The impact of the biophysical environment on the platelet storage lesion (PSL) has mainly focused on reduced temperature storage, overlooking the significance of storage-induced shear stress. Shear stress in platelet storage refers to the frictional force acting parallel to the bag surface and exists solely through the implementation of agitation. This study investigates whether minimizing exposure to agitation-induced shear stress can alleviate the unexplained loss of function in stored platelet concentrates for neonatal transfusion (neonatal PCs). Using particle tracking analysis, fluid motion was measured in neonatal and adult platelet storage bags under agitation frequencies ranging from 20-60 rpm. Platelets stored at 20-60 rpm agitation over 8 days were examined by biochemical analysis, aggregation, and expression of activation markers. Results indicate that neonatal PCs experience significantly higher storage-induced shear stress compared to adult doses, leading to reduced functionality and increased activation from day 2 of storage. Adjusting the neonatal PC agitation frequency to 20 rpm improved functionality in early storage, while 40 rpm maintains this improvement throughout storage with reduced activation, compared to 60 rpm storage. This study confirms that small volume PC storage for neonatal use contributes to the PSL through the induction of shear stress, suggesting further evaluation of the recommended agitation frequency for neonatal PCs or postponement of the production of neonatal PCs until requested for neonatal transfusion.
Keywords: Agitation; neonatal; platelet; shear stress.
Context Approximately 1–5% of all neonates and up to 50% of critically ill newborns, present with low platelet counts, and will require platelet transfusion support.Platelet concentrates stored for neonatal transfusion have previously shown an accelerated reduction in quality during storage compared to platelet concentrates stored for adult transfusion and therefore may not provide as effective a therapeutic product.The current study hypothesized this loss of function over storage (known as the platelet storage lesion) to be a result of shear stress induced by agitation, exacerbated by the use of smaller bags in the neonatal preparation.Findings Our findings show that storage of platelet concentrates as smaller bags suitable for neonatal transfusion accelerates the platelet storage lesion, which experience a 4-fold greater shear stress than the adult preparation.The shear stress experienced by platelet concentrates stored for neonatal transfusion could be reduced by reducing the speed of agitation, thereby reducing the extent of the platelet storage lesion.Impact This study provides evidence that small volume storage promotes shear stress in platelet concentrates stored for neonatal transfusion, and optimizing storage conditions to reduce the shear stress induced by agitation can help to offset the platelet storage lesion.Further evaluation is required to establish a recommended agitation frequency for platelet concentrates stored for neonatal transfusion. An alternative strategy might include postponement of the production of platelet concentrates for neonatal transfusion until a neonatal transfusion is requested.