
•Dialyzer efficiency:
•Dialyzer clearance (KD or K)
•Mass transfer-area coefficient (KoA)
•Dialyzer flux:
•Ultrafiltration coefficient (KUF)
•β2-microglobulin clearance, β2-microglobulin sieving
coefficient, or membrane pore size
•Available evidence comparing the use of low- versus
high-flux membranes
•Interrelation between dialyzer efficiency and dialyzer flux
•Expanded hemodialysis (HDx): Medium cut-off
(MCO) membrane
•Albumin and amino acids loss during
hemodialysis
•Dialyzer monitoring and related alarms:
•I. Transmembrane pressure (TMP)
monitoring
•II. Blood leak detector
•III. Pressure monitors
NephroTube Synopsis of Conventional Hemodialysis, First Edition, 2024
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22. NephroTube Synopsis of Conventional Hemodialysis, First Edition, 2024
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Dialyzer
Blood urea at
inlet is 100 mg/dL
Blood urea at
outlet is 40 mg/dL
Extraction ratio = (100 – 40)/100 = 60%

23. Talk Outline: Chapter 5 :Dialyzers Overview
•Dialyzer structure
•The flow direction of blood and dialysate: Counter-current flow
•Materials of the dialyzer membranes
•Physical properties of the dialyzer
•Dialyzer sterilization
•Dialyzer reuse
•Dialyzer efficiency and flux:
•Extraction ratio (ER)
•Dialyzer efficiency:
•Dialyzer clearance (KD or K)
•Mass transfer-area coefficient (KoA)
•Dialyzer flux:
•Ultrafiltration coefficient (KUF)
•β2-microglobulin clearance, β2-microglobulin sieving
coefficient, or membrane pore size
•Available evidence comparing the use of low- versus
high-flux membranes
•Interrelation between dialyzer efficiency and dialyzer flux
•Expanded hemodialysis (HDx): Medium cut-off
(MCO) membrane
•Albumin and amino acids loss during
hemodialysis
•Dialyzer monitoring and related alarms:
•I. Transmembrane pressure (TMP)
monitoring
•II. Blood leak detector
•III. Pressure monitors
NephroTube Synopsis of Conventional Hemodialysis, First Edition, 2024
You can get this book free from www.NephroTube.com
ability to remove small solutes <500 Da by diffusion.

24. Talk Outline: Chapter 5 :Dialyzers Overview
•Dialyzer structure
•The flow direction of blood and dialysate: Counter-current flow
•Materials of the dialyzer membranes
•Physical properties of the dialyzer
•Dialyzer sterilization
•Dialyzer reuse
•Dialyzer efficiency and flux:
•Extraction ratio (ER)
•Dialyzer efficiency:
•Dialyzer clearance (KD or K)
•Mass transfer-area coefficient (KoA)
•Dialyzer flux:
•Ultrafiltration coefficient (KUF)
•β2-microglobulin clearance, β2-microglobulin sieving
coefficient, or membrane pore size
•Available evidence comparing the use of low- versus
high-flux membranes
•Interrelation between dialyzer efficiency and dialyzer flux
•Expanded hemodialysis (HDx): Medium cut-off
(MCO) membrane
•Albumin and amino acids loss during
hemodialysis
•Dialyzer monitoring and related alarms:
•I. Transmembrane pressure (TMP)
monitoring
•II. Blood leak detector
•III. Pressure monitors
NephroTube Synopsis of Conventional Hemodialysis, First Edition, 2024
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ability to remove small solutes <500 Da by diffusion.

25. Dialyzer clearance (KD or K)
KD = QB X ER
NephroTube Synopsis of Conventional Hemodialysis, First Edition, 2024
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The in vitro KD values given by the manufacturer are typically greater than the actual in
vivo blood clearance levels
It is the volume of blood from
which a solute is removed
(cleared) in a given unit of time.
If the ER of urea is 70% at QB of 200 mL/min, then KD of urea = 0.7 X 200 = 140 mL/min.

