Unravelling the Antifibrinolytic Mechanism of Action of the 1,2,3-Triazole Derivatives

A new family of antifibrinolytic drugs has been recently discovered, combining a triazole moiety, an oxadiazolone, and a terminal amine. Two of the molecules of this family have shown activity that is greater than or similar to that of tranexamic acid (TXA), the current antifibrinolytic gold standard, which has been associated with several side effects and whose use is limited in patients with renal impairment. The aim of this work was to thoroughly examine the mechanism of action of the two ideal candidates of the 1,2,3-triazole family and compare them with TXA, to identify an antifibrinolytic alternative active at lower dosages. Specifically, the antifibrinolytic activity of the two compounds (1 and 5) and TXA was assessed in fibrinolytic isolated systems and in whole blood. Results revealed that despite having an activity pathway comparable to that of TXA, both compounds showed greater activity in blood. These differences could be attributed to a more stable ligand-target binding to the pocket of plasminogen for compounds 1 and 5, as suggested by molecular dynamic simulations. This work presents further evidence of the antifibrinolytic activity of the two best candidates of the 1,2,3-triazole family and paves the way for incorporating these molecules as new antifibrinolytic therapies.

Are Data Driving Our Ambulances? Liberal Use of Tranexamic Acid in the Prehospital Setting

BACKGROUND

Current data on tranexamic acid (TXA) supports early administration for severe hemorrhagic shock. Administration by EMS has been facilitated by developing protocols and standing orders informed by these data. In this study, patterns of TXA use by EMS agencies serving a large level 1 trauma center were examined. We hypothesized that current widespread TXA use often includes administration outside of data-driven indications.

METHODS

The trauma registry at a level 1 trauma center was queried for patients who received TXA. To determine the practice patterns and appropriateness of administration of TXA, patients' physiologic state in the prehospital environment based on EMS records, physiologic state on arrival to hospital, and interventions performed in both settings were examined. Over 20 separately managed EMS systems that administer TXA transport patients to this trauma center, allowing for a broad survey of practices.

RESULTS

From 2016 to 2021 1089 patients received TXA, 406 (37.3%) having treatment initiated by EMS services. Of these, the average prehospital systolic blood pressure (SBP) was 108.2 mmHg and initial ED SBP was 107.8 mmHg. Only 58.4% of these patients received blood transfusion after arrival to this trauma center. Compliance with standard indications was low with only 14.6% of administrations meeting any data-driven SBP indication. Similar levels of compliance were seen across high volume EMS services.

DISCUSSION

Tranexamic acid use has become common in trauma and has been adopted by many EMS systems. These results indicate TXA in the prehospital setting is over-used as administration is not being limited to indications that have shown benefit in prior data.

In Vivo Effect of Single Intra-Articular Injection of Tranexamic Acid on Articular Cartilage and Meniscus: Study in a Rat Model

BACKGROUND

Tranexamic acid (TXA) has been increasingly used in arthroscopic surgery to prevent hemarthrosis. Despite its effectiveness, safety concerns have been raised regarding its potential cytotoxicity to articular cartilage and meniscus following intra-articular injection.

METHODS

To evaluate the impact of TXA on cartilage and meniscus, a rat model of knee instability was utilized wherein anterior cruciate ligament (ACL) transection surgery was followed by a single intra-articular injection of TXA at varying concentrations (0, 20, 50, 100, and 150 mg/mL) in saline solution. Cell viability assessment of the cartilage and meniscus (n = 6 per group) was conducted at 24 hours, and gross observation and histological analysis of the medial tibial plateau and medial meniscus were conducted at 2, 4, and 8 weeks (n = 6 per group and time point).

RESULTS

The chondrocyte viability was significantly decreased in the 50, 100, and 150 mg/mL TXA groups compared with the specimens injected with saline solution only (saline group) (p = 0.001, p < 0.001, p < 0.001, respectively), as was meniscal cell viability (p = 0.042, p < 0.001, p < 0.001, respectively). At week 8, the saline and 20 and 50 mg/mL groups showed relatively normal appearances, whereas the 100 and 150 mg/mL groups exhibited increased and varying severity of cartilage and meniscal degeneration. In the 150 mg/mL group, the mean Osteoarthritis Research Society International score was significantly higher than that in the saline and 20 mg/mL groups (p = 0.010 and p = 0.007). Additionally, the mean meniscus score in the 150 mg/mL group was significantly higher than that in the saline, 20 mg/mL, and 50 mg/mL groups (p = 0.020, p = 0.021, p = 0.031, respectively).

CONCLUSIONS

Our findings indicate that concentrations of TXA at or above 100 mg/mL can lead to decreased cell viability in both cartilage and meniscus, resulting in significant cartilage degeneration in rats with ACL transection. Furthermore, the use of 150 mg/mL of TXA led to significant meniscal degeneration.

CLINICAL RELEVANCE

It is prudent to avoid using concentrations of TXA at or above 100 mg/mL for intra-articular injection, as such concentrations may result in adverse effects on the cartilage and meniscus.

The Effect of Tranexamic Acid With or Without Tourniquet on Blood Loss in Total Knee Arthroplasty at a Community Hospital

Tourniquets have long been used in total knee arthroplasty due to the theoretical improvement of bleeding control, integration of cement-bone interface, visibility, and efficiency of the overall surgery. However, this has become increasingly disputed. Comparative studies in total knee arthroplasty employing chemical prophylaxis, i.e., tranexamic acid, have been conducted. This retrospective cohort study evaluated the effect of tranexamic with or without a tourniquet on mean blood loss, hemoglobin, and length of stay in total knee arthroplasty patients. A total of 153 patients' records met the inclusion criteria, 95 patients (62%) were in the tranexamic acid-only group while 58 patients (38%) were in the tranexamic acid plus tourniquet group. Based on mean blood loss in mL (827.5 without vs. 810.1 with the tourniquet, p=0.805), hemoglobin counts in g/dL (12.6 without vs. 12.5 with the tourniquet, p=0.598), and length of stay in days (1.0 days without vs. 1.1 with the tourniquet, p=0.204), there was no statistical difference between the tranexamic alone vs. tranexamic plus tourniquet groups. There were no statistical differences in the mean BMI between groups (32.3 without vs. 32.4 with tourniquets, p=0.901). The patient population had more women (64.1%) than men (35.9%) (p=0.001), but no significant difference in gender based on tourniquet use (p=0.521). The tourniquet group averaged three years younger than the tranexamic alone group (age mean 68.2 without vs 65.3 with tranexamic, p=0.029). This study found no identifiable difference in the three observed variables, indicating that tourniquet provides limited to no additional benefit in reducing blood loss over tranexamic alone in total knee arthroplasty, while tranexamic alone has no deleterious decrease in mean hemoglobin or increase in length of stay.

Efficacy of Tranexamic Acid in Reducing Myomectomy-Associated Blood Loss among Patients with Uterine Myomas at Federal Teaching Hospital Abakaliki: A Randomized Control Trial

Background

Myomectomy can be associated with life-threatening conditions such as bleeding. Excessive bleeding usually necessitates blood transfusion. Interventions to reduce bleeding during myomectomy will help reduce the need for blood transfusion with its associated complications. Tranexamic acid has been used to reduce bleeding in other surgical procedures, and its usage during myomectomy merits evaluation.

Objective

To assess the efficacy of tranexamic acid in reducing myomectomy-associated blood loss.

