The effect of three different doses of tranexamic acid on blood loss after cardiac surgery with mild systemic hypothermia (32 degrees C)

The effect of tranexamic acid on intraoperative blood loss in patients undergoing brain meningioma resections: Study protocol for a randomized controlled trial

INTRODUCTION

Tranexamic acid (TXA) has been proven to prevent thrombolysis and reduce bleeding and blood transfusion requirements in various surgical settings. However, the optimal dose of TXA that effectively reduce intraoperative bleeding and blood product infusion in patients undergoing neurosurgical resection of meningioma with a diameter ≥ 5 cm remains unclear.

METHODS

This is a single-center, randomized, double-blinded, paralleled-group controlled trial. Patients scheduled to receive elective tumor resection with meningioma diameter ≥ 5 cm will be randomly assigned the high-dose TXA group, the low-dose group, and the placebo. Patients in the high-dose TXA group will be administered with a loading dose of 20 mg/kg TXA followed by continuous infusion TXA at a rate of 5 mg/kg/h. In the low-dose group, patients will receive the same loading dose of TXA followed by a continuous infusion of normal saline. In the control group, patients will receive an identical volume of normal saline. The primary outcome is the estimated intraoperative blood loss calculated using the following formula: collected blood volume in the suction canister (mL)-the volume of flushing (mL) + the volume from the gauze tampon (mL). Secondary outcomes include calculated intraoperative blood loss, intraoperative coagulation function assessed using thromboelastogram (TEG), intraoperative cell salvage use, blood product infusion, and other safety outcomes.

DISCUSSION

Preclinical studies suggest that TXA could reduce intraoperative blood loss, yet the optimal dose was controversial. This study is one of the early studies to evaluate the impact of intraoperative different doses infusion of TXA on reducing blood loss in neurological meningioma patients.

TRIAL REGISTRATION

ClinicalTrials.gov, NCT05230381. Registered on February 8, 2022.

Tranexamic acid is associated with improved hemostasis in elderly patients undergoing coronary-artery surgeries in a retrospective cohort study

Background

More elderly patients undergo coronary artery bypass surgery (CABG) than younger patients. Whether tranexamic acid (TA) is still effective and safe in elderly patients undergoing CABG surgeries is still unclear.

Methods

In this study, a cohort of 7,224 patients ≥70 years undergoing CABG surgery were included. Patients were categorized into the no TA group, TA group, high-dose group, and low-dose group according whether TA was administered and the dose administered. The primary endpoint was blood loss and blood transfusion after CABG. The secondary endpoints were thromboembolic events and in-hospital death.

Results

The blood loss at 24 and 48 h and the total blood loss after surgery in patients in the TA group were 90, 90, and 190 ml less than those in the no-TA group, respectively (p < 0.0001). The total blood transfusion was reduced 0.38-fold with TA administration compared to that without TA (OR = 0.62, 95% CI 0.56-0.68, p < 0.0001). Blood component transfusion was also reduced. High-dose TA administration reduced the blood loss by 20 ml 24 h after surgery (p = 0.032) but had no relationship with the blood transfusion. TA increased the risk of perioperative myocardial infarction (PMI) by 1.62-fold [p = 0.003, OR = 1.62, 95% CI (1.18-2.22)] but reduced the hospital stay time in patients who were administered TA compared to that of patients who did not receive TA (p = 0.026).

Conclusion

We revealed that elderly patients undergoing CABG surgeries had better hemostasis after TA administration but increased the risk of PMI. High-dose TA was effective and safe compared with low-dose TA administration in elderly patients undergoing CABG surgery.

Effect of High- vs Low-Dose Tranexamic Acid Infusion on Need for Red Blood Cell Transfusion and Adverse Events in Patients Undergoing Cardiac Surgery: The OPTIMAL Randomized Clinical Trial

IMPORTANCE

Tranexamic acid is recommended for reducing blood loss and transfusion in cardiac surgery. However, it remains unknown whether a high dose of tranexamic acid provides better blood-sparing effect than a low dose without increasing the risk of thrombotic complications or seizures in cardiac surgery.

OBJECTIVE

To compare the efficacy and adverse events of high-dose vs low-dose tranexamic acid in patients undergoing cardiac surgery with cardiopulmonary bypass.

