Pressure and flow in the extracorporeal circuit

The impact of pressure and now changes in the extracorporeal circuit on dia lysis efficiency in response to altered hematocrit is discussed in the ligh t of the known properties of blood, published studies and the author's as y et unpublished measurements. Increasing the hematocrit from 0.35 to 0.45 mu st be expected to reduce the efficiency of urea elimination by 3 - 5%, whic h can be offset by increasing dialysis time or blood now. The change in phy sical parameters thus represents no obstacle to normalizing the hematocrit. However, basing the erythropoietin dose on the predialysis hematocrit shou ld be reconsidered.