26. Dialyzer clearance (KD or K)
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•Thickness of the membrane
•Density and size of the pores
•Surface area of the membrane
•Blood flow rate (QB)

27. Talk Outline: Chapter 5 :Dialyzers Overview
•Dialyzer structure
•The flow direction of blood and dialysate: Counter-current flow
•Materials of the dialyzer membranes
•Physical properties of the dialyzer
•Dialyzer sterilization
•Dialyzer reuse
•Dialyzer efficiency and flux:
•Extraction ratio (ER)
•Dialyzer efficiency:
•Dialyzer clearance (KD or K)
•Mass transfer-area coefficient (KoA)
•Dialyzer flux:
•Ultrafiltration coefficient (KUF)
•β2-microglobulin clearance, β2-microglobulin sieving
coefficient, or membrane pore size
•Available evidence comparing the use of low- versus
high-flux membranes
•Interrelation between dialyzer efficiency and dialyzer flux
•Expanded hemodialysis (HDx): Medium cut-off
(MCO) membrane
•Albumin and amino acids loss during
hemodialysis
•Dialyzer monitoring and related alarms:
•I. Transmembrane pressure (TMP)
monitoring
•II. Blood leak detector
•III. Pressure monitors
NephroTube Synopsis of Conventional Hemodialysis, First Edition, 2024
You can get this book free from www.NephroTube.com
ability to remove small solutes <500 Da by diffusion.

28. Mass transfer-area coefficient (KoA)
•It is the solute's theoretical maximum dialyzer clearance, assuming
that both QB and QD are limitless.
•“Ko” is the permeability coefficient of the dialyzer membrane for a
given solute. It is affected mainly by:
•Thickness of the membrane
•Density and size of the pores.
•“A” is the total effective surface area of the dialyzer membrane.
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29. NephroTube Synopsis of Conventional Hemodialysis, First Edition, 2024
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KoA
Low-efficiency
dialyzer
membranes
KoA urea of
<500 ml/min
High-efficiency
dialyzer
membranes
KoA urea of
>600 ml/min

30. NephroTube Synopsis of Conventional Hemodialysis, First Edition, 2024
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31. Talk Outline: Chapter 5 :Dialyzers Overview
•Dialyzer structure
•The flow direction of blood and dialysate: Counter-current flow
•Materials of the dialyzer membranes
•Physical properties of the dialyzer
•Dialyzer sterilization
•Dialyzer reuse
•Dialyzer efficiency and flux:
•Extraction ratio (ER)
•Dialyzer efficiency:
•Dialyzer clearance (KD or K)
•Mass transfer-area coefficient (KoA)
•Dialyzer flux:
•Ultrafiltration coefficient (KUF)
•β2-microglobulin clearance, β2-microglobulin sieving
coefficient, or membrane pore size
•Available evidence comparing the use of low- versus
high-flux membranes
•Interrelation between dialyzer efficiency and dialyzer flux
•Expanded hemodialysis (HDx): Medium cut-off
(MCO) membrane
•Albumin and amino acids loss during
hemodialysis
•Dialyzer monitoring and related alarms:
•I. Transmembrane pressure (TMP)
monitoring
•II. Blood leak detector
•III. Pressure monitors
NephroTube Synopsis of Conventional Hemodialysis, First Edition, 2024
You can get this book free from www.NephroTube.com
ability to remove small solutes <500 Da by diffusion.
ability to remove water and middle molecules 500-15,000 Da

32. Talk Outline: Chapter 5 :Dialyzers Overview
•Dialyzer structure
•The flow direction of blood and dialysate: Counter-current flow
•Materials of the dialyzer membranes
•Physical properties of the dialyzer
•Dialyzer sterilization
•Dialyzer reuse
•Dialyzer efficiency and flux:
•Extraction ratio (ER)
•Dialyzer efficiency:
•Dialyzer clearance (KD or K)
•Mass transfer-area coefficient (KoA)
•Dialyzer flux:
•Ultrafiltration coefficient (KUF)
•β2-microglobulin clearance, β2-microglobulin sieving
coefficient, or membrane pore size
•Available evidence comparing the use of low- versus
high-flux membranes
•Interrelation between dialyzer efficiency and dialyzer flux
•Expanded hemodialysis (HDx): Medium cut-off
(MCO) membrane
•Albumin and amino acids loss during
hemodialysis
•Dialyzer monitoring and related alarms:
•I. Transmembrane pressure (TMP)
monitoring
•II. Blood leak detector
•III. Pressure monitors
NephroTube Synopsis of Conventional Hemodialysis, First Edition, 2024
You can get this book free from www.NephroTube.com
ability to remove small solutes <500 Da by diffusion.
ability to remove water and middle molecules 500-15,000 Da

