title: Greater Volume of Acute Normovolemic Hemodilution May Aid in Reducing Blood Transfusions After Cardiac Surgery.
abstract: BACKGROUND
  Perioperative red blood cell transfusions (RBC) are associated with increased morbidity and mortality after cardiac surgery. Acute normovolemic hemodilution (ANH) is recommended to reduce perioperative transfusions; however, supporting data are limited and conflicting. We describe the relationship between ANH and RBC transfusions after cardiac surgery using a multi-center registry.
  
  
  METHODS
  We analyzed 13,534 patients undergoing cardiac surgery between 2010 and 2014 at any of the 26 hospitals participating in a prospective cardiovascular perfusion database. The volume of ANH (no ANH, <400 mL, 400 to 799 mL, ≥ 800 mL) was recorded and linked to each center's surgical data. We report adjusted relative risks reflecting the association between the use and amount of ANH and the risk of perioperative RBC transfusion. Results were adjusted for preoperative risk factors, procedure, body surface area, preoperative hematocrit, and center.
  
  
  RESULTS
  The ANH was used in 17% of the patients. ANH was associated with a reduction in RBC transfusions (RRadj [adjusted risk ratio] 0.74, p < 0.001). Patients having 800 mL or greater of ANH had the most profound reduction in RBC transfusions (RRadj 0.57, p < 0.001). Platelet and plasma transfusions were also significantly lower with ANH. The ANH population had superior postoperative morbidity and mortality compared with the no ANH population.
  
  
  CONCLUSIONS
  There is a significant association between ANH and reduced perioperative RBC transfusion in cardiac surgery. Transfusion reduction is most profound with larger volumes of ANH. Our findings suggest the volume of ANH, rather than just its use, may be an important feature of a center's blood conservation strategy.
authors.affiliation: Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts.
authors.forename: Joshua
authors.initials: J
authors.lastname: Goldberg
authors.affiliation: Department of Cardiac Surgery, University of Michigan, Ann Arbor, Michigan.
authors.forename: Theron A
authors.initials: TA
authors.lastname: Paugh
authors.affiliation: Specialty Care, Nashville, Tennessee.
authors.forename: Timothy A
authors.initials: TA
authors.lastname: Dickinson
authors.affiliation: St. John Providence Health System Detroit Hospitals, Detroit, Michigan.
authors.forename: John
authors.initials: J
authors.lastname: Fuller
authors.affiliation: Division of Cardiac Surgery, Henry Ford Hospital, Detroit, Michigan.
authors.forename: Gaetano
authors.initials: G
authors.lastname: Paone
authors.affiliation: Department of Cardiac Surgery, University of Michigan, Ann Arbor, Michigan.
authors.forename: Patty F
authors.initials: PF
authors.lastname: Theurer
authors.affiliation: Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts.
authors.forename: Kenneth G
authors.initials: KG
authors.lastname: Shann
authors.affiliation: Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts.
authors.forename: Thoralf M
authors.initials: TM
authors.lastname: Sundt
authors.affiliation: Department of Cardiac Surgery, University of Michigan, Ann Arbor, Michigan.
authors.forename: Richard L
authors.initials: RL
authors.lastname: Prager
authors.affiliation: Department of Cardiac Surgery, University of Michigan, Ann Arbor, Michigan. Electronic address: likosky@med.umich.edu.
authors.forename: Donald S
authors.initials: DS
authors.lastname: Likosky
mesh_terms: D000368:Aged; D001804:Blood Transfusion, Autologous / Q000706:statistics & numerical data*; D001810:Blood Volume; D006348:Cardiac Surgical Procedures; D017707:Erythrocyte Transfusion / Q000706:statistics & numerical data*; D005260:Female; D006400:Hematocrit; D006438:Hemodilution / Q000379:methods*; D006801:Humans; D008297:Male; D008875:Middle Aged; D011300:Preoperative Care / Q000379:methods*; D011446:Prospective Studies