Safety of tranexamic acid in surgically treated isolated spine trauma

BACKGROUND Tranexamic acid(TXA),a synthetic antifibrinolytic drug,effectively reduces blood loss by inhibiting plasmin-induced fibrin breakdown.This is the first study in the United Kingdom to investigate the effectiveness of TXA in the surgical management of isolated spine trauma.AIM To assess the safety of TXA in isolated spine trauma.The primary and secondary outcomes are to assess the rate of thromboembolic events and to evaluate blood loss and the incidence of blood transfusion,respectively.METHODS This prospective observational study included patients aged≥17 years with isolated spine trauma requiring surgical intervention over a 6-month period at two major trauma centers in the United Kingdom.RESULTS We identified 67 patients:26(39%)and 41(61%)received and did not receive TXA,respectively.Both groups were matched in terms of age,gender,American Society of Anesthesiologists grade,and mechanism of injury.A higher proportion of patients who received TXA had a subaxial cervical spine injury classification or thoracolumbar injury classification score>4(74%vs 56%).All patients in the TXA group underwent an open approach with a mean of 5 spinal levels involved and an average operative time of 203 min,compared with 24 patients(58%)in the non TXA group who underwent an open approach with an average of 3 spinal levels involved and a mean operative time of 159 min.Among patients who received TXA,blood loss was<150 and 150–300 mL in 8(31%)and 15(58%)patients,respectively.There were no cases of thromboembolic events in any patient who received TXA.CONCLUSION Our study demonstrated that TXA is safe for isolated spine trauma.It is challenging to determine whether TXA effectively reduces blood loss because most surgeons prefer TXA for open or multilevel cases.Further,larger studies are necessary to explore the rate,dosage,and mode of administration of TXA.

Different administration routes of tranexamic acid in the treatment of melasma

Melasma is a prevalent and challenging skin condition that affects the face and causes distress in many patients and physicians.Tranexamic acid(TA)has been found to be effective for treating melasma and can be administered through multiple routes.This review details the mechanisms of action of TA in treatment of melasma and assesses the efficacy and safety associated with different administrations,which can contribute to selecting appropriate melasma treatment plan for different patients.

Efficacy and safety of intravenous tranexamic acid in total shoulder arthroplasty:A meta-analysis

BACKGROUND Total shoulder arthroplasty(TSA)results in a large amount of perioperative blood loss due to severe trauma.AIM To investigate the safety and efficacy of intravenous tranexamic acid(TXA)in TSA.METHODS We searched the PubMed,Cochrane Library,Embase and Web of Science databases for randomized controlled trials(RCTs)on the use of TXA in TSA.And all the results were checked and assessed by Reference Citation Analysis(https://www.referencecitationanalysis.com/).A meta-analysis was performed with Review Manager 5.3 to calculate the odds ratio(OR)or weighted mean difference(WMD)of related outcome indicators.RESULTS A total of 5 RCTs with level 1 evidence were included.There were 369 cases,with 186 in the TXA group and 183 in the placebo group.The meta-analysis showed that TXA can significantly reduce total blood loss during the perioperative period[WMD=-249.56,95%confidence interval(CI):-347.6 to-151.52,P<0.0001],and the incidence of adverse reactions was low(OR=0.36,95%CI:0.16-0.83,P=0.02).Compared with the placebo group,the TXA group had significantly less total haemoglobin loss(WMD=-34.39,95%CI:-50.56 to-18.22),less haemoglobin fluctuation before and after the operation(WMD=-0.6,95%CI:-0.93 to-0.27)and less 24-h drain output(WMD=-136.87,95%CI:-165.87 to-106.49).There were no significant differences in the operation time(P=0.11)or hospital length of stay(P=0.30)between the two groups.CONCLUSION The application of intravenous TXA in the perioperative period of TSA can significantly reduce the total volume of perioperative blood loss and reduce the incidence of adverse reactions,so TXA is worthy of widespread clinical use.