33. NephroTube Synopsis of Conventional Hemodialysis, First Edition, 2024
You can get this book free from www.NephroTube.com
Flux
Low-flux
membrane
dialyzer
KUF (water
permeability or
ultrafiltration) of
<10mL/h/mmHg.
High-flux
membrane
dialyzer
KUF (water
permeability or
ultrafiltration) of
>20mL/h/mmHg.
Factors affecting KUF:
•Membrane thickness.
•Pore size

34. Issues related to high-flux membrane dialyzers:
•Over ultrafiltration with the use of high-flux membrane dialyzers.
•Back-filtration (back-leak) with the use of high-flux membrane
dialyzers.
•Membrane fouling with the use of high-flux membrane dialyzers.
NephroTube Synopsis of Conventional Hemodialysis, First Edition, 2024
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35. Talk Outline: Chapter 5 :Dialyzers Overview
•Dialyzer structure
•The flow direction of blood and dialysate: Counter-current flow
•Materials of the dialyzer membranes
•Physical properties of the dialyzer
•Dialyzer sterilization
•Dialyzer reuse
•Dialyzer efficiency and flux:
•Extraction ratio (ER)
•Dialyzer efficiency:
•Dialyzer clearance (KD or K)
•Mass transfer-area coefficient (KoA)
•Dialyzer flux:
•Ultrafiltration coefficient (KUF)
•β2-microglobulin clearance, β2-microglobulin sieving
coefficient, or membrane pore size
•Available evidence comparing the use of low- versus
high-flux membranes
•Interrelation between dialyzer efficiency and dialyzer flux
•Expanded hemodialysis (HDx): Medium cut-off
(MCO) membrane
•Albumin and amino acids loss during
hemodialysis
•Dialyzer monitoring and related alarms:
•I. Transmembrane pressure (TMP)
monitoring
•II. Blood leak detector
•III. Pressure monitors
NephroTube Synopsis of Conventional Hemodialysis, First Edition, 2024
You can get this book free from www.NephroTube.com
ability to remove small solutes <500 Da by diffusion.
ability to remove water and middle molecules 500-15,000 Da

36. NephroTube Synopsis of Conventional Hemodialysis, First Edition, 2024
You can get this book free from www.NephroTube.com

37. NephroTube Synopsis of Conventional Hemodialysis, First Edition, 2024
You can get this book free from www.NephroTube.com

38. Talk Outline: Chapter 5 :Dialyzers Overview
•Dialyzer structure
•The flow direction of blood and dialysate: Counter-current flow
•Materials of the dialyzer membranes
•Physical properties of the dialyzer
•Dialyzer sterilization
•Dialyzer reuse
•Dialyzer efficiency and flux:
•Extraction ratio (ER)
•Dialyzer efficiency:
•Dialyzer clearance (KD or K)
•Mass transfer-area coefficient (KoA)
•Dialyzer flux:
•Ultrafiltration coefficient (KUF)
•β2-microglobulin clearance, β2-microglobulin sieving
coefficient, or membrane pore size
•Available evidence comparing the use of low- versus
high-flux membranes
•Interrelation between dialyzer efficiency and dialyzer flux
•Expanded hemodialysis (HDx): Medium cut-off
(MCO) membrane
•Albumin and amino acids loss during
hemodialysis
•Dialyzer monitoring and related alarms:
•I. Transmembrane pressure (TMP)
monitoring
•II. Blood leak detector
•III. Pressure monitors
NephroTube Synopsis of Conventional Hemodialysis, First Edition, 2024
You can get this book free from www.NephroTube.com
ability to remove small solutes <500 Da by diffusion.
ability to remove water and middle molecules 500-15,000 Da

39. NephroTube Synopsis of Conventional Hemodialysis, First Edition, 2024
You can get this book free from www.NephroTube.com
HEMO study MPO study
•The primary outcome (death from any
cause) and also secondary outcomes
were not significantly different between
the high- and low- flux groups.
•In the high- flux group, there were
significant reductions in the risk of death
from cardiac causes and the combined
outcome of first hospitalizations or death
from a cardiac cause.
•No difference in survival was found
between the use of high- or low- flux
dialysis membranes in patients with
normal albumin levels.
•Patients with serum albumin ≤4 g/dl had
significantly better survival rates in the
high- flux group.
•A post hoc secondary analysis showed
that high- flux membranes may
significantly improve survival in diabetic
patients.