Materials and Methods

This is a prospective double-blinded randomized trial conducted on women who had abdominal myomectomy. Patients were randomized into two groups. The study group received perioperative intravenous tranexamic acid (TXA) while the control group received a placebo. Intraoperative blood loss was calculated by measuring the volume in the suction apparatus and weighing the surgical swabs. In addition, blood collected postoperatively from the wound drains and drapes were measured. Haemoglobin concentrations were determined preoperatively and on second postoperative day for all cases. Any adverse effect was noted in both groups. The data was processed using Epi Info software (7.2.1, CDC, Atlanta, Georgia). The relationships between categorical data were analyzed using X2 and Student's t-test to determine relationships between continuous variables, with a P value of 0.05 considered statistically significant, and correlation coefficients were calculated using Pearson's formula, and probability of 0.05 was set for statistical significance.

Results

Symptomatic uterine myomas constituted 17.3% of all gynaecological admissions and 21.3% of gynaecological operations at Federal Teaching Hospital Abakaliki. The mean intraoperative blood loss among patients that had perioperative tranexamic acid infusion was 413.6 ± 165.6 ml, while that of patients with placebo infusion was 713.6 ± 236.3 ml. Perioperative tranexamic acid infusion therefore reduced mean intraoperative blood loss by 300 ml, and this was statistically significant (SMD = -0.212, 95% CI: -403.932 to -196.067, P < 0.0001). Perioperative tranexamic acid reduced mean total blood loss by a value of 532.3 ml, and this is statistically significant (SMD = 30.622, 95% CI: 393.308 to 670.624, P < 0.0001). Tranexamic acid also improved postoperative haemoglobin concentration by 1.8 g/dl compared with placebo, and this is statistically significant (SMD = -0.122, 95% CI: 1.182 to 2.473, P < 0.0001). Tranexamic acid infusion decreased hospital stay by about 2 days, and this difference was statistically significant (SMD = -3.929, 95% CI: -3.018 to -0.983, P = 0.0003). There was no adverse drug reaction in the course of the study.

Conclusion

The use of tranexamic acid during myomectomy reduced intraoperative and postoperative blood loss. It is also associated with decreased hospital stay. This trial is registered with NCT04560465.

Is High-Dose Tranexamic Safe in Spine Surgery? A Systematic Review and Meta-Analysis

STUDY DESIGN

Literature review and meta-analysis.

OBJECTIVES

Single-center series may be underpowered to detect whether high-dose (HD) tranexamic acid (TXA) confers a higher risk of complications. We sought to determine the safety and efficacy of HD TXA as compared to low-dose (LD) or placebo.

METHODS

A systematic literature review was performed to find studies where spine surgery patients were given HD TXA (loading dose ≥30 mg/kg). Complication rates were pooled, and meta-analyses performed on outcomes of interest. Articles were evaluated for risk of bias and a strength of evidence assessment was given for each conclusion.

RESULTS

Twenty three studies (n = 2331) were included. The pooled medical complication rate was 3.2% in pediatric patients, 8.2% in adults. Using lower dose TXA or placebo as the reference, meta-analysis showed no difference in medical complications (n = 1,723, OR 1.22 [95% CI, .78 to 1.22]; P = .388; I2 = 0%) or thrombotic events (n = 1158 patients, OR 1.27 [95% CI, .71 to 2.63]; P = .528; I2 = 0%). Compared to LD, HD TXA was associated with less intraoperative blood loss (823 patients, WMD = -285 [95% CI, -564 to -5.90]; P = .0454; I2 = 86%), fewer perioperative transfusions (n = 505, OR .28 [95% CI, .082 to .96]; P = .043; I2 = 76%) and lower perioperative transfusion volumes (n = 434, WMD -227.7 mL [95% CI, -377.3 to -78.02]; P = .0029; I2 = 0%).

CONCLUSION

Compared to LD TXA or placebo, there is moderate evidence that HD is not associated with an increased risk of medical complications. Compared to LD, there is moderate evidence that HD reduces transfusion requirements. High-Dose TXA can be safely utilized in healthy patients undergoing major spine surgery.

Real-world decision-making in the management of patients presenting with major bleeding on rivaroxaban: the Auckland regional experience

BACKGROUND

Rivaroxaban is used increasingly as an oral anticoagulant; however, a specific reversal agent is not currently available in the Australasian setting. There is also variation across international consensus guidelines regarding advice on the management of bleeding.

AIMS

To review the real-world management of rivaroxaban-associated major bleeding across the public hospitals of New Zealand's largest city.

METHODS

A retrospective cohort analysis was performed of patients prescribed rivaroxaban who presented to four metropolitan hospital Emergency Departments between 1 August 2018 and 31 May 2021 with major bleeding as defined by the International Society on Thrombosis and Haemostasis.

RESULTS

One hundred and twelve patients were identified, accounting for 115 major bleeding presentations. Upper gastrointestinal (34%) and intracranial (31%) bleeding sites were most common. Procedural intervention was required in 44% of patients. Haemostatic management involved tranexamic acid (TXA) in 26%, prothrombin complex concentrate (PCC) in 55% (dose range 1000-6000 IU or 10-65 IU/kg), vitamin K in 16% and fresh frozen plasma in 1%. Rivaroxaban was discontinued permanently following 56 (49%) events, switched to another anticoagulant in 24 (21%) and withheld in 30 (26%) from 2 days to 3 months (median 8.5 days). All-cause mortality at 90 days after bleeding was 17% (19 patients), and the incidence of combined venous and arterial thrombotic events was 10%.

CONCLUSIONS

There is considerable heterogeneity in the acute clinical management of patients presenting with rivaroxaban-related major bleeding. The use of PCC and dosage administered is inconsistent. TXA was utilised in only approximately one-quarter of all cases. Evidence-based guidance for treating rivaroxaban-related bleeding would improve the management of these patients and potentially improve clinical outcomes.

Engineered Molecular Therapeutics Targeting Fibrin and the Coagulation System: a Biophysical Perspective

The coagulation cascade represents a sophisticated and highly choreographed series of molecular events taking place in the blood with important clinical implications. One key player in coagulation is fibrinogen, a highly abundant soluble blood protein that is processed by thrombin proteases at wound sites, triggering self-assembly of an insoluble protein hydrogel known as a fibrin clot. By forming the key protein component of blood clots, fibrin acts as a structural biomaterial with biophysical properties well suited to its role inhibiting fluid flow and maintaining hemostasis. Based on its clinical importance, fibrin is being investigated as a potentially valuable molecular target in the development of coagulation therapies. In this topical review, we summarize our current understanding of the coagulation cascade from a molecular, structural and biophysical perspective. We highlight single-molecule studies on proteins involved in blood coagulation and report on the current state of the art in directed evolution and molecular engineering of fibrin-targeted proteins and polymers for modulating coagulation. This biophysical overview will help acclimatize newcomers to the field and catalyze interdisciplinary work in biomolecular engineering toward the development of new therapies targeting fibrin and the coagulation system.

The Effect of Systemic Tranexamic Acid on Hypercoagulable Complications and Perioperative Outcomes Following Three-Column Osteotomy for Adult Spinal Deformity

STUDY DESIGN

Retrospective cohort study.

OBJECTIVE

Thoracolumbar 3-column osteotomy (3CO) is a powerful technique for correction of rigid adult spinal deformity (ASD). However, it can be associated with high-volume blood loss. This study seeks to investigate the efficacy and safety of tranexamic acid (TXA) in 3CO ASD patients.

METHODS

ASD patients who underwent 3CO from 2006 to 2019 were retrospectively reviewed. Outcomes were compared between TXA and non-TXA patients, and TXA doses.

