Is tranexamic acid exposure related to blood loss in hip arthroplasty? A pharmacokinetic-pharmacodynamic study

Intravenous Carbazochrome Sodium Sulfonate Improves Visual Clarity in Patients Undergoing Arthroscopic Rotator Cuff Repair: A Randomised Controlled, Triple-Blinded, Prospective Study

PURPOSE

To investigate the clinical efficacy of intravenous carbazochrome sodium sulfonate (CSS), an oxidation substance of epinephrine, in improving visual clarity (VC), perioperative hemostasis, and anti-inflammatory effects during arthroscopic rotator cuff repair.

METHODS

This was a single-center, single-surgeon, randomized, controlled, triple-blinded, prospective study. Between August 2023 and August 2024, 195 patients undergoing arthroscopic rotator cuff repair were enrolled and randomly assigned to 1 of 3 groups: Group A received an intravenous infusion of CSS; group B received an intravenous infusion of tranexamic acid; and group C received an intravenous infusion of 0.9% sodium chloride. Patients with massive rotator cuff tear, frozen shoulder, hypertension, severe liver or renal dysfunction, long-term use of anticoagulants or antiplatelet drugs, bleeding disorders, or severe cardiopulmonary diseases were excluded. After each surgical procedure, a trained and independent evaluator assessed the clarity of images based on the VC scale, and all related clinical outcomes were recorded. The primary outcome was arthroscopic VC. The secondary outcomes were operative duration, irrigation fluid volume, red blood cell count of discarded irrigation fluid samples, intraoperative mean blood pressure, inflammatory marker levels, hemoglobin levels, visual analog scale (VAS) pain score, and shoulder joint enlargement rate.

RESULTS

In total, 195 patients were enrolled, and they were randomized into 1 of 3 groups: Group A comprised 65 patients (21 men and 44 women) with a mean age of 56.4 years; group B, 65 patients (29 men and 36 women) with a mean age of 57.0 years; and group C, 65 patients (24 men and 41 women) with a mean age of 56.7 years. VC scale scores were not significantly different during arthroscopic examination (5 [range, 4 to 5] in group A vs 5 [range, 4 to 5] in group B vs 5 [range, 4 to 5] in group C; P = .859), but group A had higher scores than groups B and C during subacromial treatment (5 [range, 5 to 5] vs 4 [range, 3 to 4] vs 3 [range, 2 to 3.5]; P < .001) and rotator cuff repair (5 [range, 5 to 5] vs 4 [range, 3 to 4] vs 3 [range, 3 to 4]; P < .001). Group A showed significant advantages over groups B and C in operative duration (50.4 ± 8.0 minutes vs 66.4 ± 13.7 minutes vs 70.2 ± 17.4 minutes; P < .001), intraoperative infusion volume (11,338.5 ± 1,381.0 mL vs 18,483.1 ± 1,808.7 mL vs 19,047.7 ± 1,984.1 mL; P < .001), postoperative shoulder joint enlargement rate (8.2% [range, 3.0% to 11.7%] vs 14.1% [range, 9.2% to 18.1%] vs 15.4% [range, 13.8% to 16.3%]; P < .001), and red blood cell count of discarded infusion samples (12.6 ± 2.3 × 109/L vs 19.6 ± 2.0 × 109/L vs 20.4 ± 2.2 × 109/L; P < .001). On postoperative days (PODs) 1, 2, and 3, hemoglobin levels were significantly lower in group C than in groups A and B. Inflammatory marker levels on PODs 1, 2, and 3 were not significantly different between groups A and B (P > .05) but were significantly lower in groups A and B than in group C (P < .05). A total of 157 patients (80.51% of the overall cohort) showed a change in the VAS pain score that met the MCID threshold 3 days after surgery. VAS scores on PODs 1, 2, and 3 were lower in group A than in groups B and C (P < .05). No adverse drug reactions or surgical complications occurred in any patients.

CONCLUSIONS

CSS can effectively improve VC, reduce perioperative blood loss, decrease the inflammatory response, and alleviate early postoperative pain and shoulder joint swelling, and it does not increase the incidence of adverse reactions and complications.

LEVEL OF EVIDENCE

Level I, randomized clinical trial.

A pharmacokinetic/pharmacodynamic analysis of intravenous tranexamic acid in adult patients undergoing elective total hip arthroplasty (ORACLE)

BACKGROUND

Uncertainty about optimal tranexamic acid (TXA) dosage has led to significant practice variation in hip arthroplasty. We aimed to identify the optimal i.v. dosage of TXA using a population pharmacokinetic/pharmacodynamic (PK/PD) approach in adults undergoing primary elective hip arthroplasty.

METHODS

Participants received an i.v. TXA bolus dose of 15 mg kg-1 of total body weight, 30 min before skin incision (maximum dose 1500 mg). Blood samples were collected at baseline, 5 min post-TXA, skin incision, skin closure, and 3, 6, and 24 h post-TXA administration. TXA activity was measured ex vivo using a tissue plasminogen activator-induced clot lysis assay, targeted to achieve 90% maximal antifibrinolysis, based on maximum lysis rate. A nonlinear mixed-effects population PK/PD model was developed. Monte Carlo simulations (n=1000) identified the dosing regimens to achieve the PK/PD target over 24 h.

