Prevention of blood loss in dialysers with DEAE-cellulose membranes does not require increased doses of heparin

Binding of heparin to DEAE-cellulose membranes may reduce bioavailable heparin, thus increasing the amount of heparin needed for anticoagulation during dialysis. To test this hypothesis, blood loss and coagulation were evaluated during dialysis with DEAE-cellulose and polysulphone membranes. The heparin dose required to effect a given increase in the baseline recalcified activated clotting time (RACT) was determined using a pharmacokinetic model. Blood remaining in the dialyser post-dialysis (RBV) was measured by red cell lysis and haemoglobinometry. Plasma thrombin-antithrombin III complex (TAT) was used to assess activation of the coagulation system. RBV and changes in TAT were determined in two crossover studies. Firstly, DEAE-cellulose membranes were used at doses of heparin calculated to increase baseline RACT by 12.5% and 25%. Secondly, DEAE-cellulose and polysulphone membranes were compared at a heparin dose calculated to increase baseline RACT by 15%. RBV for DEAE-cellulose membranes was independent of the dose of heparin and did not differ from that found for polysulphone membranes. TAT concentrations increased during dialysis; however, there was no difference between the two membranes. These results show that DEAE-cellulose membranes do not require increased heparin to avoid dialyser-associated blood loss.