Efficacy and Safety of Tranexamic Acid in Major Non-Cardiac Surgeries at High Risk for Transfusion: A Systematic Review and Meta-Analysis

A systematic review and meta-analysis of systematic and topical tranexamic acid administration in aesthetic plastic surgery

INTRODUCTION

Tranexamic acid has been widely used in plastic surgery. However, its efficacy has yet to be fully established. This meta-analysis aimed to determine its effectiveness in aesthetic plastic surgery.

METHODS

Following PRISMA guidelines, we conducted a meta-analysis of prospective randomised clinical trials that compared the effects of topical or systematic administration of tranexamic acid versus the control group in aesthetic plastic surgeries. The study was registered on the International Register of Systematic Reviews (PROSPERO) and is available online ( www.crd.york.uk/prospero , CRD42023492585).

RESULTS

Eleven studies encompassing 960 patients were included for the synthesis after critical evaluation. Systematic (MD - 18.05, 95% Cl, - 22.01, - 14.09, p < 0.00001) and topical (MD - 74.93, 95% Cl, - 88.79, - 61.07, p < 0.00001) administration of tranexamic acid reduced total blood loss. Topical tranexamic acid reduced drainage output (p < 0.0006).

CONCLUSION

Tranexamic acid reduced blood loss in aesthetic plastic surgery. More strictly defined RCTs, using high-quality methodology, are needed to evaluate the advantages and disadvantages of tranexamic acid in aesthetic plastic surgery.

Hospital policy of tranexamic acid to reduce transfusion in major non-cardiac surgery (TRACTION): protocol for a phase IV randomised controlled trial

INTRODUCTION

Tranexamic acid (TXA) is an inexpensive and widely available medication that reduces blood loss and red blood cell (RBC) transfusion in cardiac and orthopaedic surgeries. While the use of TXA in these surgeries is routine, its efficacy and safety in other surgeries, including oncologic surgeries, with comparable rates of transfusion are uncertain. Our primary objective is to evaluate whether a hospital-level policy implementation of routine TXA use in patients undergoing major non-cardiac surgery reduces RBC transfusion without increasing thrombotic risk.

METHODS AND ANALYSIS

A pragmatic, registry-based, blinded, cluster-crossover randomised controlled trial at 10 Canadian sites, enrolling patients undergoing non-cardiac surgeries at high risk for RBC transfusion. Sites are randomised in 4-week intervals to a hospital policy of intraoperative TXA or matching placebo. TXA is administered as 1 g at skin incision, followed by an additional 1 g prior to skin closure. Coprimary outcomes are (1) effectiveness, evaluated as the proportion of patients transfused RBCs during hospital admission and (2) safety, evaluated as the proportion of patients diagnosed with venous thromboembolism within 90 days. Secondary outcomes include: (1) transfusion: number of RBC units transfused (both at a hospital and patient level); (2) safety: in-hospital diagnoses of myocardial infarction, stroke, deep vein thrombosis or pulmonary embolism; (3) clinical: hospital length of stay, intensive care unit admission, hospital survival, 90-day survival and the number of days alive and out of hospital to day 30; and (4) compliance: the proportion of enrolled patients who receive a minimum of one dose of the study intervention.

ETHICS AND DISSEMINATION

Institutional research ethics board approval has been obtained at all sites. At the completion of the trial, a plain language summary of the results will be posted on the trial website and distributed in the lay press. Our trial results will be published in a peer-reviewed scientific journal.

TRIAL REGISTRATION NUMBER

NCT04803747.

Consensus of the Brazilian association of hematology, hemotherapy and cellular therapy on patient blood management: Antifibrinolytics

The use of strategies to reduce blood loss and transfusions is essential in the treatment of surgical patients, including in complex cardiac surgeries and those that use cardiopulmonary bypass. Antifibrinolytics, such as epsilon-aminocaproic acid (EACA) and tranexamic acid (TXA), are widely used in these procedures, as well as in other types of surgeries. These medicines are included in the World Health Organization (WHO) list of 'essential medicines'. Scientific evidence demonstrates the effectiveness of EACA in reducing bleeding and the need for transfusions in heart surgery. EACA is highly recommended for use in heart surgery by the American Society of Anesthesiology Task Force on Perioperative Blood Management. Regarding the safety of EACA, there is no robust evidence of any significant thrombotic potential. TXA has also been shown to be effective in reducing the use of blood transfusions in cardiac and non-cardiac surgeries and is considered safer than other antifibrinolytic agents. There is no evidence of any increased risk of thromboembolic events with TXA, but doses greater than 2 g per day have been associated with an increased risk of seizures. It is also important to adjust the dose in patients with renal impairment. In conclusion, antifibrinolytics, such as EACA and TXA, are effective in reducing blood loss and transfusion use in cardiac and non-cardiac surgeries, without causing serious adverse effects.