Tranexamic acid may be a useful pharmacotherapy for endoscopically resistant small bowel angiodysplasia

Small bowel angiodysplasia(SBAD)is reported to account for nearly 50%of cases of small bowel bleeding.When SBAD occurs frequently,it is difficult to treat all the angiodysplasias endoscopically,and gastrointestinal bleeding often recurs.Hormone therapy,somatostatin analogs,thalidomide and vascular endothelial growth factor(VEGF)-neutralizing antibodies have been reported to reduce gastrointestinal angiodysplasia(GIAD)bleeding.However,there is no strong evidence to recommend them.Also,there are no guidelines for their use.Hereditary hemorrhagic telangiectasia(HHT)is a hereditary disease caused by abnormalities in VEGF,resulting in multiple GIADs.A treatment guideline has been created for GIAD in HHT,and the use of tranexamic acid,an antifibrinolytic agent,is the first recommendation pharmacotherapy for GIAD with gastrointestinal bleeding that is difficult to treat endoscopically.It has been reported that fibrinolysis is accelerated in GIAD patients who are not HHT,similar to HHT patients.The use of tranexamic acid for gastric antral vascular ectasia in GIAD has been reported to be useful.However,there are very few reports of its use for SBAD.There are concerns with tranexamic acid use regarding the development of thrombosis/embolism,but there are few reports of such side effects.Future clinical trials including tranexamic acid for SBAD are desired.

Application of Tranexamic Acid in Shoulder Arthroscopic Surgery:A Randomised Controlled Trial

Objective To explore the optimal administration route of tranexamic acid(TXA)in shoulder arthroscopic surgery.Methods Patients undergoing arthroscopic rotator cuff repair were randomly divided into four groups:control group(without TXA treatment),intravenous group(TXA was intravenously administered 10 minutes before surgery),irrigation group(TXA was added to the irrigation fluid during subacromial decompression and acromioplasty),and intravenous plus irrigation group(TXA was applied both intravenously and via intra-articular irrigation).The primary outcome was visual clarity assessed with visual analog scale(VAS)score,and the secondary outcomes included irrigation fluid consumption and time to subacromial decompression and acromioplasty procedure.Results There were 134 patients enrolled in the study,including 33 in the control group,35 in the intravenous group,32 in the irrigation group,and 34 in the intravenous plus irrigation group.The median and interquartile range of VAS scores for the intravenous,irrigation,and intravenous plus irrigation groups were 2.70(2.50,2.86)(Z=-3.677,P=0.002),2.67(2.50,2.77)(Z=-3.058,P<0.001),and 2.91(2.75,3.00)(Z=-6.634,P<0.001),respectively,significantly higher than that of the control group[2.44(2.37,2.53)].Moreover,the control group consumed more irrigation fluid than the intravenous group,irrigation group,and intravenous plus irrigation group(all P<0.05).The intravenous plus irrigation group consumed less irrigation fluid than either the intravenous group or the irrigation group(both P<0.001).There was no difference in subacromial decompression and acromioplasty operative time among the four groups.Conclusion TXA applied both topically and systematically can improve intraoperative visual clarity,and the combined application is more effective.

Efficacy,effectiveness,and safety of combination laser and tranexamic acid treatment for melasma:A meta-analysis

Background: Melasma is an acquired pigmentation condition characterized by its refractory nature and a high risk of recurrence. Treatment of melasma is challenging owing to its unclear etiology, stubborn resistance to treatment, and frequent relapses. Therefore, this study aimed to compare the efficacy, effectiveness, and safety of monotherapy and combination therapy(combination of laser and tranexamic acid(TXA)) for the treatment of melasma using a network meta-analysis.Method: The PRISMA guidelines were used in this meta-analysis, with a literature search conducted in reputable sources, such as Cochrane, Science Direct, Pub Med, and Google Scholar.Results: From the initial search, 1 504 relevant studies were identified. After careful analysis, three studies were included in the meta-analysis. The results showed no significant differences in the Melasma Area and Severity Index(MASI) score between monotherapy(control group) and a combination therapy of laser and TXA. The mean difference in MASI score was 1.87(95% confidence interval(CI),-0.78–4.52;P=0.17), indicating no significant difference between the two treatment approaches. Side effects were more common in the combination treatment group than in the control group. The odds ratio for experiencing side effects was 8.85(95% CI, 1.57–50.01;P=0.01).Conclusion: Both the monotherapy and combination therapy groups showed therapeutic improvement;however,the combination therapy group showed a higher incidence of side effects.

