***TASK*** the task is to summarize an input biomedical literature in six sentences 
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    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
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    Input: Background Desmopressin-induced release of tissue plasminogen activator from endothelial cells may explain the absence of its hemostatic effect in patients undergoing cardiac surgery . Prior administration of the antifibrinolytic drug tranexamic acid might unmask such an effect , and combination therapy might thereby improve postoperative hemostasis . Methods and Results A double-blinded design r and omly allocated 163 adult patients undergoing coronary revascularization , valve replacement , both procedures , or repair of atrial septal defect to four treatment groups : placebo , tranexamic acid given as 10 mg/kg over 30 minutes followed by 1 mg . kg−1 . hr−1 for 12 hours initiated before skin incision , desmopressin given as 0.3 μg/kg over 20 minutes after protamine infusion , and both drugs . One surgeon performed all operations . Blood loss consisted of mediastinal tube drainage over 12 hours . Follow-up visits sought evidence of myocardial infa rct ion and stroke  . Desmopressin decreased neither the 12-hour blood loss nor the amount of homologous red cells transfused . Tranexamic acid alone significantly reduced 12-hour blood loss , by 30%1 ( mean , 318 versus 453 ml ; Conclusions Desmopressin exerts no hemostatic effect , with or without prior administration of antifibrinolytic drug . Prophylactic tranexamic acid alone appears economical and safe in decreasing blood loss and transfusion requirement after cardiac surgery Intraoperatively administered , tranexamic acid ( TA ) does not reduce bleeding in total hip replacement ( THR ) . Therefore , its prophylactic use was attempted in the present study because this has been shown to be more effective in cardiac surgery . We investigated 40 patients undergoing THR in a prospect i ve , r and omized , double-blinded study . Twenty patients received TA given in two bolus doses of 10 mg/kg each , the first just before surgical incision and the second 3 h later . In addition , a continuous infusion of TA , 1.0 mg · kg−1 · h−1 for 10 h , was given after the first bolus dose . The remaining 20 patients formed a control group . Both groups used preoperative autologous blood donation and intraoperative autotransfusion . Intraoperative bleeding was significantly less ( P = 0.001 ) in the TA group compared with the control group ( 630 ± 220 mL vs 850 ± 260 mL ) . Postoperative drainage bleeding was correspondingly less ( P = 0.001 ) ( 520 ± 280 vs 920 ± 410 mL ) . Up to 10 h postoperatively , plasma D-dimer concentration was halved in the TA group compared with the control group . One patient in each group had an ultrasound-verified late deep vein thrombosis . In conclusion , we found TA , administrated before surgical incision , to be efficient in reducing bleeding during THR . Implication s In a prospect i ve , double-blinded study of 40 patients undergoing total hip replacement , the preoperative administration of tranexamic acid  reduced bleeding by 35 % , probably by decreasing induced fibrinolysis . Whether tranexamic acid therapy can replace predonation of autologous blood or intraoperative autotransfusion requires further study The objective of this study was to determine whether topical tranexamic acid ( TXA ) carried similar hemostatic effect compared with intravenous TXA in total hip arthroplasty ( THA ) . Three hundred and three THA patients were enrolled and r and omized into 3 groups : no TXA group , topical and intravenous TXA group . The results showed that the topical and intravenous TXA group had reduced but similar blood transfusion rates ( 5.88 % v. s. 5.94 % , P = 0.816 ) . No significant difference was detected in total blood loss between the two TXA groups [ ( 963.4 ± 421.3 ) ml vs. ( 958.5 ± 422 ) ml P = 0.733 ] . We conclude that topical use of TXA was equally effective and safe compared with intravenous TXA in reducing blood loss and transfusion rate following THA without substantial complications Background : Tranexamic acid has been used to reduce bleeding and the subsequent need for blood transfusion in many surgeries . Because orthognathic surgery can be associated with significant bleeding , this study evaluated the efficacy of prophylactic intravenous ( IV ) tranexamic acid on blood loss during bimaxillary osteotomy . Methods : Thirty-two consecutive patients , scheduled for elective bimaxillary osteotomy , were included in the study and 16 were r and omly assigned to each group . They received tranexamic acid ( 20 mg/kg ) or equal volume of placebo ( normal saline ) intravenously just before induction of anesthesia . Intraoperative blood loss , pre and post operative hemoglobin ( Hb ) and hematocrit ( Hct ) concentration , duration of surgery , hospital stay time , and rate of blood transfusion were recorded for each patient . Results : Intraoperative blood loss in the tranexamic group and control group were 585.9 and 790 mL respectively ( P=0.008 ) . Postoperative Hb concentration at the 6th hour was greater in the tranexamic group ( P=0.008 ) . There was no significant difference in the Hct concentration between the study groups . There was no significant difference in blood transfusion rate , hospital stay time and duration of surgery between the study groups . Conclusion : Preoperative IV administration