Proposed procedure for evaluating platelet concentrate units to be used for transfusion

Platelet concentrate samples from 100 units collected by apheresis at The American Red Cross Blood Bank located at Columbia, S.C. and from 31 units collected by apheresis at The Santa Barbara Tri-County Blood Bank located in Santa Barbara, California were sent overnight to Fishers, Indiana and tested for platelet factor 3 activity. The maximum dilution that would support normal clotting was determined for each unit. Units with maximum dilutions of 1:100 or greater were considered to have sufficient platelet factor 3 activity to be used for a transfusion. Ninety-six percent of the units sent from Columbia, South Carolina and 94.55% of the units sent from Santa Barbara, California were suitable for use based on their platelet factor 3 activity. This study shows the feasibility of sending platelet concentrates long distances and the importance of testing for platelet factor 3 activity.