Alterations of red blood cell shape in patients with severe trauma

Background: Trauma is accompanied by a decrease in red blood cell (RBC) deformability, which may manifest itself earlier than secondary septic complications. The mechanisms of this phenomenon are not clear. The aim of this study is to determine when the alterations of RBC shape appear in trauma patients. Methods: RBC shape was examined by scanning electron microscopy in 43 patients with multisystem trauma. Blood samples were taken at admission and every 24 hours afterward for 4 to 10 days. The patients were divided into two groups: the survivors and those who died of septic complications. The control group consisted of 10 healthy volunteers. Results: A significant decrease in the percentage of discoid erythrocytes, compared with the volunteers, was observed in both groups of patients at admission (77.6 +/- 11.9 and 66.7 +/- 5.8 vs. 96.0 +/- 2.9%, p < 0.01). The percentage of irreversibly changed RBC (spherostomatocytes, spherocytes) was lower in survivors (12.9 +/- 2.0% vs. 20.3 +/- 9.4%,p < 0.01). This phenomenon remained constant until the end of the study. The survivors only showed a tendency toward the improvement of RBC shape. Conclusion: RBC shape alterations appear within the first hours after trauma and persist for at least 7 to 10 days. These changes are more severe in patients with secondary septic complications.