A comparison in vivo dacron wool (Swank) and polyester mesh (Pall) micropore blood transfusion filters in the prevention of pulmonary microembolism associated with massive transfusion.

Experiments were performed to compare the effectiveness in vivo of the two most widely used micropore blood transfusion filters in preventing detrimental physiologic changes associated with transfusion of microaggregate-containing blood. Exchange transfusion with stored blood having an elevated screen filtration pressure (SFP) through polyester mesh (Pall) filters (Group PM) was followed by decreases in arterial blood pH and O2 consumption, increases in arterial blood pyruvate and lactate concentrations, and a decrease in pulmonary DO2. The lungs of 5 of 6 animals revealed emboli far out in the pulmonary microcirculation. These changes did not occur in animals transfused through dacron wool (Swank) filters (Group DW). Even though an increase after transfusion in pulmonary Qs/Qt in Group PM did not achieve statistical significance when compared to pretransfusion Qs/Qt, it was significantly higher than that in animals in Group DW. Both filters removed considerable quantities of microaggregates; however, the polyester mesh (Pall) filters permitted passage of small microaggregates and development of ditrimental physiologic changes. Dacron wool (Swank) filters completely removed measurable microaggregates and detrimental changes did not occur.