Banked Blood Microfiltration I. MICROFILTER COMPOSED OF FIVE POLYURETHANE FOAM LAYERS WITH GRADED PORE SIZE

Abstract
Aggregates of amorphous material which develop with storage of banked blood may be a source of pulmonary microembolism in patients having massive transfusions. To remove such debris, blood microfilters were developed and are in routine clinical use. The evaluation of 1 such filter, the Bentley PF 127 model B, which is composed of 5 layers of polyurethane foam is described. The time of filtration as a function of the pressure applied, the number of particles removed, the observed changes in blood cells and the results of scanning EM of the filter after filtration of human banked blood, are reported.