Autologous re-transfusion drain compared with no drain in total knee arthroplasty: a randomised controlled trial.

Background: Post-operative anaemia following total knee arthroplasty is reported to impede functional mobility in the early period following surgery, whereas allogeneic blood transfusions, used to correct low post-operative haemoglobin levels, have concomitant disadvantages. The use of a post-operative autologous blood re-transfusion drainage system as well as no drainage system following total knee arthroplasty have been shown to reduce peri-operative blood loss and allogeneic blood transfusions, compared to the regularly used closed-suction drains. No randomised studies have been performed, to the best of our knowledge, that indicate the superiority of either method.

Materials And Methods: An open, randomised controlled study was conducted in 115 patients undergoing total knee arthroplasty who were randomly allocated to an autotransfusion drain or no drainage system. The primary end-point was haemoglobin level on the first post-operative day.

Results: In the autotransfusion group 515 mL (0-1,500 mL) of drained blood was re-transfused within the first 6 hours after surgery. Haemoglobin levels on the first (11.6 vs 11.0 g/dL), second (11.0 vs 10.3 g/dL) and third (10.5 vs 9.8 g/dL) days after surgery were significantly higher in the autotransfusion group. Total peri-operative net blood loss (1,576 mL vs 1,837 mL; -P=0.03) and allogeneic transfusion rates (10.2% vs 19.6%; P=0.15) were lower in the autotransfusion group. There were no differences in pain scores, range of motion or adverse events during hospital stay and the first 3 months after surgery.

Discussion: Compared with no drainage, the use of a post-operative autologous blood re-transfusion drainage system following total knee arthroplasty results in higher post-operative haemoglobin levels and less total blood loss.