Effect of tranexamic acid on the treatment of patients with upper gastrointestinal bleeding: A double-blinded randomized controlled clinical trial

Objective:To determine the efficacy of tranexamic acid(TXA)in the management of acute upper gastrointestinal(GI)bleeding.Methods:A total of 70 patients with acute upper GI bleeding were included in this double-blinded randomized controlled clinical trial from September 2018 to December 2018.Patients were divided into the control group(received fluid therapy and intravenous infusion of pantoprazole,35 cases)and the TXA group(received intravenous TXA besides the treatment of control group,35 cases).Rebleeding,admission duration,and need for blood transfusion were compared between the two groups.Results:Fifteen patients(42.9%)in the TXA group and 10 patients(28.6%)in the control group stayed in hospital for more than 3 days during their admission(P=0.21).Rebleeding occurred in 8 patients(22.9%)and 5 patients(14.3%)of the TXA group and the control group,respectively(P=0.35).More patients in the TXA group(21 cases,60%)received blood transfusion than the control group(8 cases,22.9%)(P=0.02).Conclusions:TXA did not improve the outcome of patients with acute upper GI bleeding.

Efficacy of topical vs intravenous tranexamic acid in reducing blood loss and promoting wound healing in bone surgery:A systematic review and meta-analysis

BACKGROUND Tranexamic acid(TXA)has been used as an anti-fibrinolytic drug for over half a century and has received much attention in recent decades.AIM To evaluate the efficacy of topical vs intravenous TXA in reducing blood loss and promoting wound healing in bone surgery.METHODS From the electronic resources,PubMed,Cochrane Library,Embase,ISI,and Scopus were used to perform a literature search over the last 10 years between 2010 and 2020.EndNote™X8 was used for managing the electronic resource.Searches were performed with mesh terms.The data were retracted blindly by two independent reviewers.Random effects were used to deal with potential heterogeneity and I2 showed heterogeneity.Chi-square(I2)tests were used to quantify the extent of heterogeneity(P<0.01 was considered statistically significant).The efficacy of topical TXA in reducing blood loss and promoting wound healing in bone surgery was compared with intravenous TXA and placebo.RESULTS According to the research design,1360 potentially important research abstracts and titles were discovered in our electronic searches,and 18 papers remained in agreement with our inclusion criteria.It was found that TXA reduced 277.51 mL of blood loss compared to placebo,and there was no significant difference between topical TXA and IV TXA in reducing blood loss in bone surgery.Our analyses also showed that TXA significantly reduced blood transfusion compared to placebo and there was no significant difference between topical TXA and IV TXA.CONCLUSION The use of both topical and intravenous TXA are equally effective in reducing blood loss in bone surgery,which might be beneficial for wound healing after surgery.

Tranexamic acid for major trauma patients in Ireland

BACKGROUND:The Clinical Randomisation of an Anti-fibrinolytic in Significant Hemorrhage-2(CRASH-2)is the largest randomized control trial(RCT)examining circulatory resuscitation for trauma patients to date and concluded a statistically significant reduction in all-cause mortality in patients administered tranexamic acid(TXA)within 3 hours of injury.Since the publication of CRASH-2,significant geographical variance in the use of TXA for trauma patients exists.This study aims to assess TXA use for major trauma patients with hemorrhagic shock in Ireland after the publication of CRASH-2.METHODS:A retrospective cohort study was conducted using data derived from the Trauma Audit and Research Network(TARN).All injured patients in Ireland between January 2013 and December 2018 who had evidence of hemorrhagic shock on presentation(as defined by systolic blood pressure[SBP]<100 mmHg[1 mmHg=0.133 kPa]and administration of blood products)were eligible for inclusion.Death at hospital discharge was the primary outcome.RESULTS:During the study period,a total of 234 patients met the inclusion criteria.Among injured patients presenting with hemorrhagic shock,133(56.8%;95%confidence interval[CI]50.2%–63.3%)received TXA.Of patients that received TXA,a higher proportion of patients presented with shock index>1(70.68%vs.57.43%)and higher Injury Severity Score(ISS>25;49.62%vs.23.76%).Administration of TXA was not associated with mortality at hospital discharge(odds ratio[OR]0.86,95%CI 0.31–2.38).CONCLUSIONS:Among injured Irish patients presenting with hemorrhagic shock,TXA was administered to 56.8%of patients.Patients administered with TXA were on average more severely injured.However,a mortality benefit could not be demonstrated.