Modern use of tranexamic acid in facial plastic surgery

PURPOSE OF REVIEW

Although tranexamic acid is commonly used in surgical fields such as obstetrics, orthopedics, and trauma, its utilization in facial plastic surgery is a recently emerging concept, and studies examining its potential impact have been few. This review highlights how tranexamic acid may be employed during facial plastic procedures and the promising impact it may have.

RECENT FINDINGS

Tranexamic acid is primarily being studied in rhinoplasties and rhytidectomies, with intravenous administration and local infiltration being the most common routs of application, respectively. During rhinoplasties, tranexamic acid has the potential to improve the visualization of the surgical field by decreasing blood loss and to improve postoperative edema and ecchymosis. For rhytidectomies, on the contrary, it may shorten time to attain hemostasis, lessen the rate of hematoma formation, and lead to lower surgical drain output. Its efficacy is preserved at low doses, and significant medication side effects have not been reported after facial plastic procedures.

SUMMARY

Altogether, tranexamic acid may present a valuable adjuvant to facial plastic surgery, as it could increase both surgeon and patient satisfaction while exhibiting a benign safety profile.

Impact on blood loss and transfusion rates following administration of tranexamic acid in major oncological abdominal and pelvic surgery: A systematic review and meta-analysis

BACKGROUND AND OBJECTIVES

Major bleeding and receiving blood products in cancer surgery are associated with increased postoperative complications and worse outcomes. Tranexamic acid (TXA) reduces blood loss and improves outcomes in various surgical specialities. We performed a systematic review and meta-analysis to investigate TXA use on blood loss in elective abdominal and pelvic cancer surgery.

METHODS

A literature search was performed for studies comparing intravenous TXA versus placebo/no TXA in patients undergoing major elective abdominal or pelvic cancer surgery.

RESULTS

Twelve articles met the inclusion criteria, consisting of 723 patients who received TXA and 659 controls. Patients receiving TXA were less likely to receive a red blood cell (RBC) transfusion (p < 0.001, OR 0.4 95% CI [0.25, 0.63]) and experienced less blood loss (p < 0.001, MD -197.8 ml, 95% CI [-275.69, -119.84]). The TXA group experienced a smaller reduction in haemoglobin (p = 0.001, MD -0.45 mmol/L, 95% CI [-0.73, -0.18]). There was no difference in venous thromboembolism (VTE) rates (p = 0.95, OR 0.98, 95% CI [0.46, 2.08]).

CONCLUSIONS

TXA use reduced blood loss and RBC transfusion requirements perioperatively, with no significant increased risk of VTE. However, further studies are required to assess its benefit for cancer surgery in some sub-specialities.

Bilateral Pseudoarthrodesis: A Case Report of Complex Bilateral Total Knee Replacement for a Severe Hemophilia A Patient with Inhibitors

CASE

We present a severe hemophilia A patient with high titers of inhibitors presenting stage IV knee arthropathy with functional bilateral arthrodesis. On presentation, his mode of ambulation was to project himself forward without the benefit of any significant ankle motion. Total knee arthroplasty was performed on both knees and allowed significant improvement in the range of motion of both knees from 5° to 100°.

CONCLUSION

Although hemophilic patients with inhibitors can represent complex cases, successful outcomes can be achieved in a multidisciplinary team setting. However, we would recommend performing this type of surgery at an earlier stage when less extensive muscle and tendon release is required.

Safety of intravenous tranexamic acid in patients undergoing supratentorial meningiomas resection: protocol for a randomised, parallel-group, placebo control, non-inferiority trial

INTRODUCTION

Growing evidence recommends antifibrinolytic agent tranexamic acid (TXA) to reduce blood loss and transfusions rate in various surgical settings. However, postoperative seizure, as one of the major adverse effects of TXA infusion, has been a concern that restricts its utility in neurosurgery.

