title: The cost of post-operative shed blood salvage after total knee arthroplasty: an analysis of 1,093 consecutive procedures.
abstract: BACKGROUND
  Requirements for allogeneic red cell transfusion after total knee arthroplasty are still high (20-50%), and salvage and reinfusion of unwashed, filtered post-operative shed blood is an established method for reducing transfusion requirements following this operation. We performed a cost analysis to ascertain whether this alternative is likely to be cost-effective.
  
  
  METHODS
  Data from 1,093 consecutive primary total knee arthroplasties, managed with (reinfusion group, n=763) or without reinfusion of unwashed salvaged blood (control group, n=330), were retrospectively reviewed. The costs of low-vacuum drains, shed blood collection canisters (Bellovac ABT, Wellspect HealthCare and ConstaVac CBC II, Stryker), shed blood reinfusion, acquisition and transfusion of allogeneic red cell concentrate, haemoglobin measurements, and prolonged length of hospital stay were used for the blood management cost analysis.
  
  
  RESULTS
  Patients in the reinfusion group received 152±64 mL of red blood cells from postoperatively salvaged blood, without clinically relevant incidents, and showed a lower allogeneic transfusion rate (24.5% vs. 8.5%, for the control and reinfusion groups, respectively; p =0.001). There were no differences in post-operative infection rates. Patients receiving allogeneic transfusions stayed in hospital longer (+1.9 days [95% CI: 1.2 to 2.6]). As reinfusion of unwashed salvaged blood reduced the allogeneic transfusion rate, both reinfusion systems may provide net savings in different cost scenarios (€ 4.6 to € 106/patient for Bellovac ABT, and € -51.9 to € 49.9/patient for ConstaVac CBCII).
  
  
  CONCLUSIONS
  Return of unwashed salvaged blood after total knee arthroplasty seems to save costs in patients with pre-operative haemoglobin between 12 and 15 g/dL. It is not cost-saving in patients with a pre-operative haemoglobin >15 g/dL, whereas in those with a pre-operative haemoglobin <12 g/dL, although cost-saving, its efficacy could be increased by associating some other blood-saving method.
authors.affiliation: GIEMSA, Facultad de Medicina, School of Medicine, University of Málaga, Málaga, Spain. mmunoz@uma.es
authors.forename: Manuel
authors.initials: M
authors.lastname: Muñoz
authors.forename: Daniel
authors.initials: D
authors.lastname: Ariza
authors.forename: Arturo
authors.initials: A
authors.lastname: Campos
authors.forename: Elisa
authors.initials: E
authors.lastname: Martín-Montañez
authors.forename: José
authors.initials: J
authors.lastname: Pavía
mesh_terms: D019645:Arthroplasty, Replacement, Knee / Q000191:economics* / Q000379:methods / Q000706:statistics & numerical data; D003362:Cost-Benefit Analysis; D017707:Erythrocyte Transfusion / Q000191:economics* / Q000379:methods / Q000706:statistics & numerical data; D006801:Humans; D007902:Length of Stay / Q000191:economics / Q000706:statistics & numerical data; D057725:Operative Blood Salvage / Q000191:economics* / Q000379:methods / Q000706:statistics & numerical data; D012189:Retrospective Studies