Abstract
Platelets were counted in eight units each of one- and three-day-old blood. Counts were done both before and after the blood had passed through a standard 170 micron filter.
In the one-day-old blood, platelet counts were within the normal range. The mean count was 237,000 platelets/microlitre. Platelet counts on three-day-old blood were lower, but generally still within the normal range. The mean count was 183,000/microlitre. Only a few platelets were retained by the filter in the transfusion set; about 90% of platelets passed the filter in both the one- and three-day-old blood.
It appears that whole blood, anticoagulated with citrate/phosphate/dextrose (CPD), and stored under Australian blood bank conditions retains platelets in sufficient numbers for at least the first three days to be clinically significant. However, it remains to be determined whether satisfactory platelet activity can be expected during this time.