Dialyzer SelectionSirirat Reungjui, MD.Khon Kaen University

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Content

1. Type of dialyzer and membrane

2. Selection of dialyzer

Effect on outcomes3.

Evolution of dialyzer

Kolff Rotating Drum,

Ca. 1943

Skeggs Leonards Plate,

Ca. 1948

Travenol-Kolff Coil,

Ca. 1956

Kiil Plate Dialyzer,Ca. 1960

Stewart Capillary Cordis Dow CDAKs

First Hollow Fiber Dialyzers,Ca. 1964 - 1967

Gambro Plate Dialyzers,Ca. 1967 - 1979

Baxter CA170High Efficiency

Baxter CT190GHigh Flux

FMC F80High Flux

StructureBlood inlet

Blood outlet

Fiber

Header

JecketSolution inlet

Solution outlet

Ideal dialyzer• Remove small and large solutes• Reliable convective and UF properties• Biocompatible / Safety• Protect blood from dialysate contaminants (backfiltration)

Retention of solutes

Uremic syndromeDeterioration of multiple biochemical

& physiological functions

Progressive renal failure

Uremic toxins

Larger, middle-molecules ( > 500 D)

Lipid-soluble and/or protein-bound

Uremic toxins

Small, water-soluble, non-protein-bound ( <

500 D)

European Uremic Toxin Work Group. JASN, 2012.

Diffusion

Concentration gradient, small molecule

Movement of water (ultrafiltration), middle mol.

Convection

Complementactivation

Hydroxyl groups

CytokineROS

Neutophil, Monocyte

Contaminant dialysate

• Type A (anaphylactic type)• Ethylene oxide, AN-69 (ACEI), contaminant dialysate, heparin, complement release ?, eosinophilia• Type B (nonspecific)• Complement activation

Dialyzer reactions

Bioincompatibility• Amyloidosis – β 2 microglobulin• Immune depression• Loss of residual renal function• Catabolism and malnutrition• Inflammation/ Atherosclerosis

Dialyzer lengthPr

essu

re positive

TMP

negativePres

sure

BloodDialysate

DialysateBlood

Definitions

Efficiency KoA (ml/min)

High < 500Moderate 500 – 700

Low > 700 KoA; Mass transfer area coefficient(maximum theoretical Cl at infinite BFR, DFR)

Kuf; Ultrafiltration coefficient

Definitions

Flux Kuf (ml/h/mmHg)

High < 10Low > 20

Permeability β 2 -microglobulin

clearance (ml/min)

High < 10Low > 20

Definitions

• Super-flux; Pressure drop Pore size Homogenous pores• High performance; High flux Biocompatible

Type of membrane

Unmodified cellulose Substituted cellulose Cellulosynthetic membrane Synthetic membrane

Substituted Cellulose

Cuprophan - Good for small solutes - Bioincompatible - Low flux

Unmodified Cellulose

• Cellulose acetate/diacetate

- Low / middle Kuf• Cellulose triacetate - Middle / high Kuf - More biocompatible

Synthetic membraneCellulose membrane

LF-BI

LF-BC cell

LF-BC syn

HF-cell

HF-syn

Low complement activation

- ++ ++ ++ +++

Reflect dialysate impurities

- - ++ - ++

Adsorption

- - +/- - +

MM removal

- - - ++ ++

RR 0.96 , p = 0.53

single-pool Kt/V 1.32 vs 1.71

HEMO study group. N Engl J Med. 2002;347(25):2010-9.

Standard

High dose

HEMO study group. N Engl J Med. 2002;347(25):2010-9.

RR 0.92, P = 0.23

Cβ2 microglobulin 3 vs 34 ml/min

RR 0.68 , pt on HD > 3.7 years

Low flux

High flux

< 27.5 mg/L

Predialysis serum β 2 M (mg/L)HEMO study group. J Am Soc Nephrol 17: 546–555, 2006.

Serum β-2 M Levels Predict Mortality

< 27.5 27.5-35 35-42.5 42.5-50 > 50

Rela

tive

ris

k

Diabetic patients, p = 0.039

Alb ≤ 4 g/dl, p = 0.032

Surv

ival

pro

babi

lity

of p

atie

nts

High-flux membraneLow-flux membrane

No. at riskHigh-flux 83 67 55 46 27 14 7 3 Low-flux 74 59 40 29 19 11 3 0

0 12 24 36 48 60 72 84 Months

Membrane Permeability Outcome (MPO) Study

Locatelli F, et al. J ASN; 20: 645–54, 2009

EGE Study group. J Am Soc Nephrol 24: 1014–23, 2013

cardiovascular event-free survival

HR 0.73P = 0.12

AVF group; HR 0.61, p = 0.03DM group; HR 0.49, p = 0.03p = 0.03

Hi Flux / Ultrapure

Conclusion• RCTs .. no difference in mortality• Suggestion; synthetic high flux membrane - Duration > 3.7 yr, DM, Alb ≤ 4 g/dl, AVF• Highest survival..high flux + ultrapure• AKI (KDIGO 2012)…Biocompatible

Thank you!

Contact Address: Prof. Somchai Doe Tel:Email: www.kku.ac.th