DESIGN, SETTING, AND PARTICIPANTS

Multicenter, double-blind, randomized clinical trial among adult patients undergoing cardiac surgery with cardiopulmonary bypass. The study enrolled 3079 patients at 4 hospitals in China from December 26, 2018, to April 21, 2021; final follow-up was on May 21, 2021.

INTERVENTIONS

Participants received either a high-dose tranexamic acid regimen comprising a 30-mg/kg bolus, a 16-mg/kg/h maintenance dose, and a 2-mg/kg prime (n = 1525) or a low-dose regimen comprising a 10-mg/kg bolus, a 2-mg/kg/h maintenance dose, and a 1-mg/kg prime (n = 1506).

MAIN OUTCOMES AND MEASURES

The primary efficacy end point was the rate of allogeneic red blood cell transfusion after start of operation (superiority hypothesis), and the primary safety end point was a composite of the 30-day postoperative rate of mortality, seizure, kidney dysfunction (stage 2 or 3 Kidney Disease: Improving Global Outcomes [KDIGO] criteria), and thrombotic events (myocardial infarction, ischemic stroke, deep vein thrombosis, and pulmonary embolism) (noninferiority hypothesis with a margin of 5%). There were 15 secondary end points, including the individual components of the primary safety end point.

RESULTS

Among 3079 patients who were randomized to treatment groups (mean age, 52.8 years; 38.1% women), 3031 (98.4%) completed the trial. Allogeneic red blood cell transfusion occurred in 333 of 1525 patients (21.8%) in the high-dose group and 391 of 1506 patients (26.0%) in the low-dose group (risk difference [RD], -4.1% [1-sided 97.55% CI, -∞ to -1.1%]; relative risk, 0.84 [1-sided 97.55% CI, -∞ to 0.96; P = .004]). The composite of postoperative seizure, thrombotic events, kidney dysfunction, and death occurred in 265 patients in the high-dose group (17.6%) and 249 patients in the low-dose group (16.8%) (RD, 0.8%; 1-sided 97.55% CI, -∞ to 3.9%; P = .003 for noninferiority). Fourteen of the 15 prespecified secondary end points were not significantly different between groups, including seizure, which occurred in 15 patients (1.0%) in the high-dose group and 6 patients (0.4%) in the low-dose group (RD, 0.6%; 95% CI, -0.0% to 1.2%; P = .05).

CONCLUSIONS AND RELEVANCE

Among patients who underwent cardiac surgery with cardiopulmonary bypass, high-dose compared with low-dose tranexamic acid infusion resulted in a modest statistically significant reduction in the proportion of patients who received allogeneic red blood cell transfusion and met criteria for noninferiority with respect to a composite primary safety end point consisting of 30-day mortality, seizure, kidney dysfunction, and thrombotic events.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT03782350.

Use of Tranexamic Acid in Liposculpture: A Double-Blind, Multicenter, Randomized Clinical Trial

BACKGROUND

Intraoperative hemostasis should be performed with great caution since bleeding is a huge enemy of patient safety during surgery. Tranexamic acid (TXA) is a lysine synthetic derivate that inhibits fibrinolysis and diminishes the bleeding by blocking the 5 lysine-binding sites for plasminogen.

PURPOSE

We are comparing the efficacy of tranexamic acid vs. placebo as a hemostatic agent in liposculpture procedures.

METHODS DESIGN, SETTING AND PARTICIPANTS

We conducted a multicenter, double-blinded, randomized, controlled clinical trial in patients who were scheduled for liposculpture in 3 plastic surgery centers (Colombia and Mexico) between January 2019 and February of 2020. Interventions: 141 patients were randomly assigned into three groups: Intravenous (1 gr of TXA), subcutaneous (1 gr of TXA) and placebo (Normal Saline). 47 patients were assigned to each group. 30 patients were male and 111 were female. Main outcome: Evaluate the amount of postoperative bleeding between groups. The primary outcome was measured by the hemoglobin (Hb) point loss at day 1 (Preoperative Hb minus Hb at day 1 postop) and the Hb (mg/dl) point loss at day 5 (Preoperative Hb minus Hb at day 5 postop).