of tranexamic acid reduces the amount of blood loss during bimaxillary osteotomy 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 UNLABELLED Perioperative bleeding following coronary artery bypass grafting ( CABG ) is associated with increased blood product usage . Although aprotonin is effective in reducing perioperative blood loss , excessive cost prohibits routine utilization . Epsilon aminocaproic acid ( EACA ) and tranexamic acid ( TA ) are inexpensive antifibrinolytic agents , which , when given prophylactically , may reduce blood loss . The present study was undertaken to compare the efficacy of TA and EACA in reducing perioperative blood loss . METHODS The study population consisted of first-time CABG patients . Patients were allocated in a prospect i ve double-blind fashion : ( 1 ) group EACA ( loading dose 15 mg/kg , continuous infusion 10 mg/kg per hour for 6 hours , N = 20 ) ; ( 2 ) group TA ( loading dose 15 mg/kg , continuous infusion 1 mg/kg per hour for 6 hours , N = 20 ) ; ( 3 ) control group ( infusion of normal saline for 6 hours , N = 19 ) . RESULTS Treatment groups were similar preoperatively . No significant difference in intraoperative blood loss or perioperative use of blood products was noted . D-dimer concentration was elevated in the control group compared to the EACA and TA groups ( p < 0.05 ) . Group TA had less postoperative blood loss than the EACA and control groups at 6 and 12 hours postoperatively ( p < 0.05 ) . TA had reduced total blood loss ( 600 + /- 49 mL ) postoperatively compared to EACA ( 961 + /- 148 mL ) and control ( 1060 + /- 127 mL , p < 0.05 ) . CONCLUSION TA and EACA effectively inhibited fibrinolytic activity intraoperatively and throughout the first 24 hours postoperatively . TA was more effective in reducing blood loss postoperatively following CABG . This suggests that TA may be beneficial as an effective and inexpensive antifibrinolytic in first-time CABG patients & NA ; We aim ed to answer the following three questions in this study : ( 1 ) Does tranexamic acid ( TA ) reduce the amount of bleeding in total knee arthroplasty ( TKA ) ? ( 2 ) Does TA reduce requirement for blood transfusion ? ( 3 ) Is there any difference on reliability and efficacy between topical and intravenous ( IV ) applications of TA ? Patients were allocated into three groups r and omly by a software program as topical , IV , and control group . TA was applied as 20 mg/kg to the IV group and as 3 g/100 mL saline to the topical group . The hemoglobin values were recorded preoperatively and postoperatively on the same day and on day 1 and day 2 . Removal of the drain postoperatively and length of hospital stay , as well as any complications such as pulmonary embolism or deep venous thrombosis , were also noted . The study comprised 40 patients in the IV group , 42 in the topical group , and 41 in the control group .  The drain output values were similar in the IV and topical groups ( p = 0.161 ) , while those of the control group were significantly higher than both the IV and topical groups ( p < 0.001 and < 0.001 ) . Transfusion was applied to 19.5 % of cases in the control group , 4.8 % in the topical group , and 5.1 % of the IV group ( χ2 = 6.522 ; p = 0.038 ) . The results of the study showed that 20 mg/kg single‐dose IV bolus or 3 g topical TA application reduced blood loss and transfusion requirement without increasing the rate of thromboembolic complications in unilateral primary TKA BACKGROUND The transfusion of allogeneic red blood cells and allogeneic coagulation products is associated with risk to the patient and the depletion of an increasingly scarce re source . This prospect i ve , r and omized , double-blind , placebo-controlled trial investigated practice s to avoid transfusion in patients undergoing first-time cardiac surgery . METHODS Patients were r and omized to one of three treatment groups : an aprotinin group , a tranexamic acid group , and a control group receiving normal saline . Intra-operative cell salvage was used for all patients . The primary outcomes were the number of patients exposed to allogeneic red blood cells , allogeneic coagulation products or any allogeneic transfusion ( allogeneic red blood cells and /or allogeneic coagulation products ) . RESULTS Patients were 2.5 times more likely to receive any allogeneic transfusion in the tranexamic group than in the aprotinin group ( 21 patients out of 60 compared with nine out of 60 , respectively ) . The relative risk of any allogeneic transfusion comparing aprotinin with tranexamic acid was 0.43 ( 95 % confidence interval 0.21 - 0.86 ; P=0.019 ) . Patients in the control group were four times more likely to receive any allogeneic transfusion when compared with the aprotinin group ( 37 patients out of 60 compared with nine out of 60 , respectively ) . The relative risk of any allogeneic transfusion comparing aprotinin with control was 0.24 ( 95 % confidence interval 0.13 - 0.46 ; P<0.001 ) . CONCLUSIONS When used in addition to intra-operative cell salvage , aprotinin is the most efficacious pharmacological therapy for reducing patient exposure to any allogeneic transfusion during first-time cardiac surgery 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 
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Exclusion of patients with major comorbidities may not be necessary ; we showed that the risk of adverse events was similar in studies that excluded patients with major comorbidities and those that did not .