RESULTS

A total of 365 ASD patients were included: 181 TXA and 184 non-TXA. The mean age was 64.6 years and 60.5% were female. Operative time was shorter in the TXA group (295.6 vs 320.2 minutes, P < .001). However, TXA was not associated with shorter operative time (β = -6.5 minutes, 95% CI -29.0 to 15.9, P = .567) after accounting for surgeon experience. There was no difference in blood loss (2020.2 vs 1914.1 mL, P = .437) between groups. Overall complications (37.0% vs 33.2%, P = .439), including hypercoagulable (2.2% vs 3.8%, P = .373) and cardiac (13.3% vs 7.1%, P = .050) complications were similar between groups. TXA was not independently associated with blood loss or TXA-related complications. Both groups had comparable intensive care unit (2.5 vs 2.0 days, P = .060) and hospital (8.9 vs 8.2 days, P = .190) stays. There were no differences in outcomes between TXA dosing subgroups.

CONCLUSIONS

Systemic TXA use during 3CO for ASD surgery was not associated with decreased blood loss. TXA patients had shorter operative times, but this was driven mainly by surgeon experience on multivariate analysis. Routine use of TXA is safe and does not increase the incidence of hypercoagulable complications even at high doses.

Population pharmacokinetics and pharmacodynamics of Tranexamic acid in women undergoing caesarean delivery

AIMS

The population pharmacokinetics (PK) and pharmacodynamics (PD) of tranexamic acid (TXA) have not been studied to prevent postpartum haemorrhage (PPH) in pregnant women. It is unclear which TXA dose assures sufficient PPH prevention. This study investigated population PK/PD of TXA in pregnant women who underwent caesarean delivery to determine the optimal prophylactic doses of TXA for future studies.

METHODS

We analysed concentration (PK) and maximum lysis (PD) data from 30 pregnant women scheduled for caesarean delivery who received 5, 10 or 15 mg/kg of TXA intravenously using population approach.

RESULTS

TXA PK was best described by a two-compartment model with first-order elimination and the following parameters: clearance (between-subject variability) of 9.4 L/h (27.7%), central volume of 10.1 L (47.4%), intercompartmental clearance of 22.4 L/h (66.7%), peripheral volume of 14.0 L (13.1%) and additive error of 1.4 mg/L. The relationship between TXA concentration and maximum lysis was characterized by a sigmoid Emax model with baseline lysis of 97%, maximum inhibition of 89%, IC50 of 6.0 mg/L (65.3%), hill factor of 8.5 (86.3%) and additive error of 7.3%. Simulations demonstrated that 500 and 650 mg of TXA maintained therapeutic targets for 30 minutes and 1 hour, respectively, in 90% of patients.

CONCLUSION

This is the first population PK and PD study of TXA in pregnant women undergoing caesarean delivery. Our analysis suggests that a 650 mg dose provides adequate PPH prophylaxis up to 1 hour, which is less than the currently used 1000 mg of TXA in pregnant women.

Use of tranexamic acid does not influence perioperative outcomes in ambulatory foot and ankle surgery-a prospective triple blinded randomized controlled trial

STUDY OBJECTIVE

TXA is an antifibrinolytic medication widely used to reduce perioperative blood loss, but it has been seldom used during foot and ankle surgery. Our study evaluates the impact of TXA use on blood loss, post-operative pain, peri-operative opioid consumption, and wound healing in ambulatory outpatient foot and ankle procedures.

DESIGN

Prospective, triple-blinded, randomized controlled trial.

SETTING

Peri-operative environment of a major academic health centre in New York City.

PATIENTS

A total of 100 participants who were scheduled for ambulatory foot and ankle surgery with a single surgeon.

INTERVENTIONS

Patients receive either 10 mg/kg TXA (TXA group) or 10 ml/kg of normal saline (placebo group) intravenously prior to skin incision.

MEASUREMENTS

Primary outcome was intra-operative blood loss. Secondary outcomes were peri-operative opioid consumption and wound complications between post-operative days 14 and 21.

MAIN RESULTS

We found no difference between TXA and placebo groups in terms of intra-operative blood loss, p value 0.71, 95% CI (63.13-19.80). There was no difference between the two groups in terms of post-operative morphine milliequivalents (MME). The incidence of wound complications was 16.3% in the TXA group compared to 15.7% in the placebo group with OR 1.04, p value 0.93, 95% CI (0.32-2.77). No adverse events associated with TXA were reported.

CONCLUSIONS

The use of TXA during foot and ankle surgery was not associated with any benefits in perioperative outcomes in our outpatient ambulatory surgical population. Considering potential risks, we do not support the routine use of TXA in this surgical model.

The efficacy and safety of tranexamic acid in high tibial osteotomy: a systematic review and meta-analysis

Objective

The present meta-analysis was conducted to evaluate the efficacy and safety of the application of tranexamic acid (TXA) in patients undergoing high tibial osteotomy (HTO).

Methods

PubMed (MEDLINE), EMBASE, and Cochrane Library were systematically searched for relevant literature from inception until 1 February 2021. A combined searching strategy of subject words and random words was adopted. After testing for potential publication bias and/or heterogeneity, we aggregated variables by using the random-effect model. The primary comparison outcome measures were total blood loss, hemoglobin decrease, drain output, wound complications, thrombotic events, and blood transfusion rate of the TXA group versus control. The meta-analysis was performed using the RevMan 5.3 software.

Results

A total of 5 studies were included involving 532 patients. The results showed that there were significant differences in the two groups concerning total blood loss (95% confidence interval [CI] − 332.74 to − 146.46, P < 0.00001), hemoglobin decrease on postoperative day (POD) 1, 2, and 5 (POD 1 95% CI − 1.34 to − 0.63, P < 0.00001; POD 2 95% CI − 1.07 to − 0.68, P < 0.00001; POD 5 95% CI − 1.46 to − 0.84, P < 0.00001), drain output (POD total 95% CI − 195.86 to − 69.41, P < 0.00001) and wound complications (RR = 0.34, 95% CI 0.12 to 0.97, P = 0.04). Nonsignificant differences were found in the incidence of thromboembolic events (RR = 0.46, 95% CI 0.09 to 2.41, P = 0.36) and blood transfusion rate (RR = 0.25, 95% CI 0.03 to 2.27, P = 0.22).

Conclusions

This meta-analysis of the available evidence demonstrated that TXA could reduce total blood loss, hemoglobin decrease, drain output, and wound complications without increasing the incidence of thromboembolic events in patients undergoing HTO. But there is no obvious evidence that TXA could reduce blood transfusion rates. Further studies, including more large-scale and well-designed randomized controlled trials, are warranted to assess the efficacy and safety issues of routine TXA use in HTO patients.

Effect of carbazochrome sodium sulfonate combined with tranexamic acid on blood loss and inflammatory response in patients undergoing total hip arthroplasty

AIMS

The purpose of this study was to examine the efficacy and safety of carbazochrome sodium sulfonate (CSS) combined with tranexamic acid (TXA) on blood loss and inflammatory responses after primary total hip arthroplasty (THA), and to investigate the influence of different administration methods of CSS on perioperative blood loss during THA.

METHODS

This study is a randomized controlled trial involving 200 patients undergoing primary unilateral THA. A total of 200 patients treated with intravenous TXA were randomly assigned to group A (combined intravenous and topical CSS), group B (topical CSS), group C (intravenous CSS), or group D (placebo).

