Extended storage of platelets in a new plastic container

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 × 109 white cells per bag; range, 0.3 to 1.0 × 109 per container) were prepared by removing as much of the platelet‐rich plasma from blood as possible. The cells were stored at 22°C on an end‐over‐ end agitator. An average of 1.04 ± 0.19 × 1011 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 × 1011; 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.