Plateletpheresis with the new Fresenius AS 104 blood cell separator

Among the many blood cell separators introduced into the international market in these last few years, the Fresenius AS 104 represents an advanced and safe thrombocytapheresis machine whose development took advantage of extensive worldwide experience with blood cell separation. Nonetheless the AS 104 has generated most interest in West Germany and most, if not all, the studies published on its platelet collection efficiency have been carried out in that country. It is normally reported that from 2.7 to 3.5 x 10(11) platelets can be collected in approximately 80 minutes. Since these results could not be duplicated routinely in our hemapheresis unit, we set up a study by modifying the standard procedure. It was possible to reduce the procedure time and to collect platelet concentrates containing more than 4 x 10(11) cells on a routine basis by using the following procedure: ACD-A/blood ratio 1:10; Interface position 6:2; blood flow rate always exceeding 65 mL/min; rpm 1750; cell collection from 4 to 7 mL/min; volume of blood processed 3.6 L followed by the rinsing of the system with 200 ml of saline; extraction of the content of the secondary separation chamber by the action of the plasma pump working at 20 mL/min for 2 min. With this procedure the platelet yield in 34 collections exceeded 3.1 x 10(11) and averaged 4.06 x 10(11). The procedure time was reduced to 56.5 minutes with a mean blood flow rate of 62.3 mL/min. The leukocyte and erythrocyte contamination of the products were in the range of 1 x 10(7) and 1 x 10(8) respectively.(ABSTRACT TRUNCATED AT 250 WORDS)