Automated Separation of Whole Blood in Top and Bottom Bags into Components Using the Compomat G4

Abstract

Background and Objectives: Whole blood can be separated by hard spin centrifugation into layers of blood components according to their specific gravity. The aim was to develop a program for an automatic separator to subsequently express the various components into their respective satellite bags in top and bottom systems with the following requirements; a red cell concentrate with a low leukocyte and platelet contamination, a ‘cell‐free’ plasma, and a buffy coat with a volume of about 50 ml with an acceptable loss of red cells. Materials and Methods: The Compomat G4 possesses an independently moving upper and lower press, to automatically express plasma or red cells to satellite bags of top and bottom systems. The influence of the extension of the lower press was studied by pooling and dividing two units of whole blood, and separating these units after centrifugation (2,960 g, 10 min) either with a program where the lower press was completely extended (program C), or with a program that left approximately 1 mm between the door and the lower press (program D). Results: The program (program d), where the lower press was not completely extended, yieded a buffy coat with a volume of 52±1 ml (mean ± SD, n = 36), which contained >75% leukocytes and >90% platelets of the original whole blood unit, with a red cell loss in the buffy coat of 21±1 ml (10.8±0.8% of the original volume). The leukocyte content of the red cell concentrates was 775±379 × 106 per unit, whereas the plasma contained 3±3×106 leukocytes and 4±3 × 109 platelets per unit. The pooling experiment indicated that complete extension of the lower press (program C) resulted in a significantly higher leukocyte contamination of the red cell concentrate (788±431 × 106 vs. 658±419 × 106; n = 12; p = 0.03), while there was no difference in the yield of red cells or plasma. The buffy coat produced with program D contained significantly more leukocytes (2,242±396 × 106 vs. 2,065±327 × 106, p × 0.005) and more platelets (96±14 × 109 vs. 92±17 × 109, p 0.02) per unit than with program C, probably because buffy coat cells sticking to the container wall are not expressed to the red cell concentrate, and thus remain in the buffy coat bag. Therefore, program D met our specifications for blood products. Conclusions: The Compomat G4 warrants reproducible separation of whole blood in top and bottom bags into red cells, buffy coat and plasma meeting our specifications.

In vitro evaluation of the quality of blood products collected and stored in systems completely free of di(2‐ethylhexyl)phthalate–plasticized materials

“…As reference, 28 WB units were collected in the routinely used DEHP‐PVC collection systems (T3941, Fresenius Kabi). WB units were placed on butane‐1,4‐diol cooling plates (Compocool, Fresenius Kabi, Bad Homburg, Germany) and, after overnight hold, processed according to the routine buffy coat procedure as previously described . After separation, AS was added to the RBC via the filter.…”

Separation of centrifuged whole blood and pooled buffy coats using the new CompoMat G5: 3 years experience

“…Because QC data show a lower number of PLTs in BC (which are randomly chosen to be combined into a platelet concentrate) and PC than in the pilot or validation studies, PLT content of BCs and PC are also subject of improvement studies. One way of improving PLT content in the BC might be decreasing the expression time in program step 20 (lower press out time) in accordance with a comparison of two Compomat G4 programs described by Van der Meer in which the lower press is or is not completely extended to the door. The latter program yielded significant more PLTs in the BC than the former.…”

“…At first, 3 G5 devices were installed and qualified for use. Initial programs, based on earlier Compomat G4 programs for separation of WB and BC pool, were calibrated. The program for WB was adjusted to obtain a BC of 50 ml and 42% haematocrit on average.…”

“…Processing of whole blood (WB) into the different components plasma, red cell concentrate (RCC), buffy coat (BC) and subsequent preparation of BC‐derived platelet concentrates (PC) can be done in several ways, varying from a process with many manual steps after centrifugation to highly automated processes. The first semi‐automated devices and improved versions such as the Compomat G4 and the Optipress II were developed in the eighties to standardize the component separation process, to allow bottom and top processing, and to improve the quality of blood components.…”

“…The basic working principle of G5 is the same as for G4 which has been described in detail by Van der Meer et al . . Briefly, two independently moving presses express the various blood components to satellite bags.…”