METHODS AND ANALYSIS

This is a randomised, placebo-controlled, non-inferiority trial. Patients with supratentorial meningiomas and deemed suitable for surgical resection will be recruited in the trial. Patients will be randomised to receive either a single administration of 20 mg/kg TXA or a placebo of the same volume with a 1:1 allocation ratio after anaesthesia induction. The primary endpoint is the cumulative incidence of early postoperative seizures within 7 days after craniotomy. Secondary outcomes include the incidence of non-seizure complications, changes of haemoglobin level from baseline, intraoperative blood loss, erythrocyte transfusion volume, Karnofsky Performance Status, all-cause mortality, and length of stay, and total hospitalisation cost.

ETHICS AND DISSEMINATION

This trial is registered at ClinicalTrial.gov and approved by the Chinese Ethics Committee of Registering Clinical Trials (ChiECRCT20200224). The findings will be disseminated in peer-reviewed journals and presented at national or international conferences relevant to subject fields.

TRIAL REGISTRATION NUMBER

NCT04595786.

Safety and Efficacy of Tranexamic Acid to Minimise Perioperative Bleeding in Hepatic Surgery: A Systematic Review and Meta-Analysis

INTRODUCTION

Perioperative bleeding poses a major risk during liver surgery, which can result in increased transfusion requirements, morbidity, and mortality. Tranexamic acid (TXA) effectively reduces perioperative bleeding and transfusion requirements in trauma patients. However, there remains a lack of evidence of its use in liver surgery. This meta-analysis of randomised controlled trials evaluated the efficacy and safety of TXA in liver resection and transplantation.

METHOD

A comprehensive search of Medline, Embase, CENTRAL and Clinicaltrials.gov databases was undertaken to identify studies from January 1947 to September 2021. The outcomes of the need for blood transfusion, thromboembolic events and mortality were extracted from the included studies. Quantitative pooling of data was based on the random effects model.

RESULTS

Six studies reporting on 429 patients were included. TXA reduced the need for perioperative blood transfusion in liver resection and transplantation (OR 0.09; 95% CI 0.01 to 0.72). More importantly, TXA did not increase the incidence of thromboembolic events (OR 2.22; 95% CI 0.47 to 10.43) and mortality (OR 0.60; 95% CI 0.13 to 2.76).

CONCLUSION

TXA safely reduces the need for blood transfusion in patients undergoing liver resection and transplantation.

Transfusion in orthopaedic surgery : a retrospective multicentre cohort study

Aims

Orthopaedic surgeries are complex, frequently performed procedures associated with significant haemorrhage and perioperative blood transfusion. Given refinements in surgical techniques and changes to transfusion practices, we aim to describe contemporary transfusion practices in orthopaedic surgery in order to inform perioperative planning and blood banking requirements.

Methods

We performed a retrospective cohort study of adult patients who underwent orthopaedic surgery at four Canadian hospitals between 2014 and 2016. We studied all patients admitted to hospital for nonarthroscopic joint surgeries, amputations, and fracture surgeries. For each surgery and surgical subgroup, we characterized the proportion of patients who received red blood cell (RBC) transfusion, the mean/median number of RBC units transfused, and exposure to platelets and plasma.

Results

Of the 14,584 included patients, the most commonly performed surgeries were knee arthroplasty (24.8%), hip arthroplasty (24.6%), and hip fracture surgery (17.4%). A total of 10.3% of patients received RBC transfusion; the proportion of patients receiving RBC transfusions varied widely based on the surgical subgroup (0.0% to 33.1%). Primary knee arthroplasty and hip arthroplasty, the two most common surgeries, were associated with in-hospital transfusion frequencies of 2.8% and 4.5%, respectively. RBC transfusion occurred in 25.0% of hip fracture surgeries, accounting for the greatest total number of RBC units transfused in our cohort (38.0% of all transfused RBC units). Platelet and plasma transfusions were uncommon.

Conclusion

Orthopaedic surgeries were associated with variable rates of transfusion. The rate of RBC transfusion is highly dependent on the surgery type. Identifying surgeries with the highest transfusion rates, and further evaluation of factors that contribute to transfusion in identified at-risk populations, can serve to inform perioperative planning and blood bank requirements, and facilitate pre-emptive transfusion mitigation strategies.

