title: How effective is acute normovolaemic haemodilution in femoro-distal bypass surgery?
abstract: BACKGROUND
  Recent guidelines have emphasised the use of autologous blood in the surgical setting. The aim of this study was to analyse the efficacy and efficiency of acute normovolaemic haemodilution (ANH) as a blood conservation intervention in patients undergoing elective femoro-distal surgery for critical limb ischaemia.
  
  
  METHODS
  Forty patients were studied prospectively. The volume of the blood collected was derived as follows: Blood volume removed = patient's blood volume (initial haematocrit - final haematocrit/average haematocrit) where final haematocrit is 30% and patient's blood volume is 70 and 65 ml/kg for a man and a woman, respectively.
  
  
  RESULTS
  Twenty-five patients were suitable for ANH and 15 patients were excluded because of poor ventricular function, anaemia or renal disease. Nine of the 25 patients (44%) had <500ml of surgical blood loss and would have avoided homologous blood transfusion (HBT). Four of the patients lost >2000ml of blood and could not avoid HBT through ANH. Twelve patients had moderate blood loss (950-1400 ml), with eight of these patients requiring transfusion. Four patients avoided exposure to homologous blood.
  
  
  CONCLUSIONS
  ANH is in evolution and as a single blood conservation intervention, contributes only modestly to blood conservation.
authors.affiliation: Department of Vascular and Endovascular Surgery, St James's University Hospital, Beckett Street, Leeds LS9 7TF, UK. jamesianspark@hotmail.com
authors.forename: J I
authors.initials: JI
authors.lastname: Spark
authors.forename: I C
authors.initials: IC
authors.lastname: Chetter
authors.forename: R C
authors.initials: RC
authors.lastname: Kester
authors.forename: D J A
authors.initials: DJ
authors.lastname: Scott
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D016063:Blood Loss, Surgical / Q000517:prevention & control; D001803:Blood Transfusion; D019917:Blood Vessel Prosthesis Implantation; D016022:Case-Control Studies; D002908:Chronic Disease; D005260:Female; D005263:Femoral Artery / Q000601:surgery; D006438:Hemodilution / Q000379:methods*; D006801:Humans; D007430:Intraoperative Care / Q000379:methods*; D007511:Ischemia / Q000601:surgery*; D007866:Leg / Q000098:blood supply*; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies