A randomized, double-blind comparison of donor tolerance of 400 mL, 200 mL, and sham red cell donation

Volume replacement could allow the safe collection of twice the normal amount of red cells in a standard donation. Studies in small numbers of donors have shown that a temporary decrease in red cell mass is well tolerated when donors give twice the usual amount (170-225 mL) of red cells in a standard 405- to 495-mL donation. Sham-donation control groups have not been included in previous studies of increased red cell donation, and perceptions of donation effects could have been biased.

In the study reported here, 17 male and 13 female volunteers were randomly assigned to make a sham donation, 1-unit donation, or 2-unit donation on an automated blood cell separator. Donor tolerance was assessed by ambulatory heart rate monitoring and by a poststudy interview. Hemoglobin, hematocrit, ferritin, serum iron, total iron-binding capacity, red cell 2,3 DPG, and serum erythropoietin were measured before and after donation for comparison of the erythropoietic responses in the three study groups.

Red cells collected totaled 206 +/- 10 mL in the 1-unit group and 414 +/- 21 mL in the 2-unit group. Changes in heart rate, systolic blood pressure, and diastolic blood pressure with donation and changes in heart rate recorded by ambulatory monitoring did not differ for the experimental groups. Postdonation changes from baseline values were evaluated on Days 2, 7, and 14. Changes in hemoglobin were significantly different between groups (p < 0.017) in all postdonation tests. There were differences between groups in erythropoietin response, red cell 2,3 DPG, ferritin levels, and hemoglobin synthesis. Hemoglobin synthesis and mean changes in 2,3 DPG, erythropoietin, ferritin, and postdonation hemoglobin were greater in the 2-unit group than in the 1-unit group.

Donor tolerance of red cell donations of 414 +/- 21 mL, a volume of red cells twice that in a standard 450-mL blood donation, does not differ from donor tolerance of standard or sham donations. Physiologic adjustments and the hematopoietic response to reduced red cell mass were greater in the 2-unit group, but the donation of 1 unit or 2 units did not cause detectable symptoms of reduced oxygen-carrying capacity.