RESULTS

There were 24 participants (18 females, 6 males), with a median (range) age of 62 (56.5-72) yr and BMI of 31.1 (23.0-41.8) kg m-2. A three-compartment model best described the 24-h data. The 15 mg kg-1 of i.v. bolus maintained TXA concentrations above the PK/PD target of 10 mg L-1 for a median duration of 4.94 h (IQR: 3.76-8.21 h). Of the various simulated regimens, only 30 mg kg-1 of i.v. TXA infusion after this bolus achieved the 24-h PK/PD target in 76-100% of patients, varying with their estimated glomerular function rates.

CONCLUSIONS

The PK/PD modelling indicated that 15 mg kg-1 of i.v. TXA bolus followed by a continuous i.v. infusion achieves the 24-h antifibrinolytic target.

CLINICAL TRIAL REGISTRATION

https://www.anzctr.org.au/Trial/Registration/TrialReview.aspx?id=377339&isClinicalTrial=False (ACTRN12619000670178); registered on May 6, 2019.

Exploratory Randomised Trial of Tranexamic Acid to Decrease Postoperative Delirium in Adults Undergoing Lumbar Fusion: A trial stopped early

Background

Postoperative delirium may be mediated by perioperative systemic- and neuro-inflammation. By inhibiting the pro-inflammatory actions of plasmin, tranexamic acid (TXA) may decrease postoperative delirium. To explore this hypothesis, we modified an ongoing randomised trial of TXA, adding measures of postoperative delirium, cognitive function, systemic cytokines, and astrocyte activation.

Methods

Adults undergoing elective posterior lumbar fusion randomly received intraoperative intravenous TXA (n=43: 10 mg kg-1 loading dose, 2 mg kg-1 h-1 infusion) or Placebo (n=40). Blood was collected pre- and at 24 h post-operatively (n=32) for biomarkers of systemic inflammation (cytokines) and astrocyte activation (S100B). Participants had twice daily delirium assessments using the 3-minute diagnostic interview for Confusion Assessment Method (n=65). Participants underwent 4 measures of cognitive function preoperatively and during post-discharge follow-up.

Results

Delirium incidence in the TXA group (7/32=22%) was not significantly less than in the Placebo group (11/33=33%); P=0.408, absolute difference=11%, relative difference=33%, effect size = -0.258 (95% CI -0.744 to 0.229). In the Placebo group (n=16), delirium severity was associated with the number of instrumented vertebral levels (P=0.001) and with postoperative interleukin -8 and -10 concentrations (P=0.00008 and P=0.005, respectively) and these associations were not significantly modified by TXA. In the Placebo group, delirium severity was associated with S100B concentration (P=0.0009) and the strength of the association was decreased by TXA (P=0.002).

Conclusions

A potential 33% relative decrease in postoperative delirium incidence justifies an adequately powered clinical trial to determine if intraoperative TXA decreases delirium in adults undergoing lumbar fusion.

Kidney disease in trials of perioperative tranexamic acid

STUDY OBJECTIVE

To assess how kidney disease is handled in randomized trials evaluating the safety and efficacy of perioperative tranexamic acid, and to evaluate its effects across levels of kidney function.

DESIGN

Systematic review and meta-analysis of randomized controlled trials.

SETTING

We screened studies from a previous comprehensive systematic review, and updated its search of PubMed, Embase, and Cochrane CENTRAL to July 31, 2023.

PATIENTS

Patients undergoing non-obstetric surgery.

INTERVENTIONS

Intravenous tranexamic acid compared to placebo or usual care without tranexamic acid.

MEASUREMENT

We summarized the handling of kidney disease in eligibility criteria, dose adjustments for kidney function, and effects of tranexamic acid on thrombotic events, seizures, and bleeding by subgroups of kidney function.

MAIN RESULTS

We evaluated 300 trials with 53,085 participants; 45,958 participants (86.6%) were enrolled in 228 trials (76.0%) that explicitly excluded patients with kidney disease. Definitions of kidney diseased used for exclusion varied widely. Most were non-specific and some corresponded to mild disease. Only 5 trials adjusted dosing for kidney function. Meta-analysis of two large trials found tranexamic acid unlikely to substantially increase or decrease the occurrence of thrombotic events in patients with eGFR <60 mL/min/1.73m2 (RR, 0.95; 95% CI: 0.83 to 1.07) or ≥ 60 mL/min/1.73m2 (RR, 1.00; 95% CI, 0.91 to 1.11; P for subgroup difference = 0.47), but both trials excluded patients with severe kidney disease. No analysis could be performed regarding seizure risk. One large trial in noncardiac surgery reported similar reduction in bleeding across subgroups of kidney function but excluded patients with creatinine clearance <30 mL/min.

CONCLUSIONS

The large evidence base supporting perioperative tranexamic acid suffers from broad and unjustified exclusion of patients with kidney disease. Typical perioperative dosing of tranexamic acid is likely safe and effective in patients with creatinine clearance >30 mL/min, but effects in more severe kidney disease are unknown.