RESULTS

Mean total blood loss (TBL) in groups A (605.0 ml (SD 235.9)), B (790.9 ml (SD 280.7)), and C (844.8 ml (SD 248.1)) were lower than in group D (1,064.9 ml (SD 318.3), p < 0.001). We also found that compared with group D, biomarker level of inflammation, transfusion rate, pain score, and hip range of motion at discharge in groups A, B, and C were significantly improved. There were no differences among the four groups in terms of intraoperative blood loss (IBL), intramuscular venous thrombosis (IMVT), and length of hospital stay (LOS).

CONCLUSION

The combined application of CSS and TXA is more effective than TXA alone in reducing perioperative blood loss and transfusion rates, inflammatory response, and postoperative hip pain, results in better early hip flexion following THA, and did not increase the associated venous thromboembolism (VTE) events. Intravenous combined with topical injection of CSS was superior to intravenous or topical injection of CSS alone in reducing perioperative blood loss. Cite this article: Bone Joint Res 2021;10(6):354-362.

Tranexamic acid to improve functional status in adults with spontaneous intracerebral haemorrhage: the TICH-2 RCT

BACKGROUND

Tranexamic acid reduces death due to bleeding after trauma and postpartum haemorrhage.

OBJECTIVE

The aim of the study was to assess if tranexamic acid is safe, reduces haematoma expansion and improves outcomes in adults with spontaneous intracerebral haemorrhage (ICH).

DESIGN

The TICH-2 (Tranexamic acid for hyperacute primary IntraCerebral Haemorrhage) study was a pragmatic, Phase III, prospective, double-blind, randomised placebo-controlled trial.

SETTING

Acute stroke services at 124 hospitals in 12 countries (Denmark, Georgia, Hungary, Ireland, Italy, Malaysia, Poland, Spain, Sweden, Switzerland, Turkey and the UK).

PARTICIPANTS

Adult patients (aged ≥ 18 years) with ICH within 8 hours of onset.

EXCLUSION CRITERIA

Exclusion criteria were ICH secondary to anticoagulation, thrombolysis, trauma or a known underlying structural abnormality; patients for whom tranexamic acid was thought to be contraindicated; prestroke dependence (i.e. patients with a modified Rankin Scale [mRS] score > 4); life expectancy < 3 months; and a Glasgow Coma Scale score of < 5.

INTERVENTIONS

Participants, allocated by randomisation, received 1 g of an intravenous tranexamic acid bolus followed by an 8-hour 1-g infusion or matching placebo (i.e. 0.9% saline).

MAIN OUTCOME MEASURE

The primary outcome was functional status (death or dependency) at day 90, which was measured by the shift in the mRS score, using ordinal logistic regression, with adjustment for stratification and minimisation criteria.

RESULTS

A total of 2325 participants (tranexamic acid, n = 1161; placebo, n = 1164) were recruited from 124 hospitals in 12 countries between 2013 and 2017. Treatment groups were well balanced at baseline. The primary outcome was determined for 2307 participants (tranexamic acid, n = 1152; placebo, n = 1155). There was no statistically significant difference between the treatment groups for the primary outcome of functional status at day 90 [adjusted odds ratio (aOR) 0.88, 95% confidence interval (CI) 0.76 to 1.03; p = 0.11]. Although there were fewer deaths by day 7 in the tranexamic acid group (aOR 0.73, 95% CI 0.53 to 0.99; p = 0.041), there was no difference in case fatality at 90 days (adjusted hazard ratio 0.92, 95% CI 0.77 to 1.10; p = 0.37). Fewer patients experienced serious adverse events (SAEs) after treatment with tranexamic acid than with placebo by days 2 (p = 0.027), 7 (p = 0.020) and 90 (p = 0.039). There was no increase in thromboembolic events or seizures.

LIMITATIONS

Despite attempts to enrol patients rapidly, the majority of participants were enrolled and treated > 4.5 hours after stroke onset. Pragmatic inclusion criteria led to a heterogeneous population of participants, some of whom had very large strokes. Although 12 countries enrolled participants, the majority (82.1%) were from the UK.

CONCLUSIONS

Tranexamic acid did not affect a patient's functional status at 90 days after ICH, despite there being significant modest reductions in early death (by 7 days), haematoma expansion and SAEs, which is consistent with an antifibrinolytic effect. Tranexamic acid was safe, with no increase in thromboembolic events.

FUTURE WORK

Future work should focus on enrolling and treating patients early after stroke and identify which participants are most likely to benefit from haemostatic therapy. Large randomised trials are needed.

TRIAL REGISTRATION

Current Controlled Trials ISRCTN93732214.

FUNDING

This project was funded by the National Institute for Health Research Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 23, No. 35. See the NIHR Journals Library website for further project information. The project was also funded by the Pragmatic Trials, UK, funding call and the Swiss Heart Foundation in Switzerland.

Do Antifibrinolytic Agents Reduce the Risk of Blood Transfusion in Children Undergoing Spinal Fusion?: A Propensity Score-matched Comparison Using a National Database

STUDY DESIGN

Retrospective cohort.

OBJECTIVE

To evaluate the effectiveness and safety of antifibrinolytic (AF) agents in reducing perioperative blood transfusion in pediatric patients undergoing spinal fusion.

SUMMARY OF BACKGROUND DATA

The potential for AF to decrease bleeding and reduce exposure to allogenic transfusions has led to widespread off-label use in a number of major pediatric surgical procedures. Recent reviews call for improving the body of evidence for their effectiveness and safety in pediatric spinal fusion.

METHODS

Children undergoing spinal fusion were identified in the American College of Surgeons National Surgical Quality Improvement Program Pediatric (NSQIP-P) 2016 and 2017 databases. Univariate analyses of patient and perioperative characteristics informed the creation of a propensity score model predicting treatment with AF, followed by 1:1 matching to allow comparison of allogenic red blood cell transfusion rates and secondary outcomes between treated and untreated patients.

RESULTS

Of 6626 total patients, 5434 (81%) received AF and 1533 (23%) received a blood transfusion. Analysis of data for 1192 propensity score-matched pairs revealed that treatment with AF was associated with a statistically nonsignificant 16% reduction in perioperative transfusion (OR 0.84, 95% confidence interval 0.68-1.05, P = 0.119) and a statistically significant 43% reduction in postoperative transfusion (OR 0.57, 95% confidence interval 0.39-0.81, P = 0.002). No differences in the incidences of postoperative seizure or thrombosis were observed, with overall rates of 7.5 and 22.5 events per 10,000 patients, respectively.

CONCLUSION

AF agents appear to reduce postoperative allogenic transfusion in children undergoing spinal fusion surgery. Adverse drug effects such as thromboembolic complications and seizure were extremely rare and warrant continued monitoring, though this is the largest study to date providing evidence for the safety profile of these drugs.

LEVEL OF EVIDENCE

3.

Tourniquet and tranexamic acid use in total knee arthroplasty

Background

There is no consensus on how tourniquet and tranexamic acid (TXA) use in total knee arthroplasty (TKA) affect blood transfusion rates and total blood loss. We compared outcome measures and transfusion rates after TKA, with and without the use of tourniquet and TXA.

Methods

A retrospective study of 477 consecutive patients undergoing primary TKA between 2008 and 2013 was performed. There were 243 in the tourniquet-assisted (TA) and 234 in the tourniquet-unassisted (TU) group. Operative times, hemoglobin levels, blood transfusion rates, complications, and length of stay were assessed. Subanalysis was performed on those patients receiving and not receiving TXA within the TU group.

