A. Khan2, D. Liberati1, A. Baylor1, L. Diebel1 1Wayne State University, School Of Medicine/Surgery, Detroit, MI, USA 2University of Medicine and Health Sciences, School Of Medicine, Basseterre, ST. KITTS, Saint Kitts and Nevis
Introduction: Duration of red blood cell (RBC) storage in the blood bank has been associated with increased morbidity and mortality in observational studies in trauma. Impairment of microvascular perfusion has been noted following transfusion of "older" RBC and trauma hemorrhagic shock (T/HS). The mechanism(s) are not completely understood. Platelet activation and aggregation occur early following T/HS and may also impair microvascular endothelial function. The RBC glycocalyx layer and the endothelial glycocalyx layer have synergistic effects on flow characteristics of RBCs; impairment of these following storage duration (RBC) or shock conditions (endothelial cells) may indirectly effect platelet adhesion under flow conditions. This was studied in a microfluidic flow study.
Methods: RBCs were obtained from the hospital blood bank and from normal volunteers. RBC hematocrit was adjusted to 23% using a balanced salt solution and endothelial monolayers were established in microfluidic flow devices. RBC + endothelial monolayers were subjected to control (21% O2) or shock conditions (hypoxia/reoxygenation + stress epinephrine concentration). After RBC perfusion the monolayers were then perfused with whole blood (with a fluorescent label specific for platelets) and platelet adhesion to the endothelial monolayer quantitated by fluorescent imaging.
Results: See Table
Conclusion: RBC transfusion increased platelet adhesion under flow conditions. This was associated with storage duration of RBC and endothelial monolayer exposure to shock conditions. Degradation of the RBC glycocalyx layer with storage duration and endothelial glycocalyx degradation following shock conditions appear to increase platelet adhesion to the endothelial layer. This may have a negative impact on the microvasculature in vitro.