RESULTS

We found the Intravenous intervention group to have a greater hemoglobin level than the other two groups on both the first postoperative day (P=0.0001) and the fifth postoperative day (P=0.001). There were no statistical differences in Hb values between the placebo and the subcutaneous intervention groups.

CONCLUSIONS

Intravenous Tranexamic acid is a good therapeutic choice to implement on liposculpture procedures to decrease postoperative bleeding.

Exposure-Response Relationship of Tranexamic Acid in Cardiac Surgery

BACKGROUND

It is unclear whether high-dose regimens of tranexamic acid in cardiac surgery (total dose, 80 to 100 mg/kg) confer a clinical advantage over low-dose regimens (total dose, approximately 20 mg/kg), particularly as tranexamic acid-associated seizure may be dose-related. The authors' aim was to characterize the exposure-response relationship of this drug.

METHODS

Databases were searched for randomized controlled trials of intravenous tranexamic acid in adult patients undergoing cardiopulmonary bypass surgery. Observational studies were added for seizure assessment. Tranexamic acid concentrations were predicted in each arm of each study using a population pharmacokinetic model. The exposure-response relationship was evaluated by performing a model-based meta-analysis using nonlinear mixed-effect models.

RESULTS

Sixty-four randomized controlled trials and 18 observational studies (49,817 patients) were included. Seventy-three different regimens of tranexamic acid were identified, with the total dose administered ranging from 5.5 mg/kg to 20 g. The maximum effect of tranexamic acid for postoperative blood loss reduction was 40% (95% credible interval, 34 to 47%), and the EC50 was 5.6 mg/l (95% credible interval, 0.7 to 11 mg/l). Exposure values with low-dose regimens approached the 80% effective concentration, whereas with high-dose regimens, they exceeded the 90% effective concentration. The predicted cumulative blood loss up to 48 h postsurgery differed by 58 ml between the two regimens, and the absolute difference in erythrocyte transfusion rate was 2%. Compared to no tranexamic acid, low-dose and high-dose regimens increased the risk of seizure by 1.2-fold and 2-fold, respectively. However, the absolute risk increase was only clinically meaningful in the context of prolonged open-chamber surgery.

CONCLUSIONS

In cardiopulmonary bypass surgery, low-dose tranexamic acid seems to be an appropriate regimen for reducing bleeding outcomes. This meta-analysis has to be interpreted with caution because the results are observational and dependent on the lack of bias of the predicted tranexamic acid exposures and the quality of the included studies.

EDITOR’S PERSPECTIVE

Selection of the optimal dosage of tranexamic acid to reduce blood loss during pediatric cleft palate surgery

Objective

The aim of the present study was to evaluate and select the optimal dosage of tranexamic acid (TXA) to reduce blood loss during cleft palate surgery in children.

Materials and Methods

This randomized double-blind clinical trial was performed on 80 children under 3 years of age that were candidates for cleft palate surgery. These children were divided into four groups as follows: the first, second, and third groups received 5, 7.5, and 10 mg/kg of TXA, respectively. Moreover, the fourth group was considered as the control group. Before induction of anesthesia and then every 15 min during the surgery, some parameters such as mean arterial pressure, heart rate, SpO₂, and ETCO₂ were recorded. Moreover, the amount of blood loss during the surgery, the level of surgeon's satisfaction, and incidence rate of complications were assessed and recorded.

Results

The amount of blood loss during the surgery in TXA groups receiving dosages of 5, 7.5, and 10 mg/kg with the means of 63.75 ± 10.62, 61.25 ± 15.03, and 61.00 ± 14.29, respectively, was significantly lower than that of the control group with the mean of 92.25 ± 19.83 (P < 0.001). Moreover, no significant difference was found between the three groups receiving TXA dosages in terms of the amount of blood loss, the level of surgeon's satisfaction (P > 0.05).

Conclusion

According to the results of the present study, all three dosages of TXA had a significant role in reducing blood loss in cleft palate surgery. Given the potential for increased risk of side effects from the drug, it seems safe to use the minimal dosage of this drug to control and reduce blood loss during cleft palate surgery in children <3 years of age.

