Preoperative haematinics and transfusion protocol reduce the need for transfusion after total knee replacement

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.

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).

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.

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.