40. Talk Outline: Chapter 5 :Dialyzers Overview
•Dialyzer structure
•The flow direction of blood and dialysate: Counter-current flow
•Materials of the dialyzer membranes
•Physical properties of the dialyzer
•Dialyzer sterilization
•Dialyzer reuse
•Dialyzer efficiency and flux:
•Extraction ratio (ER)
•Dialyzer efficiency:
•Dialyzer clearance (KD or K)
•Mass transfer-area coefficient (KoA)
•Dialyzer flux:
•Ultrafiltration coefficient (KUF)
•β2-microglobulin clearance, β2-microglobulin sieving
coefficient, or membrane pore size
•Available evidence comparing the use of low- versus
high-flux membranes
•Interrelation between dialyzer efficiency and dialyzer flux
•Expanded hemodialysis (HDx): Medium cut-off
(MCO) membrane
•Albumin and amino acids loss during
hemodialysis
•Dialyzer monitoring and related alarms:
•I. Transmembrane pressure (TMP)
monitoring
•II. Blood leak detector
•III. Pressure monitors
NephroTube Synopsis of Conventional Hemodialysis, First Edition, 2024
You can get this book free from www.NephroTube.com
ability to remove small solutes <500 Da by diffusion.
ability to remove water and middle molecules 500-15,000 Da

41. Interrelation between dialyzer efficiency and
dialyzer flux
•Typically, the high-flux dialyzers usually have high efficiency and vice
versa.
•But this is not always the situation.

42. Talk Outline: Chapter 5 :Dialyzers Overview
•Dialyzer structure
•The flow direction of blood and dialysate: Counter-current flow
•Materials of the dialyzer membranes
•Physical properties of the dialyzer
•Dialyzer sterilization
•Dialyzer reuse
•Dialyzer efficiency and flux:
•Extraction ratio (ER)
•Dialyzer efficiency:
•Dialyzer clearance (KD or K)
•Mass transfer-area coefficient (KoA)
•Dialyzer flux:
•Ultrafiltration coefficient (KUF)
•β2-microglobulin clearance, β2-microglobulin sieving
coefficient, or membrane pore size
•Available evidence comparing the use of low- versus
high-flux membranes
•Interrelation between dialyzer efficiency and dialyzer flux
•Expanded hemodialysis (HDx): Medium cut-off
(MCO) membrane
•Albumin and amino acids loss during
hemodialysis
•Dialyzer monitoring and related alarms:
•I. Transmembrane pressure (TMP)
monitoring
•II. Blood leak detector
•III. Pressure monitors
NephroTube Synopsis of Conventional Hemodialysis, First Edition, 2024
You can get this book free from www.NephroTube.com
ability to remove small solutes <500 Da by diffusion.
ability to remove water and middle molecules 500-15,000 Da

43. Expanded hemodialysis (HDx): Medium cut-off
(MCO) membrane
NephroTube Synopsis of Conventional Hemodialysis, First Edition, 2024
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44. Expanded hemodialysis (HDx): Medium cut-off
(MCO) membrane
NephroTube Synopsis of Conventional Hemodialysis, First Edition, 2024
You can get this book free from www.NephroTube.com
•It reduces inflammatory mediators.
•It improves erythropoiesis stimulating resistance.
•Improves the physical components of QOL.
•It improves uremic pruritus.
•It provides clinical benefits and better outcomes.

