***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 
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    Input: BACKGROUND Perioperative anemia leads to increased morbidity and mortality and potentially inhibits rehabilitation after hip fracture surgery . As such , the optimum transfusion threshold after hip fracture surgery is unknown . PATIENTS AND METHODS A total of 120 elderly , cognitively intact hip fracture patients admitted from their own home were r and omly assigned to receive transfusion at a hemoglobin threshold of 10.0 g per dL ( liberal ) versus 8.0 g per dL ( restrictive ) in the entire perioperative period . Patients were treated according to a well-defined multimodal rehabilitation program . Primary outcome was postoperative functional mobility measured with the cumulated ambulation score ( CAS ) . RESULTS Patients in the liberal group received transfusions more frequently than those in the restrictive group ( 44 patients vs. 22 patients ; p < 0.01 ) and received more transfusions during hospitalization ( median , 2 units [ interquartile range , 1 - 2 ] vs. 1 [ 1 - 2 ] ; p < 0.0001 ) . There were no significant differences in postoperative rehabilitation scores ( CAS : median , 9 [ 9 - 15 ] vs. 9 [ 9 - 13.5 ] ; p = 0.46 ) or in length of stay ( median , 18 days vs. 16 days , respectively ; p = 0.46 ) . There were fewer patients in the liberal transfusion group with cardiovascular complications ( 2 % vs. 10 % ; p = 0.05 ) and a lower mortality ( 0 % vs. 8 % ; p = 0.02 ) . CONCLUSION Although a liberal transfusion trigger did not result in increased ambulation scores , restrictive transfusion thresholds should be treated with caution in elderly high-risk hip fracture patients , until their safety has been proved in larger r and omized studies 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 Objective To evaluate the immediate effects of red blood cell transfusion on central venous oxygen saturation and lactate levels in septic shock patients with different transfusion triggers . Methods We included patients with a diagnosis of septic shock within the last 48 hours and hemoglobin levels below 9.0g/dL Patients were r and omized for immediate transfusion with hemoglobin concentrations maintained above 9.0g/dL ( Group Hb9 ) or to withhold transfusion unless hemoglobin felt bellow 7.0g/dL ( Group Hb7 ) . Hemoglobin , lactate , central venous oxygen saturation levels were determined before and one hour after each transfusion . Results We included 46 patients and 74 transfusions . Patients in Group Hb7 had a significant reduction in median lactate from 2.44 ( 2.00 - 3.22 ) mMol/L to 2.21 ( 1.80 - 2.79 ) mMol/L , p = 0.005 , which was not observed in Group Hb9 [ 1.90 ( 1.80 - 2.65 ) mMol/L to 2.00 ( 1.70 - 2.41 ) mMol/L , p = 0.23 ] . Central venous oxygen saturation levels increased in Group Hb7 [ 68.0 ( 64.0 - 72.0)% to 72.0 ( 69.0 - 75.0)% , p < 0.0001 ] but not in Group Hb9 [ 72.0 ( 69.0 - 74.0)% to 72.0 ( 71.0 - 73.0)% , p = 0.98 ] . Patients with elevated lactate or central venous oxygen saturation < 70 % at baseline had a significant increase in these variables , regardless of baseline hemoglobin levels . Patients with normal values did not show a decrease in either group . Conclusion Red blood cell transfusion increased central venous oxygen saturation and decreased lactate levels in patients with hypoperfusion regardless of their baseline hemoglobin levels . Transfusion did not appear to impair these variables in patients without hypoperfusion . Clinical Trials.gov OBJECTIVE In elective orthopaedic hip- and knee replacement surgery patients , we studied the effect of implementation of a uniform transfusion policy on RBC usage . STUDY DESIGN AND METHODS A r and omized , controlled study . A new uniform , restrictive transfusion policy was compared with st and ard care , which varied among the three participating hospitals . Only prestorage leucocyte-depleted RBC(s ) were used . Primary end-point was RBC usage , related to length of hospital stay . Secondary end-points were Hb levels , mobilization delay and postoperative complications . RESULTS Six hundred and three patients were evaluated .  