***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: 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 Children with cyanotic heart disease undergoing cardiac surgery in which cardiopulmonary bypass is used are at increased risk of postoperative bleeding . In this study , the authors investigated the possibility of reducing postoperative blood loss by using aprotinin and tranexamic acid alone or a combination of these two agents . METHODS In a prospect i ve , r and omized , blind study , 100 children undergoing cardiac surgery were investigated . In group 1 ( n = 25 ) patients acted as the control and did not receive either study drugs . In group 2 ( n = 25 ) patients received aprotinin ( 30.000 KIU.kg(-1 ) after induction of anesthesia , 30.000 KIU.kg(-1 ) in the pump prime and 30.000 KIU.kg(-1 ) after weaning from bypass ) . In group 3 ( n = 25 ) patients received tranexamic acid ( 100 mg.kg(-1 ) after induction of anesthesia , 100 mg.kg(-1 ) in the pump prime and 100 mg.kg(-1 ) after weaning from bypass ) . In group 4 ( n = 25 ) patients received a combination of the two agents in the same manner . Total blood loss and transfusion requirements during the period from protamine administration until 24 h after admission to the intensive care unit were recorded . In addition , hemoglobin , platelet counts and coagulation studies were recorded . RESULTS Postoperative blood loss was significantly higher in the control group ( group 1 ) compared with children in other groups who were treated with aprotinin , tranexamic acid or a combination of the two agents ( groups 2 , 3 and 4 ) during the first 24 h after admission to cardiac intensive care unit ( 40 + /- 18 ml.kg(-1).24 h(-1 ) , aprotinin ; 35 + /- 16 ml.kg(-1).24 h(-1 ) , tranexamic acid ; 34 + /- 19 ml.kg(-1).24 h(-1 ) , combination ; 35 + /- 15 ml.kg(-1).24 h(-1 ) ) . The total transfusion requirements were also significantly less in the all treatment groups . Time taken for sternal closure was longer in the control group ( 68 + /- 11 min ) compared with treatment groups 2 , 3 and 4 , respectively ( 40 + /- 18 , 42 + /- 11 , 42 + /- 13 min , P < 0.05 ) . The coagulation parameters were not found to be significantly different between the three groups . CONCLUSIONS Our results suggested that both agents were effective to reduce postoperative blood loss and transfusion requirements in patients with cyanotic congenital heart disease . However , the combination of aprotinin and tranexamic acid did not seem more effective than either of the two drugs alone Background Enhanced bleeding remains a serious problem after cardiac surgery , and fibrinolysis is often involved . We speculate that lower plasma concentrations of plasminogen activator inhibitor – 1 ( PAI-1 ) preoperatively and tissue plasminogen activator/PAI-1 ( t-PA/PAI-1 ) complex postoperatively might predispose for enhanced fibrinolysis and increased postoperative bleeding . Methods Totally 88 adult patients ( mean age 66 ± 10 years ) scheduled for cardiac surgery , were enrolled into a prospect i ve study . Blood sample s were collected pre-operatively , on admission to the recovery and at 6 and 24 hours postoperatively . Patients with a surgical bleeding that was diagnosed during reoperation were discarded from the study . The patients were allocated to two groups depending on the 24-hour postoperative chest tube drainage ( CTD ) : Group I > 500ml , Group II ≤ 500ml . Associations between CTD , PAI-1 , t-PA/PAI-1 complex and D-dimer were analyzed with SPSS . Results Nine patients were excluded because of surgical bleeding . Of the 79 remaining patients , 38 were allocated to Group I and 41 to Group II . The CTD volumes correlated with the preoperative plasma levels of PAI-1 ( r = − 0.3 , P = 0.009 ) . Plasma concentrations of preoperative PAI-1 and postoperative t-PA/PAI-1 complex differed significantly between the groups ( P < 0.001 and P = 0.012 , respectively ) . Group I displayed significantly lower plasma concentrations of fibrinogen and higher levels of D-dimer from immediately after the operation and throughout the first 24 hours postoperatively . Conclusions Lower plasma concentrations of PAI-1 preoperatively and t-PA/PAI-1 complex postoperatively leads to higher plasma levels of D-dimer in association with more postoperative bleeding after cardiac surgery We have investigated hemostatic parameters including platelet activation in 56 pediatric patients with or without cyanosis undergoing cardiopulmonary bypass ( CPB ) and cardiac surgery to repair congenital defects . Patients were participants in a study assessing the effects of tranexamic acid on surgery-related blood loss . Parameters monitored included blood loss , prothrombin F1.2 , thrombin-antithrombin complexes , t-PA , PAI-1 , plasminogen , fibrin D-dimer , and plasma factor XIII . Additionally , flow cytometry monitored platelet degranulation ( P-selectin or CD63 ) , as well as surface-bound fibrinogen , von Willebr and factor and factor XIIIa . Cyanotic patients had evidence of supranormal coagulation activation as both fibrin D-dimer and PAI-1 levels were elevated prior to surgery . While the extent of expression of P-selectin or CD63 was not informative , platelet-associated factor XIIIa was elevated in cyanotic patients at baseline . In both patient groups , CPB altered platelet activation state and coagulation status irrespective of the use of tranexamic acid OBJECTIVE This study compared the efficacy of aminocaproic acid and tranexamic acid in reducing postoperative blood loss , as well as blood and blood product requirements in children with cyanotic congenital heart disease . DESIGN A prospect i ve r and omized study . SETTING Cardiac center of a tertiary care , referral hospital . PARTICIPANTS One hundred fifty children in the age group of 2 months to 14.5 years with cyanotic congenital heart disease undergoing corrective surgery on cardiopulmonary bypass ( CPB ) .  