Results

Mean operative duration was 66.4 minutes in the TA group and 87.5 minutes in the TU group (P < .0001). Mean postoperative drop in hemoglobin was greater in TU group (3.1 g/dL vs 2.8 g/dL, P = .002). The transfusion rate was 9.5% in TA compared with 11.5% in TU patients (P = .46) with comparable mean units transfused (2.6 vs 2.2, P = .30). There was no difference in wound infection (P = .82) and total complication rates (P = .27) between groups. Those patients given TXA had a lower hemoglobin drop (2.6 g/dL vs 3.3 g/dL, P = .04) with similar transfusion (13.3% vs 11%, P = .61) and complication (P = .95) rates.

Conclusions

TU TKA had a greater operative duration and postoperative drop in hemoglobin than TA TKA. However, transfusion rates were similar between groups. TXA use reduced the operative decrease in hemoglobin with no effect on complication or transfusion rates.

Level of Evidence

Level III, retrospective cohort study.

Tranexamic Acid for Acute Hemorrhage: A Narrative Review of Landmark Studies and a Critical Reappraisal of Its Use Over the Last Decade

The publication of the Clinical Randomization of an Antifibrinolytic in Significant Hemorrhage-2 (CRASH-2) study and its intense dissemination prompted a renaissance for the use of the antifibrinolytic agent tranexamic acid (TXA) in acute trauma hemorrhage. Subsequent studies led to its widespread use as a therapeutic as well as prophylactic agent across different clinical scenarios involving bleeding, such as trauma, postpartum, and orthopedic surgery. However, results from the existing studies are confounded by methodological and statistical ambiguities and are open to varied interpretations. Substantial knowledge gaps remain on dosing, pharmacokinetics, mechanism of action, and clinical applications for TXA. The risk for potential thromboembolic complications with the use of TXA must be balanced against its clinical benefits. The present article aims to provide a critical reappraisal of TXA use over the last decade and a "thought exercise" in the potential downsides of TXA. A more selective and individualized use of TXA, guided by extended and functional coagulation assays, is advocated in the context of the evolving concept of precision medicine.

The impact of patient blood management on blood utilization and clinical outcomes in complex spine surgery

BACKGROUND

Patient blood management (PBM) is especially applicable in major spine surgery, during which bleeding and transfusion are common. What remains unclear in this setting is the overall impact of bundled PBM measures on transfusion requirements and clinical outcomes. We compared these outcomes before and after implementing a PBM program.

STUDY DESIGN AND METHODS

We conducted a retrospective review of 928 adult complex spine surgery patients performed by a single surgeon between January 2009 and June 2016. Although PBM measures were phased in over time, tranexamic acid (TXA) administration became standard protocol in July 2013, which defined our pre- and post-PBM periods. Transfusion rates for all blood components before and after PBM implementation were compared, as were morbid event rates and mortality.

RESULTS

Baseline characteristics were similar before and after PBM. Before PBM, the mean number of units/patient decreased for red blood cells (RBCs; by 19.5%; p = 0.0057) and plasma (by 33%; p = 0.0008), but not for platelets (p = 0.15). After risk adjustment by multivariable analyses, the composite outcome of morbidity or mortality showed a nonsignificant trend toward improvement after PBM (odds ratio [OR], 0.64; 95% confidence interval [CI], 0.39-1.01; p = 0.055), and the risk of thrombotic events was unchanged (OR, 1.12; 95% CI, 0.42-2.58; p = 0.80).

CONCLUSION

In complex spine surgery, a multifaceted PBM program that includes TXA can be advantageous by reducing transfusion requirements without changing clinical outcomes.

Tranexamic acid and perioperative bleeding in children: what do we still need to know?

PURPOSE OF REVIEW

Perioperative bleeding and blood product transfusion are associated with significant morbidity and mortality. Prevention and optimal management of bleeding decreases risk and lowers costs. Tranexamic acid (TXA) is an antifibrinolytic agent that reduces bleeding and transfusion in a broad number of adult and pediatric surgeries, as well as in trauma and obstetrics. This review highlights the current pediatric indications and contraindications of TXA. The efficacy and safety profile, given current and evolving research, will be covered.

RECENT FINDINGS

Based on the published evidence, prophylactic or therapeutic TXA administration is a well-tolerated and effective strategy to reduce bleeding, decrease allogeneic blood product transfusion, and improve pediatric patients' outcomes. TXA is now recommended in recent guidelines as an important part of pediatric blood management protocols.

SUMMARY

Based on TXA pharmacokinetics, the authors recommend a dosing regimen of between 10 to 30 mg/kg loading dose followed by 5 to 10 mg/kg/h maintenance infusion rate for pediatric trauma and surgery. Maximal efficacy and minimal side-effects with this dosage regime will have to be determined in larger prospective trials including high-risk groups. Furthermore, future research should focus on determining the ideal TXA plasma therapeutic concentration for maximum efficacy and minimal side-effects.

[Efficacy and safety of a loading high-dose tranexamic acid followed by postoperative five doses in total hip arthroplasty: A randomized controlled trial]

OBJECTIVE

To evaluate the efficacy and safety of a loading high-dose tranexamic acid (TXA) followed by postoperative 5 doses in total hip arthroplasty (THA) by a randomized controlled trial.

METHODS

Seventy-two patients who underwent primary unilateral THA between December 2017 and March 2018 were randomly divided into two groups (36 patients in each group). A single dose of 20 mg/kg TXA was administered intravenously before 5-10 minutes of operation in group A; and a single dose of 40 mg/kg TXA was administered intravenously in group B at the same time point. All patients received 5 doses of 1 g TXA at 3, 6, 12, 18, and 24 hours after the first dose. There was no significant difference in gender, age, weight, height, body mass index, disease type, and combined medical diseases between the two groups ( P>0.05). Total blood loss (TBL), lowest postoperative hemoglobin (Hb) level, fibrinolysis parameters [fibrin (ogen) degradation products (FDP), D-dimer], inflammatory factors [C-reaction protein (CRP), interleukin-6 (IL-6)], adverse events (thrombosis, pulmonary embolism) were recorded and compared between groups.

RESULTS

The TBL was significantly lower in group B than in group A ( P<0.05). Furthermore, the lowest postoperative Hb level was significantly higher in group B than in group A ( P<0.05). There was no significant difference in FDP and D-dimer before operation between the two groups ( P>0.05). The levels of FDP and D-dimer were significantly lower in group B than in group A at 12 and 36 hours postoperatively ( P<0.05). There was no significant difference in CRP and IL-6 before operation between the two groups ( P>0.05). The levels of CRP and IL-6 were significant lower in group B than in group A at 12, 24, and 36 hours postoperatively ( P<0.05). There was no significant difference at 14 days ( P>0.05). There were 2 patients with intramuscular venous thrombosis in group A and 1 in group B after operation, and there was no significant difference in the incidence of embolic events ( P>0.05). No deep venous thrombosis or pulmonary embolism occurred in all groups.

CONCLUSION

A loading high-dose TXA followed by postoperative 5 doses can further reduce the blood loss, provide additional fibrinolysis and inflammation control in THA, without increasing the risk of embolic events.

Approaches to Bloodless Surgery for Oncology Patients

Providing optimal care to surgical oncology patients who cannot be transfused for religious or other reasons can be challenging. However, with careful planning, using a combination of blood-conserving methods, these "bloodless" patients have clinical outcomes that are similar to other patients who can be transfused. Bloodless surgery can be accomplished safely for most patients, including those undergoing technically challenging oncologic surgery. This article reviews best practices used in a bloodless program during the preoperative, intraoperative, and postoperative periods, with the aim of achieving optimal outcomes when transfusion is not an option for surgical oncology patients.

Optimal route for administering tranexamic acid in primary unilateral total hip arthroplasty: Results from a multicenter cohort study

AIM

This study aimed to compare the efficacy and safety of different tranexamic acid (TXA) routes following primary total hip arthroplasty (THA).