Cite this article: Bone Jt Open 2021;2(10):850–857.

Tranexamic acid in head and neck procedures: a systematic review and meta-analysis of randomized controlled trials

OBJECTIVE

We conducted a meta-analysis of all randomized controlled trials (RCTs) that examined the benefits of tranexamic acid (TXA) among cancer patients undergoing head and neck (H&N) procedures.

METHODS

We screened five databases from inception until 20 June 2021 and evaluated the risk of bias of the eligible studies. We pooled continuous outcomes using the weighted mean difference (WMD) with 95% confidence interval (CI).

RESULTS

Five studies, comprising seven RCTs, met the inclusion criteria. This meta-analysis included a total of 540 patients; 265 and 275 patients were assigned to the TXA and control group, respectively. Overall, the included RCTs revealed a low risk of bias. The volume of postoperative bleeding was significantly lower in favor of the TXA group compared with the control group (n = 7 RCTs, WMD = - 51.33 ml, 95% CI [- 101.47 to - 1.2], p = 0.04). However, no significant difference was found between both groups regarding the volume of intraoperative bleeding (n = 6 RCTs, WMD = - 3.48 ml, 95% CI [- 17.11 to 10.15], p = 0.62), postoperative hemoglobin (n = 3 RCTs, WMD = 0.42 mg/dl, 95% CI [- 0.27 to 1.11], p = 0.23), duration of drainage tube removal (n = 4 RCTs, MD = - 0.41 days, 95% CI [- 1.14 to 0.32], p = 0.27), and operation time (n = 6 RCTs, WMD = 1.59 min, 95% CI [- 10.09 to 13.27], p = 0.79). TXA was safe and did not culminate in thromboembolic events or major coagulation derangements.

CONCLUSION

TXA administration is safe and significantly reduces the volume of postoperative bleeding. However, no difference is identified between TXA and control groups regarding the volume of intraoperative bleeding, postoperative hemoglobin level, duration of drainage tube removal, and operation time.

Safety of Tranexamic Acid in Hip and Knee Arthroplasty in High-risk Patients

BACKGROUND

With increasing use of tranexamic acid in total hip and knee arthroplasties, safety concerns remain. Using national claims data, this study examined tranexamic acid use in patients with preexisting comorbidities. The hypothesis was that tranexamic acid use is not associated with increased complication risk in hip and knee arthroplasty patients with comorbidities.

METHODS

Among 765,011 total hip/knee arthroplasties (2013 to 2016, Premier Healthcare claims), tranexamic acid use was assessed in three high-risk groups: group I with patients with a history of venous thromboembolism, myocardial infarction, seizures, or ischemic stroke/transient ischemic attack (n = 27,890); group II with renal disease (n = 44,608); and group III with atrial fibrillation (n = 45,952). The coprimary outcomes were blood transfusion and new-onset "composite complications" (venous thromboembolism, myocardial infarction, seizures, and ischemic stroke/transient ischemic attack). Associations between tranexamic acid use and outcomes were measured separately by high-risk group. The odds ratios and Bonferroni-adjusted 99.9% CIs are reported.

RESULTS

Overall, 404,974 patients (52.9%) received tranexamic acid, with similar frequencies across high-risk groups I (13,004 of 27,890 [46.6%]), II (22,424 of 44,608 [50.3%]), and III (22,379 of 45,952 [48.7%]). Tranexamic acid use was associated with decreased odds of blood transfusion in high-risk groups I (721 of 13,004 [5.5%] vs. 2,293 of 14,886 [15.4%]; odds ratio, 0.307; 99.9% CI, 0.258 to 0.366), group II (2,045 of 22,424 [9.1%] vs. 5,159 of 22,184 [23.3%]; odds ratio, 0.315; 99.9% CI, 0.263 to 0.378), and group III (1,325 of 22,379 [5.9%] vs. 3,773 of 23,573 [16.0%]; odds ratio, 0.321; 99.9% CI, 0.266 to 0.389); all adjusted comparisons P < 0.001. No increased odds of composite complications were observed in high-risk group I (129 of 13,004 [1.0%] vs. 239 of 14,886 [1.6%]; odds ratio, 0.89, 99.9% CI, 0.49 to 1.59), group II (238 of 22,424 [1.1%] vs. 369 of 22,184 [1.7%]; odds ratio, 0.98; 99.9% CI, 0.58 to 1.67), and group III (187 of 22,379 [0.8%] vs. 290 of 23,573 [1.2%]; odds ratio, 0.93; 99.9% CI, 0.54 to 1.61); all adjusted comparisons P > 0.999.

