Extended storage of platelets in a new plastic container. I. Biochemical and morphologic changes.

A new polyvinyl chloride container plasticized with tri(2-ethylhexyl) trimellitate (PL 1240 plastic) was evaluated for use in extended platelet storage. Six leukocyte-rich platelet concentrates (mean, 0.6 X 10(9) white cells per bag; range, 0.3 to 1.0 X 10(9) per container) were prepared by removing as much of the platelet-rich plasma from blood as possible. The cells were stored at 22 degrees C on an end-over-end agitator. An average of 1.04 +/- 0.19 X 10(11) platelets was recovered, and the mean pH dropped from 7.23 on day 0 to 6.68 by day 5. At the completion of the storage period. PO2 averaged 80 torr, PCO2 was 35 torr, bicarbonate concentration was 0.5 mM, and lactate concentration 29.5 mM. Thirty-one additional units of platelet concentrates, not deliberately prepared to be leukocyte-rich, on day 5 had a pH of 6.75 +/- 0.39 (mean platelet yield, 0.97 +/- 0.21 X 10(11); PO2 and PCO2 averaged 50 and 48 torr, respectively). Following storage, the cells had an average phase microscopic morphology score of 244 (n = 17). Platelets appeared to be preserved well throughout storage when assessed by transmission and scanning electron microscopy. We conclude that platelets can be stored for 5 days in PL 1240 plastic containers with good preservation of pH and cell ultrastructure.