title: A safe, simple and cost-effective protocol for blood transfusion in primary total knee replacement.
abstract: BACKGROUND
  Patients undergoing total knee replacement (TKR) in the UK usually have either blood cross-matched or have an auto-transfusion of drained blood postoperatively. A previous retrospective audit of blood requirements in patients who had undergone primary TKR showed that a large amount of cross-matched blood was wasted as the CT ratio (ratio of number of units of blood cross-matched to number of units transfused) of 4.9:1 was obtained. The range recommended by the Blood Transfusion Society is 2:1 to 3:1.
  
  
  METHODS
  A protocol was introduced to group and save plus antibody screen for all patients and to cross-match 2 units of blood pre-operatively in patients with either a haemoglobin of less than 12.5 g/dl or with multiple red cell antibodies in their blood. The trigger point for blood transfusion postoperatively was also reduced from 9.0 g/dl to 8.0 g/dl, unless the patient was clinically symptomatic.
  
  
  RESULTS
  A further prospective study involving 50 patients was carried out using the new protocol. Five patients required cross-matching pre-operatively, three with haemoglobin less than 12.5 g/dl and two with multiple red cell antibodies. Postoperatively, the patients with haemoglobin of less than 12.5 g/dl required blood transfusion of 2 units each, reducing the CT ratio to 1.7:1. The patients with red cell antibodies did not require a blood transfusion.
  
  
  CONCLUSIONS
  The benefits from above protocol are 2-fold: patient safety, as risks of transfusion are avoided; and cost saving, in regards to haematology technician time and auto-transfusion sets which cost around pound 70 each.
authors.affiliation: Orthopaedic and Haematology Department, Royal Glamorgan Hospital, Ynysmaerdy, Llantrisant CF72 8XR, South Wales, UK.
authors.forename: A
authors.initials: A
authors.lastname: Mehra
authors.forename: J
authors.initials: J
authors.lastname: Murray
authors.forename: C
authors.initials: C
authors.lastname: deAlwis
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D019645:Arthroplasty, Replacement, Knee / Q000191:economics / Q000379:methods*; D001803:Blood Transfusion / Q000191:economics / Q000379:methods*; D002985:Clinical Protocols; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D019106:Postoperative Hemorrhage / Q000191:economics / Q000209:etiology; D011446:Prospective Studies