Topical use of tranexamic acid:Are there concerns for cytotoxicity?

Tranexamic acid(TXA)has revolutionized modern blood management in orthopaedic surgery,especially in total joint arthroplasty,by significantly reducing blood loss and transfusion rates.It is an antifibrinolytic agent and a synthetic derivative of the amino acid lysine,which can inhibit the activation of plasminogen and the fibrin breakdown process.The administration of TXA can be intravenous(IV),topical,and oral.In patients where the IV administration is contraindicated,topical use is preferred.Topical administration of the drug theoretically increases concentration at the operative site with reduced systemic exposure,reduces cost,and gives the surgeon the control of the administration.According to recent studies,topical administration of TXA is not inferior compared to IV administration,in terms of safety and efficacy.However,there are concerns regarding the possible toxicity in the cartilage tissue with the topical use of TXA mainly in hemiarthroplasty operations of the hip,unilateral knee arthroplasties,total knee arthroplasties where the patella is not resurfaced,and other intraarticular procedures,like anterior cruciate ligament reconstruction.The purpose of the present review is to present all the recent updates on the use of TXA focusing on the toxicity on chondrocytes and the articular cartilage that may or may not be provoked by the topical use of TXA.

The emerging role of tranexamic acid and its principal target,plasminogen,in skeletal health

The worldwide burden of skeletal diseases such as osteoporosis,degenerative joint disease and impaired fracture healing is steadily increasing.Tranexamic acid(TXA),a plasminogen inhibitor and anti-fibrinolytic agent,is used to reduce bleeding with high effectiveness and safety in major surgical procedures.With its widespread clinical application,the effects of TXA beyond anti-fibrinolysis have been noticed and prompted renewed interest in its use.Some clinical trials have characterized the effects of TXA on reducing postoperative infection rates and regulating immune responses in patients undergoing surgery.Also,several animal studies suggest potential therapeutic effects of TXA on skeletal diseases such as osteoporosis and fracture healing.Although a direct effect of TXA on the differentiation and function of bone cells in vitro was shown,few mechanisms of action have been reported.Here,we summarize recent findings of the effects of TXA on skeletal diseases and discuss the underlying plasminogen-dependent and-independent mechanisms related to bone metabolism and the immune response.We furthermore discuss potential novel indications for TXA application as a treatment strategy for skeletal diseases.

Clinical efficacy of the topical application of tranexamic acid in tendon release in the hand:A randomized controlled trial

Purpose:To study the clinical effectiveness of the topical application of tranexamic acid in hand tendon release.Methods:This was a randomized controlled trial conducted after receiving approval from the local ethics committee according to guidelines from the Helsinki Declaration.Eighty patients who underwent hand tendon release operation in our hospital from January 2021 to December 2022 were included and randomly divided into 2 groups.Patients in the tranexamic acid group(40 cases)received intraoperative topical application of 2 g of tranexamic acid after tendon release,while patients in the conventional group(40 cases)did not receive topical application of tranexamic acid during operation.The operation time,perioperative hemoglobin changes,total blood loss,incidence of early postoperative complications,and total active movement(TAM)before surgery and 6 months after surgery were compared between the 2 groups.The continuous variable which follows normal distribution expressed by mean±SD and used t-test to compare between groups.Meanwhile,categorical variables were used by Chi-square test,and a p<0.05 indicated that the differences were statistically significant.Results:Both groups were followed up for 7-18 months,with a mean of 10.3 months.Postoperative decrease in hemoglobin was significantly less in the tranexamic acid group than in the conventional group(t=7.611,p<0.001).The total blood loss in the tranexamic acid group(74.33±20.50)mL was less than that in the conventional group(83.05±17.73)mL,and the difference was statistically significant(p<0.05).Both groups showed improvement in thumb/finger flexion and extension range of motion after surgery,and the TAM improved compared with those before surgery,and the difference was statistically significant(p<0.001).The TAM improved more significantly in the tranexamic acid group(87.68°±10.44°)than in the conventional group(80.47°±10.93°)at 6 months after surgery,with a statistically significant difference(t=3.013,p<0.001).There was no significant difference in operation time and incidence of early postoperative complications between the 2 groups(p=0.798,0.499,respectively).Conclusion:The topical application of tranexamic acid during hand tendon release can significantly reduce postoperative bleeding and improve surgical efficacy,which is worth promoting.

