title: Mechanical methods of reducing blood transfusion in cardiac surgery: randomised controlled trial.
abstract: OBJECTIVE
  To assess the effectiveness of two mechanical methods of blood conservation in reducing the need for allogeneic red blood cells or coagulation products during cardiac surgery.
  
  
  METHODS
  Randomised controlled trial.
  
  
  METHODS
  Regional cardiac centre in a teaching hospital in Southampton.
  
  
  METHODS
  263 adults aged 18-80 years undergoing elective coronary artery bypass surgery entered the study, of whom 252 completed the trial. All patients received routine perioperative care. Patients were allocated to one of three treatment groups: intraoperative cell salvage, intraoperative cell salvage with acute perioperative normovolaemic haemodilution, or no mechanical blood conservation. There were 84 patients in each group.
  
  
  METHODS
  Numbers of patients who received allogeneic blood or coagulation products, and the mean number of units of blood transfused per patient.
  
  
  RESULTS
  Of the patients in the intraoperative cell salvage group, 26 were given a transfusion of allogeneic blood, compared with 43 in the control group (odds ratio 0.43 (95% confidence interval 0.23 to 0.80)). The mean number of units of allogeneic blood transfused per patient in the intraoperative cell salvage group was 0.68 units (SD=1.55), compared with 1.07 (1.56) units in the control group. 32 of the patients in the intraoperative cell salvage group were given any blood product, compared with 47 in the control group (odds ratio 0.47 (0.25 to 0.89); P=0.019). Combining acute perioperative normovolaemic haemodilution with intraoperative cell salvage conferred no additional benefits.
  
  
  CONCLUSIONS
  An intraoperative cell salvage device should be used in elective coronary artery bypass grafting. Pharmacological strategies may achieve further reductions in blood transfusions. Yet further reductions in blood transfusions could be achieved if the lower safe limit of haemoglobin concentration in patients undergoing cardiac surgery were known.
authors.affiliation: C S Mott Children's Hospital, Section of Pediatric Anesthesiology, Room F3900, Box 0211, Ann Arbor, MI 48109-0211, USA.
authors.forename: Neil
authors.initials: N
authors.lastname: McGill
authors.forename: Denise
authors.initials: D
authors.lastname: O'Shaughnessy
authors.forename: Ruth
authors.initials: R
authors.lastname: Pickering
authors.forename: Mike
authors.initials: M
authors.lastname: Herbertson
authors.forename: Ravi
authors.initials: R
authors.lastname: Gill
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001773:Blood Cells / Q000637:transplantation*; D016063:Blood Loss, Surgical; D001803:Blood Transfusion; D016001:Confidence Intervals; D001026:Coronary Artery Bypass; D006801:Humans; D007432:Intraoperative Period; D008875:Middle Aged; D016017:Odds Ratio; D014184:Transplantation, Homologous