***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: A 2008 r and omized trial of critically ill , but stable , children reported the safety of transfusing red blood cells at a hemoglobin threshold of 7 g/dL. In 2009 , we adopted the same transfusion criteria in our  hematopoietic stem cell transplantation patients .  Regression modeling was used to compare data obtained during primary admission for hematopoietic stem cell transplantation in calendar years before and after our practice change . Sixty-six patients admitted in the preintervention year were compared with 75 postintervention . Pre- and post patients were similar in diagnoses and type of transplantations . Postintervention , median hemoglobin pretransfusion significantly decreased from 8.8 g/dL to 6.8 g/dL ( P < .0001 ) . In addition , transfused red blood cell units received by patients dropped from 4 ( interquartile range [ IQR ] 3 , 8) to 3 ( IQR , 2 , 5 ) , ( P = .002 ) , and number of transfusion days per patients decreased from 4 ( IQR , 2,5 ) to 3 ( IQR , 2 , 5 ) , ( P = .01 ) . There were no differences in length of stay , time to engraftment , or 100-day mortality . Median blood product charges per patient significantly decreased ( $ 3,624 [ IQR , $ 2,265 , $ 6,040 ] to $ 2,185 [ IQR , $ 1,812 , $ 3,997 ] , P = .004 ) . Our initial experience suggests that implementation of a conservative transfusion strategy in otherwise stable children undergoing hematopoietic stem cell transplantation appears safe and lowers transfusion exposures BACKGROUND Red blood cell ( RBC ) transfusion thresholds have yet to be examined in large r and omized trials in hematologic malignancies . This pilot study in acute leukemia uses a restrictive compared to a liberal transfusion strategy . STUDY DESIGN AND METHODS A r and omized ( 2:1 ) study was conducted of restrictive ( LOW ) hemoglobin ( Hb ) trigger ( 7 g/dL ) compared to higher ( HIGH ) Hb trigger ( 8 g/dL ) . The primary outcome was feasibility of conducting a larger trial . The four requirements for success required that more than 50 % of the eligible patients could be consented , more than 75 % of the patients r and omized to the LOW arm tolerated the transfusion trigger , fewer than 15 % of patients crossed over from the LOW arm to the HIGH arm , and no indication for the need to pause the study for safety concerns . Secondary outcomes included fatigue , bleeding , and RBCs and platelets transfused . RESULTS Ninety patients were consented and r and omly assigned to LOW to HIGH . The four criteria for the primary objective of feasibility were met . When the number of units transfused was compared , adjusting for baseline Hb , the LOW arm was transfused on average 8.0 ( 95 % confidence interval [ CI ] , 6.9 - 9.1 ) units/patient while the HIGH arm received 11.7 ( 95 % CI , 10.1 - 13.2 ) units ( p = 0.0003 ) . There was no significant difference in bleeding events or neutropenic fevers between study arms . CONCLUSION This study establishes feasibility for trial of Hb thresholds in leukemia through demonstration of success in all primary outcome metrics and a favorable safety profile . This population requires further study to evaluate the equivalence of liberal and restrictive transfusion thresholds in this unique clinical setting Objective : To examine the impact of a restrictive vs. liberal transfusion strategy on arterial lactate and oxygen content differences in children with single-ventricle physiology post cavopulmonary connection . Children with single-ventricle physiology are routinely transfused postoperatively to increase systemic oxygen delivery , and transfusion thresholds in this population have not been studied . Design : Prospect i ve , r and omized , controlled , clinical trial . Setting : Pediatric cardiac intensive care unit in a teaching hospital . Patients : Infants and children ( n = 60 ) with variations of single-ventricle physiology presenting for cavopulmonary connection . Interventions : Subjects were r and omized to a restrictive ( hemoglobin of < 9.0 g/dL ) , or liberal ( hemoglobin of ≥13.0 g/dL ) transfusion strategy for 48 hrs post operation . Primary outcome measures were mean and peak arterial lactate . Secondary end points were arteriovenous ( C(a-v)o2 ) and arteriocerebral oxygen content ( C(a-c)o2 ) differences and clinical outcomes . Measurements and Main Results : A total of 30 children were in each group . There were no significant preoperative differences . Mean hemoglobin in the restrictive and liberal groups were 11 ± 1.3 g/dL and 13.9 ± 0.5 g/dL , respectively ( p < .01 ) . No differences in mean ( 1.4 ± 0.5 mmol/L [ Restrictive ] vs. 1.4 ± 0.4 mmol/L [ Liberal ] ) or peak ( 3.1 ± 1.5 mmol/L [ Restrictive ] vs. 3.2 ± 1.3 mmol/L [ Liberal ] ) lactate between groups were found . Mean number of red blood cell transfusions were 0.43 ± 0.6 and 2.1 ± 1.2 ( p < .01 ) , and donor exposure was 1.2 ± 0.7 and 2.4 ± 1.1 to ( p < .01 ) , for each group , respectively . No differences were found in C(a-v)o2 , C(a-c)o2 , or clinical outcome measures . Conclusion : Children with single-ventricle physiology do not benefit from a liberal transfusion strategy after cavopulmonary connection . A restrictive red blood cell transfusion strategy  decreases the number of transfusions , donor exposures , and potential risks in these children . Larger studies with clinical outcome measures are needed to determine the transfusion threshold for children post cardiac repair or palliation for congenital heart disease BACKGROUND Whether a restrictive threshold for hemoglobin level in red-cell transfusions , as compared with a liberal threshold , reduces postoperative morbidity and health care costs after cardiac surgery is uncertain . METHODS We conducted a multicenter , parallel-group trial in which patients older than 16 years of age who were undergoing nonemergency cardiac surgery were recruited from 17 centers in the United Kingdom . Patients with a postoperative hemoglobin level of less than 9 g per deciliter were r and omly assigned to a restrictive transfusion threshold ( hemoglobin level < 7.5 g per deciliter ) or a liberal transfusion threshold ( hemoglobin level < 9 g per deciliter ) . The primary outcome was a serious infection ( sepsis or wound infection ) or an ischemic event ( permanent stroke [ confirmation on brain imaging and deficit in motor , sensory , or coordination functions ] , myocardial infa rct ion , infa rct ion of the gut , or acute kidney injury ) within 3 months after r and omization . Health care costs , excluding the index surgery , were estimated from the day of surgery to 3 months after surgery . RESULTS A total of 2007 patients underwent r and omization ; 4 participants withdrew , leaving 1000 in the restrictive-threshold group and 1003 in the liberal-threshold group .  Transfusion rates after r and omization were 53.4 % and 92.2 % in the two groups , respectively . The primary outcome occurred in 35.1 % of the patients in the restrictive-threshold group and 33.0 % of the patients in the liberal-threshold group ( odds ratio , 1.11 ; 95 % confidence interval [ CI ] , 0.91 to 1.34 ; P=0.30 ) ; there was no indication of heterogeneity according to subgroup . There were more deaths in the restrictive-threshold group than in the liberal-threshold group ( 4.2 % vs. 2.6 % ; hazard ratio , 1.64 ; 95 % CI , 1.00 to 2.67 ; P=0.045 ) . Serious postoperative complications , excluding primary - outcome events , occurred in 35.7 % of participants in the restrictive-threshold group and 34.2 % of participants in the liberal-threshold group . Total costs did not differ significantly between the groups . CONCLUSIONS A restrictive transfusion threshold after cardiac surgery was not superior to a liberal threshold with respect to morbidity or health care costs . ( Funded by the National Institute for Health Research Health Technology Assessment program ; Current Controlled Trials number , IS RCT N70923932 . ) BACKGROUND The hemoglobin threshold at which postoperative red-cell transfusion is warranted is controversial . We conducted a r and