Hemolyzed specimens are rejected for coagulation testing based on concerns of artifactual interference. Prothrombin time (PT), activated partial thromboplastin time (aPTT), and selected factor assay test results for consecutive pairs of hemolyzed and subsequently recollected (mean, 72 minutes later) nonhemolyzed patient specimens were compared. Specimens from healthy human subjects were subjected to mechanically induced hemolysis, and PT and aPTT results compared with concurrently drawn nonhemolyzed control samples. In 50 paired patient specimens, there were statistically significant differences in PT (15.8 +/- 8.4 vs 16.3 +/- 8.7 seconds, P < .01) and aPTT (31.6 +/- 18 vs 32.5 +/- 19 seconds, P < .01) between hemolyzed and nonhemolyzed specimens, respectively. Specimens from healthy subjects showed no difference in PT and a minor difference in aPTT. A policy of rejecting hemolyzed specimens for coagulation tests should be revisited because the observed difference, when present, is unlikely to be considered clinically meaningful.

There is no evidence of a deterioration in quality, activation of coagulation or complement, or a mixed lymphocyte reaction attributable to the prestorage pooling process with up to 7 days of storage.

Plasma manufactured after a 24-hour room temperature hold contains coagulation factors comparable to FFP except for a possible reduction of up to 20% in FVIII. This plasma appears suitable as a transfusable product and extension of liquid storage to 7 days merits consideration.