During arterial thrombosis, RBCs promote platelet margination, increase platelet-thrombus interactions, and enhance platelet adhesion and activation. (A) Arterial thrombi arise in vessels with high shear rates, which promotes the rapid formation of platelet-rich thrombi. Potential contributions of normal and abnormal RBCs to arterial and venous thrombosis/thromboembolism. Here, we review the above mechanisms of RBC contribution to hemostasis.įigure 1.

Finally, blood clot structure and maturation are dependent on the inclusion of RBCs in forming thrombi. Additionally, RBCs generate microparticles which have been shown to reduce clotting time. RBC surface interactions govern signaling between platelets and RBCs and also aid in the conversion of prothrombin to thrombin. Of note, morphologic pathology, such as that found in sickle cell disease, leads to increased risk of thrombotic disease. First and foremost, RBC biomechanics are the principal determinant of viscosity and flow dynamics of blood, which strongly influence all features of hemostasis. Red Blood Cells (RBCs) have been increasingly recognized to play important roles in hemostasis and the mechanisms by which they do so continue to be elucidated. 2Division of Pediatric Critical Care Medicine, The Center for Blood Oxygen Transport and Hemostasis, University of Maryland School of Medicine, Baltimore, MD, United States.1Division of Pediatric Hematology and Oncology, Oregon Health and Sciences University, Portland, OR, United States.The reduced erythrocyte rigidity and subsequent decreased whole-blood viscosity should enhance tissue perfusion in the microcirculation. Removal of mannitol from the suspension returned red cell deformability to preadministration values, indicating that the increased erythrocyte deformability required the presence of mannitol and the relative hyperosmolarity induced by this agent. This effect was independent of the hematocrit. This decrease appeared at high shear rates only, where erythrocyte deformability is critical in determining viscosity. Wholeblood viscosity decreased at 30 minutes and 2 hours, but not at 4 hours after mannitol administration. Complete blood counts, serum osmolarities, and erythrocyte microsieving studies were also performed on each sample. Blood samples were drawn immediately prior to, and 30 minutes, 2, and 4 hours after administration of mannitol. ✓ To determine the effect of mannitol on blood viscosity, serial measurements were carried out on venous blood in patients undergoing craniotomies for intracranial aneurysms.

Test viscosity of hemoglobin in rbc