Abstract 12311: Platelet Force Measurements are Predictive of Triage Category and Blood Transfusion After Trauma

Introduction: Platelets rapidly adhere, aggregate and contract forcefully at wound sites to initiate hemostasis. This process, known as primary hemostasis, is a critical component of clot formation after trauma. However, the clinical value of monitoring primary hemostasis after trauma remains unknown. This pilot study aimed to identify the potential clinical value of monitoring primary hemostasis after trauma by measuring platelet forces. Methods: Blood was sampled from Emergency Department trauma patients at a U.S. Level I trauma center. Primary hemostasis was measured as contractile force generated by platelet micro-aggregates formed within a microfluidic device. Citrated blood was flowed through a microfluidic channel at high shear rate for 15 seconds, causing platelet aggregates to rapidly form, activate, and contract at collagen-coated micro-force sensors. The maximum platelet force generated over five minutes was recorded in nanonewtons (nN). ANOVA was used to compare platelet force for each trauma triage category: Healthy non-trauma control vs. Modified vs. Full trauma team activation. Logistic regression was used to identify the association of platelet force with the need for any blood product transfusion within 24 hours of hospitalization. Results: N=28 trauma patients and N=7 healthy control subjects were included in this pilot analysis of an ongoing cross-sectional observational study. Of the trauma subjects 7/28 (25%) met Full trauma team activation criteria, and 7/28 (25%) required a blood-product transfusion. Mean (SD) platelet force was 227(63) nN for healthy controls, 157(48) nN for Modified, and 126(35) nN for Full trauma team activations (ANOVA, p=0.004). Platelet forces were 164 (45) nN for non-transfused vs. 112(20) nN for transfused subjects (t-test, p=0.008). The platelet force unit Odds Ratio for blood product transfusion was 0.965 (95%CI= 0.936, 0.996), indicating that the odds of receiving a transfusion was decreased significantly by 3.5% for every one nN increase of platelet force. Conclusions: Directly measuring primary hemostasis using platelet forces may enhance trauma triage and predict the need for blood product transfusion after trauma.