Blood Warmer: Used with rapid transfusion rates (e.g. >50 mL/kg/hr), in already hypothermic patients or rare conditions where cold fluid delivery is problematic (e.g. cold agglutinins); massive transfusion (avoid hypothermia)
Blood filter: removal of microaggregates during blood transfusion; platelet, leucocyte and fibrin aggregates form in stored blood and are thought to produce pulmonary microembolism -> pulmonary dysfunction