The effect of perioperative sequential application of multiple doses of tranexamic acid on postoperative blood loss after PLIF: a prospective randomized controlled trial

BACKGROUND

Tranexamic acid (TXA) has been utilized in spinal surgery to effectively reduce intraoperative blood loss (IBL) and allogeneic blood transfusion rates. However, the traditional TXA regimen might last the entire duration of hyperfibrinolysis caused by surgical trauma, resulting in its limited ability to reduce postoperative blood loss (PBL). Therefore, the aim of this study was to investigate the effectiveness of perioperative sequential administration of multiple doses of TXA in reducing PBL in patients who underwent posterior lumbar interbody fusion (PLIF).

METHODS

From October 2022 to June 2023, 231 patients who were diagnosed with lumbar degenerative disease and scheduled to undergo PLIF were prospectively enrolled in the present study. The patients were randomly divided into three groups. Moreover, all patients received an intravenous injection of TXA at a dose of 15 mg/kg 15 min before the surgical skin incision. Patients in Group A received a placebo of normal saline after surgery, while patients in Group B received three additional intravenous injections of TXA at a dose of 15 mg/kg every 24 h. Patients in Group C received three additional intravenous injections of TXA at a dose of 15 mg/kg every 5 h. The primary outcome measure was PBL. In addition, this study assessed total blood loss (TBL), IBL, routine blood parameters, liver and kidney function, coagulation parameters, fibrinolysis indexes, inflammatory indicators, drainage tube removal time (DRT), length of hospital stay (LOS), blood transfusion rate, and incidence of complications for all subjects.

RESULTS

The PBL, TBL, DRT, and LOS of Group B and Group C were significantly lower than those of Group A ( P <0.05). The level of D-dimer (D-D) in Group C was significantly lower than that in Group A on the first day after the operation ( P =0.002), and that in Group B was significantly lower than that in Group A on the third day after the operation ( P =0.003). The interleukin-6 levels between the three groups from 1 to 5 days after the operation were in the order of Group A > Group B > Group C. No serious complications were observed in any patient. The results of multiple stepwise linear regression analysis revealed that PBL was positively correlated with incision length, IBL, smoking history, history of hypertension, preoperative fibrinogen degradation product level, and blood transfusion. It was negatively correlated with preoperative levels of fibrinogen, red blood cells, blood urea nitrogen, and age. Compared to female patients, male patients had an increased risk of PBL. Finally, the incidence of PBL was predicted.

CONCLUSIONS

Sequential application of multiple doses of TXA during the perioperative period could safely and effectively reduce PBL and TBL, shorten DRT and LOS, reduce postoperative D-D generation, and reduce the postoperative inflammatory response. In addition, this study provided a novel prediction model for PBL in patients undergoing PLIF.

Pharmacological interventions for the prevention of bleeding in people undergoing elective hip or knee surgery: a systematic review and network meta-analysis

BACKGROUND

Hip and knee replacement surgery is a well-established means of improving quality of life, but is associated with a significant risk of bleeding. One-third of people are estimated to be anaemic before hip or knee replacement surgery; coupled with the blood lost during surgery, up to 90% of individuals are anaemic postoperatively. As a result, people undergoing orthopaedic surgery receive 3.9% of all packed red blood cell transfusions in the UK. Bleeding and the need for allogeneic blood transfusions has been shown to increase the risk of surgical site infection and mortality, and is associated with an increased duration of hospital stay and costs associated with surgery. Reducing blood loss during surgery may reduce the risk of allogeneic blood transfusion, reduce costs and improve outcomes following surgery. Several pharmacological interventions are available and currently employed as part of routine clinical care.

OBJECTIVES

To determine the relative efficacy of pharmacological interventions for preventing blood loss in elective primary or revision hip or knee replacement, and to identify optimal administration of interventions regarding timing, dose and route, using network meta-analysis (NMA) methodology.

SEARCH METHODS

We searched the following databases for randomised controlled trials (RCTs) and systematic reviews, from inception to 18 October 2022: CENTRAL (the Cochrane Library), MEDLINE (Ovid), Embase (Ovid), CINAHL (EBSCOhost), Transfusion Evidence Library (Evidentia), ClinicalTrials.gov and WHO International Clinical Trials Registry Platform (ICTRP).

SELECTION CRITERIA

We included RCTs of people undergoing elective hip or knee surgery only. We excluded non-elective or emergency procedures, and studies published since 2010 that had not been prospectively registered (Cochrane Injuries policy). There were no restrictions on gender, ethnicity or age (adults only). We excluded studies that used standard of care as the comparator. Eligible interventions included: antifibrinolytics (tranexamic acid (TXA), aprotinin, epsilon-aminocaproic acid (EACA)), desmopressin, factor VIIa and XIII, fibrinogen, fibrin sealants and non-fibrin sealants.

DATA COLLECTION AND ANALYSIS

We performed the review according to standard Cochrane methodology. Two authors independently assessed trial eligibility and risk of bias, and extracted data. We assessed the certainty of the evidence using CINeMA. We presented direct (pairwise) results using RevMan Web and performed the NMA using BUGSnet. We were interested in the following primary outcomes: need for allogenic blood transfusion (up to 30 days) and all-cause mortality (deaths occurring up to 30 days after the operation), and the following secondary outcomes: mean number of transfusion episodes per person (up to 30 days), re-operation due to bleeding (within seven days), length of hospital stay and adverse events related to the intervention received.

