Purpose: An increase of hemoglobin (Hb) mass is the key target of blood doping practices to enhance performance as it is a main determinant of maximal oxygen uptake. Although detection methods exist for doping with recombinant EPO and homologous blood transfusions, autologous transfusions remain virtually undetectable. In this context, the most sensitive parameter would be a determination of Hb mass itself. The purpose therefore was to establish whether Hb mass measurements by the optimized CO-rebreathing method allow screening for the withdrawal and reinfusion of autologous red blood cells.
Methods: The optimized CO-rebreathing method was used for evaluation of Hb mass in two groups at three time points (duplicate measurements: 1) baseline, 2) after donation, and 3) after reinfusion). Group I (N = 6) was to donate and receive 1 unit of packed red cells (PRC) in contrast to two PRC in group II (N = 4). The time span between withdrawal and reinfusion was 2 d.
Results: The mean Hb content of the blood units was 59.0 ± 3.9 g (group I) and 108.3 ± 1.3 g (group II). Hb mass decreased significantly after blood withdrawal (−89 ± 16 g in group I and −120 ± 14 g in group II) and increased significantly after reinfusion (group I: 70 ± 16 g; group II: 90 ± 9 g) but was lower than at baseline (group I: −19 ± 17 g; group II: −30 ± 14 g). The total error of measurements for the duplicate measures ranged between 0.8 and 3.1% (Hb mass: 6.4-22.1 g).
Conclusion: Hb mass determination with the optimized CO-rebreathing method has sufficient precision to detect the absolute differences in Hb mass induced by blood withdrawal and autologous reinfusion. Thus, it may be suited to screen for artificially induced alterations in Hb mass.