***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: The aim of the present study was to investigate aspects of coagulation and fibrinolysis during knee arthroplasties in order to find out . 1 . whether an increased fibrinolysis is correlated to an increased blood loss 2 . whether there is a difference in markers for coagulation and fibrinolysis in peripheral venous blood compared to those in blood from the wounds 3 . whether the administration of tranexamic acid modifies the fibrinolytic response .  Twenty-four patients were included . Twelve patients were given tranexamic acid intravenously at the end of the operation . The dose was repeated three hours later . The other 12 patients were given an equivalent amount of placebo . The administration was r and omised and double-blind . Levels of prothrombin fragments 1 + 2 , D-dimers , plasminogen , alpha 2-antiplasmin , tissue plasminogen activator ( tPA ) , and plasminogen activator inhibitor ( PAI-1 ) in venous blood were investigated just before the operation , at the end of the operation and three hours later . At the end of the operation blood for analysis was also drawn from the wound . Coagulation and fibrinolysis was activated during and after surgery . The activation was significantly higher in blood from the wounds than in peripheral venous blood . We found no direct correlation between the degree of fibrinolysis and blood loss . The administration of tranexamic acid  reduced fibrinolysis in the wounds but not in peripheral venous blood . The postoperative blood loss was reduced by half The aim of this r and omized prospect i ve study was to clarify risks associated with a drain-clamping method using tranexamic acid and carbazochrome sodium sulfonate hydrate after total knee arthroplasty ( TKA ) . Subjects comprised 100 patients scheduled to undergo TKA , r and omized into 2 groups : 50 patients received the drain-clamping method using tranexamic acid and carbazochrome sodium sulfonate hydrate and 50 patients received drain-clamping with saline . Although bleeding volume was significantly lower in the group with tranexamic acid and carbazochrome sodium sulfonate hydrate , risk of asymptomatic deep venous thrombosis as detected by ultrasonography was comparable between groups . Tranexamic acid and carbazochrome sodium sulfonate hydrate in the drain-clamping method help reduce bleeding after TKA without increasing the risk of deep venous thrombosis BACKGROUND Total knee arthroplasty ( TKA ) is often carried out using a tourniquet and shed blood is collected in drains . Tranexamic acid decreases the external blood loss . Some blood loss may be concealed , and the overall effect of tranexamic acid on the haemoglobin ( Hb ) balance is not known . METHODS Patients with osteoarthrosis had unilateral cemented TKA using spinal anaesthesia . In a double-blind fashion , they received either placebo  ( n=24 ) or tranexamic acid 10 mg kg(-1 ) ( n=27 ) i.v . just before tourniquet release and 3 h later . The decrease in circulating Hb on the fifth day after surgery , after correction for Hb transfused , was used to calculate the loss of Hb in grams . This value was then expressed as ml of blood loss . RESULTS The groups had similar characteristics . The median volume of drainage fluid after placebo was 845 ( interquartile range 523 - 990 ) ml and after tranexamic acid was 385 ( 331 - 586 ) ml ( P<0.001 ) . Placebo patients received 2 ( 0 - 2 ) units and tranexamic acid patients 0 ( 0 - 0 ) units of packed red cells ( P<0.001 ) . The estimated blood loss was 1426 ( 1135 - 1977 ) ml and 1045 ( 792 - 1292 ) ml , respectively ( P<0.001 ) . The hidden loss of blood ( calculated as loss minus drainage volume ) was 618 ( 330 - 1347 ) ml and 524 ( 330 - 9620 ) ml , respectively ( P=0.41 ) . Two patients in each group developed deep vein thrombosis . CONCLUSIONS Tranexamic acid decreased total blood loss by nearly 30 % , drainage volume by approximately 50 % and drastically reduced transfusion . However , concealed loss was only marginally influenced by tranexamic acid and was at least as large as the drainage volume Purpose The surgical stress of total knee arthroplasty ( TKA ) procedure and the application of intra-operative pneumatic thigh tourniquet increases local fibrinolytic activity , which contributes significantly to post-operative blood loss .  