Skip to main content


  • Poster presentation
  • Open Access

Renal replacement therapy with high cutoff hemofilters: impact of convection and diffusive on cytokine clearances and protein status

  • 1,
  • 2,
  • 3,
  • 4,
  • 5,
  • 6 and
  • 3
Critical Care20048 (Suppl 1) :P151

  • Published:


  • Renal Replacement Therapy
  • Clearance Rate
  • High Cutoff
  • High Baseline Level
  • Dialysate Flow


High cutoff hemofilters are characterized by an increased effective pore size designed to facilitate the elimination of inflammatory mediators in sepsis. This study compares diffusive versus convective high cutoff renal replacement therapy (RRT) in terms of cytokine clearance rates and effects on plasma proteins.


Twenty-four patients with sepsis-induced acute renal failure were studied. A polyflux hemofilter with a cutoff point of approximately 60 kDa was used for RRT. Patients were randomly allocated to either continuous venovenous hemofiltration (CVVH) with an ultrafiltration rate of 1 l/hour (group 1) or 2.5 l/hour(group 2), or to continuous venovenous hemodialysis (CVVHD) with a dialysate flow rate of 1 l/hour (group 3) or 2.5 l/hour (group 4). IL-1ra, IL-1β, IL-6, tumor necrosis factor-α (TNF-α), and plasma proteins were measured daily.


CVVH achieved a significantly higher IL-1ra clearance compared with CVVHD (P = 0.0003). No difference was found for IL-6 (P = 0.935). Increasing the ultrafiltration volume or dialysate flow led to a highly significant increase in IL-1ra and IL-6 clearance rate (P < 0.00001). Peak clearance was 46 ml/min for IL-1ra and 51 ml/min for IL-6. TNF-α clearance was poor for both RRT modalities. A significant decline in plasma IL-1ra and IL-6 was observed in patients with high baseline levels. Protein and albumin loss were highest during the 2.5 l/h hemofiltration mode.


High cutoff RRT is a novel strategy to clear cytokine more effectively. Convection has an advantage over diffusion in the clearance capacity of IL-1ra but is associated with higher plasma protein losses.

Authors’ Affiliations

University Hospital Charité, CCM, Berlin, Germany
Department of Cardiology, Berlin, Germany
Department of Nephrology, Berlin, Germany
Department of Anesthesiology, Berlin, Germany
Department of Surgery, Berlin, Germany
Department of Intensive Care, Austin &, Repatriation Medical Centre, Melbourne, Australia


© BioMed Central Ltd. 2004