Glanzmann Thrombasthenia: Managing Gingival Bleeding Triggered by Tooth Eruption—A Rare Case Report

Glanzmann thrombasthenia (GT) is a rare and often underdiagnosed congenital bleeding disorder caused by mutations in the genes encoding glycoproteins GPIIb or GPIIIa, resulting in platelet dysfunction. Inherited in an autosomal recessive manner, GT is characterized by the inability of platelets to aggregate. Clinically, it presents with mucocutaneous bleeding, such as easy and extensive bruising, severe epistaxis, menorrhagia, gingival bleeding, postpartum hemorrhage, and unexpected bleeding following procedures, despite a normal platelet count. We present a case involving a 6-year-old male patient who experienced spontaneous gingival bleeding for the past 4 weeks due to the eruption of his first permanent molars. The bleeding was particularly severe at night, disrupting the child’s sleep. The patient had been diagnosed with GT at the age of 16 months. Dental management was pursued, and the use of tranexamic acid mouthwash, combined with meticulous oral hygiene, resulted in an excellent response.

UV Assisted Preliminary DNA Binding Studies and Single-crystal X-ray Structure of 4-{(4-Nitrophenyl-sulfonamido)methyl}cyclohexanecarboxylic Acid

A new sulfonamide, 4-{（4-nitrophenylsulfonamido）methyl}cyclohexanecarboxylic acid（C14H18N2O6S）, has been synthesized by the reaction of tranexamic acid and 4-nitrobenzenesulfonyl chloride in basic medium at room temperature. The molecular structure was determined by FT-IR, NMR, elemental analysis and single-crystal X-ray technique. X-ray diffraction shows that the compound crystallizes in the monoclinic system, space group P21/c with a = 13.5980（7）, b = 4.9877（2）, c = 23.3878（13） A, β = 93.254（3）°, Z = 4, V = 1583.67（14） A3, μ = 0.237 mm-1, F（000） = 720, R = 0.0471 and w R = 0.1182. The molecules are related by inversion and paired into dimers via C–H…O interactions. The dimmers are interlinked due to strong N–H…O bonds, where O-atoms are of sulfonyl groups. The molecules are stabilized in the form of infinite two-dimensional network with base vectors [0 1 0] and [0 0 –1] in the plane（1 0 2）. The existence of good intermolecular interactions suggests the biological importance of the synthesized molecule. The compound was screened for its interaction with FS-DNA using UV-visible spectroscopy. UV-visible spectroscopic results depict that the compound interacts with DNA by mixed binding mode intercalation along with hydrogen bonding. Negative values of ΔG（–23.34, –17.79 k J·mol-1） indicate spontaneity of the compound-DNA adduct formation.

4-((4-Chlorophenylsulfonamido)methyl)cyclohexanecarboxylic Acid： Synthesis, Crystal Structure and Biological Activities

In this study, a novel 4-（（4-chlorophenylsulfonamido）methyl）cyclohexanecarboxylic acid（C（14）H（18）ClNO4S） was synthesized by the reaction of tranexamic acid and 4-chlororbenzene sulfonyl chloride in basic medium at room temperature. The molecular structure was determined by FT-IR, NMR, elemental analysis and single-crystal X-ray analysis. The compound crystallizes in the monoclinic system, space group P21/c with a = 12.3120（11）, b = 16.5987（19）, c = 7.6873（7） ？, β = 90.495（6）o, Z = 4 and V = 1570.9（3） ？~3, crystal size（mm） = 0.38 × 0.16 × 0.14 and Rint = 0.045. In this compound, the carboxylic acid A（O（1）/C（1）/C（2）） and the sulfonyl B（O（3）/S（1）/O（4）） moieties are of course planar. The molecules are dimerized due to the O–H…O type of H-bonding with the R22（8） ring motifs. The dimmers are interlinked through C–H…O and N–H…O types of H-bonding. The synthesized compound was screened against four bacterial and two fungal strains and inactive against all strains. Antioxidant activity was checked against DPPH. Enzyme inhibition activity was carried out using three different enzymes and the title compound was more potent α-chymotrypsin inhibitor.

