title: Preoperative autologous blood donation - part II. Adapting the predeposit concept to the physiological basics of erythropoiesis improves its efficacy.
abstract: OBJECTIVE
  Only two clinical parameters have been demonstrated to be of decisive impact on efficacy [i.e. increase in red blood cell (RBC)]-mass] of the autologous predeposit; the time interval between predeposit and elective surgery that correlates positively with increase in RBC-mass, and the haematocrit-level at predeposit that correlates negatively with it. These two determinants of efficacy might be applied most efficaciously by combining them within one predeposit-session.
  
  
  METHODS
  Prospective study concerning the efficacy of two different autologous predeposit-concepts in osteoarthritis (n=160) and rheumatoid arthritis patients (n=74); the conventional ''two separately collected units concept'' (one RBC-unit each on two separate predeposit-sessions) and the new ''one double deposit'' concept (two RBC-units on one predeposit-session). The increase in RBC-mass was calculated with the haematocrit-method. Statistical analysis by ANOVA with post-hoc-test to Scheffé/H-test, and U-test; P<0.05 with Bonferroni-correction when appropriate.
  
  
  RESULTS
  In either group of patients, increase in RBC-mass was higher with the new than the conventional predeposit concept (osteoarthritis: 261+/-114 vs 168+/-133 mL; P<0.000; rheumatoid arthritis: 239+/-112 vs 149+/-152 mL; P=0.039). Efficacy of either concept between osteoarthritis and rheumatoid arthritis patients was not different (new concept: 261+/-114 vs 238+/-112; P=0.765; conventional concept: 168+/-133 vs 149+/-152; P=0.941).
  
  
  CONCLUSIONS
  An autologous predeposit-concept considering the physiological basics of erythropoiesis (i.e. long time-interval between predeposit and elective surgery for RBC-regeneration, and a low haematocrit-level at/after autologous predeposit in order to stimulate erythrpoiesis) enhances RBC-recovery in a clinically relevant extent both in osteoarthritis and rheumatoid arthritis patients. Concerning efficacy of autologous predeposit, no differences were demonstrated between osteoarthritis and rheumatoid arthritis patients.
authors.affiliation: Department of Anesthesiology, Intensive Care and Transfusion Medicine, ENDO-Klinik Hamburg GmbH, Hamburg, Germany. g.singbartl@gmx.de
authors.forename: G
authors.initials: G
authors.lastname: Singbartl
authors.forename: S
authors.initials: S
authors.lastname: Malgorzata
authors.forename: A
authors.initials: A
authors.lastname: Quoss
mesh_terms: D000368:Aged; D001172:Arthritis, Rheumatoid / Q000097:blood / Q000601:surgery; D001804:Blood Transfusion, Autologous; D004906:Erythrocyte Count; D004920:Erythropoiesis / Q000502:physiology*; D005260:Female; D006400:Hematocrit; D006801:Humans; D008297:Male; D008875:Middle Aged; D010003:Osteoarthritis / Q000097:blood / Q000601:surgery; D011446:Prospective Studies