Improved storage of platelets for transfusion in a new container

Abstract

The storage of platelet concentrates (PC) at 22°C in Polyvinylchloride containers has been limited to 3 days. Even within this time interval, fall in pH to 6.0 or less with associated loss of viability occurs in a substantial number of PC. Previous work demonstrated that the fall in pH resulted from increased production of lactic acid due to hypoxic conditions within the container and could be prevented by storage in a container constructed from material that was more permeable to oxygen than conventional Polyvinylchloride plastic, PL-146. We have now studied PC storage in a new polyolefin plastic, PL-732. This material has increased permeability to oxygen, and pH fall to less than 6.0 does not occur during 5 days of storage. In autologous studies using chromium-51 labeling, mean in vivo recovery and survival T1/2 were 51% and 3.1 days, respectively, after 5 days of storage. After the same storage interval, mean corrected platelet increments in thrombocytopenic patients were 15.7, 11.1, and 6.9 × 103/cu mm/sq m/1011 platelets infused at 1-3,4-6, and 24 hr after infusion. In paired studies in the same patient, PC stored for 5 days in PL-732 were consistently superior to PC stored for 3 days in PL-146. At 4-6 and 24 hr after infusion, bleeding times were shortened appropriately for the elevation of the platelet count achieved. These good results were achieved by agitating PC (50 ml) on a flat-bed agitator at 70 cycles per minute. Inconsistent results were observed in autologous studies with two other forms of agitation. We conclude that the use of PL-732 will permit the satisfactory storage of PC for 5 days at 22°C. Storage of PC at 4°C has not been evaluated in this container.