Purpose A new intraoperative filtered salvaged blood re-transfusion system has been developed for primary total hip arthroplasty (THA) that filters and re-transfuses the blood that is lost during THA. This system is intended to increase postoperative haemoglobin (Hb) levels, reduce perioperative net blood loss and reduce the need for allogeneic transfusions. It supposedly does not have the disadvantages of intraoperative cell-washing/separating re-transfusion systems, such as extensive procedure, high costs and need for specialised personnel. To re-transfuse as much as blood as possible, postoperatively drained blood was also re-transfused. Methods A randomised, controlled, blinded, single-centre trial was conducted in which 118 THA patients were randomised to an intraoperative autologous blood re-transfusion (ABT) filter system combined with a postoperative ABT filter unit or highvacuum closed-suction drainage. Results On average, 577 ml of blood was re-transfused in the ABT group: 323 ml collected intraoperatively and 254 ml collected postoperatively. Hb level was higher in the ABT vs the high-vacuum drainage group: 11.4 vs. 10.8 g/dl, p =0.02 on day one (primary endpoint) and 11.0 vs. 10.4 g/dl, p = 0.007 on day three. Total blood loss was less in the autotransfusion group: 1472 vs. 1678 ml, p =0.03. Allogeneic transfusions were needed in 3.6 % of patients in the ABT group and 6.5 % in the drainage group, p =0.68. Conclusion The use of a new intraoperative ABT filter system combined with a postoperative ABT unit resulted in higher postoperative Hb levels and less total blood loss compared with a high-vacuum drain following THA.

Autologous retransfusion and no-drainage are both blood-saving measures in total hip replacement (THR). A new combined intra-and post-operative autotransfusion filter system has been developed especially for primary THR, and we conducted a randomised controlled blinded study comparing this with no-drainage.A total of 204 THR patients were randomised to autologous blood transfusion (ABT) (n = 102) or no-drainage (n = 102). In the ABT group, a mean of 488 ml (SD 252) of blood was retransfused. The mean lowest post-operative haemoglobin level during the hospital stay was higher in the autotransfusion group (10.6 g/dl (7.8 to 13.9) vs 10.2 g/dl (7.5 to 13.3); p = 0.01). The mean haemoglobin levels for the ABT and no-drainage groups were not significantly different on the first day (11.3 g/dl (7.8 to 13.9) vs 11.0 g/dl (8.1 to 13.4); p = 0.07), the second day (11.1 g/dl (8.2 to 13.8) vs 10.8 g/dl (7.5 to 13. It has been reported that total hip replacement (THR) is associated with a mean total blood loss of 1500 ml and a post-operative decline in haemoglobin (Hb) levels of a mean of 3.0 g/dl.1 Lower post-operative Hb levels following THR are associated with a lower functional score, longer hospital stay and an increased homologous blood transfusion rate. 2-4Homologous blood transfusions (HBT) are also related to poorer outcomes following THR, such as higher post-operative infection rates, delayed wound healing and prolonged hospital stay. [5][6][7][8] Retransfusion of blood that is lost during and after surgery has been introduced to reduce peri-operative net blood loss, maintain higher post-operative Hb levels and reduce the use of HBT. The results of a recent Cochrane review on peri-operative cell salvage show that autologous retransfusion reduced HBT requirements by 54% compared with regular drains in orthopaedic procedures. 9Post-operative autologous blood transfusion (ABT) filter systems for the retransfusion of filtered drained blood are often used in primary THR. However, the currently available intra-operative cell-saver devices wash the blood, separate the various cells and permit retransfusion of the red blood cells. Unfortunately, they are expensive to run and are often reserved for revision surgery. As a result, the 500 ml or so of blood that is generally lost during primary THR is not used for retransfusion. Therefore, a new system has been developed for primary THR, which filters the intraoperatively collected blood, in the same manner as the filters in post-operative ABT systems. This intra-operative retransfusion filter system is claimed to be easier to handle and less expensive than intra-operative washing/separating devices, and therefore suitable for use in