Background: Unilateral total knee replacement (TKR) can result in a substantial blood loss and 30-50% of these patients receive allogeneic blood transfusion (ABT), this transfusion rate may be even higher among anaemic patients.
Patients and methods: We assessed the requirements for ABT in 156 consecutive patients undergoing surgery for primary TKR, who received iron ferrous sulphate (256 mg/day; 80 mg of Fe(2+)), vitamin C (1000 mg/day) and folic acid (5mg/day) during the 30-45 days preceding surgery, and who were transfused if Hb <80 g/L and/or clinical signs/symptoms of acute anaemia/hypoxemia (Group 2). A previous series of 156 TKR patients serves as a control group (Group 1).
Results: Compared to those in Group 1, patients in Group 2 presented a lower transfusion rate (5.8% vs. 32%, for Group 2 and Group 1, respectively; p<0.01), and a lower transfusion index (1.78+/-0.44 vs. 2.22+/-0.65 units per transfused patient, respectively; p<0.05). After patient's stratification according to a preoperative Hb above or below 130 g/L, the differences in transfusion rate remained significant, although 19% of patients from Group 2 still needed ABT if their preoperative Hb <130 g/L.
Conclusion: This protocol seems to be effective for avoiding ABT in non-anaemic TKR patients, whereas for anaemic patients another blood saving strategy, such us preoperative erythropoietin administration or postoperative blood salvage, should be added to further increase its effectiveness.