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 .
Silent myocardial ischaemia and haemoglobin concentration: a randomized controlled trial of transfusion strategy in lower limb arthroplasty.
BACKGROUND AND OBJECTIVES Red cell transfusion is commonly used in orthopaedic surgery . Evidence suggests that a restrictive transfusion strategy may be safe for most patients . However , concern has been raised over the risks of anaemia in those with ischaemic cardiac disease .  Perioperative silent myocardial ischaemia ( SMI ) has a relatively high incidence in the elderly population undergoing elective surgery . This study used Holter monitoring to compare the effect of a restrictive and a liberal red cell transfusion strategy on the incidence of SMI in patients without signs or symptoms of ischaemic heart disease who were undergoing lower limb arthroplasty . MATERIAL S AND METHODS We performed a multicentre , controlled trial in which 260 patients undergoing elective hip and knee replacement surgery were enrolled and r and omized to transfusion triggers that were either restrictive ( 8 g/dl ) or liberal ( 10 g/dl ) . Participants were monitored with  continuous ambulatory electrocardiogram ( ECG ) ( Holter monitoring ) , preoperatively for 12 h and postoperatively for 72 h. The tapes were analysed for new ischaemia by technicians blinded to treatment . The total ischaemia time in minutes was divided by the recording time in hours and an ischaemic load in min/h was calculated . Haemoglobin levels were measured preoperatively , postoperatively in the recovery room , and on days one , three and five after surgery . RESULTS The mean postoperative haemoglobin concentration was 9.87 g/dl in the restrictive group and 11.09 g/dl in the liberal group . In the restrictive group , 34 % were transfused a total of 89 red cell units , and in the liberal group 43 % were given a total of 119 red cell units . A postoperative episode of silent ischaemia was experienced by 21/109 ( 19 % ) patients in the restrictive group and by 26/109 ( 24 % ) patients in the liberal group [ mean difference -4.6 % ; 95 % confidence interval ( CI ) : -15.5 % to 6 % , P = 0.41 ) . There was no significant difference ( P = 0.53 ) between the overall ischaemic load in the restrictive group ( median 0 min/h , range 0 - 4.18 ) and the liberal group ( median 0 min/h , range 0 - 19.48 ) . In those patients who did experience postoperative SMI , the mean ischaemic load was 0.48 min/h in the restrictive group and 1.51 min/h in the liberal group ( ratio 0.32 , 95 % CI : 0.14 - 0.76 , P = 0.011 ) . The median postoperative length of hospital stay in the restrictive group was 7.3 days [ range 5 - 11 ; interquartile range ( IQR ) 6 - 8 ] compared with 7.5 days ( range 5 - 13 ; IQR 7 - 8 ) in the liberal group . The numbers were not large enough to conclude equivalence . CONCLUSIONS In patients without preoperative evidence of myocardial ischaemia undergoing elective hip and knee replacement surgery , a restrictive transfusion strategy seems unlikely to be associated with an increased incidence of SMI . A proportion of these patients experience moderate SMI , regardless of the transfusion trigger . Use of a restrictive transfusion strategy did not increase length of hospital stay , and use of this strategy would lead to a significant reduction in red cell transfusion in orthopaedic surgery . Our data did not indicate any potential for harm in employing such a strategy in patients with no prior evidence of cardiac ischaemia who were undergoing elective orthopaedic surgery
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 .