human
***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: 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 Two groups of patients having primary or revision total hip replacement were studied during a period of 11 months . The first group of 40 consecutive patients consented to have whole blood collected coincident with acute normovolemic hemodilution . An inventory of autologous red blood cells , plasma , and platelets was prepared in the operating room as a preliminary to surgery . Subsequently , the same supplies and equipment were used for autotransfusion intraoperatively . In a case-control study , another 40 patients having total hip replacements were matched for age , gender , and weight . The second group of patients refused hemodilution and received autotransfusion alone . The perioperative transfusion requirements of the two groups were compared . The total blood product donor exposure rate of the first group was ¼ of the controls ( 0.6 and 2.4 donor units per patient , respectively ) . The average length of stay in the hospital after surgery for the first group was shortened significantly ( 6.2 versus 8.4 days ) , possibly from less immunogenic insult associated with increased transfusions of autologous blood products . Hemodilution , followed by autotransfusion , was cost effective in primary and revision total hip replacements , autotransfusion alone was cost effective only in revision arthroplasty BACKGROUND / AIM Total knee replacement ( TKR ) surgery is one of the most frequent and the most extensive procedures in orthopedic surgery , accompanied with some serious complications . Perioperative blood loss is one of the most serious losses , so it is vital to recognize and treat such losses properly . Autologous blood transfusion is the only true alternative for the allogeneic blood . The aim of this study was to to examine if autologous blood transfusion reduces usage of allogenic blood in total knee replacement surgery , as well as to examine possible effect of autologous blood transfusion on postoperative complications , recovery and hospital stay of patients after total knee replacement surgery . METHODS During the controlled , prospect i ve , r and omised study we compared two groups of patients ( n = 112 ) with total prosthesis implanted in their knee . The group I consisted of the patients who received the transfusion of other people 's ( allogeneic ) blood ( n = 57 ) and the group II of the patients  whose blood was collected postoperatively and then given them [ their own ( autologous ) blood ] ( n = 55 ) . The transfusion trigger for both groups was hemoglobin level of 85 g/L. RESULTS In the group of patients whose blood was collected perioperatively only 9 ( 0.9 % ) of the patients received  transfusion of allogeneic blood , as opposed to the control group in which 98.24 % of the patients received the transfusion of allogeneic blood ( p < or = 0.01 ) . The patients whose blood was collected stayed in hospital for 6.18 days , while the patients of the control group stayed 7.67 days ( p < 0.01 ) . CONCLUSION Autologous blood transfusion is a very effective method for reducing consumption of allogenic blood and thus , indirectly for reducing all complications related to allogenic blood transfusion . There is also a positive influence on postoperative recovery after total knee replacement surgery due to the reduction of hospital stay , and indirectly on the reduction of hospital costs Background Total hip replacement ( THR ) is associated with a significant perioperative blood loss , and 30–50 % of these patients receive allogeneic blood transfusion ( ABT ) . We evaluated the clinical utility of washed shed blood ( WSB ) return to reduce ABT in THR patients . Study design and methods Data from 108 consecutive THR patients were prospect ively collected .  WSB salvage and reinfusion ( OrthoPAT ) was intended for 60 ( Reinfusion group ) , whereas the remaining 48 patients served as control group . Patients received ABT if haemoglobin < 8 g/dl or clinical signs and symptoms of acute anemia . Results WSB return was possible in 49 patients ( 205 ± 151 ml of erythrocyte/patient ) , without any clinical ly relevant incident . Return of WSB decreased both the ABT rate ( 48 vs. 15 % , for control and reinfusion groups , respectively ; P = 0.001 ) and the ABT index ( 371 ± 154 ml RBC vs. 53 ± 117 ml RBC , respectively ; P = 0.001 ) , without differences between cemented and uncemented THR . In addition , patients from reinfusion group showed a trend to lower postoperative infection rate ( 10 vs. 2 % , respectively ; P = 0.086 ) . Conclusions Perioperative salvage and return of WSB in THR seems to effectively reduce the requirements for ABT . However , for patients with preoperative Hb < 13 g/dl , some additional blood saving method should be associated to WSB return BACKGROUND Unilateral total knee replacement ( TKR ) results in a substantial blood loss and 30 to 50 percent of patients