Abstract des Autors

Purpose: Acute changes of the blood volume were evaluated by primarily looking at the fluctuations of the hemoglobin concentration. A better quantitative method for the evaluation of blood volume changes could be the direct determination of the hemoglobin mass. The aim of this paper was to record the changes of the blood parameters with multiple direct blood volume determinations within four weeks of a whole blood donation of 500 ml. Materials and methods: The examination included ten healthy students (women n = 1; men n = 9) of the University of Leipzig. The blood volume was determined six times within five weeks using the CO-rebreathing method in the closed system. The first two measurements were taken before a whole blood donation and immediately afterwards. Four further measurements were taken at an interval of one week. The parameters hemoglobin concentration (Hb), hematocrit (HCT), blood volume (BV), erythrocytes volume (RCV) and total hemoglobin mass (tHb-mass) were determined for each measurement. Subsequently, the data was evaluated by using ANOVA with repeated measurements. Results: tHb-mass: Mean value and standard deviation: T1: 948 ± 197 g; T2: 865 ± 179 g; T3: 876 ± 183 g; T4: 904 ± 179 g; T5: 919 ± 196 g; T6: 922 ± 167 g. Significant differences could be determined between the measurements T1 and T2 (p < 0.0001), T1 and T3 (p < 0.0001) and T1 and T4 (p < 0.001). Blood volume: Mean value and standard deviation: T1: 6392 ± 964 ml; T2: 5869 ± 982 ml; T3: 6180 ± 878 ml; T4: 6043 ± 1019 ml; T5: 6054 ± 969 ml; T6: 6148 ± 938 ml. A significant difference could be determined between the measurements T1 and T2 (p < 0.001). Hemoglobin concentration: Mean value and standard deviation: T1: 9.16 ± 0.97 mmol/l; T2: 9.11 ± 0.76 mmol/l; T3: 8.64 ± 0.79 mmol/l; T4: 9.25 ± 0.55 mmol/l; T5: 9.36 ± 0.82 mmol/l; T6: 9.29 ± 0.57 mmol/l. Significant differences could be determined between the measurements T3 and T4 (p < 0.05), T3 and T5 (p < 0.01) and T3 and T6 (p < 0.05). Conclusion: Four weeks after the blood donation, 69 % of the hemoglobin mass lost during blood donation could again be determined. In the case of a logistic growth curve, the complete regeneration of the Hb-mass would take about nine weeks. The blood donation intervals defined by the German Medical Association seem to be long enough to compensate the loss of hemoglobin mass from a blood donation. The hemoglobin concentration does not clearly indicate the blood loss from donating blood.