In vitro characteristics of 'undercollected' units of whole blood in CP2D-A

Blood donation volumes less than 350 ml are classified as 'undercollected' at the NSW Red Cross Blood Transfusion Service (BTS) and are discarded. This study evaluated the in vitro characteristics during storage of both undercollected units and units of acceptable volume. Thirty-two units of whole blood were each collected into 63 ml of CP2D-A, with blood volumes ranging from 180 to 456 ml. The units were stored between 4 and 6 degrees C for 35 days and in vitro measurements were performed weekly. Biochemical parameters measured included ATP, extracellular pH, total haemoglobin, haematocrit, mean cell volume, plasma sodium and potassium, plasma haemoglobin, 2,3-DPG and lactate levels. All parameters were within the BTS acceptable quality control limits for whole blood. Thus, it appears feasible to transfuse undercollected units with volumes between 180 and 350 ml. However, routine transfusion of undercollected homologous units is undesirable. In contrast, it may be preferable to transfuse an autologous unit, even if it was undercollected. The performance of in vivo survival studies would provide confirmatory data on this proposition.