Oxygenator Volume Control by Parallel Ultrafiltration to Remove Plasma Water

Abstract

A technique of hemoconcentration during and after cardiopulmonary bypass using parallel ultrafiltration (hemodiafiltration) is described and evaluated. Fifty-nine (59) adult patients were evaluated with thirty-five (35) being ultrafiltered intra-operatively and twenty-four (24) not being ultrafiltered. The technique of ultrafiltration is presented as a viable method of achieving significant hemoconcentration (p <.001). The ultrafiltered group demonstrated a drop in hematocrit between pre-pump and post-pump samples of 11%, whereas the group which was not ultrafiltered demonstrates a 16% drop in hematocrit between the same two samples. Operative fluid balance index is also significantly lower in the ultrafiltered group (p <.001), which had a positive index of 727 ml/m2 as compared to the non-ultrafiltered group which had a positive index of 1206 ml/m2. Comparisons of platelet counts, fibrinogen levels and plasma hemoglobin levels between the groups indicate no significant disruption of formed elements of plasma proteins associated with the use of ultrafiltration. There were no system failures during this series and no complications attributed to the use of parallel ultrafiltration.