INTRODUCTION

Platelet transfusions were first introduced in the 1960s as a separate component for transfusion. Since then, the use of platelet transfusions has continued to increase, with current concerns focused on the appropriate use of this therapy for thrombocytopenic patients or those with platelet dysfunction.

PLATELET PRODUCTS AVAILABLE FOR TRANSFUSION

Whole blood-derived platelet concentrates or apheresis platelets

Platelets are obtained from either donated whole blood or by apheresis procedures. Two methods of preparing platelets from whole blood are illustrated in Figure 14.1. Almost all of Europe uses the buffy-coat method of platelet preparation from whole blood, and Canada is converting to this method of platelet preparation. Only the United States continues to use the platelet-rich plasma (PRP) method of platelet preparation. Comparative studies have shown no differences in the quality of these platelet concentrates, with storage times up to 5 days. However, there are several advantages to the buffy-coat platelet preparation system: (1) preparation can be fully automated; (2) platelets can be prepared from whole blood up to 24 h from collection rather than requiring platelet preparation within 6 h, as mandated for PRP platelet concentrates; (3) platelets are routinely pre-storage pooled, allowing rapid platelet release from the production facility; (4) the residual WBC count is less than that of PRP platelets; (5) pooled platelets are usually stored in additive solution rather than plasma, making more plasma available for other purposes as well as reducing the risk of transfusion-related acute lung injury (TRALI); and (6) with storage of platelets beyond the current 5 days, platelet viability may be better maintained in the buffy-coat form rather than in PRP concentrates.