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Yaroustovsky et al. Blood purification in intensive care patients

Extracorporeal methods based on patient’s blood substances has become possible. [35,36]
perfusion through exogenous hepatocytes were not
widely used due to their high complexity and cost, the The principle of Prometheus-therapy is based
insufficient cell mass for liver regeneration (≥ 400 g on plasma separation on the AlbuFlow filter, the
would be needed) as well as low biocompatibility and membrane of which is permeable to molecules of
infection risk. up to 250 kD, including albumin, clotting factors and
fibrinogen. Separated plasma regenerates when
Modern extracorporeal blood purification methods it successively passes through absorbers with ion
without using biological components comprise exchange and neutral resin. Removal of low molecular
high-volume plasma exchange, albumin dialysis weight water soluble compounds is provided by the
[Molecular Adsorbent Recirculating System (MARS )], performance of HF or HD. This technique is the most
®
single-pass albumin dialysis (SPAD) and methods effective for eliminating albumin-bound toxins such as
that combine plasma separation and adsorption unconjugated bilirubin and bile acids. [37,38]
[Fractionated Plasma Separation and Adsorption
(FPSA) Prometheus )]. In assessing the safety and efficacy of MARS and
®
Prometheus therapies in adult patients with ALF
In acute liver failure, plasma exchange provides a after cardiac surgery, we analyzed the dynamics
reduction in bilirubinemia, but this is achieved only of hydrophobic and hydrophilic toxic substance
at high exchange volumes (up to 10 L), and the lack concentrations as well as the severity of hepatocyte
of specificity and high risk of allergic and infectious cytolysis and the impairment of liver synthetic
complications reduce the benefits and limit the use function. A key aspect in the evaluation of MARS
of this method. [27,28] SPAD therapy uses standard and Prometheus liver support system safety in
equipment for kidney replacement therapy with a patients after cardiac surgery was the absence of
highly porous membrane dialyzers and albumin a negative influence on hemodynamics and lung
containing dialysis solutions to remove hydrophobic oxygenation function. In evaluating the safety of
substances. these systems, monitoring the dynamics of serum
albumin is recommended, which is important in the
The emergence of new hi-tech techniques, such as setting of initial dysproteinemia in ALF and the use of
albumin dialysis (MARS-therapy) and fractionated high permeability hemo- or plasma filters. According
plasma separation and adsorption (Prometheus- to several authors, the serum albumin concentration
therapy), allow optimistic results to be obtained with during MARS-therapy remains unchanged
complex intensive therapy for this severe category of
patients. [29] because the diameter of the filter pores (50 kDa)
does not exceed the size of the albumin molecule
The beneficial effect of these procedures on clinical (65 kDa). [26,38] However, the albumin loss during
and laboratory parameters is explained by the Prometheus-therapy can reach 3 g/L (P = 0.055). [31,39]
removal of vasoactive substances and toxins, leading We observed no significant negative dynamics of
to improvements in organ and tissue perfusion, serum albumin [oscillations: 32 (30-35) and 30 (26-
hemodynamic parameters and kidney function and 35) g/L, P = 0.052, before and after MARS-therapy;
reducing portal hypertension, intracranial pressure 33 (31-34) and 31 (28-36) g/L, P = 0.051, before and
and hepatic encephalopathy. [30,31] The experience from after Prometheus-therapy], which is probably due to
implementing this therapy in adults allows the use of the adequate routine correction of hypoproteinemia
extracorporeal liver support to be recommended in in patients with ALF. [39] Likewise, despite published
pediatric practice. [32-34] data on the loss of coagulation factors during
Prometheus-therapy, [40] we did not observe clinically
MARS-therapy is a method of albumin dialysis that significant hemorrhagic complications.
uses a filter permeable to substances with a molecular
weight of up to 50 kDa. The toxins accumulated on The use of both liver support systems in cardio
the filter membrane are subsequently bound to the surgical patients provided a significant reduction in
donor albumin used as a dialysate. Simultaneously, the total bilirubin concentration, and Prometheus-
the albumin dialysate is purified by passing through therapy allowed the clearance of unconjugated
activated carbon, anion exchange resin and a low- bilirubin. During MARS-therapy, the initial level of total
permeability dialyzer, which provides a link between bilirubin was 230 (181-256) μmol/L whereas during
the albumin circuit and the traditional bicarbonate- Prometheus-therapy, it was 333 (189-450) μmol/L;
based dialysis solution. Thus, the simultaneous the concentrations of unconjugated bilirubin were
selective removal of albumin-bound and water-soluble 103 (72-135) and 119 (74-166) μmol/L, respectively.
Vessel Plus ¦ Volume 1 ¦ June 27, 2017 53