receive allogeneic blood transfusion ( ABT ) . Therefore , the effectiveness of a restrictive transfusion trigger ( hemoglobin [ Hb ] level < 8 g/dL ) plus stimulation of erythropoiesis was evaluated , with or without blood salvage , for reducing ABT in TKR patients . STUDY DESIGN AND METHODS A series of 139 consecutive of primary TKR patients received perioperative iron sucrose ( 2 x 200 mg/48 hr , intravenously [ IV ] ) , plus preoperative erythropoietin ( EPO ; 1 x 40.000 UI , sc ) if preoperative Hb level was less than 130 g per L ( Group A ) . This protocol was applied to another series of 173 consecutive TKR patients who also received postoperative unwashed shed blood ( USB ) if preoperative Hb level was less than 130 g per L ( Group B ) . Perioperative clinical and laboratory data were gathered . RESULTS No adverse effects of iron sucrose , EPO , or USB administration were witnessed , and only 13 patients received ABT overall ( 4 % ) . No major differences in perioperative blood counts or iron metabolism variables were observed between groups , but stimulation of erythropoiesis seemed to be more pronounced in those patients receiving EPO ( p < 0.05 ) . There were no differences in postoperative complications between groups , but length of hospital stay for patients with a preoperative Hb level of less than 130 g per L was shorter in Group B ( p < 0.05 ) . CONCLUSION This blood saving protocol seems to be effective for reducing ABT in TKR patients . Which patients are more likely to benefit from either perioperative iron administration or selective addition of postoperative blood salvage to pharmacologic treatment , however , needs to be further evaluated BACKGROUND The purpose of this study was to assess current practice s in blood management in elective orthopedic surgery in Europe . STUDY DESIGN AND METHODS For this 225-center prospect i ve survey , data were collected on 3996 patients .  Actual perioperative blood loss was compared to preoperative estimates . Differences in Hb levels and other outcome variables for patients receiving allogeneic versus autologous transfusions  were evaluated . The probability of allogeneic transfusion  based on selected predictor variables was estimated . RESULTS A total of 2640 ( 67 % ) hip and 1305 ( 33 % ) knee arthroplasty patients were evaluated .  Estimated blood loss ( median , 750 mL ) was significantly lower than computed blood loss ( median , 1944 mL ) . A total of 2762 ( 69 % ) patients received  transfusions  , including 1393 ( 35 % ) autologous-only and 1024 ( 25 % ) allogeneic-only . The probability of allogeneic transfusion  decreased with increasing baseline Hb , but differentially so for men and women . Transfusion triggers were Hb levels of 8.93 + /- 1.83 g per dL for allogeneic transfusions , and 21 percent of these occurred when the Hb level was greater than 10 g per dL. Autologous blood transfusion was associated with a significantly lower rate ( 1 % ) of wound infections than allogeneic blood transfusion ( 4.2 % ) . CONCLUSION Accurate assessment of preoperative Hb levels , better estimation of perioperative blood loss , efficient use of autologous blood , adherence to transfusion guidelines , and pharmacologic alternatives contribute to effective and comprehensive blood and anemia management BACKGROUND Immunosuppression after major surgery increases the risk of infections . Natural killer cells play a pivotal part in defence against infection . We aim ed to investigate the immunomodulatory effects of different types of postoperative blood transfusion by use of a new assay for measuring the frequency of peripheral blood natural killer precursor cells ( NKpf assay ) . METHODS We measured the natural killer cell precursor ( NKp ) frequency before and 5 days after surgery in 120 patients undergoing joint replacement surgery . The patients were assigned to one of five groups according to the type of transfusion received : non-transfused ( n=32 ) , allogeneic non-leukodepleted blood ( eight ) , allogeneic leukodepleted blood ( 30 ) , autologous predeposited blood ( ten ) , and autologous salvaged blood collected within the first 24 h after surgery ( 40 ) . We also measured interferon gamma and interleukin 10 concentrations before and after surgery . FINDINGS The mean postoperative NKp frequency for all patients was lower than the preoperative values , except in patients receiving autologous salvaged blood , which was higher than all other groups ( p<0.0001 ) . Postoperative NKp frequencies for patients receiving allogeneic or autologous predeposited blood responded similarly ( p=0.99 ) , but these patients had lower NKp frequencies than did the non-transfused group ( p<0.0001 ) . Postoperative interferon gamma concentrations were higher in the autologous salvaged blood group ( p<0.0001 ) than in other groups , which did not differ from each other . Interleukin  
    Output:
    
agent
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 .
