Background/aims: Artificial liver support represents a potentially useful option for the treatment of severe liver failure. A sufficient 'dose' might be crucial for such treatments to provide a survival benefit. The aim of this study was to compare in vivo efficiency and resulting delivered treatment dose of two commercially available devices that use different therapeutic principles: albumin dialysis (AD, MARS) and fractionated plasma separation (FPS, Prometheus).
Methods: Eight patients with acute-on-chronic liver failure were treated alternately with AD and FPS. Thirty-two treatments at identical blood and dialysate flow rates were evaluated. Clearance and reduction ratio (a measure of delivered treatment dose) were compared for bilirubin subfractions, ammonia and urea.
Results: FPS achieved significantly higher clearance for all measured protein-bound and water-soluble markers. This resulted in significantly higher reduction ratios for FPS compared to AD. Unconjugated bilirubin, a marker for strongly albumin-bound toxins, was influenced only by FPS.
Conclusions: FPS provided a higher delivered treatment dose than a matching treatment with AD. Reduction ratios of bilirubin and urea should be reported in clinical studies on liver dialysis, since delivered dose is likely to be linked to the clinical effectiveness of extracorporeal liver support therapies.