[Blood filtration for the prevention of microaggregate damage: various critical aspects]

Recent studies shown that patients receiving more than 20% of their total blood volume through 170 mu standard blood filters, may occur in severe organic damage such as pulmonary, cerebral, renal embolism due to microaggregates contained in stored blood. Microaggregate size varies from 10-200 mu; they are composed of platelets, leucocytes, red cells debris and fibrin strands, which take form few hours after blood storage begins and whose number progressively increases. In this study we analyzed microaggregate composition, factors causing their formation, side effects due to massive transfusion and blood filtration techniques capable to prevent a direct blood infusion. There is a variety of available filters, but screen filters seem to offer more important and practical advantages than depth filters do. The use fine pore filters is recommended when more than three blood units are to be infused during only one administration.