The effect of the interruption of agitation on platelet quality during storage for transfusion

A considerable amount of data and the CFR suggest that platelet concentrates (PCs) should be stored with continuous, gentle agitation before transfusion. However, there are only limited data concerning the mechanisms of platelet damage that may occur when agitation is interrupted, and there are no CFR guidelines concerning shipment between periods of storage.

PCs were prepared by the platelet-rich plasma method and stored for 5 days at 20 to 24 degrees C; agitation was interrupted for 1 to 3 days either by simply stopping the agitator or by placing the PCs in a stationary shipping container. Measurements of platelet metabolism and quality were made during storage and on Day 5.

With interruption on the agitator, the production of lactic acid was increased during the interruption in proportion to the number of platelets in the PC and the duration of the interruption. The pO(2) was increased during agitation interruption, which suggested a decline in oxygen utilization. With the use of the hypotonic shock response and the extent of shape change as reflections of platelet quality, there was no evidence of platelet damage unless the pH fell to or below 6.5. No PC reached this level after an interruption of agitation for only 1 day, irrespective of which day was chosen for interruption. PCs whose agitation was interrupted for 2 and 3 days were at risk of having a pH less than 6.5 if their contents were greater than 1.25 x 10(11) and 0.75 x 10(11) platelets, respectively. Interruption of agitation for 1 day in the shipping container produced results essentially identical to those produced by interruption on the agitator.

Interruption of agitation of PCs for 1 day, either on the agitator or in the shipping container, produces no platelet damage measurable by these in vitro techniques. However, an interruption of agitation for 2 days can result in significant damage in some components. Further studies will be required to learn more about the mechanisms that lead to the metabolic changes described and to determine if the same generalizations apply to apheresis PCs and PCs prepared from pooled buffy coats.