CONCLUSIONS

Although effective in reducing blood transfusions, tranexamic acid is not associated with increased complications, irrespective of patient high-risk status at baseline.

EDITOR’S PERSPECTIVE

Does systemic lupus erythematosus increase the risk of complications from total hip arthroplasty?

Background

Patients with systemic lupus erythematosus are more likely to receive THA than the general population. However, it is controversial whether SLE increases the risk of complications from THA. The purpose of this retrospective study was to reassess the risks from THA in patients with SLE under the management model of enhanced recovery after surgery.

Methods

Patients with systemic lupus erythematosus diagnosed from December 2011 to December 2017 and treated with THA were compared with THA patients with osteoarthritis. The data were extracted from the medical record system of our department. The chi-square test and t-test were used for comparison.

Results

The postoperative blood loss in patients with SLE was significantly higher than that in the control group, and the postoperative hemoglobin (Hb) and hematocrit (Hct) in the control group were lower than those in the control group (P < 0.05). There was no significant difference in the rate of blood transfusion (9.733 vs 8.133 P = 0.3148) or other complications between the two groups (P > 0.05).

Conclusion

Well-controlled and well-managed SLE will not increase the risk of complications in THA, but can increase the amount of perioperative blood loss. Therefore, perioperative blood management is still essential in SLE patients.

Prophylactic tranexamic acid use in non-cardiac surgeries at high risk for transfusion

BACKGROUND

Tranexamic acid (TXA) reduces transfusion in a wide range of surgical populations, although its real-world use in non-cardiac surgeries has not been well described. The objective of this study was to describe prophylactic TXA use in non-cardiac surgeries at high risk for transfusion.

METHODS

This is a retrospective cohort study of all adult patients undergoing major non-cardiac surgery at ≥5% risk of perioperative transfusion at five Canadian hospitals between January 2014 and December 2016. Canadian Classification of Health Interventions procedure codes within the Discharge Abstract Database were linked to transfusion and laboratory databases. TXA use was ascertained electronically from The Ottawa Hospital Data Warehouse and via manual chart review for Winnipeg hospitals. For each surgery, we evaluated the percentage of patients who received TXA as well as the specifics of TXA dosing and administration.

RESULTS

TXA use was evaluable in 14 300 patients. Overall, 17% of surgeries received TXA, ranging from 0% to 68% among individual surgeries. TXA use was more common in orthopaedic (n = 2043/4942; 41%) and spine surgeries (n = 239/1322; 18%) compared to other surgical domains (n = 109/8036; 1%). TXA was commonly administered as a bolus (n = 2097/2391; 88%). The median TXA dose was 1000 mg (IQR 1000-1000 mg).

CONCLUSION

TXA is predominantly used in orthopaedic and spine surgeries, with little uptake in other non-cardiac surgeries at high risk for red blood cell transfusion. Further studies are needed to evaluate the effectiveness and safety of TXA and to understand the barriers to TXA administration in a broad range of non-cardiac surgeries.

Safety and efficacy of tranexamic acid in minimizing perioperative bleeding in extrahepatic abdominal surgery: meta-analysis

BACKGROUND

Perioperative bleeding is associated with increased morbidity and mortality in patients undergoing elective abdominal surgery. The antifibrinolytic agent tranexamic acid (TXA) has been shown to reduce perioperative bleeding and mortality risk in patients with traumatic injuries, but there is a lack of evidence for its use in elective abdominal and pelvic surgery. This meta-analysis of RCTs evaluated the effectiveness and safety of TXA in elective extrahepatic abdominopelvic surgery.

METHODS

PubMed, Embase, and ClinicalTrial.gov databases were searched to identify relevant RCTs from January 1947 to May 2020. The primary outcome, intraoperative blood loss, and secondary outcomes, need for perioperative blood transfusion, units of blood transfused, thromboembolic events, and mortality, were extracted from included studies. Quantitative pooling of data was based on a random-effects model.

