***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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    ***EXAMPLES*** 
    Input: Pediatric patients who undergo posterior spinal fusion surgery to correct scoliosis often require multiple blood transfusions . Tranexamic acid is a synthetic antifibrinolytic drug that reduces transfusion requirements in cardiac surgery and total knee arthroplasty . We evaluated the efficacy of prophylactic tranexamic acid to reduce perioperative blood transfusion requirements in a prospect i ve , double-blinded , placebo control study . Forty patients , 9–18 yr of age , were r and omized to either tranexamic acid ( initial dose of 10 mg/kg and infusion of 1 mg · kg−1 · h−1 ) or placebo ( isotonic saline ) . Perioperative management was st and ardized . A uniform transfusion threshold for noncell saved red blood cells was 7.0 g/dL. The total amount of blood transfused in the perioperative period was significantly reduced in the Tranexamic group ( P = 0.045 ) . No thrombotic complications were detected in either group . The administration of prophylactic tranexamic acid in patients with scoliosis undergoing posterior spinal fusion surgery has the potential to reduce perioperative blood transfusion requirements Background : Previous studies have noted that the use of antifibrinolytic medications can help reduce blood loss and transfusion requirements during cardiac , total joint arthroplasty , and spine surgery . Tranexamic acid ( TXA ) has been investigated in these patient groups but consensus with respect to the dosing regimen has not been achieved , especially in the pediatric scoliosis literature . The purpose of this study was to compare the effects of 2 TXA dosing regimens on reducing transfusion requirements . Methods : A retrospective chart review was performed on all idiopathic scoliosis patients undergoing posterior spinal instrumentation and fusion from 2005 to 2006 to determine total perioperative transfusion requirements . Transfusion requirements for those patients receiving either a low ( 10 mg/kg loading , 1 mg/kg/h infusion ) or high ( 20 mg/kg loading , 10 mg/kg/h infusion ) dose of TXA were compared . Results : High-dose TXA ( n = 11 ) showed a trend toward a reduction in transfusion requirements compared with the low dose ( n = 15 ) for idiopathic scoliosis patients undergoing posterior only instrumentation and fusion ( 687.9 ± 778.1 mL vs 1372.6 ± 1077.3 mL ; P = 0.07 ; 95 % confidence interval for the mean difference , −66.3 mL to 1435.7 mL ) . Although substantial , this difference was underpowered to show a difference . Conclusions : The use of the higher dose of TXA result ed in a 50 % reduction in transfusion requirements for idiopathic scoliosis patients . Given previous studies , there appears to be a dose-response effect . A prospect i ve dose-ranging study is now required to determine the optimal dose for pediatric patients with idiopathic scoliosis . Level of Evidence : III , retrospective cohort study Background : Excessive bleeding often occurs during pediatric scoliosis surgery and is attributed to numerous factors , including accelerated fibrinolysis . The authors hypothesized that administration of tranexamic acid would reduce bleeding and transfusion requirements during scoliosis surgery . Methods : Forty-four patients scheduled to undergo elective spinal fusion were r and omly assigned to receive either 100 mg/kg tranexamic acid before incision followed by an infusion of 10 mg · kg−1 · h−1 during surgery ( tranexamic acid group ) or 0.9 % saline ( placebo group ) . General anesthesia was administered according to a st and ard protocol . Blood loss , transfusion requirements , coagulation parameters , and complications were assessed . Results : In the tranexamic acid group , blood loss was reduced by 41 % compared with placebo ( 1,230 ± 535 vs. 2,085 ± 1,188 ml ; P < 0.01 ) . The amount of blood transfused did not differ between groups ( 615 ± 460 vs. 940 ± 718 ml ; P = 0.08 ) . Administration of tranexamic acid was a multivariate predictor of blood loss , as was American Society of Anesthesiologists physical status and preoperative platelet count . No apparent adverse drug effects occurred in any patient . Conclusion : Intraoperative administration of tranexamic