45. Talk Outline: Chapter 5 :Dialyzers Overview
•Dialyzer structure
•The flow direction of blood and dialysate: Counter-current flow
•Materials of the dialyzer membranes
•Physical properties of the dialyzer
•Dialyzer sterilization
•Dialyzer reuse
•Dialyzer efficiency and flux:
•Extraction ratio (ER)
•Dialyzer efficiency:
•Dialyzer clearance (KD or K)
•Mass transfer-area coefficient (KoA)
•Dialyzer flux:
•Ultrafiltration coefficient (KUF)
•β2-microglobulin clearance, β2-microglobulin sieving
coefficient, or membrane pore size
•Available evidence comparing the use of low- versus
high-flux membranes
•Interrelation between dialyzer efficiency and dialyzer flux
•Expanded hemodialysis (HDx): Medium cut-off
(MCO) membrane
•Albumin and amino acids loss during
hemodialysis
•Dialyzer monitoring and related alarms:
•I. Transmembrane pressure (TMP)
monitoring
•II. Blood leak detector
•III. Pressure monitors
NephroTube Synopsis of Conventional Hemodialysis, First Edition, 2024
You can get this book free from www.NephroTube.com
ability to remove small solutes <500 Da by diffusion.
ability to remove water and middle molecules 500-15,000 Da

46. NephroTube Synopsis of Conventional Hemodialysis, First Edition, 2024
You can get this book free from www.NephroTube.com
Albumin loss during hemodialysisAmino acids loss during hemodialysis
•Conventional low- flux hemodialysis
albumin leakage is usually absent.
•Conventional high- flux hemodialysis
albumin loss is usually absent or low (<2.4
g/4 h treatment).
•Albumin loss with high cut- off dialyzers
varied from less than 1 g to nearly 8 g per 4
h hemodialysis session.
•With the use of MCO dialyzer, albumin
losses of 2.0–4.0 g per session were
reported.
•Data suggest that patients lose
approximately 6–8 g of total amino acids
per session
•A loss of up to 12 g of amino acids per
session has been reported.

47. Talk Outline: Chapter 5 :Dialyzers Overview
•Dialyzer structure
•The flow direction of blood and dialysate: Counter-current flow
•Materials of the dialyzer membranes
•Physical properties of the dialyzer
•Dialyzer sterilization
•Dialyzer reuse
•Dialyzer efficiency and flux:
•Extraction ratio (ER)
•Dialyzer efficiency:
•Dialyzer clearance (KD or K)
•Mass transfer-area coefficient (KoA)
•Dialyzer flux:
•Ultrafiltration coefficient (KUF)
•β2-microglobulin clearance, β2-microglobulin sieving
coefficient, or membrane pore size
•Available evidence comparing the use of low- versus
high-flux membranes
•Interrelation between dialyzer efficiency and dialyzer flux
•Expanded hemodialysis (HDx): Medium cut-off
(MCO) membrane
•Albumin and amino acids loss during
hemodialysis
•Dialyzer monitoring and related alarms:
•I. Transmembrane pressure (TMP)
monitoring
•II. Blood leak detector
•III. Pressure monitors
NephroTube Synopsis of Conventional Hemodialysis, First Edition, 2024
You can get this book free from www.NephroTube.com
ability to remove small solutes <500 Da by diffusion.
ability to remove water and middle molecules 500-15,000 Da

48. Talk Outline: Chapter 5 :Dialyzers Overview
•Dialyzer structure
•The flow direction of blood and dialysate: Counter-current flow
•Materials of the dialyzer membranes
•Physical properties of the dialyzer
•Dialyzer sterilization
•Dialyzer reuse
•Dialyzer efficiency and flux:
•Extraction ratio (ER)
•Dialyzer efficiency:
•Dialyzer clearance (KD or K)
•Mass transfer-area coefficient (KoA)
•Dialyzer flux:
•Ultrafiltration coefficient (KUF)
•β2-microglobulin clearance, β2-microglobulin sieving
coefficient, or membrane pore size
•Available evidence comparing the use of low- versus
high-flux membranes
•Interrelation between dialyzer efficiency and dialyzer flux
•Expanded hemodialysis (HDx): Medium cut-off
(MCO) membrane
•Albumin and amino acids loss during
hemodialysis
•Dialyzer monitoring and related alarms:
•I. Transmembrane pressure (TMP)
monitoring
•II. Blood leak detector
•III. Pressure monitors
NephroTube Synopsis of Conventional Hemodialysis, First Edition, 2024
You can get this book free from www.NephroTube.com
ability to remove small solutes <500 Da by diffusion.
ability to remove water and middle molecules 500-15,000 Da

49. Blood in
Dialysate in
Dialysate
effluent pump
Positive
pressure
Negative
pressure
Water movement
(Ultrafiltration)
Dialysate out
Blood out
Adjustable inflow
resistance by
clamp
NephroTube Synopsis of Conventional Hemodialysis, First Edition, 2024
You can get this book free from www.NephroTube.com