***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: 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 Two groups of patients having primary or revision total hip replacement were studied during a period of 11 months . The first group of 40 consecutive patients consented to have whole blood collected coincident with acute normovolemic hemodilution . An inventory of autologous red blood cells , plasma , and platelets was prepared in the operating room as a preliminary to surgery . Subsequently , the same supplies and equipment were used for autotransfusion intraoperatively . In a case-control study , another 40 patients having total hip replacements were matched for age , gender , and weight . The second group of patients refused hemodilution and received autotransfusion alone . The perioperative transfusion requirements of the two groups were compared . The total blood product donor exposure rate of the first group was ¼ of the controls ( 0.6 and 2.4 donor units per patient , respectively ) . The average length of stay in the hospital after surgery for the first group was shortened significantly ( 6.2 versus 8.4 days ) , possibly from less immunogenic insult associated with increased transfusions of autologous blood products . Hemodilution , followed by autotransfusion , was cost effective in primary and revision total hip replacements , autotransfusion alone was cost effective only in revision arthroplasty BACKGROUND / AIM Total knee replacement ( TKR ) surgery is one of the most frequent and the most extensive procedures in orthopedic surgery , accompanied with some serious complications . Perioperative blood loss is one of the most serious losses , so it is vital to recognize and treat such losses properly . Autologous blood transfusion is the only true alternative for the allogeneic blood . The aim of this study was to to examine if autologous blood transfusion reduces usage of allogenic blood in total knee replacement surgery , as well as to examine possible effect of autologous blood transfusion on postoperative complications , recovery and hospital stay of patients after total knee replacement surgery . METHODS During the controlled , prospect i ve , r and omised study we compared two groups of patients ( n = 112 ) with total prosthesis implanted in their knee . The group I consisted of the patients who received the transfusion of other people 's ( allogeneic ) blood ( n = 57 ) and the group II of the patients  whose blood was collected postoperatively and then given them [ their own ( autologous ) blood ] ( n = 55 ) . The transfusion trigger for both groups was hemoglobin level of 85 g/L. RESULTS In the group of patients whose blood was collected perioperatively only 9 ( 0.9 % ) of the patients received  transfusion of allogeneic blood , as opposed to the control group in which 98.24 % of the patients received the transfusion of allogeneic blood ( p < or = 0.01 ) . The patients whose blood was collected stayed in hospital for 6.18 days , while the patients of the control group stayed 7.67 days ( p < 0.01 ) . CONCLUSION Autologous blood transfusion is a very effective method for reducing consumption of allogenic blood and thus , indirectly for reducing all complications related to allogenic blood transfusion . There is also a positive influence on postoperative recovery after total knee replacement surgery due to the reduction of hospital stay , and indirectly on the reduction of hospital costs Background Total hip replacement ( THR ) is associated with a significant perioperative blood loss , and 30–50 % of these patients receive allogeneic blood transfusion ( ABT ) . We evaluated the clinical utility of washed shed blood ( WSB ) return to reduce ABT in THR patients . Study design and methods Data from 108 consecutive THR patients were prospect ively collected .  WSB salvage and reinfusion ( OrthoPAT ) was intended for 60 ( Reinfusion group ) , whereas the remaining 48 patients served as control group . Patients received ABT if haemoglobin < 8 g/dl or clinical signs and symptoms of acute anemia . Results WSB return was possible in 49 patients ( 205 ± 151 ml of erythrocyte/patient ) , without any clinical ly relevant incident . Return of WSB decreased both the ABT rate ( 48 vs. 15 % , for control and reinfusion groups , respectively ; P = 0.001 ) and the ABT index ( 371 ± 154 ml RBC vs. 53 ± 117 ml RBC , respectively ; P = 0.001 ) , without differences between cemented and uncemented THR . In addition , patients from reinfusion group showed a trend to lower postoperative infection rate ( 10 vs. 2 % , respectively ; P = 0.086 ) . Conclusions Perioperative salvage and return of WSB in THR seems to effectively reduce the requirements for ABT . However , for patients with preoperative Hb < 13 g/dl , some additional blood saving method should be associated to WSB return BACKGROUND Unilateral total knee replacement ( TKR ) results in a substantial blood loss