METHODS

We collected data from the National Health Database on patients registered from January 2013 to September 2017. The patients were divided based on TXA administration route into a control group (without TXA), intravenous group, topical group and combined group. The primary outcome was transfusion; secondary outcomes were total blood loss, haemoglobin level, decrease in haemoglobin on postoperative day 3, and incidence of complications.

RESULTS

Data were collected on 7667 primary THA, 4662 with TXA and 3005 without TXA. The transfusion rate was 28.7% in the control group, 12.7% in the topical group, 8.9% in the intravenous group, and 6.1% in the combined group, and the inter-group differences were significant (P < .01). The combined group showed significantly smaller total blood loss (1.23 ± 0.52 L), smaller reduction in haemoglobin level (26.5 ± 11.1 g/L) and higher haemoglobin level on postoperative day 3 (107.0 ± 15.5 g/L) than the other three groups (P < .05). The three TXA groups showed significantly lower incidence of deep vein thrombosis than the control group (0.08% vs 0.47%, P = .001) as well as a lower rate of other complications (0.34% vs 0.67%, P = .044).

CONCLUSION

TXA is effective and safe to decrease blood loss and transfusion following primary THA, regardless of whether it is administered intravenously, topically or both. Intravenous or combined routes may produce better haemostatic effects, so they may be suggested in the absence of contraindications.

Finding the Optimal Regimen for Oral Tranexamic Acid Administration in Primary Total Hip Arthroplasty: A Randomized Controlled Trial

BACKGROUND

Previous studies have confirmed that, compared with intravenous and intra-articular formulations, oral tranexamic acid (TXA) provides equivalent reduction in blood loss, at a substantially reduced cost and greater ease of administration. However, the optimal oral dosage regimen to achieve maximum blood-loss reduction remains unclear. The aim of this study was to assess the efficacy of a regimen of multiple doses of oral TXA on blood loss in primary total hip arthroplasty.

METHODS

In this randomized controlled trial, 200 patients were randomized to 1 of 4 interventions. Group A received a single dose of 2.0 g of TXA orally at 2 hours preoperatively. In addition to this same preoperative dose, Group B received 1.0 g of TXA orally at 3 hours postoperatively, Group C received 1.0 g of TXA orally at 3 and 9 hours postoperatively, and Group D received 1.0 g of TXA orally at 3, 9, and 15 hours postoperatively. All patients received a 1.0-g topical dose of TXA. The primary outcome was total blood loss. Secondary outcomes included hemoglobin reduction, transfusion rate, thromboembolic complications, and adverse events.

RESULTS

The mean total blood loss (and standard deviation) was significantly less in Groups B, C, and D (792.2 ± 293.0, 630.8 ± 229.9, and 553.0 ± 186.1 mL, respectively) than in Group A (983.6 ± 286.7 mL) (p < 0.001). Moreover, Groups C and D had a lower mean reduction in hemoglobin than did Groups A and B. However, no differences were identified between Groups C and D for blood loss and hemoglobin reduction. Additionally, no differences were observed among the groups regarding thromboembolic complications and transfusions.

CONCLUSIONS

The multiple postoperative doses of oral TXA further reduced blood loss compared with a single preoperative bolus. The regimen of a preoperative dose and 3 postoperative doses of oral TXA produced maximum effective reduction of blood loss in total hip arthroplasty.

LEVEL OF EVIDENCE

Therapeutic Level I. See Instructions for Authors for a complete description of levels of evidence.

Structural studies of plasmin inhibition

Plasminogen (Plg) is the zymogen form of the serine protease plasmin (Plm), and it plays a crucial role in fibrinolysis as well as wound healing, immunity, tissue remodeling and inflammation. Binding to the targets via the lysine-binding sites allows for Plg activation by plasminogen activators (PAs) present on the same target. Cellular uptake of fibrin degradation products leads to apoptosis, which represents one of the pathways for cross-talk between fibrinolysis and tissue remodeling. Therapeutic manipulation of Plm activity plays a vital role in the treatments of a range of diseases, whereas Plm inhibitors are used in trauma and surgeries as antifibrinolytic agents. Plm inhibitors are also used in conditions such as angioedema, menorrhagia and melasma. Here, we review the rationale for the further development of new Plm inhibitors, with a particular focus on the structural studies of the active site inhibitors of Plm. We compare the binding mode of different classes of inhibitors and comment on how it relates to their efficacy, as well as possible future developments.

Efficacy and Safety of Tranexamic Acid in Pediatric Patients Undergoing Cardiac Surgery: A Single-Center Experience

Aims: This study evaluated the efficacy and safety of tranexamic acid (TXA) undergoing cardiac surgery. Methods: Using a retrospective cohort study design, 2,026 consecutive pediatric patients who underwent surgical repair of atrial or ventricular septal defect or complete repair of Tetralogy of Fallot were included, and divided into a control group and a TXA group. Results: Compared with that in the control group, there were statistically significant reduction of both the 12-h and total postoperative blood loss in the TXA group [6.573 ± 0.144 vs. 5.499 ± 0.133 ml kg^-1, mean difference (MD) 1.074 ml kg^-1, p < 0.001; 12.183 ± 0.298 vs. 9.973 ± 0.276 ml kg^-1, MD, 2.210 ml kg^-1, p < 0.001]. There was a statistically significant reduction of the MD of 12-h postoperative blood loss due to TXA in patients aged < 1 year compared with that in patients aged ≥1 year (MD, 1.544 vs. 0.681 ml kg-1, P = 0.007). There were statistically significant reduction of the MD of both the 12-h and total postoperative blood loss due to TXA in patients weighing < 10 kg compared with that in patients weighing ≥10 kg (MD, 1.542 vs. 0.456 ml kg-1, P < 0.001, and MD, 2.195 vs. 0.929 ml kg-1, P = 0.036, respectively). There was a statistically significant reduction of the MD of total postoperative blood loss due to TXA in cyanotic patients compared with that in acyanotic patients (MD, 3.381 vs. 1.038 ml kg^-1, P = 0.002). There was no significant difference in the postoperative volume or exposure of allogeneic transfusion, in-hospital morbidity or mortality between the groups. Conclusions: TXA took effects in reduction of postoperative blood loss but not the allogeneic transfusion requirement in pediatric patients undergoing cardiac surgery, particularly in infants weighing < 10 kg and cyanotic children. Moreover, the study suggested the use of TXA was safe in pediatric cardiac surgery.

Tranexamic Acid Is Efficacious at Decreasing the Rate of Blood Loss in Adolescent Scoliosis Surgery: A Randomized Placebo-Controlled Trial

BACKGROUND

Tranexamic acid (TXA) is an antifibrinolytic drug that reduces surgical blood loss. Evidence supporting its efficacy in surgery for adolescent idiopathic scoliosis is not robust. This trial was designed to validate the clinical efficacy of TXA in surgery for adolescent idiopathic scoliosis.

METHODS

This institutional review board-approved prospective double-blinded trial involved 111 patients with adolescent idiopathic scoliosis who were randomized to receive either a placebo or TXA (50-mg/kg loading dose and 10-mg/kg/h infusion). Power analysis indicated that 50 patients per group would provide power to detect a >20% difference in blood loss. Two-way analysis of variance (ANOVA) was applied to compare blood loss rates (slopes) using the group-by-time interaction F test.