MAIN RESULTS

We included a total of 102 studies. Twelve studies did not report the number of included participants; the other 90 studies included 8418 participants. Trials included more women (64%) than men (36%). In the NMA for allogeneic blood transfusion, we included 47 studies (4398 participants). Most studies examined TXA (58 arms, 56%). We found that TXA, given intra-articularly and orally at a total dose of greater than 3 g pre-incision, intraoperatively and postoperatively, ranked the highest, with an anticipated absolute effect of 147 fewer blood transfusions per 1000 people (150 fewer to 104 fewer) (53% chance of ranking 1st) within the NMA (risk ratio (RR) 0.02, 95% credible interval (CrI) 0 to 0.31; moderate-certainty evidence). This was followed by TXA given orally at a total dose of 3 g pre-incision and postoperatively (RR 0.06, 95% CrI 0.00 to 1.34; low-certainty evidence) and TXA given intravenously and orally at a total dose of greater than 3 g intraoperatively and postoperatively (RR 0.10, 95% CrI 0.02 to 0.55; low-certainty evidence). Aprotinin (RR 0.59, 95% CrI 0.36 to 0.96; low-certainty evidence), topical fibrin (RR 0.86, CrI 0.25 to 2.93; very low-certainty evidence) and EACA (RR 0.60, 95% CrI 0.29 to 1.27; very low-certainty evidence) were not shown to be as effective compared with TXA at reducing the risk of blood transfusion. We were unable to perform an NMA for our primary outcome all-cause mortality within 30 days of surgery due to the large number of studies with zero events, or because the outcome was not reported. In the NMA for deep vein thrombosis (DVT), we included 19 studies (2395 participants). Most studies examined TXA (27 arms, 64%). No studies assessed desmopressin, EACA or topical fibrin. We found that TXA given intravenously and orally at a total dose of greater than 3 g intraoperatively and postoperatively ranked the highest, with an anticipated absolute effect of 67 fewer DVTs per 1000 people (67 fewer to 34 more) (26% chance of ranking first) within the NMA (RR 0.16, 95% CrI 0.02 to 1.43; low-certainty evidence). This was followed by TXA given intravenously and intra-articularly at a total dose of 2 g pre-incision and intraoperatively (RR 0.21, 95% CrI 0.00 to 9.12; low-certainty evidence) and TXA given intravenously and intra-articularly, total dose greater than 3 g pre-incision, intraoperatively and postoperatively (RR 0.13, 95% CrI 0.01 to 3.11; low-certainty evidence). Aprotinin was not shown to be as effective compared with TXA (RR 0.67, 95% CrI 0.28 to 1.62; very low-certainty evidence). We were unable to perform an NMA for our secondary outcomes pulmonary embolism, myocardial infarction and CVA (stroke) within 30 days, mean number of transfusion episodes per person (up to 30 days), re-operation due to bleeding (within seven days), or length of hospital stay, due to the large number of studies with zero events, or because the outcome was not reported by enough studies to build a network. There are 30 ongoing trials planning to recruit 3776 participants, the majority examining TXA (26 trials).

AUTHORS' CONCLUSIONS

We found that of all the interventions studied, TXA is probably the most effective intervention for preventing bleeding in people undergoing hip or knee replacement surgery. Aprotinin and EACA may not be as effective as TXA at preventing the need for allogeneic blood transfusion. We were not able to draw strong conclusions on the optimal dose, route and timing of administration of TXA. We found that TXA given at higher doses tended to rank higher in the treatment hierarchy, and we also found that it may be more beneficial to use a mixed route of administration (oral and intra-articular, oral and intravenous, or intravenous and intra-articular). Oral administration may be as effective as intravenous administration of TXA. We found little to no evidence of harm associated with higher doses of tranexamic acid in the risk of DVT. However, we are not able to definitively draw these conclusions based on the trials included within this review.

Efficacy and safety of single- and double-dose intravenous tranexamic acid in hip and knee arthroplasty: a systematic review and meta-analysis

OBJECTIVE

With the increasing prevalence of osteoarthritis of the hip and knee, total joint replacement, the end-stage treatment, provides pain relief and restoration of function, but is often associated with massive blood loss. Tranexamic acid (TXA) has been reported to reduce perioperative blood loss in hip or knee arthroplasty. However, the optimal dose of TXA administration remains controversial. Therefore, we performed a meta-analysis combining data from 5 trials comparing the efficacy and safety of one fixed dose of 1 g intravenously administered TXA with two doses of 1 g each administered intravenously for hip or knee arthroplasty.

METHODS

PubMed, Medline, Embase, Web of Science, and The Cochrane Library were searched from January 2000 to February 2023. Our meta-analysis included randomized controlled trials and cohort studies comparing the efficacy and safety of different doses of intravenous TXA (IV-TXA) for THA or TKA. The observation endpoints included total blood loss, postoperative hemoglobin drop, blood transfusion rate, length of hospital stay, incidence of deep venous thrombosis (DVT), and incidence of pulmonary embolism (PE). Meta-analysis was performed according to Cochrane's guidelines and PRISMA statement. The Danish RevMan5.3 software was used for data merging.

