The Bottom and Top System: A New Technique for Blood Component Preparation and Storage

Blood transfusion in a modern sense means the transfusion of red cells, when necessary supplemented by other components. The demand for plasma and plasma fractions and for platelets for therapeutic use has had an influence on the technique for preparing red cells. Automated devices have made it possible to perform collection as well as separation under more standardized conditions. Improved techniques for storage of red cells have prolonged the shelf life somewhat but most of the available methods disregard the rapid loss of 2,3–diphosphoglycerate and the accompanying increase in oxygen affinity. Methods are available which reduce the number of contaminating leukocytes to low levels, but information is still incomplete as to the degree of depletion actually needed.

Section: Component Preparationmentioning

confidence: 99%

Section: Component Preparationmentioning

confidence: 99%

Liquid–Stored Red Blood Cells for Transfusion

Högman¹

1999

“…Several authors [14]have reported an inverse relationship between post storage pH and platelet concentration in 50 ml plasma, while others [20]indicated the lack of a strict relationship. We recently reported [12]that the total number of platelets and pH had a close correlation (r = –0.86) when stored in specific polyolefin containers.…”

Section: Discussionmentioning

confidence: 99%

“…All units were stored for 16–20 h (‘overnight’) at 20 °C and centrifuged using hard spin conditions (3,100 g for 12.5 min [8]). Plasma, red blood cells and buffy coat were separated subsequently on an automated extractor system (Optipress®, Baxter) [14]. Buffy coats (volume 55±5 ml; Hct 54±3%) were retained in the collection bag and were stored for 2–6 h at room temperature without agitation.…”

Section: Methodsmentioning

confidence: 99%

Platelets Stored in a New-Generation ContainerDifferences between Plasma and Platelet Additive Solution II

Wildt‐Eggen¹,

Schrijver²,

Smid³

et al. 1998

Background and Objectives: In order to preserve platelet concentrates (PCs) with high yields, a new polyolefin platelet storage container (PL 2410, 1.3L, Baxter, La Châtre, France) with increased gas permeability in combination with a larger surface area has been developed. The storage capacity was studied with platelets in plasma and platelets additive solution. Materials and Methods: Platelet concentrate pools (PCs) of different yields suspended in either plasma (PCs-PL; n = 30) or PAS II (PCs-PAS; n = 37) were prepared. For preparation of PCs with a low, intermediate and high number of platelets 3, 5 and 6 buffy coat (BCs) were pooled with different volumes of plasma and 5 and 6 BCs were pooled with different volumes of PAS II, in order to obtain PCs of equal volumes comparable with routine conditions. All PCs were stored on a flatbed shaker at 22±2 °C and evaluated on days 1, 2, 5 and 7 by determining platelet and white cell counts, pH (37 °C), pO₂, pCO₂ and swirling score. Results: Platelet yields ranged from 1.5 up to 5.5 × 10¹¹ platelets/U. On day 7 all PCs-PL (n = 4) with platelet yields above 4.5 × 10¹¹/U had a pH value below 6.8 (range 5.91–6.79). While 7 of 8 PCs-PAS units with platelet yields above 4.0 × 10¹¹/U showed a pH value below 6.8 (range 6.31–6.70). Conclusion: During 7 days of storage in a new 1.3-liter platelet container, the pH was maintained above 6.8 in PCs in plasma with a yield between 1.5- and 4.5 × 10¹¹/U; when PAS II was used, the maximum platelet yield allowed for comparable pH maintenance was somewhat lower (4.0 × 10¹¹/U).

“…Quality aspects, reduction of labor and the aim to provide reproducible blood components without extensive training were motivations to build automated blood separation equipment [1, 2]. The introduction of these component separation devices, e.g.…”

Section: Introductionmentioning

confidence: 99%

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

Meer¹,

Pietersz²,

Hinloopen³

et al. 1999

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, yielded 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.