RESULTS

Some 19 studies reporting on 2205 patients who underwent abdominal, pelvic, gynaecological or urological surgery were included. TXA reduced intraoperative blood loss (mean difference -188.35 (95 per cent c.i. -254.98 to -121.72) ml) and the need for perioperative blood transfusion (odds ratio (OR) 0.43, 95 per cent c.i. 0.28 to 0.65). TXA had no impact on the incidence of thromboembolic events (OR 0.49, 0.18 to 1.35). No adverse drug reactions or in-hospital deaths were reported.

CONCLUSION

TXA reduces intraoperative blood loss during elective extrahepatic abdominal and pelvic surgery without an increase in complications.

Variation in prophylactic tranexamic acid administration among anesthesiologists and surgeons in orthopedic surgery: a retrospective cohort study

PURPOSE

Tranexamic acid (TXA) reduces red blood cell transfusion in various orthopedic surgeries, yet the degree of practice variation in its use among anesthesiologists and surgeons has not been described. To target future knowledge transfer and implementation strategies, and to better understand determinants of variability in prophylactic TXA use, our primary objective was to evaluate the influence of surgical team members on the variability of prophylactic TXA administration.

METHODS

This was a retrospective cohort study of all adult patients undergoing primary total hip arthroplasty (THA), hip fracture surgery, and spine fusion ± vertebrectomy at two Canadian hospitals between January 2014 and December 2016. We used Canadian Classification of Health Interventions procedure codes within the Discharge Abstract Database which we linked to the Ottawa Data Warehouse. We described the percentage of patients that received TXA by individual surgery, the specifics of TXA dosing, and estimated the effect of anesthesiologists and surgeons on prophylactic TXA using multivariable mixed-effects logistic regression analyses.

RESULTS

In the 3,900 patients studied, TXA was most commonly used in primary THA (85%; n = 1,344/1,582), with lower use in hip fracture (23%; n = 342/1,506) and spine fusion surgery (23%; n = 186/812). The median [interquartile range] total TXA dose was 1,000 [1,000-1,000] mg, given as a bolus in 92% of cases. Anesthesiologists and surgeons added significant variability to the odds of receiving TXA in hip fracture surgery and spine fusion, but not primary THA. Most of the variability in TXA use was attributed to patient and other factors.

CONCLUSION

We confirmed the routine use of TXA in primary THA, while observing lower utilization with more variability in hip fracture and spine fusion surgery. Further study is warranted to understand variations in use and the barriers to TXA implementation in a broader population of orthopedic surgical patients at high risk for transfusion.

Study protocol for a multicentre, 2×2 factorial, randomised, controlled trial evaluating the interest of intravenous iron and tranexamic acid to reduce blood transfusion in hip fracture patients (the HiFIT study)

INTRODUCTION

Blood transfusion and anaemia are frequent and are associated with poor outcomes in patients with hip fracture (HF). We hypothesised that preoperative intravenous iron and tranexamic acid (TXA) may reduce the transfusion rate in these patients.

METHODS AND ANALYSIS

The HiFIT study is a multicentre, 2×2 factorial, randomised, double-blinded, controlled trial evaluating the effect of iron isomaltoside (IIM) (20 mg/kg) vs placebo and of TXA (intravenously at inclusion and topically during surgery) versus placebo on transfusion rate during hospitalisation, in patients undergoing emergency surgery for HF and having a preoperative haemoglobin between 95 and 130 g/L. 780 patients are expected. The primary endpoint is the proportion of patients receiving an allogenic blood transfusion of packed red blood cells from the day of surgery until hospital discharge (or until D30 if patient is still hospitalised). Enrolment started on March 2017 in 11 French hospitals. The study was stopped between July 2017 and August 2018 (because of investigation of serious AEs with IIM in Spain) and slowed down since March 2020 (COVID-19 crisis). The expected date of final follow-up is May 2022. Analyses of the intent-to-treat and per-protocol populations are planned.

ETHICS AND DISSEMINATION

The HiFIT trial protocol has been approved by the Ethics Committee of Comité de Protection des Personnes Ouest II and the French authorities (ANSM). It will be carried out according to the principles of the Declaration of Helsinki and the Good Clinical Practice guidelines. The results will be disseminated through presentation at scientific conferences and publication in peer-reviewed journals. The HiFIT trial will be the largest study evaluating iron and TXA in patients with HF.

