title: Prevalence of anaemia before major joint arthroplasty and the potential impact of preoperative investigation and correction on perioperative blood transfusions.
abstract: BACKGROUND
  Preoperative investigation and treatment of anaemia is recommended before orthopaedic surgery. We measured the prevalence of anaemia among admissions presenting for elective major joint arthroplasty (MJA), assessed their transfusion requirements, and investigated factors associated with perioperative blood transfusion.
  
  
  METHODS
  All admissions to a dedicated elective orthopaedic hospital during 2000-2001 were studied. The patients' database was merged with the haematology and transfusion databases. Population estimates for different types of anaemia and their blood transfusion requirements were generated using local reference ranges (males <130 g litre(-1); females <115 g litre(-1)).
  
  
  RESULTS
  One thousand three hundred and twenty-two admissions were included; haematology data were complete for 1142 (544 primary hip, 490 primary knee, 77 revision hip, 31 revision knee). About 19.6% were anaemic [7.1% haemoglobin (Hb) <110 g litre(-1); 1.6% Hb<100 g litre(-1)]. Overall, 21.3% of admissions were transfused (mean 0.58 units per case: 95% CI 0.50-0.61). For anaemic admissions, 42.0% were transfused (mean 1.11 units per case: 95% CI 0.90-1.32). Mean red cell use for admissions with normocytic normochromic anaemia (12.7% of admissions) and hypochromic anaemia (4.6%) was 1.04 (95% CI 0.78-1.31) and 1.14 (95% CI 0.71-1.57) units per admission, respectively. Factors strongly associated independently with transfusion were preoperative haemoglobin </=110 g litre(-1) [odds ratio: 13.92 (95% CI 7.77-24.9) and revision hip surgery (OR: 17.80 (9.59-33.02)].
  
  
  CONCLUSIONS
  The prevalence of preoperative anaemia among admissions undergoing elective MJA is approximately 20%. Patients most likely to avoid transfusions with preoperative intervention are those with low haemoglobin undergoing revision hip surgery.
authors.affiliation: Department of Anaesthesia, Intensive Care, and Pain Medicine, Edinburgh University, Edinburgh Royal Infirmary, Little France, Edinburgh EH16 4SU, UK.
authors.forename: E
authors.initials: E
authors.lastname: Saleh
authors.forename: D B L
authors.initials: DB
authors.lastname: McClelland
authors.forename: A
authors.initials: A
authors.lastname: Hay
authors.forename: D
authors.initials: D
authors.lastname: Semple
authors.forename: T S
authors.initials: TS
authors.lastname: Walsh
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000740:Anemia / Q000150:complications / Q000453:epidemiology* / Q000628:therapy; D019644:Arthroplasty, Replacement, Hip; D019645:Arthroplasty, Replacement, Knee; D016063:Blood Loss, Surgical / Q000517:prevention & control; D001803:Blood Transfusion; D005260:Female; D006454:Hemoglobins / Q000032:analysis; D006801:Humans; D008297:Male; D008875:Middle Aged; D011300:Preoperative Care / Q000379:methods*; D015995:Prevalence; D012086:Reoperation; D012189:Retrospective Studies; D012606:Scotland / Q000453:epidemiology
chemical_list: D006454:Hemoglobins