Blood management protocol for total knee arthroplasty to reduce blood wastage and unnecessary transfusion.

Purpose: To compare outcomes of 2 cohorts of patients who underwent total knee arthroplasty (TKA) before and after the introduction of a blood management protocol.

Methods: Records of 97 and 96 consecutive patients who underwent unilateral TKA before and after introduction of the blood management protocol, respectively, were reviewed. Before introduction of the protocol, patients were cross-matched for blood before surgery. Transfusion after surgery was at the discretion of the surgeons or the on-call doctors. After introduction of the protocol, only patients with a preoperative haemoglobin level of <110 g/l underwent 'type and screening' of blood group. 2 units of blood were cross-matched preoperatively when multiple red-cell antibodies were identified or postoperatively when blood transfusion was required. Only patients with a postoperative haemoglobin level of <80 g/l or being symptomatic received blood transfusion until the haemoglobin level reached >100 g/l. Those with a postoperative haemoglobin level of 80 to 100 g/l were given iron sulphate 300 mg twice daily for a month.

Results: The 2 groups did not differ significantly in age, sex ratio, pre- and post-operative haemoglobin levels, and drain output. Comparing outcome before and after introduction of the protocol, the transfusion rate (10.3% vs. 3.1%, p=0.046), crossmatch rate (100% vs. 3.1%, p<0.001), and crossmatch to transfusion ratio (9.7:1 vs. 1:1, p<0.001) decreased. Among transfused patients, the decreased postoperative haemoglobin level indicated a lower transfusion trigger point (100 g/l vs. 75 g/l, p<0.006) No patient developed infection, cardiovascular or cerebrovascular complications within 30 days.

Conclusion: The blood management protocol for TKA is effective in reducing unnecessary allogeneic blood transfusions and wastage of unused blood, without an increase in postoperative complications.