omized trial to determine whether a higher threshold for blood transfusion would improve recovery in patients who had undergone surgery for hip fracture . METHODS We enrolled 2016 patients who were 50 years of age or older , who had either a history of or risk factors for cardiovascular disease , and whose hemoglobin level was below 10 g per deciliter after hip-fracture surgery . We r and omly assigned patients to a liberal transfusion strategy ( a hemoglobin threshold of 10 g per deciliter ) or a restrictive transfusion strategy ( symptoms of anemia or at physician discretion for a hemoglobin level of < 8 g per deciliter ) . The primary outcome was death or an inability to walk across a room without human assistance on 60-day follow-up . RESULTS A median of 2 units of red cells were transfused in the liberal- strategy group and none in the restrictive- strategy group . The rates of the primary outcome were 35.2 % in the liberal- strategy group and 34.7 % in the restrictive- strategy group ( odds ratio in the liberal- strategy group , 1.01 ; 95 % confidence interval [ CI ] , 0.84 to 1.22 ) , for an absolute risk difference of 0.5 percentage points ( 95 % CI , -3.7 to 4.7 ) . The rates of in-hospital acute coronary syndrome or death were 4.3 % and 5.2 % , respectively ( absolute risk difference , -0.9 % ; 99 % CI , -3.3 to 1.6 ) , and rates of death on 60-day follow-up were 7.6 % and 6.6 % , respectively ( absolute risk difference , 1.0 % ; 99 % CI , -1.9 to 4.0 ) . The rates of other complications were similar in the two groups . CONCLUSIONS A liberal transfusion strategy , as compared with a restrictive strategy , did not reduce rates of death or inability to walk independently on 60-day follow-up or reduce in-hospital morbidity in elderly patients at high cardiovascular risk . ( Funded by the National Heart , Lung , and Blood Institute ; FOCUS Clinical Trials.gov number , NCT00071032 . ) IMPORTANCE There is limited information about the effect of erythropoietin or a high hemoglobin transfusion threshold after a traumatic brain injury . OBJECTIVE To compare the effects of erythropoietin and 2 hemoglobin transfusion thresholds ( 7 and 10 g/dL ) on neurological recovery after traumatic brain injury . DESIGN , SETTING , AND PARTICIPANTS R and omized clinical trial of 200 patients ( erythropoietin , n = 102 ; placebo , n = 98 ) with closed head injury who were unable to follow comm and s and were enrolled within 6 hours of injury at neurosurgical intensive care units in 2 US level I trauma centers between May 2006 and August 2012 . The study used a factorial design to test whether erythropoietin would fail to improve favorable outcomes by 20 % and whether a hemoglobin transfusion threshold of greater than 10 g/dL would increase favorable outcomes without increasing complications . Erythropoietin or placebo was initially dosed daily for 3 days and then weekly for 2 more weeks ( n = 74 ) and then the 24- and 48-hour doses were stopped for the remainder of the patients ( n = 126 ) . There were 99 patients assigned to a hemoglobin transfusion threshold of 7 g/dL and 101 patients assigned to 10 g/dL. INTERVENTIONS Intravenous erythropoietin ( 500 IU/kg per dose ) or saline . Transfusion threshold maintained with packed red blood cells . MAIN OUTCOMES AND MEASURES Glasgow Outcome Scale score dichotomized as favorable ( good recovery and moderate disability ) or unfavorable ( severe disability , vegetative , or dead ) at 6 months postinjury . RESULTS There was no interaction between erythropoietin and hemoglobin transfusion threshold . Compared with placebo ( favorable outcome rate : 34/89 [ 38.2 % ; 95 % CI , 28.1 % to 49.1 % ] ) , both erythropoietin groups were futile ( first dosing regimen : 17/35 [ 48.6 % ; 95 % CI , 31.4 % to 66.0 % ] , P = .13 ; second dosing regimen : 17/57 [ 29.8 % ; 95 % CI , 18.4 % to 43.4 % ] , P 
    Output:
    
There is low- quality evidence that a restrictive RBC transfusion policy has little or no effect on : mortality at 30 to 100 days , bleeding , or hospital stay .