RESULTS

Five cohort studies involving 5542 patients met the inclusion criteria. Our meta-analysis showed that the two groups were significantly higher in total blood loss (mean difference (MD) = - 65.60, 95% confidence interval (CI) [- 131.46, 0.26], P = 0.05); blood transfusion rate (risk difference (RD) = 0.00, 95% CI [- 0.01, 0.02], P = 0.55); postoperative hemoglobin (MD = 0.02, 95% CI [- 0.09, 0.13], P = 0.31); postoperative hospital stay days (MD = - 0.13), 95% CI [- 0.35, 0.09], P = 0.25); DVT (RD = 0.00, 95% CI [- 0.00, 0.01], P = 0.67); PE (RD = 0.00, 95% CI [- 0.01, 0.00], P = 0.79). There was some inherent heterogeneity due to variance in sample size across each major study.

CONCLUSION

1 dose of 1 g and 2 doses of 1 g IV-TXA each time have similar effects on reducing blood loss, blood transfusion rate, postoperative hemoglobin level, and postoperative hospital stay after TKA or THA, without increasing the risk of postoperative complications risk. For patients at high risk of thromboembolic events, one dose of 1 g TXA throughout surgery may be preferred. However, higher-quality RCT is needed to explore the optimal protocol dose to recommend the widespread use of TXA in total joint arthroplasty. Trial registration We conducted literature selection, eligibility criteria evaluation, data extraction and analysis on the research program registered in Prospero (CRD42023405387) on March 16, 2023.

Surgeon-Specific Treatment Selection Bias and Heterogeneous Perioperative Practices in an Observational Spine Surgery Study. A Statistical Tutorial with Implications for Analysis of Observational Studies of Perioperative Interventions

BACKGROUND

It is essential that treatment effects reported from retrospective observational studies are as reliable as possible. In a retrospective analysis of spine surgery patients, we obtained a spurious result: tranexamic acid (TXA) had no effect on intraoperative blood loss. This statistical tutorial explains how this result occurred and why statistical analyses of observational studies must consider the effects of individual surgeons.

METHODS

We used an observational database of 580 elective adult spine surgery patients, supplemented with a review of perioperative medication records. We tested whether common statistical methods (multivariable regression or propensity score-based methods) could adjust for surgeons' selection bias in TXA administration.

RESULTS

Because TXA administration (frequency, timing, and dose) and surgeon were linked (collinear), estimating and testing the independent effect of TXA on outcome using multivariable regression without including surgeon as a variable would provide biased (spurious) results. Likewise, because of surgeon/TXA linkage, assumptions of propensity score-based analysis were violated, statistical methods to improve comparability between groups failed, and spurious blood loss results were worsened. Others numerous differences among surgeons existed in intraoperative and postoperative practices and outcomes.

CONCLUSIONS

In observational studies in which individual surgeons determine whether their patients receive the treatment of interest, consideration must be given to inclusion of surgeon as an independent variable in all analyses. Failure to include the surgeon in an analysis of observational data carries a substantial risk of obtaining spurious results, either creating a spurious treatment effect or failing to detect a true treatment effect.

The role of tranexamic acid in breast and body contouring surgery: a review of the literature

Background: Postoperative seroma and haematoma are two of the most common complications follow-ing large surface area surgeries. A review of the literature was performed to evaluate evidence for the use of tranexamic acid in reducing postoperative seroma and haematoma formation in breast surgery and body contouring surgery. Methods A literature search was performed using MEDLINE, the Cochrane Database of Systematic Review, the Cochrane Central Register of Controlled Trials (CENTRAL), the Database of Abstracts of Reviews of Ef-fect (DARE) and PubMed in English from 1 Jan 1990–30 Mar 2020. The search terms ‘TXA’, ‘breast reduction’, ‘mammaplasty’, ‘breast implants’, ‘breast implantation’, ‘breast reconstruction’, ‘mastectomy’, ‘tissue ex-pansion’, ‘body contouring’, ‘breast’ and ‘abdominoplasty’ were used alone and in combination. Results: A total of six articles were found including three randomised controlled trials, two cohort studies and one retrospective study. Two ongoing trials were found on The Cochrane Central Register of Con-trolled Trials (CENTRAL). No systematic reviews were found. Conclusion: Literature surrounding the use of TXA in breast and body contouring surgery is sparse com-pared to what is available in other surgical sub-specialties. The literature available shows promising results with the use of TXA in controlling haematoma, drain output and seroma formation in breast surgery and body contouring surgery with minimal morbidity in these patient groups.

Topical administration of tranexamic acid in elderly patients undergoing short femoral nailing for intertrochanteric fracture: A randomised controlled trial

INTRODUCTION

Topical application of tranexamic acid (TXA) has been proposed as an alternative to intravenous administration to reduce perioperative bleeding in orthopaedic surgery. The purpose of this randomised controlled trial was to evaluate the efficacy and safety of 1 g topically applied TXA in patients undergoing fixation of intertrochanteric hip fractures by short femoral nailing.

METHODS

A total of 121 patients were enrolled between May 2018 and January 2020. Patients were randomly allocated (1:1) to receive either 10 mL (1 g) of TXA or 10 mL of normal saline (NS) injected through the subfascial drain following wound closure. Total blood loss, total drain output and blood transfusion requirements up to postoperative day 3 were recorded. Rates of thromboembolic complications and mortality up to 90 days postoperatively were also compared.

