Changes in coagulation factor activity and content of di(2-ethylhexyl)phthalate in frozen plasma units during refrigerated storage for up to five days after thawing

Thawed plasma is typically transfused to supply coagulation factors but factor activity declines during refrigerated storage. Refrigerating thawed plasma for longer than 24 hours could reduce plasma wastage and make plasma more readily available for emergency transfusions. We measured coagulation factor activity and di(2-ethylhexyl)phthalate (DEHP) concentration in frozen plasma (FP) thawed and stored at 1 to 6°C for up to 5 days.

FP units prepared using "top-and-bottom" collection sets were thawed, refrigerated, and sampled aseptically at 0, 24, 72, and 120 hours after thawing (n = 54). Clotting factor activities and prothrombin times (PTs) were measured using an automated coagulation factor analyzer. DEHP was measured by high-performance liquid chromatography after hexane extraction (n = 11). Unit sterility was confirmed using an automated microbial detection system.

Factor (F)V and FVIII, but not FVII, declined significantly within 24 hours. By Day 5, mean losses were 20, 14, and 41%, in FV, FVII, and FVIII, respectively; fibrinogen activity did not change. PT values were prolonged by 9% on Day 5. Mean DEHP levels increased from 22 ppm at thaw to 66 ppm on Day 5.

The bulk of coagulation factor activity losses during storage occurred in the first 24 hours. Coagulation factor activities remaining in FP after 5 days did not differ from those previously reported in similar products frozen within 24 hours of phlebotomy. While DEHP levels in 5-day-thawed FP are not of concern for adult patients, for infants, DEHP levels can be minimized by using FP refrigerated for no more than 24 hours.