50. Accepted TMP limit
•Manufacturers typically provide information about the maximum
TMP for dialyzers in their brochure.
•The European Renal Best Practice (ERBP) guidelines suggest a TMP
limit of +300 mmHg as a safe upper limit.
NephroTube Synopsis of Conventional Hemodialysis, First Edition, 2024
You can get this book free from www.NephroTube.com

51. Transmembrane pressure alarm
NephroTube Synopsis of Conventional Hemodialysis, First Edition, 2024
You can get this book free from www.NephroTube.com
TMP may be increased if:
- The surface area of the dialyzer decreased due to
clotting.
- Using a small surface area dialyzer with a targeted
high ultrafiltration volume.
TMP will decrease in case of opening the
dialysate compartment of the dialyzer
to the atmosphere.

52. Talk Outline: Chapter 5 :Dialyzers Overview
•Dialyzer structure
•The flow direction of blood and dialysate: Counter-current flow
•Materials of the dialyzer membranes
•Physical properties of the dialyzer
•Dialyzer sterilization
•Dialyzer reuse
•Dialyzer efficiency and flux:
•Extraction ratio (ER)
•Dialyzer efficiency:
•Dialyzer clearance (KD or K)
•Mass transfer-area coefficient (KoA)
•Dialyzer flux:
•Ultrafiltration coefficient (KUF)
•β2-microglobulin clearance, β2-microglobulin sieving
coefficient, or membrane pore size
•Available evidence comparing the use of low- versus
high-flux membranes
•Interrelation between dialyzer efficiency and dialyzer flux
•Expanded hemodialysis (HDx): Medium cut-off
(MCO) membrane
•Albumin and amino acids loss during
hemodialysis
•Dialyzer monitoring and related alarms:
•I. Transmembrane pressure (TMP)
monitoring
•II. Blood leak detector
•III. Pressure monitors
NephroTube Synopsis of Conventional Hemodialysis, First Edition, 2024
You can get this book free from www.NephroTube.com
ability to remove small solutes <500 Da by diffusion.
ability to remove water and middle molecules 500-15,000 Da

53. NephroTube Synopsis of Conventional Hemodialysis, First Edition, 2024
You can get this book free from www.NephroTube.com
A B
+ -
Conductivity
monitor
Temperature
monitor
Dialysate outflow
Drain
Blood leak
detector
Balancing chamber
(Part of volumetric control system.
See Fig. 4.3 for more details of
other parts of this system)
Bypass
valve“Pure” dialysate
Bypass
circuit
Dialyzer
Pure water
from water
unit
A B
Deaeration
Proportionating
system
Concentrates
“Pure” dialysate
A B
Water preparation system
Heater
Ruptured
dialyzer
fibers

54. Talk Outline: Chapter 5 :Dialyzers Overview
•Dialyzer structure
•The flow direction of blood and dialysate: Counter-current flow
•Materials of the dialyzer membranes
•Physical properties of the dialyzer
•Dialyzer sterilization
•Dialyzer reuse
•Dialyzer efficiency and flux:
•Extraction ratio (ER)
•Dialyzer efficiency:
•Dialyzer clearance (KD or K)
•Mass transfer-area coefficient (KoA)
•Dialyzer flux:
•Ultrafiltration coefficient (KUF)
•β2-microglobulin clearance, β2-microglobulin sieving
coefficient, or membrane pore size
•Available evidence comparing the use of low- versus
high-flux membranes
•Interrelation between dialyzer efficiency and dialyzer flux
•Expanded hemodialysis (HDx): Medium cut-off
(MCO) membrane
•Albumin and amino acids loss during
hemodialysis
•Dialyzer monitoring and related alarms:
•I. Transmembrane pressure (TMP)
monitoring
•II. Blood leak detector
•III. Pressure monitors
NephroTube Synopsis of Conventional Hemodialysis, First Edition, 2024
You can get this book free from www.NephroTube.com
ability to remove small solutes <500 Da by diffusion.
ability to remove water and middle molecules 500-15,000 Da

55. NephroTube Synopsis of Conventional Hemodialysis, First Edition, 2024
You can get this book free from www.NephroTube.com
Clotted

56. Thank You