Recovery of extra plasma during preparation of platelet concentrates using a new centrifugation support

During blood component preparation of standard blood donations a major loss of plasma occurs whenever platelet concentrates (PC) are produced, especially when the platelets are prepared by the platelet-rich plasma (PRP) method. This loss is partly due to the use of plasma for resuspension of the platelet pellet but the main loss is associated with the slow first spin used to prepare PRP. This slow first spin results in an undesirably low haematocrit and a red-cell concentrate which contains a large volume of trapped plasma which is lost to the fractionation plant. We have developed a method of recovering most of this plasma from the soft-spun red cells by including the red-cell concentrate (RCC) in the second spin during preparation of the platelet pellet. To allow recovery of the second spin plasma from the half-full RCC bag we have developed a simple bag support, the Perth BagRap. Development of the method proved difficult due to the high g forces but the final technique evolved was simple and inexpensive. The method was easily introduced into routine use and resulted in a 53% increase in plasma per three-product unit.