Comparison of Blood-Conserving and Allogenic Transfusion-Sparing Effects of Antifibrinolytics in Scoliosis Correction Surgery

Background:

Intraoperative antifibrinolytic drug administration is a safe and effective method of reducing blood loss and allogenic transfusions in patients undergoing spine deformity correction.

Aim:

This study aimed to compare the effectiveness of two antifibrinolytic drugs tranexamic acid (TXA) and epsilon amino caproic acid (EACA) in reducing peri-operative blood loss and transfusion requirements against a placebo control in patients with idiopathic scoliosis undergoing correction surgery.

Setting and Design:

This is a prospective, randomized, double-blinded, controlled comparative study.

Methodology:

Patients in TXA group received 50 mg.kg⁻¹ bolus and 10 mg.kg⁻¹.h⁻¹ infusion as against 100 mg.kg⁻¹ and 10 mg.kg⁻¹.h⁻¹ infusion in EACA group. The placebo group had saline bolus and infusion. Parameters observed included baseline demographic and deformity data, duration of surgery, total peri-operative blood loss, and allogenic packed red cell transfusion requirements.

Statistical Analysis:

Mean and standard deviation were used to represent the quantitative continuous data, and percentage was used to represent categorical data. The Student's t-test and ANOVA were used to compare means between groups. Bonferroni's multiple comparison test was used to find out the association between categorical variables.

Results:

A total of 36 patients were enrolled with 12 patients in each group. Peri-operative blood loss was 50.1% lower in patients receiving TXA and 17.7% lower in patients receiving EACA compared with the placebo group. The volume of total packed red cell transfusion was 66.7% lower in patients receiving TXA and 45.6% lower in patients receiving EACA compared with placebo.

Conclusion:

TXA was more effective in reducing total peri-operative blood loss and allogenic transfusion requirement in idiopathic scoliosis correction surgery compared to EACA.

Effectiveness and Safety of the Combined Use of Tranexamic Acid: A Comparative Observational Study of 1909 Cases

BACKGROUND

Tranexamic acid (TA) use in lower‑limb arthroplasty has been valued in these surgeries high‑risk hemorrhagic due to its antifibrinolytic action. The objective of the present study was to determine the effectiveness of the combined intravenous (IV) and intraarticular (IA) administration of TA in lower‑limb arthroplasty.

METHODS

We conduct a prospective observational study between January 1, 2014, and December 31, 2017, including all programmed lower‑limb arthroplasties. Patients were divided into four groups: no TA, 15 mg/kg IV TA, 3 g IA TA, and 15 mg/kg IV and 3 g IA. The effect on calculated total blood loss (milliliter of red blood cell [RBC]), hemoglobin, transfusion, and duration of hospitalization was studied after adjustment on age, American Society of Anesthesiologists, surgery, and postoperative curative anticoagulation. Complications related to TA administration were systematically reported.

RESULTS

A total of 1909 patients were included - "no TA," n = 184; "IV," n = 1137; "IA," n = 214; and "IV + IA," n = 374. In the IV + IA group, a decrease in blood loss was observed compared to the no TA group (+ 220 ml 95% confidence interval [CI] [184; 255] of RBC P < 0.001) and in the IA group (+ 65 ml 95% CI [30; 99] of RBC P < 0.001). The length of hospital stay of the IV + IA group was shorter compared to the no TA group (hazard ratio [HR] 0.35, 95% CI [0.29; 0.43], P < 0.001) to the IA group (HR 0.57, 95% CI [0.48; 0.69], P < 0.001) and the IV group (HR 0.45, 95% CI [0.39; 0.50], P < 0.001). One case of deep vein thrombosis occurred in the group without TA.

CONCLUSION

Administration of combined TA appears effective and safe; further studies are needed in order to establish a consensual protocol.

Effectiveness and Safety of the Combined Use of Tranexamic Acid: A Comparative Observational Study of 1909 Cases

BACKGROUND

Tranexamic acid (TA) use in lower-limb arthroplasty has been valued in these surgeries high-risk hemorrhagic due to its antifibrinolytic action. The objective of the present study was to determine the effectiveness of the combined intravenous (IV) and intraarticular (IA) administration of TA in lower-limb arthroplasty.