Recurrence of unilateral angioedema of the tongue:A case report

BACKGROUND Angioedema is a disorder characterized by edema of the face,lips,tongue,and extremities due to increased vascular permeability.Angioedema of the tongue usually occurs bilaterally,and the incidence of unilateral angioedema of the tongue is rare.This study reports a rare case of unilateral angioedema of the tongue with no identifiable cause and repeated recurrence even after discontinuation of an angiotensin-converting enzyme inhibitor.CASE SUMMARY The patient was a 65-year-old woman with pre-existing hypertension and hyperlipidemia and had been receiving 20 mg/d of lisinopril.She was diagnosed with angioedema due to unilateral swelling of the tongue.No airway obstruction was observed,and the symptoms improved following the administration of 0.3 mg of epinephrine intramuscularly and 125 mg of methylprednisolone intravenously.Although lisinopril was discontinued,unilateral angioedema of the tongue continued to recur every 2-5 mo,with the symptoms improving following the administration of prednisolone and an antihistamine.Daily oral administration of 500 mg of tranexamic acid after dinner prevented the recurrence of angioedema.CONCLUSION Careful monitoring and identification of the underlying mechanism play a crucial role in the treatment of angioedema.

Successful reconstruction of an ankle defect with free tissue transfer in a hemophilia A patient with repetitive hemoarthrosis:A case report

BACKGROUND Hemophilia, an uncommon yet consequential hereditary bleeding disorder, manifests as two clinically indistinguishable forms that hinder the normal functioning of the coagulation cascade. This impairment renders individuals more susceptible to excessive bleeding during significant surgical interventions. Moreover, individuals with severe hemophilia frequently encounter recurring hemarthrosis, resulting in progressive joint destruction and, subsequently, the need for hip and knee replacement surgeries.CASE SUMMARY The patient was a 53-year-old man with hemophilia A as the underlying disease and had self-injected factor Ⅷ twice weekly for several decades. He had undergone ankle fusion surgery for recurrent hemarthrosis at the Department of Orthopedic Surgery 1 mo prior and was referred to our department because of skin necrosis after a hematoma at the surgical site. An anterolateral thigh perforator free flap was created after three cycles of factor Ⅷ administration in addition to the concomitant administration of tranexamic acid(TXA)(Transamin 250 mg cap, 1 cap tid, q8h). After the operation, from postoperative days(PODs) 1-5, the factor Ⅷ dose and interval were maintained, and q12h administration was tapered to q24h administration after POD 6. Because the patient’s flap was stable 12 d after the operation, factor Ⅷ administration was tapered to twice a week. At 6 mo follow-up, the patient recovered well without any complications.CONCLUSION To the best of our knowledge, there are very few reports of successful free flaps in patients with hemophilia, and none have been reported in patients with hemophilia A. Moreover, there are several reports on the efficacy of TXA in free flaps in general patients;however, there are no case reports of combining factor Ⅷ and TXA in patients with hemophilia. Therefore, we report this case to contribute to future academic research.

Cost Effective Trend in Epistaxis Management

Background: Epistaxis affects much of the population and is a common medical complaint seen across a variety of medical settings. Current standard of care treatment includes a range of options from topical therapy to invasive intranasal device insertion in the absence of on-demand specialist involvement. Aim: The aim of this article is to not only highlight superior outcomes in patients with acute nontraumatic epistaxis that are treated with noninvasive nebulized tranexamic acid instead of more invasive options, but also monetary benefit to the community through reduced costs. Case Presentation: this case report highlights a successful epistaxis resolution with use of tranexamic acid in a 64-year-old female after she was subjected to intranasal device insertion that did not resolve bleeding. Conclusion: Nebulized tranexamic acid is a cost-effective medication that not only reduces rates of recurrence, but it also increases patient satisfaction while minimizing overall healthcare costs, and therefore should be the first choice therapy in uncomplicated epistaxis management.

