The effect of stationary versus rocked storage of whole blood on red blood cell damage and platelet function.

Background: Increasingly, cold-stored whole blood (WB) is being considered for the resuscitation of civilian trauma patients. It is unclear whether the WB should be agitated to enhance the function of the platelets (PLTs) or whether agitation will cause RBC damage.

Study Design And Methods: WB units were collected by standard procedures using a PLT-sparing inline leukoreduction filter and stored between 1 and 6°C. On Storage Day 3 each unit was divided into 4 subunits that were stored under one of the following conditions for 21 days: unrocked, manually rocked once daily, continuously rocked end over end, or continuously rocked horizontally. From Day 3 to Day 10, hemolysis and the mechanical fragility index (MFI) for RBC injury were measured daily and again on Days 15 and 21 (n = 9-16 units tested each time). On Days 4 and 10, rapid thromboelastogram (rTEG) measurements were performed (n = 8-10 units tested each time).

Results: Hemolysis and MFI increased significantly between Day 3 and Day 21 (p < 0.0001) for all RBC rocking conditions, as well as the unrocked units. Only the manually and horizontally rocked units demonstrated higher hemolysis (on Day 21) and MFI (starting on Day 10) compared to the unrocked units. Only the α-angle and maximum amplitude in the end-over-end rocked units increased significantly between Day 4 and Day 10. There were no significant differences between the rocked and unrocked units on Day 10 for any rTEG variable.

Conclusions: Rocking does not appear to enhance in vitro PLT activity in cold-stored WB and can lead to increased hemolysis.