acid significantly reduces blood loss during spinal surgery in children with scoliosis BACKGROUND Aprotinin and epsilon aminocaproic acid are antifibrinolytic agents used to reduce postoperative blood loss after cardiopulmonary bypass . We compared low dose aprotinin with epsilon aminocaproic acid and a combination of the two agents to reduce postoperative blood loss in infants with congenital cyanotic heart disease undergoing corrective surgical procedures . METHODS This prospect i ve study was conducted r and omly on 300 children . Group I ( n = 80 ) acted as the control and did not receive either of the study drugs . Group II ( n = 100 ) received low dose aprotinin , group III ( n = 60 ) received epsilon aminocaproic acid , and group IV ( n = 60 ) received a combination of the two antifibrinolytic agents . RESULTS The control group had the longest time for sternal closure , maximum blood loss at 24 hours , and greatest requirements for packed red blood cells and platelets . Fibrinogen levels were significantly lower , and levels of fibrin breakdown products were significantly higher compared with the groups given either or both of the antifibrinolytics . CONCLUSIONS Epsilon aminocaproic acid is as efficacious as low dose aprotinin in reducing postoperative blood loss and packed red blood cell and platelet requirements in children with congenital cyanotic heart disease . The combination of the two was slightly more effective UNLABELLED In this prospect i ve cohort study of 548 children undergoing open-heart surgery  , we evaluated demographic and perioperative factors to identify variables associated with perioperative blood loss and blood product transfusions . Using multivariate analysis , younger patient age was found to be the variable most significantly associated with bleeding and transfusions . Higher preoperative hematocrit , complex surgery , lower platelet count during cardiopulmonary bypass ( CPB ) , and longer duration of deep hypothermic circulatory arrest were also significantly associated with bleeding and transfusion . Excessive postoperative chest tube ( CT ) drainage was associated with intraoperative bleeding . Independently associated variables accounted for 76 % of the variability in CT output measured after 2 h in intensive care . Patients were subdivided into children aged < or = 1 yr ( infants ) and children > 1 yr ; infants bled more intraoperatively ( P<0.005 ) ; had greater cumulative CT output at 2 , 6 , 12 , and 24 h ( P<0.0001 ) ; and received more blood products ( P<0.0001 ) . Factors associated with bleeding and transfusions varied with patient age . Lower body core temperature during CPB was highly associated with blood loss and transfusions in infants , whereas resternotomy , preoperative congestive heart failure , and prolonged duration of CPB were significant factors associated with bleeding and transfusions in children > 1 yr old . IMPLICATION S Knowledge of the factors associated with blood loss and blood product transfusions can help to identify children at risk of excessive bleeding after open-heart surgery Background : Surgical correction of craniosynostosis in children is associated with substantial intraoperative bleeding . Tranexamic acid ( TXA ) decreases intraoperative blood loss during cardiac or orthopedic surgery in children . We hypothesized that intraoperative TXA would reduce blood transfusion relative to placebo in patients pretreated with erythropoietin .  Methods : Forty consecutive children , American Society of Anesthesiologists status 1 or 2 , scheduled to undergo surgical correction of craniosynostosis were r and omly assigned to receive either intravenous TXA or saline , 0.9 % , intraoperatively . All children received preoperative erythropoietin  ( 600 U/kg once a week for 3 weeks before surgery ) . Perioperative blood loss , number and volume of transfusions , percentage of children who underwent transfusion , and side effects were noted after surgery and at the end of the study . Surgeon satisfaction and cost of treatment were also recorded . Results : There was no significant difference between groups in demographic or surgical data . In the TXA group , the volume of packed erythrocytes transfused was significantly reduced by 85 % ( from 11 to 1.6 ml/kg ) intraoperatively