RESULTS

There was no statistically significant difference in total blood loss, total drain output or proportion of patients requiring transfusions. Median total blood loss was 1.088 L (IQR: 0.760-1.795) in the TXA group and 1.078 L (IQR: 0.797-1.722) in the NS group (P = .703). Median total drain output was 60 mL (IQR: 40-140) in the TXA group and 70 mL (IQR: 30-168) in the NS group (P = .696). Blood transfusions were administered in 29 patients (47.5%) in the TXA group and 27 patients (45.0%) in the NS group (P = .782). There was also no difference in frequency of thrombotic complications or mortality within 90 days. There were five thrombotic events in the TXA group and four in the NS group (P = .751). The 90-day mortality rate was 6.6% (4 patients) in the TXA group and 3.3% (2 patients) in the NS group (P = .680).

CONCLUSION

A 1 g dose of topically administered TXA did not produce any difference in blood loss, transfusion requirements, thromboembolic complications, or 90-day mortality. Future trials may consider the effect of larger doses in patients undergoing hip fracture fixation surgery.

Pharmacokinetics of tranexamic acid after intravenous, intramuscular, and oral routes: a prospective, randomised, crossover trial in healthy volunteers

BACKGROUND

In response to the World Health Organization call for research on alternative routes for tranexamic acid (TXA) administration in women with postpartum haemorrhage, we examined the pharmacokinetics of TXA after i.v., i.m., or oral administration.

METHODS

We conducted a randomised, open-label, crossover trial in 15 healthy volunteers who received i.v. TXA 1 g, i.m. TXA 1 g, or oral TXA solution 2 g. Blood samples were drawn up to 24 h after administration. Tranexamic acid concentration was measured with liquid chromatography-mass spectrometry, and the parameters of the pharmacokinetic models were estimated using population pharmacokinetics.

RESULTS

The median time to reach a concentration of 10 mg L^-1 was 3.5 min for the i.m. route and 66 min for the oral route, although with the oral route the target concentration was reached in only 11 patients. Median peak concentrations were 57.5, 34.4, and 12.8 mg L^-1 for i.v., i.m., and oral routes, respectively. A two-compartment open model with body weight as the main covariate best fitted the data. For a 70 kg volunteer, the population estimates were 10.1 L h^-1 for elimination clearance, 15.6 L h^-1 for intercompartmental clearance, 7.7 L for the volume of central compartment, and 10.8 L for the volume of the peripheral compartment. Intramuscular and oral bioavailabilities were 1.0 and 0.47, respectively, showing that i.m. absorption is fast and complete. Adverse events were mild and transient, mainly local reactions and low-intensity pain.

CONCLUSIONS

The i.m. (but not oral) route appears to be an efficient alternative to i.v. tranexamic acid. Studies in pregnant women are needed to examine the impact of pregnancy on the pharmacokinetics.

CLINICAL TRIAL REGISTRATION

EudraCT 2019-000285-38; NCT03777488.

Tranexamic acid and reduction of blood transfusion in lower limb trauma surgery: a randomized controlled study

INTRODUCTION

Post-operative blood loss in lower limb trauma fractures increases morbidity. Very few studies have evaluated the efficacy of Tranexamic Acid (TXA) in reducing blood loss and the consequent requirement of blood transfusion in the Indian population.

METHODS

This was a randomized controlled study of 100 patients with lower limb trauma. Fifty patients were given 1 g of TXA before surgery, and 50 patients were not given TXA. The requirement of blood transfusion, fall in Hb, the number of days admitted in the hospital after surgery were recorded, and evidence of deep vein thrombosis (DVT) was monitored.

RESULTS

Baseline demographics between the groups were comparable. The required blood transfusion and fall in Hb in patients receiving intra-operative TXA were significantly lower than those not given TXA (p < 0.0001). There was no significant difference in the length of hospital stay between the two groups (p = 0.6). There was no significant difference in the incidence of DVT in both groups.

DISCUSSION

TXA helps reduce the morbidity of trauma patients by reducing the requirement for blood transfusion. Its use is safe in lower limb trauma surgery and lowers the cost of therapy to the patient.

Population pharmacokinetic model of cefazolin in total hip arthroplasty

Cefazolin is an antibiotic recommended for infection prevention in total hip arthroplasty (THA). However, the dosing regimen necessary to achieve therapeutic concentrations in obese patients remains unclear. The aim of this study was to conduct a population analysis of cefazolin pharmacokinetics (PK) and assess whether cefazolin administration should be weight adapted in THA. Adult patients undergoing THA surgery received an injection of 2000 mg of cefazolin, doubled in the case of BMI > 35 kg/m² and total body weight > 100 kg. A population PK study was conducted to quantify cefazolin exposure over time compared to the therapeutic concentration threshold. A total of 484 cefazolin measurements were acquired in 100 patients, of whom 29% were obese. A 2-compartment model best fitted the data, and creatinine clearance determined interpatient variability in elimination clearance. Our PK simulations using a 2000 mg cefazolin bolus showed that cefazolin concentrations remained above the threshold throughout surgery, regardless of weight or renal function. A 2000 mg cefazolin single injection without adaptation to weight or renal function and without intraoperative reinjection was efficient in maintaining therapeutic concentrations throughout surgery. The optimal target concentration and necessary duration of its maintenance remain unclear.

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.

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.

