Improvement of blood component quality--automatic separation of blood components in a new bag system.

We report here on a new multiple bag system with top and bottom drainage of the primary bag which allows automatic separation of blood components on a routine basis. 100 units of 450 ml fresh whole blood (CPD) were centrifuged by hard spin centrifugation and then separated into leukocyte-poor red cell concentrates in additive solution (volume 284 +/- 22 ml, Hct 63.5 +/- 3.2%, platelets 3.1 +/- 1.4 X 10(9)/unit [3.1 +/- 1.2%], leukocytes 1.9 +/- 1.2 X 10(8) [8.3 +/- 5.0%]) and plasma (FFP) with acceptably low cell contamination (volume 262 +/- 33 ml, platelets 14.6 +/- 5.6 X 10(3)/microliter, leukocytes 0.04 +/- 0.03 X 10(3)/microliter). The residual buffy coat of whole blood stored for 16-20 h at room temperature was suitable for the preparation of leukocyte-poor platelet concentrates (n = 20; platelets 0.67 +/- 0.17 X 10(11) (69.8 +/- 15.0%); leukocytes 0.1 +/- 0.1 X 10(8] which showed quite good platelet function in vitro. The removal of leukocytes and platelets caused significantly less in vitro hemolysis during storage when compared to conventionally prepared red cell concentrates with and without buffy coat. Further advantages of the reduction of the cell contamination in red cell concentrates before storage are discussed. From this it can be concluded that leukocyte-poor red cell concentrates with less than 20% residual leukocytes should become the regular red cell preparation also for surgery, especially as the recommended separation technique can easily be performed on a routine basis. Red cell concentrates still containing the whole buffy coat are no longer acceptable.