and by 57 % ( from 16.6 to 7.2 ml/kg ) throughout the study period ( P < 0.05 ) . Compared with the placebo group , the percentage of children requiring blood transfusion was lower in the TXA group during surgery ( 9 [ 45 % ] of 20 vs. 2 [ 11 % ] of 19 children ; P < 0.05 ) and during the whole study period ( 14 [ 70 % ] of 20 vs. 7 [ 37 % ] of 19 ; P < 0.05 ) . Preoperative and postoperative hematologic parameters were comparable in both groups . There were no adverse events . Conclusion : In children undergoing surgical correction of craniosynostosis and pretreated with erythropoietin  , intraoperative TXA reduces the transfusion requirement Study Design . A retrospective study of the effectiveness of Amicar ( epsilon aminocaproic acid ) . Objective . Evaluate the effectiveness of Amicar in decreasing perioperative blood loss and transfusion requirements in same-day anterior ( ASF ) and posterior spinal fusion ( PSF ) with segmental spinal instrumentation ( SSI ) for idiopathic scoliosis . Summary of Background Data . Preliminary prospect i ve , prospect i ve r and omized double-blind , and fibrinogen studies have demonstrated Amicar to be effective in decreasing perioperative blood loss in patients with idiopathic scoliosis undergoing PSF with SSI . Increased fibrinogen secretion is a possible explanation . Methods . There were 73 consecutive patients divided into 3 study groups based on the administration of Amicar : Group 1 ( n = 16 ) , no Amicar ; Group 2 ( n = 18 ) , Amicar for the PSF with SSI only ; and Group 3 ( n = 39 ) , Amicar for both ASF and PSF with SSI . All patients were managed using the same general anesthesia technique , intraoperative procedure , postoperative care path , and indications for transfusion ( hemoglobin < 7g/dL ) . Total perioperative blood loss ( estimated intraoperative blood loss for both procedures and measured postoperative chest tube and PSF wound suction drainage ) and total transfusion requirements between groups were compared using one-way ANOVA . Results . There were statistically significant decreases in mean estimated intraoperative PSF with SSI , total perioperative blood loss , and transfusion requirements in the 2 Amicar groups . However , Amicar had no significant effect on estimated intraoperative ASF blood loss , chest tube drainage , or PSF wound suction drainage . Total perioperative blood loss and transfusion requirements ( cell saver , autologous , directed , and allogeneic blood ) were : 3442.8 ± 1344.0 mL and 1537.1 ± 905.1 mL in Group 1 ; 2089.8 ± 684.0 mL and 485.2 ± 349.8 mL in Group 2 ; and 2184.1 ± 1163.7 mL and 531.5 ± 510.5 mL in Group 3 . There were no Amicar related complications . Conclusion . Amicar was highly effective in decreasing total perioperative blood loss and transfusion requirements in same-day ASF and PSF with SSI for idiopathic scoliosis . It results in less preoperative autologous blood donation , perioperative blood transfusion , costs , and potential transfusion-related complications . It was mosteffective in decreasing intraoperative estimated PSF with SSI blood loss . It had no significant effect during the ASF , postoperative chest tube , or PSF wound suction drainage . We now recommend that it be used for the PSF with SSI procedure only We performed a prospect i ve , r and omized , placebo-controlled , double-blind trial to assess the efficacy of aprotinin in 61 children ( median age 3.7 yr ) undergoing reoperative open heart surgery ( OHS ) . Three demographically similar groups were studied : large-dose aprotinin ( ALD ) , small-dose aprotinin ( ASD ) , and placebo ( P ) . Over the first 24 postoperative hours fewer patients in the aprotinin groups received packed red cells ( ALD , 53 % ; ASD , 89 % ; and P , 95 % ; P = 0.001 ) , platelets ( ALD , 32 % ; ASD , 50 % ; and P , 65 % ; P = 0.04 ) , and fresh frozen plasma ( ALD , 16 % ; ASD , 17 % ; and P , 60 % ; P = 0.003 ) than placebo patients . Most importantly , aprotinin patients had fewer exposures to banked blood components ( ALD , median 1 U ; and ASD , median 2 U ) than P ( median 6 U ; P 
    Output:
    
Antifibrinolytics are effective in reducing blood loss and transfusion requirements in major pediatric surgery .
TXA and EACA also appear to have reasonable side-effect profiles .