Platelet function and hemolysis in centrifugal pumps: in vitro investigations

The effects of centrifugal pumps on blood components other than erythrocyte s, namely platelets and their interaction with the coagulation system, are not very well known. In a comparative study with three centrifugal pumps (B ioMedicus BP-80, St. Jude Isoflow, and Sarns Delphin) and the Stockert roll er pump hemolysis, platelet counts, thromboplastin and partial thromboplast in times, as well as resonance thrombography (RTG) parameters for the asses sment of platelet and coagulation function were evaluated in vitro. Normali zed indices of hemolysis (NIH) with ACD anticoagulation after 360 minutes w ere 0.008 +/- 0.004 (Isoflow), 0.018 +/- 0.017 (BP-80), 0.085 +/- 0.051 (De lphin), and 0.049 +/- 0.010 g/1001 (roller pump). Plasmatic coagulation was activated in all circuits. Platelet function was severely inhibited by the BP-80, indicated by increase in RTG platelet time to 358% +/- 150% of init ial values compared to 42% +/- 29% (Isoflow), 40% +/- 20% (Delphin), and 12 % +/- 10% (roller pump). Fibrin polymerization was affected similarly. The large surface area of the BP-80 leads to an extensive activation of platele ts and plasminogen.