(P-BC-19) Decreased Platelet Counts in Whole Blood Units (WBU) Compared to Screening Samples in Select Donors

Background/Case Studies: Transfusion of whole blood is critical in the early management of hypovolemic shock patients. In military settings, whole blood resuscitation may be more advantageous than component therapy due to ease of storage and transfusion. Maintaining quality and consistency of blood products from point of collection to transfusion is critical to delivering efficacious resuscitation. This study aimed to examine differences between platelet counts in WBU donor screening samples and the collected WBU.

Study

Design/Methods: This study included 30 participants who were consented and enrolled in a study involving WBU collection. A screening sample was collected in EDTA before WBU collection, and a complete blood count was run on the sample. After eligibility was established, a 500 mL WBU was collected from the participant according to standard clinical practice. On the day of collection, a 500 µL aliquot was prepared from the thoroughly mixed WBU and a complete blood count was run on the aliquot. Platelet counts in the WBU were adjusted based on the ratio of anticoagulant to blood in the WBU collection set. A paired T-test was performed to compare the screening sample platelet count to the adjusted WBU platelet count.

Results/Findings: The adjusted platelet counts in the WBU samples were statistically significantly reduced compared to the screening samples from a mean of 218.1 x 10³/µL to 175.8 x 10³/µL (p < .001). The decrease in platelet count between paired samples was variable. In 11 of the 30 samples, platelets decreased by over 20%, while platelet count was only slightly decreased or maintained in the remaining samples (Figure A).

Conclusions: Early transfusion of balanced ratios of platelets and red blood cells leads to improved outcomes and reduced mortality in trauma patients. As the military moves toward the use of whole blood for treatment in operational environments, ensuring whole blood maintains the necessary components for resuscitation will be essential to maintaining efficacy during resuscitation. This study determined that platelets may be reduced in WBUs during collection in a subset of donors. The platelet drop may be due to platelet activation and adherence to the medical tubing leading from the donor to the blood bag. Future research should further characterize platelet drop during WBU collection and potentially develop methods for reducing this phenomenon.