Storage of platelets collected by apheresis

Increasingly, platelets obtained by apheresis must be shipped some distance prior to infusion. We have studied the effect of storage and the size of the storage container on in vitro platelet function over a 48‐hour period. Five donors each donated twice at 2‐week intervals with one donation of 200 ml taken into a 300‐ml bag and the other into a 2000‐ml bag. The platelets collected into the 2000‐ml bag maintained pH well over 48 hours. The Po 2 stayed at a high level, and the Pco 2 decreased by 48 hours. The lactate accumulation was 38 mg per dl, and the aggregation and hypotonic shock response were maintained well. In comparison, platelets stored in the 300‐ml bag had a rapid decrease in pH accompanied by a marked rise in Pco 2 . Lactate accumulation was also high at 124 mg per dl at 48 hours. Aggregation, 14 C‐serotonin uptake, hypotonic shock response, and platelet recovery were reduced. Exposure to a high concentration of the plasticizer, di‐2‐ethylhexyl phthalate, equivalent to that which occurs in the 2000‐ml bag did not affect platelet function. Storage of the apheresis platelets in a double volume of plasma in the 2000‐ml bag likewise had little effect. The data indicate that, as measured by in vitro response, apheresis platelets can be maintained for up to 48 hours if stored in a 2000‐ml bag.