The effect of intravenous tranexamic acid on visual clarity during arthroscopic rotator cuff repair: A randomized, double-blinded, placebo-controlled pilot study

OBJECTIVE

The aim of this study was to determine the effect of intravenous (IV) tranexamic acid (TRX) use on visual clarity during arthroscopic rotator cuff repair.

METHODS

This prospective, randomized, double-blinded, placebo-controlled study was conducted in patients scheduled for an arthroscopic rotator cuff repair. In total, 60 patients were randomly distributed into two groups: control (28 patients: 11 male, 17 female; mean age=53 years, age range=19-65) and TRX (32 patients: 15 male, 17 female; mean age=50, age range=18-69). In the TRX group, the arthroscopy was performed through the bolus IV administration of 10 mg/kg TRX in 100 ml isotonic saline solution. In the control group, the arthroscopy was performed through the bolus IV administration of 100 ml isotonic saline solution. In both the groups, the IV administration was carried out after the induction of anesthesia. At the end of each procedure, the surgeon rated the visual clarity on a scale from 1 to 10. In addition, operation time (minutes), irrigation amount used in operation (lt), and the need of pressure increase because of bleeding were recorded.

RESULTS

No adverse effects were seen during the study period. Visual clarity in TRX group was significantly better than the control group (the mean visual clarity scores=8.1/10 (range=7-10) vs 7/10 (range=5-9); p=0.018). The amount of solution was significantly less in the TRX group (10.2 lt (range=3.5-21)) than in the control group (15.8 lt (range=5.8-27); p=0.007, post-hoc power=95.7%), although the operation time was slightly longer in the TRX group (106 minutes (range=50-210)) than in the control group (99 minutes (range=45-165); p=0.24). Moreover, the need for the increase in pressure owing to bleeding was found significantly less in the TRX group (5.8 times (range=(0-9)) than in the control group (9.6 times (range=0-13); p=0.04, post-hoc power=94.5%).

CONCLUSION

Preoperative IV TRX administration seems to be effective in improving visual clarity and reducing the need for high pressure and the amount of irrigation fluid during the arthroscopic rotator cuff repair.

LEVEL OF EVIDENCE

Level II, Therapeutic study.

Hypothesis for a partially non urinary elimination of tranexamic acid in haemorrhagic caesarean section: Traces pilot pharmacokinetic study: Pharmacokinetics of tranexamic acid in obstetrics

BACKGROUND

In previous studies, the choice of doses of tranexamic acid was empirically defined as no pharmacokinetic study had been conducted in haemorrhagic caesarean section.

OBJECTIVE

The objective was to build a pharmacokinetic model in patients receiving a single 0.5, 1 or 2 g intravenous bolus.

METHOD

A preliminary monocentric open study was performed in the Lille centre. Blood samples and one urinary sample were collected in the 6 h following the injection. Nine patients were included. Tranexamic acid concentration was measured using liquid chromatography system coupled with tandem mass spectrometry. We used Monolix 2019R1 for population pharmacokinetic modelling. A structural model was constructed followed by the investigation of potential covariates.

RESULTS

Data were best described with a two-compartment model with a double first-order elimination from the central compartment. The model was improved when the variable ideal weight per dose was affected as a covariate for the apparent volume of distribution. Assuming a dose of 1 g and a height of 160 cm, the pharmacokinetic parameters were estimated at 10.26 L.h^-1 for total clearance, 11.5 L for the volume of the central compartment, 15.8 L for the volume of the second compartment, a diffusional clearance of 30.36 L.h^-1 , and a urinary excretion fraction of 25.8%.

CONCLUSIONS

The population pharmacokinetic model of tranexamic acid in haemorrhagic caesarean section was successfully established in our tiny sample of patients. The results of this preliminary TRACES pharmacokinetic study suggested that elimination of tranexamic acid is partially non urinary in contrast with healthy patients.

Serum Concentrations and Pharmacokinetics of Tranexamic Acid after Two Means of Topical Administration in Massive Weight Loss Skin-Reducing Surgery

Supplemental Digital Content is available in the text.

Background:

Topical administration of tranexamic acid to reduce bleeding is receiving increasing attention, as it is inexpensive, simple, and possibly beneficial in most surgery. Concerns regarding potential systemic adverse effects such as thromboembolic events and seizures may prevent general use of tranexamic acid. Although serum concentrations after topical application are assumed to be low, proper pharmacokinetic studies of tranexamic acid after topical application are lacking.

Methods:

The authors have investigated systemic absorption of tranexamic acid after two means of topical administration in patients undergoing abdominoplasty after massive weight loss: a bolus of 200 ml of 5 mg/ml into the wound cavity versus moistening the wound surface with 20 ml of 25 mg/ml. Twelve patients were recruited in each group. Serum concentrations achieved were compared with those after administration of 1 g as an intravenous bolus to arthroplasty patients. Serial blood samples for tranexamic acid analysis were obtained for up to 24 hours.

Results:

After intravenous administration, the peak serum concentration was 66.1 ± 13.0 µg/ml after 6 ± 2 minutes. Peak serum concentration after topical moistening was 5.2 ± 2.6 µg/ml after 80 ± 33 minutes, and in the topical bolus group, it was 4.9 ± 1.8 µg/ml after 359 ± 70 minutes. Topical moistening resulted in homogenous and predictable absorption across the individuals included, whereas topical bolus administration caused variable and unpredictable serum concentrations.