RESULTS

The risk of clinically relevant blood loss (>20 mL/kg) was more than twice as high in the placebo group than in the TXA group (44% versus 21%, relative risk = 2.1, 95% confidence interval = 1.2 to 3.7). Compared with the placebo group, the TXA group had a 27% reduction in intraoperative blood loss, a significantly lower rate of intraoperative bleeding per hour (mean and standard deviation, 190 ± 73 versus 230 ± 80 mL, p = 0.01; F = 9.77, p < 0.001) and per fused spinal level (82 ± 32 versus 110 ± 40 mL, p < 0.001), less intraoperative blood loss (836 ± 373 versus 1,031 ± 484 mL, p = 0.02), and less postoperative bleeding (in the drain) (498 ± 228 versus 645 ± 318 mL, p = 0.009). Six patients who received a placebo and no patient who received TXA required an allogenic blood transfusion. No perioperative adverse events, including thromboembolic events or seizures, were observed. Three independent factors were predictive of blood loss: TXA administration, duration of surgery, and number of levels fused. Greater intraoperative blood loss was the only independent variable predictive of a longer hospital stay.

CONCLUSIONS

Use of TXA in patients undergoing surgery for adolescent idiopathic scoliosis significantly reduced blood loss, by 27%, compared with that in the placebo group. The rate of intraoperative blood loss per hour and per level fused and the amount of postoperative blood loss were significantly lower in the TXA group. More placebo-treated patients received allogenic blood. Patients with greater intraoperative blood loss spent a longer time in the hospital.

LEVEL OF EVIDENCE

Therapeutic Level I. See Instructions for Authors for a complete description of levels of evidence.

The antifibrinolytic and anti-inflammatory effects of multiple doses of oral tranexamic acid in total knee arthroplasty patients: a randomized controlled trial

Essentials Perioperative blood loss and inflammatory response can significantly affect recovery after surgery. We studied the effects of multiple-dose oral tranexamic acid on blood loss and inflammatory response. A postoperative four-dose regimen brought about maximum reduction in postoperative blood loss. A postoperative four-dose regimen reduced inflammatory response and promoted early rehabilitation. SUMMARY: Background Tranexamic acid (TXA) can reduce blood loss and the inflammatory response at multiple doses in total knee arthroplasty patients. However, the optimal regimen has not been determined. Objectives To identify the most effective regimen for achieving maximum reductions in blood loss and the inflammatory response. Patients/Methods Two hundred and seventy-five patients were randomized to receive a placebo (group A), a single 2-g oral dose of TXA 2 h preoperatively followed by 1 g of oral TXA 3 h postoperatively (group B), a single dose followed by 1 g of oral TXA 3 h and 7 h postoperatively (group C), a single dose followed by 1 g of oral TXA 3 h, 7 h and 11 h postoperatively (group D), or a single dose followed by 1 g of oral TXA 3 h, 7 h, 11 h and 15 h postoperatively (group E). The primary outcome was total blood loss on postoperative day (POD) 3. Secondary outcomes included a decrease in the hemoglobin level, coagulation parameters, inflammatory marker levels, and thromboembolic complications. Results Groups D and E had significantly lower blood loss and smaller decreases in hemoglobin level than groups A, B, and C, with no significant difference on POD 3 between groups D and E. Significantly enhanced coagulation was identified for the four multiple-dose regimens; however, all thromboelastographic parameters remained within normal ranges. Group E had the lowest inflammatory marker levels and pain, and the greatest range of motion. No thromboembolic complications were identified. Conclusion The four-dose regimen yielded the maximum reductions in blood loss and inflammatory response, improved analgesia, and promoted early rehabilitation. Further studies are required to ensure that these findings are reproducible.

Comparison of three routes of administration of tranexamic acid in primary unilateral total knee arthroplasty: Analysis of a national database

INTRODUCTION

The ideal route for the administration of tranexamic acid (TXA) remains undecided. This study aimed to compare the efficacy and safety of three routes of TXA following primary total knee arthroplasty (TKA).

MATERIALS AND METHODS

We prospectively collected patients' data through the National Health Database from January 2013 to September 2017. The patients were divided into a control group, intravenous group, topical group, and combined group according to the different routes of TXA. The primary outcome was the incidence of transfusion, and secondary outcomes were total blood loss, hemoglobin level and extent of hemoglobin decrease on postoperative day 3, and incidence of complications.

RESULTS

Of the total of 7133 primary TKA procedures collected, 4201 employed TXA and 2932 did not. The transfusion rate was 19.8% in the control group and 7.5% in the topical group, significantly higher than that in the intravenous (4.0%, p < 0.001) and combined (4.2%, p < 0.01) groups. The topical group had higher blood loss (0.97 ± 0.47 L), greater reduction in hemoglobin level (31.2 ± 10.1 g/L), and lower hemoglobin level (102.6 ± 12.7 g/L) on postoperative day 3, compared with the intravenous and combined groups (p < 0.05 for all). The differences between the intravenous and combined groups were not significant (p > 0.05). The incidence of deep vein thrombosis in the topical group (1.1%) was significantly higher than that in the control (0.4%, p = 0.007) and intravenous groups (0.3%, p = 0.003).

CONCLUSION

Intravenous and combined administration of TXA was equivalent in reducing blood loss and transfusion requirement, and superior to topical routes.

Intravenous Tranexamic Acid Reduces Postoperative Blood Loss After High Tibial Osteotomy

BACKGROUND

Medial opening wedge high tibial osteotomy (HTO) entails extensive soft tissue release that may lead to substantial perioperative bleeding. Although tranexamic acid (TXA) is a well-established blood-conserving agent in total joint arthroplasty, its potential to reduce blood loss in patients undergoing HTO has not been studied extensively.

QUESTIONS/PURPOSES

(1) Does TXA reduce total estimated blood loss in HTO? (2) Does TXA use in HTO affect in-hospital endpoints as measured by visual analog scale (VAS) pain scores at rest the day after surgery, wound complications in the immediate postoperative period, blood transfusions, or symptomatic deep vein thrombosis?

METHODS

Between January 2015 and May 2017, a single surgeon performed 156 HTOs, all of which were done using the medial opening wedge technique. We began using intravenous TXA for all HTOs in June 2016. This left us with 89 patients who were treated during a time when no TXA was used and 67 patients who were treated when all patients received TXA. Two patients in the control group had simultaneous TKA in the contralateral leg and one patient in each group had missing data so these patients were excluded, leaving 86 (97%) patients in the control group and 66 (98.5%) in the TXA group available for analysis in this retrospective study. There were no demographic differences between the groups in terms of age, sex, body mass index, and baseline hemoglobin values. Total estimated blood loss was the primary outcome variable, which was calculated using total blood volume and decrease in hemoglobin values. Secondary outcome variables included pain VAS at rest the day after surgery, wound complications in the immediate postoperative period, allogeneic blood transfusions, and occurrence of symptomatic thromboembolic manifestations. The decision on when to transfuse was based on predetermined criteria. An orthopaedic surgeon not involved in patient care collected the patient data from electronic medical records and did chart review.

RESULTS

The TXA group had less total blood loss (372 ± 36 mL versus 635 ± 53 mL, mean difference 263 mL [95% confidence interval, 248-278]; p < 0.001). Between groups, differences in VAS pain scores at rest the day after surgery favored the TXA group but were small and unlikely to be clinically important. There were two wound complications in the control group (one hematoma and one superficial wound infection) and none in the TXA group. No patients in either group received a blood transfusion, and no symptomatic thromboembolic events were detected in either group.

