Introduction: Total knee replacement commonly results in postoperative requirement of blood transfusion. Allogeneic blood transfusion carries transfusion related risks, continuing effort to reduce allogeneic blood transfusion is important. The purpose of this study was to asses the economic justification of the use of an autologous blood transfusion after total knee replacement and to determine whether it reduces allogeneic blood transfusion and length of postoperative hospital stay.

Patients and Methods: Retrospectively, 149 patients undergoing primary unilateral total knee replacement using vacuum drain were selected. Demographics, pre and postoperative haemoglobin were recorded. Need for allogeneic blood and postoperative hospital stay were also recorded.

Results: 8% (n12) received allogeneic blood. The average amounts received were 2 units. Mean length of stay in those received allogeneic blood were (n12) 8.1 days. Mean length of hospital stay in those not transfused (n137) were 5.5 days (p< 0.05). The cost of allogeneic blood per patient £29.31. Total cost of retansfusion system per patients £60.8. Excess bed occupancy in those transfused £55.21. The cost saving for employing a retransfuion system (55.21+29.31)−60.8 = £24.44 per patient.

Conclusion: Employing autologous retransfusion system is effective method of reducing allogeneic blood requirement. Retransfusion system will reduce in hospital stay to the level seen patients not transfused. There would be a significant economic benefit in utilising such system in district general hospitals.

Allogenic blood is becoming a scarce commodity, with many advocating autologous retransfusion systems to reduce the transfusion burden post primary arthroplasty. Many units have not embraced this, as the costs involved are perceived to be prohibitively expensive.

The inpatient stays of 149 consecutive patients undergoing primary total knee arthroplasty, performed in a single unit by multiple surgeons, were reviewed. Length of post-operative stays and blood transfusion requirements were noted, and cost implications of allogenic and autologous transfusion determined.

The total post-operative transfusion requirement was 28 units of allogenic blood in 12 patients (8%). The total transfusion cost per patient was £28.80. With the cheapest autologous re-infusion system costing £60.08 per patient, a marginal cost of £31.28 would need to be offset, to make such a system viable solely from an economic point of view. The average post operative stay was increased from 5.6 to7.7 days in those requiring blood transfusion. This extra bed occupancy was estimated to cost a minimum of £42.68 per patient.

Autologous drainage systems not only lessen the risks associated with allogenic blood, but have been shown previously to shorten hospital stay and significantly reduce allogenic transfusion requirement. By doing so, they would easily offset the increased expenditure needed to institute such a system.