Conclusion:

Topical administration of tranexamic acid in patients undergoing abdominoplasty results in low serum concentrations, which are highly unlikely to cause systemic effects.

Short-term safety of tranexamic acid use in posterior cervical decompression and fusion surgery

Posterior cervical decompression and fusion (PCDF) can result in substantial blood loss, leading to blood transfusions and associated complications, such as infections, hypotension and organ damage. The antifibrinolytic tranexamic acid (TXA), an inhibitor of the activation of plasminogen, has been shown to be beneficial in multiple surgical procedures without any apparent increase in postoperative complications. However, there are only few studies reporting TXA utilization in cervical spine surgery and there is currently no literature detailing the short-term safety of its use in this setting. The purpose of our study is to determine the safety profile of TXA in posterior cervical decompression and fusion. From January 2015 to April 2018, 47 patients were identified to have undergone PCDF, 19 with the utilization of a TXA protocol at our institution. The incidence of adverse events was evaluated in the perioperative period and at 1 month follow-up. Of 39 patients, Nineteen (49%) received TXA as per our instructional protocol and 20 (51%) did not. Post-operative blood was significantly reduced (453 ml vs 701 ml; p = 0.03) in the group that received TXA. There was also a significant reduction in duration of surgery associated with TXA use (269 min vs 328 min; p = 0.05). There were no complications on the first 30 days after surgical intervention on the TXA group. TXA use during PCDF is a safe, effective method to reduce postoperative blood loss. Considering the limited number of patients in this study, these results should be validated on a larger group of patients.

A systematic review of tranexamic acid usage in patients undergoing femoral fracture surgery

BACKGROUND

Patients undergoing femoral fracture surgery frequently require blood transfusion. Tranexamic acid (TXA) has been widely used to decrease transfusion rate in joint replacement surgery. Therefore, we conducted a systematic review to evaluate the efficacy and safety of TXA usage in femoral fracture surgery.

MATERIALS AND METHODS

Studies involving TXA usage in femoral fracture surgery were searched through four electronic databases. The end points included total blood loss, postoperative hemoglobin decline, transfusion rate, thromboembolic events, 90-day mortality, and operative time. The present study was performed following Cochrane Reviewers' Handbook and Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement and was carried out by using Stata 14.0 software.

RESULTS

Eleven studies concerning intravenous (IV) application of TXA and three studies concerning topical administration of TXA were included. Twelve studies were randomized controlled trials (RCTs), and one was a retrospective cohort study. Regarding IV TXA, our paper indicated that the IV TXA group had less total blood loss (weighted mean difference [WMD] = -319.282, P = 0.000), lower postoperative hemoglobin decline (WMD = -1.14, P = 0.000) and lower transfusion rate (risk difference [RD] = -0.172, P = 0.000). No significant differences were found in thromboembolic events (RD = 0.008, P = 0.507), 90-day mortality (RD = 0.009, P = 0.732) and operative time (WMD = -2.227, P = 0.103). Regarding topical TXA, no significant differences were found in the transfusion rate (RD = -0.098, P = 0.129), postoperative hemoglobin decline (WMD = -1.137, P = 0.231), thromboembolic events (RD = -0.017, P = 0.660) and operative time (WMD = -4.842, P = 0.136).

CONCLUSION

Our meta-analysis demonstrated that both IV and topical application of TXA reduced transfusion rate in femoral fracture surgery. However, still further studies are needed to identify the optimal route of administration, TXA dosage and timing. In addition, high-quality RCTs with a large sample size are required to figure out the safety of TXA application, especially in the elderly, before its wide recommendation.

Is tranexamic acid exposure related to blood loss in hip arthroplasty? A pharmacokinetic-pharmacodynamic study

AIMS

Tranexamic acid (TXA) is an antifibrinolytic agent, decreasing blood loss in hip arthroplasty. The present study investigated the relationship between TXA exposure markers, including the time above the in vitro threshold reported for inhibition of fibrinolysis (10 mg l^-1 ), and perioperative blood loss.

METHODS

Data were obtained from a prospective, double-blind, parallel-arm, randomized superiority study in hip arthroplasty. Patients received a preoperative intravenous bolus of TXA 1 g followed by a continuous infusion of either TXA 1 g or placebo over 8 h. A population pharmacokinetic study was conducted to quantify TXA exposure.

RESULTS

In total, 827 TXA plasma concentrations were measured in 166 patients. A two-compartment model fitted the data best, total body weight determining interpatient variability in the central volume of distribution. Creatinine clearance accounted for interpatient variability in clearance. At the end of surgery, all patients had TXA concentrations above the therapeutic target of 10 mg l^-1 . The model-estimated time during which the TXA concentration was above 10 mg l^-1 ranged from 3.3 h to 16.3 h. No relationship was found between blood loss and either the time during which the TXA concentration exceeded 10 mg l^-1 or the other exposure markers tested (maximum plasma concentration, area under the concentration-time curve).

CONCLUSION

In hip arthroplasty, TXA plasma concentrations were maintained above 10 mg l^-1 during surgery and for a minimum of 3 h with a preoperative TXA dose of 1 g. Keeping TXA concentrations above this threshold up to 16 h conferred no advantage with regard to blood loss.