CONCLUSIONS

This study demonstrates that the systemic administration of TXA reduces postoperative blood loss in medial opening wedge HTO; however, insofar as no transfusions were administered to patients even before the routine use of TXA in this series, and no clinically important differences in pain scores were identified, the clinical benefit of routine use of TXA in patients undergoing HTO is uncertain. Our study was too small to make safety-related claims on rare endpoints such as wound complications or thromboembolic events. Larger, and preferably randomized, trials are needed to help define whether it is important to use TXA in this setting. Our data can help inform sample size calculations for such studies.

LEVEL OF EVIDENCE

Level III, therapeutic study.

Identifying the period of greatest blood loss after lower limb arthroplasty

Background

The use of tranexamic acid (TXA) in total hip replacement (THR) typically reduces blood loss by approximately 400 mL, and typical total blood loss is still approximately 1 L. A barrier to harnessing the full potential of TXA is disagreement on the optimum timing of administration. To address this, we aimed to identify the period of greatest blood loss.

Methods

We analyzed the perioperative data of 870 patients who had undergone THR, total knee replacement, or unicompartmental knee replacement just before the introduction of TXA to our unit. Total blood loss was calculated on postoperative day (POD) 1 and POD2 using an equation based on change in hematocrit.

Results

Average total blood loss at POD2 was 1505, 1322, and 611 mL for THR, total knee replacement, and unicompartmental knee replacement, respectively. Between 86% and 96% of this blood loss occurred in the period between skin closure and POD1. Intraoperative loss did not correlate with total loss at POD2. Blood transfusion was more likely if the patient was female (odds ratio [OR], 6.8) or if they had preoperative anemia (OR, 8.3) than if there was a high-volume blood loss (OR, 1.6).

Conclusions

Approximately 90% of blood loss occurs between skin closure and the first postoperative 24 hours. “Intraoperative blood loss” and “transfusion rate” are not reliable markers of total blood loss. The full potential of TXA could be harnessed by using it during the period of greatest blood loss, that is, during the first postoperative 24 hours.

Assessment of the effect of addition of 24 hours of oral tranexamic acid post-operatively to a single intraoperative intravenous dose of tranexamic acid on calculated blood loss following primary hip and knee arthroplasty (TRAC-24): a study protocol for a randomised controlled trial

BACKGROUND

While it is has been proven that tranexamic acid (TXA) reduces blood loss in primary total hip and knee arthroplasty (THA and TKA), there is little published evidence on the use of TXA beyond 3 h post-operatively. Most blood loss occurs after wound closure and the primary aim of this study is to determine if the use of oral TXA post-operatively for up to 24 h will reduce calculated blood loss at 48 h beyond an intra-operative intravenous bolus alone following primary THA and TKA. To date, most TXA studies have excluded patients with a history of thromboembolic disease.

METHODS/DESIGN

This is a phase IV, single-centred, open-label, parallel-group, randomised controlled trial. Participants are randomised to one of three groups: group 1, an intravenous (IV) bolus of TXA peri-operatively plus oral TXA post-operatively for 24 h; group 2, an IV bolus of TXA peri-operatively or group 3, standard care (no TXA). Eligible participants, including those with a history of thromboembolic disease, are allocated to these groups with a 2:2:1 allocation ratio. The primary outcome is the indirectly calculated blood loss 48 h after surgery. Researchers and patients are not blinded to the treatment; however, staff processing blood samples are. Originally 1166 participants were required to complete this study, 583 THA and 583 TKA. However, following an interim analysis after 100 THA and 100 TKA participants had been recruited to the study, the data monitoring ethics committee recommended stopping group 3 (standard care).

DISCUSSION

TRAC-24 will help to determine whether an extended TXA dosing regimen can further reduce blood loss following primary THA and TKA. By including patients with a history of thromboembolic disease, this study will add to our understanding of the safety profile of TXA in this clinical situation.

TRIAL REGISTRATION

ISRCTN registry, ISRCTN58790500 . Registered on 3 June 2016, EudraCT: 2015-002661-36.

Multiple boluses of intravenous tranexamic acid to reduce hidden blood loss and the inflammatory response following enhanced-recovery primary total hip arthroplasty: a randomised clinical trial

AIMS

The aim of this study was to examine the efficacy and safety of multiple boluses of intravenous (IV) tranexamic acid (TXA) on the hidden blood loss (HBL) and inflammatory response following primary total hip arthroplasty (THA).

PATIENTS AND METHODS

A total of 150 patients were allocated randomly to receive a single bolus of 20 mg/kg IV TXA before the incision (group A), a single bolus followed by a second bolus of 1 g IV-TXA three hours later (group B) or a single bolus followed by two boluses of 1 g IV-TXA three and six hours later (group C). All patients were treated using a standard peri-operative enhanced recovery protocol. Primary outcomes were HBL and the level of haemoglobin (Hb) as well as the levels of C-reactive protein (CRP) and interleukin-6 (IL-6) as markers of inflammation. Secondary outcomes included the length of stay in hospital and the incidence of venous thromboembolism (VTE).

RESULTS

The mean HBL was significantly lower in group C (402.13 ml standard deviation (sd) 225.97) than group A (679.28 ml sd 277.16, p < 0.001) or B (560.62 ml sd 295.22, p = 0.010). The decrease in the level of Hb between the pre-operative baseline and the level on the third post-operative day was 30.82 g/L (sd 6.31 g/L) in group A, 27.16 g/L (sd 6.83) in group B and 21.98 g/L (sd 3.72) in group C. This decrease differed significantly among the three groups (p < 0.01). The mean level of CRP was significantly lower in group C than in the other two groups on the second (p ≤ 0.034) and third post-operative days (p ≤ 0.014). The levels of IL-6 were significantly lower in group C than group A on the first three post-operative days (p = 0.023). The mean length of stay was significantly lower in group C than group A (p = 0.023). No VTE or other adverse events occurred.

CONCLUSION

Multiple boluses of IV-TXA can effectively reduce HBL following primary THA. A regime of three boluses leads to a smaller decrease in the level of Hb, less post-operative inflammation and a shorter length of stay in hospital than a single bolus. Cite this article: Bone Joint J 2017;99-B:1442-9.

The efficiency and safety of tranexamic acid for reducing blood loss in open myomectomy: A meta-analysis of randomized controlled trials

OBJECTIVE

This meta-analysis aimed to perform a meta-analysis including randomized controlled trials (RCTs) to assess the efficiency and safety of tranexamic acid (TXA) for reducing blood loss and transfusion requirements in patients undergoing open myomectomy.

METHODS

A systematic search was performed in Medline (1966-2017.03), PubMed (1966-2017.03), Embase (1980-2017.03), ScienceDirect (1985-2017.03,) and the Cochrane Library. Study evaluated the efficiency and safety of TXA in myomectomy was selected. Meta-analysis was performed using Stata 11.0 software.

RESULTS

Four RCTs including 328 patients met the inclusion criteria. The present meta-analysis indicated that there were significant differences between groups in terms of total blood loss (standard mean difference [SMD] = -1.512, 95% confidence interval [CI]: -2.746 to -0.278, P = .016), postoperative hemoglobin level (SMD = 0.650, 95% CI: 0.045-1.255, P = .035), transfusion requirements (SMD = -0.102, 95% CI: -0.199 to -0.006, P = .038), and duration of surgery (SMD = -0.514, 95% CI: -0.749 to -0.280, P = .000). In addition, no adverse effect was identified in treatment groups.

CONCLUSIONS

Intravenous administration of TXA in open myomectomy was associated with significantly reduced total blood loss, postoperative hemoglobin decline, duration of surgery, and transfusion requirements. Based on the limitations of the current meta-analysis, high-quality RCTs with long-term follow-up are still required.