This document discusses dialyzers, which are used in renal dialysis to remove waste and excess fluid from the blood of patients with kidney failure. It describes the key components of a dialyzer, including the semipermeable membrane and four ports, as well as specifications like surface area, clearance rates, and sterilization methods. Various types of dialyzers are covered, such as coil dialyzers, parallel plate dialyzers, and hollow fiber dialyzers. Membrane materials including cellulose, synthetic, and cellulosynthetic are also outlined. An ideal dialyzer is said to efficiently clear toxins while avoiding protein and cell losses.

1. DIALYZER
Yousaf khan
Renal dialysis lecturer
IPMS-KMU

2. DIALYZER
 Dialyzer shell
(polyurethane) is a box or
tube with four port (2
blood and 2 dialysis)
 Dialyzer – blood and
dialysis solution
 Movement of molecule
across semipermeable
membrane

3. DIALYZER
An ideal dialyzer should have
 High clearance of small and medium MW toxins
 Adequate UF
 Negligible losses of protiens and amino acids
 Non toxic composition
 Minimal activation of cell or thrombotic pathways
 Minimal blood volume
 Reliability
 Reusability
 Low cost

4. DIALYZER TECHNICAL SPECIFICATION
 Priming volume very from 40-150 ml.
 Surface area vary from 0.5-2.2m2
 KUF from 2.5 to 85ml/h/mmHg
 KoA urea varies from 200 to 1200 (<300 represents a low
efficiency dialyzer and >600 a high efficiency dialyzer)
 Specification sheets also provide clearance for urea and
vitamin B12.
 Dialyzer are sterilzed by gamma irradiation, ethylene oxide or
by steam
 Must be pre rinsed with >2L rinsing solution prior to
connecting to patient to prevent release of fragments from the
dialysis circuit

5. DIALYZER MEMBRANE
Cellulose:
 Obtained form processed cotton (regenerated cellulose,
cuprammonium cellulose, cuprammonium rayon and
saponified cellulose)
Substituted cellulose:
 Cellulose polymer has a large number of free hydroxyl group
at its surface
 Free hydroxyl group are responsible for blood cell activation
causing bio-incompatibiltiy of the dialyzer (cellulose acetate,
cellulose diacetate, triacetate)

6. DIALYZER MEMBRANE
Cellulosynthetic:
 A synthetic material ( a tertiary amino compound) is added to
liquefied cellulose during formation of the membrane as result
the surface of the membrane is altered and biocompatibility is
increased (cellosyn or hemphan)
Synthetics:
 Not cellulose based but are synthetic plastics and materials
used include polyacrylonitrile (PAN) polysulfone,
polycarbonate, polyamide and polymethyl-methacrylate
(PMMA)

7. DIALYZER TYPES
Coil dialyzer:
 Flattened cellulose tubing wrapped as a coil and through
which patients blood flow during dialysis.
 The blood channels was long to obtain the needed surface
area, and resistance was high
 UF was unpredictable and blood leak were frequent.

8. PARALLEL PLATE DIALYZER
 Sheets of membrane are placed between supporting plates.
 The plates have ridges and grooves to support the membrane and
allow flow of dialysate along it
 Resistance to blood flow is low. The surface area vary from 0.25 to
1.5 msq.
Advantage:
 Blood volume is about 50-100 ml at 100 mmHg increase with high
TMP
 Heparin requirement usually low, minimal clotting in the blood
compartment
 Ultrafiltration is reasonably predictable and controllable
Disadvantage:
 Formation of local thrombi around inlet and outlet ports and corners
 May lead to bacterial growth and endotoxin formation therefore
plates are not often reused

9. HOLLOW FIBER DIALYZER
 Numerous hollow fiber
 Hollow fiber are tiny its diameter 150-250um
 Number of fiber20000 or more, depending upon length, kind of
membrane and surface area of dialyzer
Advantage :
 Low blood volume 60-90ml
 Resistance to blood flow is low
 Ultrafiltration can be precisely controlled
 Well adapted to reuse
Disadvantage:
 Deaeration of fiber predialysis is necessary to prevent air lock of the
fibers
 More heparin is required for most of the patients
 Adverse patient reaction

10. DIALYZER TYPE

11. REACTION TO MEMBRANES
Type A reaction
 Within minutes of starting
dialysis with
 Dyspnoea, wheeze
 A feeling of warmth,
urticaria
 Cough, hypotension
 Collapse or cardiac arrest
Type B reaction
 More common but much
milder often occur 20-40
min after starting dialysis
 Usually cause back and
chest pain

12. Thank you