Tranexamic acid , an antifibrinolytic drug , is commonly used to control post-operative blood loss . The recommended mode of administration of tranexamic acid is either oral or intravenous . However , the mechanism of action of the tranexamic acid points towards the possible effectiveness it may have following local/intra-articular application . This prospect i ve , double-blinded , r and omized preliminary study evaluated the efficacy of intra-articular tranexamic acid in reducing TKA-associated post-operative blood loss . Methods Fifty consenting patients with osteoarthritis of the knee scheduled for primary unilateral cemented-TKA were r and omly allocated to one of the two groups : Tranexamic Acid ( TA ) group ( n = 25 , 500 mg/5 ml tranexamic acid ) and the control group ( n = 25 , 5 ml 0.9 % saline ) . The drug and control solution were administered intra-articularly through the drain tube immediately after the wound closure . Parameters related to blood loss ( drop in haemoglobin , haematocrit differential ) and the drain output [ volume ( ml ) ] were compared between the two groups . Results On a comparative basis , TA-group obtained significant reduction in the drain output [ 95 % CI : 360.41–539.59 , p < 0.001 ] at 48 h post-operatively . Even though the control group received sixfold more blood transfusion than TA-group , it showed a greater drop in haemoglobin and haematocrit ( p < 0.05 ) . Conclusions Local application of tranexamic acid seems to be effective in reducing post-TKA blood loss as well as blood transfusion requirements . Level of evidence Therapeutic study , Level II After total knee arthroplasty ( TKA ) the technique of wound management is not st and ardised . In this prospect i ve study the efficacy of autologous blood reinfusion from the wound was investigated . One hundred patients ( 100 TKAs ) were enrolled in this sequential cohort study . In one-half of the operations , a reinfusion system with suction and in the other half one wound drain without suction were used . Blood loss , transfusion requirements , range of motion , Insall scores and the incidence of complications were studied . The use of a reinfusion system did not decrease the homologous transfusion requirements . The blood loss in the group with a suction drainage system was significantly higher . Our experiences since May 2002 with one drain without suction in 787 consecutive TKAs confirm all findings of the current study .RésuméAprès une arthroplastie totale du genou le problème des pertes sanguines , n’est pas aujourd’hui un problème st and ardisé . Lors d’une étude prospect i ve , l’efficacité de l’autotransfusion a été appréciée . Cent prothèses totales ont été enrôlées dans une cohorte . La moitié d’entre eux ont bénéficié d’une retransfusion des pertes sanguines du redon et pour l’autre moitié , le redon simple a été utilisé , sans récupération du sang post-opératoire . Les pertes de sang , la nécessité de transfusion , la mobilité , le score Insall et les complications ont été étudiés . L’utilisation d’une récupération avec retransfusion du sang post-opératoire ne diminue pas le nombre de transfusions homologues . Les pertes sanguines dans le groupe avec drainage simple sont plus importantes . Notre expérience depuis mai 2002 avec l’utilisation d’un drain sans aspiration dans 787 prothèses totales du genou consécutives confirment ses données Background The antifibrinolytic tranexamic acid reduces surgical blood loss , but studies have not identified an optimal regimen . Questions / purpose sWe studied different dosages , timings , and modes of administration to identify the most effective regimen of tranexamic acid in achieving maximum reduction of blood loss in TKA . Methods We prospect ively studied five regimens ( four intravenous , one local ; 40 patients each ) with a control group ( no tranexamic acid ) . The four intravenous ( 10-mg/kg dose ) regimens included ( 1 ) intraoperative dose ( IO ) given before tourniquet deflation , ( 2 ) additional preoperative dose ( POIO ) , ( 3 ) additional postoperative dose ( IOPO ) , and ( 4 ) all three doses ( POIOPO ) . The fifth regimen was a single local application ( LA ) . Two independent parameters of drain loss and total blood loss , calculated by the hemoglobin balance method , were evaluated statistically . Results Both parameters were reduced in all