TRIAL REGISTRATION NUMBER

clinicalTrials.gov identifier: NCT02972294; EudraCT Number 2016-003087-40.

Postoperative Low-Dose Tranexamic Acid After Major Spine Surgery: A Matched Cohort Analysis

Objective

This was a retrospective, cohort study investigating the efficacy and safety of continuous low-dose postoperative tranexamic acid (PTXA) on drain output and transfusion requirements following adult spinal deformity surgery.

Methods

One hundred forty-seven patients undergoing posterior instrumented thoracolumbar fusion of ≥ 3 vertebral levels at a single institution who received low-dose PTXA infusion (0.5–1 mg/kg/hr) for 24 hours were compared to 292 control patients who did not receive PTXA. The cohorts were propensity matched based on age, sex, American Society of Anesthesiologist physical status classification, body mass index, number of surgical levels, revision surgery, operative duration, and total intraoperative TXA dose (n = 106 in each group). Primary outcome was 72-hour postoperative drain output. Secondary outcomes were number of allogeneic blood transfusions.

Results

There was no significant difference in postoperative drain output in the PTXA group compared to control (660 ±420 mL vs. 710 ±490 mL, p = 0.46). The PTXA group received significantly more crystalloid (6,100 ±3,100 mL vs. 4,600 ±2,400 mL, p < 0.001) and red blood cell transfusions postoperatively (median [interquartile range]: 1 [0–2] units vs. 0 [0–1] units; incidence rate ratio [95% confidence interval], 1.6 [1.2–2.2]; p = 0.001). Rates of adverse events were comparable between groups.

Conclusion

Continuous low-dose PTXA infusion was not associated with reduced drain output after spinal deformity surgery. No difference in thromboembolic incidence was observed. A prospective dose escalation study is warranted to investigate the efficacy of higher dose PTXA.

Functional Testing for Tranexamic Acid Duration of Action Using Modified Viscoelastometry

Introduction

Tranexamic acid (TXA) is the standard medication to prevent or treat hyperfibrinolysis. However, prolonged inhibition of lysis (so-called "fibrinolytic shutdown") correlates with increased mortality. A new viscoelastometric test enables bedside quantification of the antifibrinolytic activity of TXA using tissue plasminogen activator (TPA).

Materials and Methods

Twenty-five cardiac surgery patients were included in this prospective observational study. In vivo, the viscoelastometric TPA test was used to determine lysis time (LT) and maximum lysis (ML) over 96 h after TXA bolus. Additionally, plasma concentrations of TXA and plasminogen activator inhibitor 1 (PAI-1) were measured. Moreover, dose effect curves from the blood of healthy volunteers were performed in vitro. Data are presented as median (25-75th percentile).

Results

In vivo TXA plasma concentration correlated with LT (r = 0.55; p < 0.0001) and ML (r = 0.62; p < 0.0001) at all time points. Lysis was inhibited up to 96 h (LT_TPA-test: baseline: 398 s [229-421 s] vs. at 96 h: 886 s [626-2,175 s]; p = 0.0013). After 24 h, some patients (n = 8) had normalized lysis, but others (n = 17) had strong lysis inhibition (ML <30%; p < 0.001). The high- and low-lysis groups differed regarding kidney function (cystatin C: 1.64 [1.42-2.02] vs. 1.28 [1.01-1.52] mg/L; p = 0.002) in a post hoc analysis. Of note, TXA plasma concentration after 24 h was significantly higher in patients with impaired renal function (9.70 [2.89-13.45] vs.1.41 [1.30-2.34] µg/mL; p < 0.0001). In vitro, TXA concentrations of 10 µg/mL effectively inhibited fibrinolysis in all blood samples.

Conclusions

Determination of antifibrinolytic activity using the TPA test is feasible, and individual fibrinolytic capacity, e.g., in critically ill patients, can potentially be measured. This is of interest since TXA-induced lysis inhibition varies depending on kidney function.

Bilateral pulmonary embolism while receiving tranexamic acid: a case report

BACKGROUND

We present a case of a suspected tranexamic acid-related bilateral pulmonary embolism in a healthy and active middle-aged woman who was receiving tranexamic acid for menorrhagia with no other known significant risk factors for thromboembolism.