Use of intravenous tranexamic acid in total knee arthroplasty： a meta-analysis of randomized controlled trials

Objective： The effect of tranexamic acid （TA） on patients receiving total knee arthroplasty （TKA） has been reported in many small clinical trials. But single trials are not sufficient enough to clarify the effectiveness and safety of TA. So, we carried out a meta-analysis of randomized controlled trials to investigate the efficacy and safety of the intravenous use of TA in TKA. Methods： Literatures were retrieved in Cochrane Library, OVID, PubMed, EMBASE, CNKI and Wanfang Data. All the related literatures were checked by two independent investigators and only the high quality randomized con- trolled trials were enrolled. Relevant data were analyzed using RevMan 5.1 to compare the difference of blood loss, transfusion and complications between TA group and con- trol group. Results： There were 353 related literatures and only 22 randomized controlled trials met the inclusion criteria. The use of TA in TKA significantly reduced total blood loss by a mean of 435.41 ml （95% C1300.62-570.21, P〈0.01）, post- operative blood loss by a mean of 406.69 ml （95% C1333.16- 480.22, P〈0.01）. TA also significantly lowered the transfu- sion rate （risk difference 0.30, 95% CI0.21-0.39, P〈0.01） and transfusion volume （mean difference 0.95 unit, 95% CI0.53- 1.37, P〈0.01）. The risks between TA group and control group in developing deep vein thrombosis and pulmonary embo- lism were not statistically significant. Conclusion： TA is beneficial for patients undergoing TKA, which can significantly reduce total blood loss, post- operative blood loss, transfusion rate, and transfusion volume. Meanwhile TA is recommended to reduce deep vein thrombosis and pulmonary embolism following TKA.

Additional Dose of Intravenous Tranexamic Acid after Primary Total Knee Arthroplasty Further Reduces Hidden Blood Loss

Background： Total knee arthroplasty （TKA） is the most frequently performed procedure in treating advanced knee osteoarthritis. Excessive perioperative blood loss can sometimes lead to postoperative anemia. Tranexamic acid （TXA） is a potent fibrinolysis inhibitor which has been extensively used at the surgical incision and closure to lower overall blood loss in adult reconstruction surgery. Our previous study suggested that about two-thirds of the total blood loss （TBL） came from hidden blood loss （HBL） on postoperative days 1 and 2. The role of reducing HBL with TXA administration in postoperative TKA patients is unknown. The current study was designed to evaluate the efficiency and safety of supplemental intravenous （IV） TXA in further redticing HBL after primary TKA. Methods： A prospective pilot study was conducted at a single institution on 43 consecutive patients who underwent unilateral TKA from September 2014 to February 2015. All patients were given 1 g of IV TXA 10-15 rain before operation and another 1 g of IV TXA at the time of wound closure on the day of surgery. On postoperative days 1 and 2, the supplemental group （n = 21） was given additional 1 g of TXA intravenously twice a day, whereas the control group （n = 22） received an equal volume of saline. Drain output, hemoglobin （Hb）, and hematocrit （HCT） were recorded preoperatively and 5 consecutive days postoperatively in both groups. HBL was calculated with the Gross formula. Pre- and post-operative lower extremity Doppler venous ultrasound was performed in all patients to detect deep vein thrombosis （DVT）. The indexes were compared using the Mann-Whitney test, whereas the results of Hb and HCT were analyzed by repeated-measures analysis of variance. The difference was considered statistically significant ifP 〈 0.05. Results： The demographics and surgical characteristics of the two groups were comparable. Supplemental group had higher Hb level on postoperative days 1-5 compared to the control; however, the difference was not significant （F = 2.732, P = 0.106）. The HCT of the supplemental group was significantly higher than that of the control group on postoperative day 5 （F= 5.254, P = 0.027）. No significant difference was found in drainage volume and TBL, but the HBL was reduced in the supplemental group （supplemental 133.1 [71.8,287.3] ml and control 296.0 [ 185.3, 421.4] ml, Z = 2.478, P = 0.013. median [interquartile range]）. There was one DVT in the control group and none in the supplemental group. All patients were tbllowed at 1 year after surgery, and no further complications were reported. Conclusion： Based on the current study, additional doses of IV TXA could potentially further reduce HBL alter primary TKA without increasing the risk of venous thromboembolism.