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

BACKGROUND: A considerable amount of data and the CFR suggest that platelet concentrates (PCs) should be stored with continuous, gentle agitation befo re transfusion. However, there are only limited data concerning the mechani sms of platelet damage that may occur when agitation is interrupted, and th ere are no CFR guidelines concerning shipment between periods of storage. STUDY DESIGN AND METHODS: PCs were prepared by the platelet-rich plasma met hod and stored for 5 days at 20 to 24 degreesC; agitation was interrupted f or 1 to 3 days either by simply stopping the agitator or by placing the PCs in a stationary shipping container. Measurements of platelet metabolism an d quality were made during storage and on Day 5. RESULTS: With interruption on the agitator, the production of lactic acid w as increased during the interruption in proportion to the number of platele ts in the PC and the duration of the interruption. The pO(2) was increased during agitation interruption, which suggested a decline in oxygen utilizat ion. With the use of the hypotonic shock response and the extent of shape c hange 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 da ys 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 essentia lly identical to those produced by interruption on the agitator. CONCLUSION: Interruption of agitation of PCs for 1 day, either on the agita tor or in the shipping container, produces no platelet damage measurable by these in vitro techniques. However, an interruption of agitation for 2 day s 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 ii the same generalizations apply to aph eresis PCs and PCs prepared from pooled buffy coats.