Effect of transfusion on the endothelium dependent dilatation of brachial artery in patients with chronic anemia

Abstract

The effect of changes in the main determinants of whole blood viscosity after red blood cell transfusion on endothelium dependent dilatation of brachial artery was studied in patients treated with symptoms of chronic anemia.

10 patients were involved in the study, 8 males, 2 females, mean age 52.7 \pm 18.7 years. Following blood tests performed at hospital admission: hemoglobin (Hgb), red blood cell count (RBC), hematocrit (Hct), white blood cell count, platelet count, plasma total protein, fibrinogen, plasma viscosity, BUN, creatinine, cholesterol, triglycerides. Flow mediated dilatation of brachial artery (FMD) was determined by Doppler method. Blood tests and FMD study were repeated after transfusion.

The main determinants of whole blood viscosity increased after transfusion. The increases of Hgb, RBC, Htc were highly significant. The central flow velocity in brachial artery decreased at rest and during hyperemia as well. FMD of brachial artery was not changed significantly after transfusion.

The change in factors determining whole blood viscosity did not cause a significant change in FMD. The probable explanation for this is that the increase of whole blood viscosity is associated with a decrease of central flow velocity. These two counteracting changes can equal each other.