Adherence to the protocol was over 95 % . Overall mean RBC usage was 0.78 U/patient in the new policy group and 0.86 U/patient in the st and ard care policy group ( mean difference 0.08;95 % CI [ -0.3 ; 0.2 ] ; P = 0.53 ) . In two hospitals , the new transfusion policy result ed in a RBC reduction of 30 % ( 0.58U RBC/patient ) ( P = 0.17 ) and 41 % ( 0.29 U RBC/patient ) ( P = 0.05 ) respectively . In the third hospital , however , RBC usage increased by 39 % ( 0.31 U RBC/patient ) ( P = 0.02 ) with the new policy , due to a more restrictive st and ard care policy in that hospital . Length of hospital stay was not influenced by either policy . CONCLUSIONS Implementation of a uniform transfusion protocol for elective lower joint arthroplasty patients is feasible , but does not always lead to a RBC reduction . Length of hospital stay was not affected Background : Several studies have indicated that a restrictive erythrocyte transfusion strategy is as safe as a liberal one in critically ill patients , but there is no clear evidence to support the superiority of any perioperative transfusion strategy in patients with cancer . Methods : In a r and omized , controlled , parallel-group , double-blind ( patients and outcome assessors ) superiority trial in the intensive care unit of a tertiary oncology hospital , the authors evaluated whether a restrictive strategy of erythrocyte transfusion ( transfusion when hemoglobin concentration < 7 g/dl ) was superior to a liberal one ( transfusion when hemoglobin concentration < 9 g/dl ) for reducing mortality and severe clinical complications among patients having major cancer surgery . All adult patients with cancer having major abdominal surgery who required postoperative intensive care were included and r and omly allocated to treatment with the liberal or the restrictive erythrocyte transfusion strategy . The primary outcome was a composite endpoint of mortality and morbidity . Results : A total of 198 patients were included as follows : 101 in the restrictive group and 97 in the liberal group . The primary composite endpoint occurred in 19.6 % ( 95 % CI , 12.9 to 28.6 % ) of patients in the liberal- strategy group and in 35.6 % ( 27.0 to 45.4 % ) of patients in the restrictive- strategy group ( P = 0.012 ) . Compared with the restrictive strategy , the liberal transfusion strategy was associated with an absolute risk reduction for the composite outcome of 16 % ( 3.8 to 28.2 % ) and a number needed to treat of 6.2 ( 3.5 to 26.5 ) . Conclusion : A liberal erythrocyte transfusion strategy with a hemoglobin trigger of 9 g/dl was associated with fewer major postoperative complications in patients having major cancer surgery compared with a restrictive strategy Background : Due to the floating of the guideline , there is no evidence -based evaluation index on when to start the blood transfusion for patients with hemoglobin ( Hb ) level between 7 and 10 g/dl . As a result , the trigger point of blood transfusion may be different in the emergency use of the existing transfusion guidelines . The present study was design ed to evaluate whether the scheme can be safely and effectively used for emergency patients , so as to be supported by multicenter and large sample data in the future . Methods : From June 2013 to June 2014 , patients were r and omly divided into the experimental group ( Peri-operative Transfusion Trigger Score of Emergency [ POTTS-E ] group ) and the control group ( control group ) . The between-group differences in the patients ’ demography and baseline information , mortality and blood transfusion-related complications , heart rate , resting arterial pressure , body temperature , and Hb values were compared . The consistency of red blood cell ( RBC ) transfusion st and ards of the two groups of patients with the current blood transfusion guideline , namely the compliance of the guidelines , utilization rate , and per-capita consumption of autologous RBC were analyzed . Results : During the study period , a total of 72 patients were recorded , and 65 of them met the inclusion criteria , which included 33 males and 32 females with a mean age of ( 34.8 ± 14.6 ) years . 50 underwent abdomen surgery , 4 underwent chest surgery , 11 underwent arms and legs surgery . There was no statistical difference between the two groups for demography and baseline information . There was also no statistical differences between the two groups in anesthesia time , intraoperative rehydration , staying time in postanesthetic care unit , emergency hospitalization , postoperative 72 h Acute Physiologic Assessment and Chronic Health Evaluation II scores , blood transfusion-related complications and mortality . Only the POTTS-E group on the 1st postoperative day Hb was lower than group control , P < 0.05 . POTTS-E group was totally ( 100 % ) conformed to the requirements of the transfusion guideline to RBC infusion , which was higher than that of the control group ( 81.25 % ) , P < 0.01 . There were no statistical differences in utilization rates of autologous blood of 
    Output:
    
The results show that it may not be safe to use a restrictive transfusion threshold of less than 80 g/L in patients with ongoing acute coronary syndrome or chronic cardiovascular disease .
Effects on mortality and other outcomes are uncertain .