CASE PRESENTATION

A 46-year-old Asian woman who was usually fit and well with no remarkable past medical history except for menorrhagia of 1-year duration for which she was receiving tranexamic acid presented to our accident and emergency department with a 2-week history of intermittent pleuritic central chest pain. She was reviewed and discharged to home with a diagnosis of musculoskeletal pain on two hospital visits because she had no significant risk factors for thromboembolism and her workup investigation results for pulmonary embolism and other differential diagnoses were largely unremarkable. On her third visit to the emergency ambulatory clinic with recurring symptoms of pleuritic chest pain, a pulmonary computed tomographic angiogram confirmed bilateral subsegmental pulmonary embolism.

CONCLUSION

This case report reinforces the possible increased risk of thromboembolism in patients receiving tranexamic acid.

Evaluation of Transfusion Practices in Noncardiac Surgeries at High Risk for Red Blood Cell Transfusion: A Retrospective Cohort Study

Perioperative bleeding is a major indication for red blood cell (RBC) transfusion, yet transfusion data in many major noncardiac surgeries are lacking and do not reflect recent blood conservation efforts. We aim to describe transfusion practices in noncardiac surgeries at high risk for RBC transfusion. We completed a retrospective cohort study to evaluate adult patients undergoing major noncardiac surgery at 5 Canadian hospitals between January 2014 and December 2016. We used Canadian Classification of Health Interventions procedure codes within the Discharge Abstract Database, which we linked to transfusion and laboratory databases. We studied all patients undergoing a major noncardiac surgery at ≥5% risk of perioperative RBC transfusion. For each surgery, we characterized the percentage of patients exposed to an RBC transfusion, the mean/median number of RBC units transfused, and platelet and plasma exposure. We identified 85 noncardiac surgeries with an RBC transfusion rate ≥5%, representing 25,607 patient admissions. The baseline RBC transfusion rate was 16%, ranging from 5% to 49% among individual surgeries. Of those transfused, the median (Q1, Q3) number of RBCs transfused was 2 U (1, 3 U); 39% received 1 U RBC, 36% received 2 U RBC, and 8% were transfused ≥5 U RBC. Platelet and plasma transfusions were overall low. In the era of blood conservation, we described transfusion practices in major noncardiac surgeries at high risk for RBC transfusion, which has implications for patient consent, preoperative surgical planning, and blood bank inventory management.

In Vivo Assessment of Thermosensitive Liposomes for the Treatment of Port Wine Stains by Antifibrinolytic Site-Specific Pharmaco-Laser Therapy

Antifibrinolytic site-specific pharmaco-laser therapy (SSPLT) is an experimental treatment modality for refractory port wine stains (PWS). Conceptually, antifibrinolytic drugs encapsulated in thermosensitive liposomes are delivered to thrombi that form in semi-photocoagulated PWS blood vessels after conventional laser treatment. Local release of antifibrinolytics is induced by mild hyperthermia, resulting in hyperthrombosis and complete occlusion of the target blood vessel (clinical endpoint). In this study, 20 thermosensitive liposomal formulations containing tranexamic acid (TA) were assayed for physicochemical properties, TA:lipid ratio, encapsulation efficiency, and endovesicular TA concentration. Two candidate formulations (DPPC:DSPE-PEG, DPPC:MPPC:DSPE-PEG) were selected based on optimal properties and analyzed for heat-induced TA release at body temperature (T), phase transition temperature (T_m), and at T > T_m. The effect of plasma on liposomal stability at 37 °C was determined, and the association of liposomes with platelets was examined by flow cytometry. The accumulation of PEGylated phosphocholine liposomes in laser-induced thrombi was investigated in a hamster dorsal skinfold model and intravital fluorescence microscopy. Both formulations did not release TA at 37 °C. Near-complete TA release was achieved at T_m within 2.0–2.5 min of heating, which was accelerated at T > T_m. Plasma exerted a stabilizing effect on both formulations. Liposomes showed mild association with platelets. Despite positive in vitro results, fluorescently labeled liposomes did not sufficiently accumulate in laser-induced thrombi in hamsters to warrant their use in antifibrinolytic SSPLT, which can be solved by coupling thrombus-targeting ligands to the liposomes.