INTRODUCTION: Because of anticoagulation, changes in blood composition, and--perhaps--extracorporeal circulation, donor apheresis should cause alterations in hemorheology and hence in the perfusion of the microvasculature. MATERIAL AND METHODS: 19 regular blood donors were included. According to our standard protocol for automated collection of blood components with the MCS 3p cell separator, we harvested 1 unit of platelets and 2 units of plasma in each case. Prior to, 1 h after, and 24 h after donation, the following parameters were measured: total serum protein (tsp), hematocrit (hc), whole blood and plasma viscosity (wbv/pv), red cell aggregability (rca) and blood flow velocity of the nail-fold capillaries (bfv). RESULTS: The following parameters decreased 1 h/24 h after donation: tsp (p < 0.001/p = 0.008), elastic wbv (p = 0.018/p < 0.001), viscous wbv (p = 0.85/p = 0.0031), pv (p < 0.001/p < 0.001), static rca (p < 0.001/p = 0.0073), dynamic rca (p < 0.001/p = 0.017). The hc showed an initial increase (p < 0.001) with a subsequent overshooting decrease after 24 h (p < 0.001). 1 h after donation bfv raised (p = 0.0065). It decreased after 24 h and remained only slightly higher than the initial level (p = 0.27). CONCLUSIONS: Automated combined collection of platelets and plasma gives rise to: i) Improvement of rheological properties of the donor's blood and increased bfv of his nail-fold capillaries within the 1st h after apheresis. ii) 24 h after donation the improved hemorheological properties remain demonstrable, but the bfv of nail-fold capillaries declines and shows a trend toward the starting-point. iii) Taken together, this is possibly reflecting adapted hemodynamic and vasoconstrictor regulation for altered hemorheological conditions.
INTRODUCTION: Because of anticoagulation, changes in blood composition, and--perhaps--extracorporeal circulation, donor apheresis should cause alterations in hemorheology and hence in the perfusion of the microvasculature. MATERIAL AND METHODS: 19 regular blood donors were included. According to our standard protocol for automated collection of blood components with the MCS 3p cell separator, we harvested 1 unit of platelets and 2 units of plasma in each case. Prior to, 1 h after, and 24 h after donation, the following parameters were measured: total serum protein (tsp), hematocrit (hc), whole blood and plasma viscosity (wbv/pv), red cell aggregability (rca) and blood flow velocity of the nail-fold capillaries (bfv). RESULTS: The following parameters decreased 1 h/24 h after donation: tsp (p < 0.001/p = 0.008), elastic wbv (p = 0.018/p < 0.001), viscous wbv (p = 0.85/p = 0.0031), pv (p < 0.001/p < 0.001), static rca (p < 0.001/p = 0.0073), dynamic rca (p < 0.001/p = 0.017). The hc showed an initial increase (p < 0.001) with a subsequent overshooting decrease after 24 h (p < 0.001). 1 h after donation bfv raised (p = 0.0065). It decreased after 24 h and remained only slightly higher than the initial level (p = 0.27). CONCLUSIONS: Automated combined collection of platelets and plasma gives rise to: i) Improvement of rheological properties of the donor's blood and increased bfv of his nail-fold capillaries within the 1st h after apheresis. ii) 24 h after donation the improved hemorheological properties remain demonstrable, but the bfv of nail-fold capillaries declines and shows a trend toward the starting-point. iii) Taken together, this is possibly reflecting adapted hemodynamic and vasoconstrictor regulation for altered hemorheological conditions.