five regimens as against the control . A significant reduction in drain loss was seen in the POIO , IOPO , and POIOPO groups whereas total blood loss was significantly reduced in the POIO , POIOPO , and LA groups . The POIOPO group had the least drain loss ( 303 mL ) and least total blood loss ( 688 mL ) . The IO group had the greatest drain loss and the IOPO group the greatest total blood loss . Conclusions Single-dose tranexamic acid did not give effective results . The two-dose regimen of POIO was the least amount necessary for effective results . When compared against the control , this regimen produced reduction of drain loss and total blood loss , whereas the IOPO regimen did not . The three-dose regimen of POIOPO produced maximum effective reduction of drain loss and total blood loss . Level of Evidence Level I , therapeutic study . See Guidelines for Authors for a complete description of levels of evidence Abstract There have been several attempts to reduce postoperative blood loss in patients undergoing total arthroplasty . Benoni et al. reported the usefulness of tranexamic acid in total knee arthroplasty ( TKA ) . We investigated its effect in TKA and total hip arthroplasty ( THA ) . Blood loss was significantly reduced in patients given tranexamic acid  in both the TKA and THA groups , and no severe complications , such as venous or pulmonary thrombosis , were noted in any of the patients who received the agent . Administration of tranexamic acid seems to be useful for reducing postoperative blood loss in TKA and THA UNLABELLED Both  acute normovolemic hemodilution ( NVHD ) and tranexamic acid ( TA ) are potentially useful allogeneic blood conservation strategies after total knee replacement . However , the relative efficacy of these blood-sparing techniques is unknown . Therefore , to compare the postoperative allogeneic blood sparing of NVHD and TA after total knee replacement , we investigated 40 patients in a prospect i ve , single-blinded study protocol . In Group TA , 30 min before deflating the limb tourniquet , an IV infusion of TA , 15 mg/kg , was administered over a 30-min period . Thereafter , a constant IV infusion of 10 mg x kg(-1 ) x hr(-1 ) was administered until 12 h after deflation of the limb tourniquet . Before induction of anesthesia , NVHD patients were bled to a target hematocrit of approximately 28 % . Intravascular blood volume was maintained with lactated Ringer 's solution . All autologous blood was transfused at the end of the surgery . Postoperatively , hematocrit was measured daily . In all cases , a hematocrit < 27 % was the postoperative transfusion trigger . Before discharge , deep vein thrombosis was excluded by Echo Doppler . Three months after surgery , the incidence of delayed thromboembolic events was assessed . The two groups were demographically comparable . In Group NVHD , 843 mL+/-289 of autologous blood was removed . Despite autologous blood transfusion , during the early postoperative period and until the third postoperative day , the NVHD group had significantly ( P < 0.01 ) lower mean hematocrits when compared with the TA group . Thereafter , because of a significantly ( P < 0.0008 ) greater allogeneic blood requirement in the NVHD group , no statistically significant difference in mean hematocrit recordings was noted among the groups . Blood accumulation in the surgical drain 12 h postoperatively , was significantly ( P < 0.0008 ) higher in the NVHD group ( 259 mL+/-156 ) when compared with the TA group ( 110 mL+/-62 ) . Significantly ( P < 0.0008 ) more allogeneic blood was transfused in the NVHD group ( 19 U/13 patients ) when compared with the TA group ( 2 U/2 patients ) . No abnormal Echo Doppler studies were reported . During the 3-mo follow-up period , a deep vein thrombosis and pulmonary embolus were documented in one patient in the NVHD group . We conclude that perioperative hemodynamic stability and allogeneic blood sparing is superior after 
    Output:
    
Results Both systemic and topical administrations reduced blood loss after TKA , but transfusion reducing effects varied in studies whether systemic or topical administrations .
The effects of TNA were influenced by doses and timings of administration .
No increased incidences of symptomatic DVT and PE were found for all reported doses , timings , and routes of TNA administration .