title: Effect on cardiovascular function and iron metabolism of the acute removal of 2 units of red cells.
abstract: BACKGROUND
  The collection from a donor of 2 red cell units at one time would decrease recipient exposure to viruses and alloantigens. If the donor is a large person, the blood volume lost and the postdonation hemoglobin and/or hematocrit should be within acceptable limits. If the donor is a large person, the blood volume lost and the postdonation hemoglobin and/or hematocrit should be within acceptable limits. The effect on cardiovascular function and iron metabolism requires description.
  
  
  METHODS
  Manual 2-unit erythropheresis was performed on eight donors, with the plasma returned. Donors had treadmill testing of maximum aerobic power (VO2max) before donation, 24 hours after, and 8 to 11 weeks after. Serial samples were drawn for iron metabolism studies.
  
  
  RESULTS
  Donors weighed 61.2 to 74.8 kg, and 9.6 to 11.4 percent of their blood volume was removed. Mean VO2max decreased from 84 percent of that predicted before donation to 74 percent 24 hours afterward. By 8 to 11 weeks, hemoglobin returned to acceptable donor levels and mean VO2max was 92 percent of that predicted. Mean hemoglobin fell from 14.4 to 11.7 g per dL (144 to 117 g/L) and rose to 13.9 g per dL (139 g/L) at 16 weeks. At 16 weeks, serum iron (120 +/- 47 vs. 83 +/- 33 micrograms/dL [21 +/- 8 vs. 15 +/- 6 mumol/L]), ferritin (40 +/- 24 vs. 18 +/- 10 ng/mL [40 +/- 20 vs. 20 +/- 10 micrograms/L]), and free erythroprotoporphyrin (19 +/- 5 vs. 28 +/- 5 micrograms/dL [0.34 +/- 0.09 vs. 0.50 +/- 0.09 mumol/L]) differed significantly from baseline levels. No major donor symptoms occurred.
  
  
  CONCLUSIONS
  Two-unit erythropheresis was done with blood volume loss and postdonation hemoglobin no worse than those that would occur in a 50-kg donor donating 450 mL. Cardiovascular effects and donor symptoms were mild. Two-unit red cell donations would be clinically advantageous, and they warrant further studies of both utility and donor safety.
authors.affiliation: Missouri-Illinois Region, American Red Cross Blood Services, St Louis.
authors.forename: L A
authors.initials: LA
authors.lastname: Sherman
authors.forename: M B
authors.initials: MB
authors.lastname: Lippmann
authors.forename: P
authors.initials: P
authors.lastname: Ahmed
authors.forename: D H
authors.initials: DH
authors.lastname: Buchholz
mesh_terms: D000328:Adult; D001782:Blood Donors; D001810:Blood Volume; D002320:Cardiovascular Physiological Phenomena; D017707:Erythrocyte Transfusion; D005260:Female; D006454:Hemoglobins / Q000032:analysis; D006801:Humans; D007501:Iron / Q000378:metabolism*; D008297:Male; D010101:Oxygen Consumption
chemical_list: D006454:Hemoglobins; D007501:Iron