Findings and Conclusion To our knowledge , this is the first meta- analysis to compare the clinical results between PAT and a control in joint replacement patients .
This meta- analysis has proven that the use of a PAT reinfusion system reduced significantly the dem and for ABT , the number of patients who require ABT and the cost of hospitalization after total knee and hip arthroplasty .
This study , together with other previously published data , suggests that PAT drains are beneficial .
Background Total hip or knee arthroplasty is an elective procedure that is usually accompanied by substantial blood loss , which may lead to acute anemia .
As a result , almost half of total joint arthroplasty patients receive allogeneic blood transfusions ( ABT ) .
Many studies have shown that post-operative auto-transfusion ( PAT ) significantly reduces the need for  ABT  , but other studies have question ed the efficacy of this method .
Benefits of postoperative shed blood reinfusion in patients undergoing unilateral total knee replacement
Introduction In patients undergoing total knee replacement ( TKR ) , most of the measured blood loss occurs during the postoperative period , and 30–50 % of these patients receive allogeneic blood transfusion ( ABT ) . For this reason , the salvage and return of unwashed filtered shed blood ( USB ) from postoperative drainage may represent an alternative to ABT in these patients . We have , therefore , evaluated the clinical utility of USB return in TKR patients , with a special focus on patients with mild anaemia . Material s and methods Data from 200 TKR patients ( group 2 ) receiving USB within the first 6 postoperative hours ( ConstaVac CBC II , Sryker ) were prospect ively collected . A retrospective series of 100 TRK patients served as the control group ( group 1 ) . Results USB return was possible in 162 patients who received a mean of 0.98±0.4 U/pte , without any clinical ly relevant incident . Return of USB decreased both the percentage of patients with ABT ( 48 % vs 11 % , for groups 1 and 2 , respectively ; p<0.01 ) and the ABT units/patient index ( 1.31±1.27 vs 0.29±0.87 units/patient , respectively ; p<0.01 ) . A transfusion protocol was not established , but there was no difference between groups with respect to either perioperative Hb levels or overall transfusion index , indicating that the transfusion criteria were uniform . However , for the subgroups of patients who needed ABT , the preoperative Hb level was 1 g/dL lower in those receiving USB ( 13.4±1.4 vs 12.4±1.2 g/dL ; p<0.05 ) . There was no difference in the postoperative complication rate , and patients in group 2 recovered the ability to walk 1 day earlier , and their hospital stay was 3 days shorter than in group 1 ( p<0.01 ) . Conclusions Return of USB after TKR seems to shorten the hospital stay and effectively reduce postoperative requirements for ABT , especially in patients with preoperative Hb > 13 g/dL. For patients with preoperative Hb < 13 g/dL , although the return of USB also decreased the requirements for ABT , a further reduction will probably be obtained with the addition of another blood-saving method
Findings and Conclusion To our knowledge , this is the first meta- analysis to compare the clinical results between PAT and a control in joint replacement patients .
This meta- analysis has proven that the use of a PAT reinfusion system reduced significantly the dem and for ABT , the number of patients who require ABT and the cost of hospitalization after total knee and hip arthroplasty .
This study , together with other previously published data , suggests that PAT drains are beneficial .
Background Total hip or knee arthroplasty is an elective procedure that is usually accompanied by substantial blood loss , which may lead to acute anemia .
As a result , almost half of total joint arthroplasty patients receive allogeneic blood transfusions ( ABT ) .
Many studies have shown that post-operative auto-transfusion ( PAT ) significantly reduces the need for  ABT  , but other studies have question ed the efficacy of this method .