Blood management after bilateral total knee arthroplasty

Four hundred sixty-one patients who had bilateral one-stage total knee replacements were reviewed to evaluate their blood management. Overall, patients received an average of 2.1 units of autologous blood and 0.9 units of allogenic blood. Seventy-six percent of the patients who preoperatively donated one unit of autologous blood required allogenic blood transfusions compared with 51% of patients who donated two units, 29% of patients who donated three units, and 27% of patients who donated four units of autologous blood. Ninety-eight percent of the patients who did not donate autologous blood required allogenic blood. Donating two units of autologous blood in combination with a perioperative cell saver reduced the incidence of allogenic blood transfusions to 8% but increased the amount of unused autologous blood to 54%. If the indication for wound drainage recovery is guided by the preoperative hematocrit (< or = 40%) or postoperative hemoglobin (> or = 11 mg/dL) the incidence of allogenic blood transfusions decreased to 17% and 13%, respectively and the amount of unused autologous blood decreased to 39% and 30%. There is no statistical difference among the three protocols regarding the need for allogenic blood transfusions and associated costs. Based on this retrospective evaluation the combination of preoperative donation of two units autologous blood and use of a postoperative cell salvage system in all patients is recommended.