and 30 to 50 percent of patients receive allogeneic blood transfusion ( ABT ) . Therefore , the effectiveness of a restrictive transfusion trigger ( hemoglobin [ Hb ] level < 8 g/dL ) plus stimulation of erythropoiesis was evaluated , with or without blood salvage , for reducing ABT in TKR patients . STUDY DESIGN AND METHODS A series of 139 consecutive of primary TKR patients received perioperative iron sucrose ( 2 x 200 mg/48 hr , intravenously [ IV ] ) , plus preoperative erythropoietin ( EPO ; 1 x 40.000 UI , sc ) if preoperative Hb level was less than 130 g per L ( Group A ) . This protocol was applied to another series of 173 consecutive TKR patients who also received postoperative unwashed shed blood ( USB ) if preoperative Hb level was less than 130 g per L ( Group B ) . Perioperative clinical and laboratory data were gathered . RESULTS No adverse effects of iron sucrose , EPO , or USB administration were witnessed , and only 13 patients received ABT overall ( 4 % ) . No major differences in perioperative blood counts or iron metabolism variables were observed between groups , but stimulation of erythropoiesis seemed to be more pronounced in those patients receiving EPO ( p < 0.05 ) . There were no differences in postoperative complications between groups , but length of hospital stay for patients with a preoperative Hb level of less than 130 g per L was shorter in Group B ( p < 0.05 ) . CONCLUSION This blood saving protocol seems to be effective for reducing ABT in TKR patients . Which patients are more likely to benefit from either perioperative iron administration or selective addition of postoperative blood salvage to pharmacologic treatment , however , needs to be further evaluated BACKGROUND The purpose of this study was to assess current practice s in blood management in elective orthopedic surgery in Europe . STUDY DESIGN AND METHODS For this 225-center prospect i ve survey , data were collected on 3996 patients .  Actual perioperative blood loss was compared to preoperative estimates . Differences in Hb levels and other outcome variables for patients receiving allogeneic versus autologous transfusions  were evaluated . The probability of allogeneic transfusion  based on selected predictor variables was estimated . RESULTS A total of 2640 ( 67 % ) hip and 1305 ( 33 % ) knee arthroplasty patients were evaluated .  Estimated blood loss ( median , 750 mL ) was significantly lower than computed blood loss ( median , 1944 mL ) . A total of 2762 ( 69 % ) patients received  transfusions  , including 1393 ( 35 % ) autologous-only and 1024 ( 25 % ) allogeneic-only . The probability of allogeneic transfusion  decreased with increasing baseline Hb , but differentially so for men and women . Transfusion triggers were Hb levels of 8.93 + /- 1.83 g per dL for allogeneic transfusions , and 21 percent of these occurred when the Hb level was greater than 10 g per dL. Autologous blood transfusion was associated with a significantly lower rate ( 1 % ) of wound infections than allogeneic blood transfusion ( 4.2 % ) . CONCLUSION Accurate assessment of preoperative Hb levels , better estimation of perioperative blood loss , efficient use of autologous blood , adherence to transfusion guidelines , and pharmacologic alternatives contribute to effective and comprehensive blood and anemia management BACKGROUND Immunosuppression after major surgery increases the risk of infections . Natural killer cells play a pivotal part in defence against infection . We aim ed to investigate the immunomodulatory effects of different types of postoperative blood transfusion by use of a new assay for measuring the frequency of peripheral blood natural killer precursor cells ( NKpf assay ) . METHODS We measured the natural killer cell precursor ( NKp ) frequency before and 5 days after surgery in 120 patients undergoing joint replacement surgery . The patients were assigned to one of five groups according to the type of transfusion received : non-transfused ( n=32 ) , allogeneic non-leukodepleted blood ( eight ) , allogeneic leukodepleted blood ( 30 ) , autologous predeposited blood ( ten ) , and autologous salvaged blood collected within the first 24 h after surgery ( 40 ) . We also measured interferon gamma and interleukin 10 concentrations before and after surgery . FINDINGS The mean postoperative NKp frequency for all patients was lower than the preoperative values , except in patients receiving autologous salvaged blood , which was higher than all other groups ( p<0.0001 ) . Postoperative NKp frequencies for patients receiving allogeneic or autologous predeposited blood responded similarly ( p=0.99 ) , but these patients had lower NKp frequencies than did the non-transfused group ( p<0.0001 ) . Postoperative interferon gamma concentrations were higher in the autologous salvaged blood group ( p<0.0001 ) than in other groups , which did not differ from each other . Interleukin  
    Output:
    