Albumin and hydroxyethyl starch 130 kDa/0.4 improve filter clearance and haemocompatibility in haemo- and plasmafiltration--an in vitro study.
BACKGROUND
Apart from their standard applications, haemofiltration (HF) and plasmafiltration (PF) may provide helpful therapy for sepsis, multiple organ- and acute liver-failure. Some colloids cause either decreases or increases in blood cell agglomeration. We hypothesized that solutions which reduce cell aggregability may lead to both improved filter clearance and better haemocompatibility due to decreasing rates of clogged hollow fibres.


METHODS
Heparinized porcine blood (5 IU/ml) was used in an in vitro circuit. The filter types tested were from GAMBRO: HF66D (effective membrane surface: 0.6 m2) and PF1000N (effective membrane surface: 0.15 m2). Albumin (ALB), hydroxyethyl starch (HES) 200/0.5, HES 130/0.4, gelatin (GEL) or normal saline (0.9%) were added to the blood (n = 6/group). Recirculation systems were run for 2 h. Spontaneous haemolysis and filter resistance >420 mmHg were selected as indications of maximal flow rates. Sieving coefficients were determined for 17 parameters at the lowest and highest blood flows and filtration rate.


RESULTS
Based on the filter types used, supplementation of ALB and HES130/0.4 led to an improved filter clearance without increasing the number of clogged capillary membranes or causing impaired haemocompatibility. Sieving coefficients for most solutes were independent of volume substitute and flow rate. Haemocompatibility and filter clearance deteriorated after addition of HES200 or GEL to the blood.


CONCLUSIONS
Under standardized in vitro conditions, we found that colloids which reduce cell aggregability cause improved HF- and PF-performance. This phenomenon may provide new options for higher clearances and may lead to new concepts in low dose anticoagulation.
Unger
Juliane K
JK
Department of Anaesthesiology, University Hospital Aachen, Rheinisch-Westfälische Technische Hochschule Aachen, Aachen, Germany. juliane.unger@charite.de
Haltern
Claudia
C
Dohmen
Bernd
B
Gressner
Axel
A
Grosse-Siestrup
Christian
C
Groneberg
David A
DA
Rossaint
Rolf
R
D000818:Animals; D001783:Blood Flow Velocity; D004867:Equipment Design; D006440:Hemofiltration / Q000295:instrumentation / Q000379:methods*; D006895:Hydroxyethyl Starch Derivatives / Q000378:metabolism / Q000493:pharmacokinetics*; D011312:Pressure; D006435:Renal Dialysis / Q000379:methods*; D012709:Serum Albumin / Q000378:metabolism*; D016060:Sorption Detoxification / Q000379:methods; D013552:Swine
D006895:Hydroxyethyl Starch Derivatives; D012709:Serum Albumin