INTERVENTIONS Patients were r and omized into 3 groups . Group A was given aminocaproic acid in a dose of 100 mg/kg after anesthetic induction , 100 mg/kg on CPB and 100 mg/kg after protamine . Group T was given tranexamic acid , 10 mg/kg , after anesthetic induction , 10 mg/kg on CPB , and 10 mg/kg after protamine . Group C was the control group . MAIN RESULT Control group had the longest sternal closure time , maximum blood loss at 24 hours , and maximum requirements of blood and blood products . Among the 2 groups given antifibrinolytics , there was no significant difference in postoperative blood loss , blood and product requirement , and reexploration rates . CONCLUSION Aminocaproic acid and tranexamic acid are equally effective in reducing postoperative blood loss , as well as blood and blood product requirements in children with cyanotic heart disease undergoing corrective surgery as compared with the control group Background : Pediatric cardiac surgery patients are at high risk for bleeding , and the antifibrinolytic drug tranexamic acid ( TA ) is often used to reduce blood loss . However , dosing schemes remain empirical as a consequence of the absence of pharmacokinetic study in this population . The authors ’ objectives were thus to investigate the population pharmacokinetics of TA in pediatric cardiac surgery patients during cardiopulmonary bypass ( CPB ) . Methods : Twenty-one patients were r and omized to receive TA either continuously ( 10 mg/kg followed by an infusion of 1 mg·kg−1·h−1 throughout the operation , and 10 mg/kg into the CPB ) or discontinuously ( 10 mg/kg , then 10 mg/kg into the CPB and 10 mg·kg−1·h−1 at the end of CPB ) . Serum concentrations were measured at eight time points with chromatography – mass spectrometry and the data were modeled using Monolix ( Lixoft , Orsay , France ) . Results : Tranexamic acid pharmacokinetics was ascribed to a two-compartment open model . The main covariate effects were body weight and CPB . Representative pharmacokinetic parameters adjusted to a 70-kg body weight were as follows : systemic clearance , 2.45 l/h ; volume of distribution in the central compartment , 14.1 l ; intercompartmental clearance , 5.74 l/h ; and peripheral volume , 32.8 l. In accordance with this model , the authors proposed a weight-adjusted dosing scheme to maintain effective TA concentrations in children during surgery , consisting of one loading dose followed by a continuous infusion . Conclusions : The authors report for the first time the pharmacokinetics of TA in children undergoing cardiac surgery with CPB , and propose a dosing scheme for optimized TA administration in those children To compare different doses of tranexamic acid , 150 consecutive children with congenital cyanotic heart disease were r and omly assigned to one of 5 groups of 30 each . Group A served as a control . Group B received 50 mg·kg−1 of tranexamic acid at induction of anesthesia . Group C received 10 mg·kg−1 at induction followed by an infusion of 1 mg·kg−1·h−1 . Group D had 10 mg·kg−1 at induction , 10 mg·kg−1 on bypass , and 10 mg·kg−1 after protamine . Group E had 20 mg·kg−1 at induction and again after protamine . The control group had the longest sternal closure time , the greatest blood loss in the first 24 hours , and the highest requirements for blood and blood products . Among the 4 groups given tranexamic acid , group D ( triple dose ) had the best results , followed by group E ( double dose ) . Group B ( single dose ) had the worst results among the groups receiving tranexamic acid BACKGROUND & OBJECTIVES Antifibrinolytic agents are used commonly in adult cardiac surgery to reduce postoperative blood loss . Paucity of literature on the use of a newer antifibrinolytic agent tranexamic acid ( TA ) in children undergoing cardiac surgery promoted us to conduct this study in children with cyanotic heart disease . METHODS One hundred and twenty consecutive children with cyanotic heart disease were r and omised into two groups . Control ( group A ) ( n=24 ) given no drug while the study ( group B , n=96 ) group was given tranexamic acid 10 mg/kg each after anaesthetic induction , on bypass and after protamine at the end of bypass . Postoperatively , total mediastinal chest tube drainage and blood and blood product usage at 24 h were recorded . Tests of coagulation including activated clotting time , fibrinogen , fibrin degradation products and platelet count were performed at 6 h postoperatively . RESULTS The two groups were comparable in terms of demographic characteristics such as age , sex , weight , operations performed , and preoperative haematocrit . Postoperatively , group B , had a significantly ( P<0.05 ) lower blood loss , blood and blood product usage , re-exploration rate compared to the control group . There was preservation of fibrinogen and lower levels of fibrin degradation products in group B. INTERPRETATION & CONCLUSION Tranexamine acid was highly effective in reducing post-operative blood loss , blood and blood product usage in children with congenital cyanotic heart disease undergoing corrective surgery BACKGROUND Trauma is a global disease , with over 2.5 million deaths annually from hemorrhage and coagulopathy . Overt hyperfibrinolysis is rare in trauma , and is associated with 
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They observed that the minimally effective concentration was significantly lower in neonatal plasma than in adult plasma.19 This concentration was significantly lower than the concentration targeted by current dosing schemes , indicating that neonates are possibly being exposed to greater levels of EACA than necessary .
They found that neonatal plasma required significantly lower TXA concentrations to completely prevent hyperfibrinolysis than adult New Insights About the Use of Tranexamic Acid in Children Undergoing Cardiac Surgery : From Pharmacokinetics to