METHODS

We conduct a prospective observational study between January 1, 2014, and December 31, 2017, including all programmed lower-limb arthroplasties. Patients were divided into four groups: no TA, 15 mg/kg IV TA, 3 g IA TA, and 15 mg/kg IV and 3 g IA. The effect on calculated total blood loss (milliliter of red blood cell [RBC]), hemoglobin, transfusion, and duration of hospitalization was studied after adjustment on age, American Society of Anesthesiologists, surgery, and postoperative curative anticoagulation. Complications related to TA administration were systematically reported.

RESULTS

A total of 1909 patients were included - "no TA," n = 184; "IV," n = 1137; "IA," n = 214; and "IV + IA," n = 374. In the IV + IA group, a decrease in blood loss was observed compared to the no TA group (+220 ml 95% confidence interval [CI] [184; 255] of RBC P < 0.001) and in the IA group (+65 ml 95% CI [30; 99] of RBC P < 0.001). The length of hospital stay of the IV + IA group was shorter compared to the no TA group (hazard ratio [HR] 0.35, 95% CI [0.29; 0.43], P < 0.001) to the IA group (HR 0.57, 95% CI [0.48; 0.69], P < 0.001) and the IV group (HR 0.45, 95% CI [0.39; 0.50], P < 0.001). One case of deep vein thrombosis occurred in the group without TA.

CONCLUSION

Administration of combined TA appears effective and safe; further studies are needed in order to establish a consensual protocol.

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.

Patient Blood Management in Pediatric Cardiac Surgery: A Review

Efforts to reduce blood product transfusions and adopt blood conservation strategies for infants and children undergoing cardiac surgical procedures are ongoing. Children typically receive red blood cell and coagulant blood products perioperatively for many reasons, including developmental alterations of their hemostatic system, and hemodilution and hypothermia with cardiopulmonary bypass that incites inflammation and coagulopathy and requires systemic anticoagulation. The complexity of their surgical procedures, complex cardiopulmonary interactions, and risk for inadequate oxygen delivery and postoperative bleeding further contribute to blood product utilization in this vulnerable population. Despite these challenges, safe conservative blood management practices spanning the pre-, intra-, and postoperative periods are being developed and are associated with reduced blood product transfusions. This review summarizes the available evidence regarding anemia management and blood transfusion practices in the perioperative care of these critically ill children. The evidence suggests that adoption of a comprehensive blood management approach decreases blood transfusions, but the impact on clinical outcomes is less well studied and represents an area that deserves further investigation.

Different dose regimes and administration methods of tranexamic acid in cardiac surgery: a meta-analysis of randomized trials

BACKGROUND

The efficacy of tranexamic acid (TXA) to reduce perioperative blood loss and allogeneic blood transfusion in cardiac surgeries has been proved in previous studies, but its adverse effects especially seizure has always been a problem of concern. This meta-analysis aims to provide information on the optimal dosage and delivery method which is effective with the least adverse outcomes.

METHODS

We searched Cochrane Central Register of Controlled Trials, MEDLINE and EMBASE for all relevant articles published before 2018/12/31. Inclusion criteria were adult patients undergoing elective heart surgeries, and only randomized control trials comparing TXA with placebo were considered. Two authors independently assessed trial quality and extracted relevant data.

RESULTS

We included 49 studies with 10,591 patients into analysis. TXA significantly reduced transfusion rate (RR 0.71, 95% CI 0.65 to 0.78, P<0.00001). The overall transfusion rate was 35%(1573/4477) for patients using TXA and 49%(2190/4408) for patients in the control group. Peri-operative blood loss (MD - 246.98 ml, 95% CI - 287.89 to - 206.06 ml, P<0.00001) and re-operation rate (RR 0.62, 95% CI 0.49 to 0.79, P<0.0001) were also reduced significantly. TXA usage did not increase risk of mortality, myocardial infarction, stroke, pulmonary embolism and renal dysfunction, but was associated with a significantly increase in seizure attack (RR 3.21, 95% CI 1.04 to 9.90, P = 0.04).The overall rate of seizure attack was 0.62%(21/3378) for patients using TXA and 0.15%(5/3406) for patients in the control group. In subgroup analysis, TXA was effective for both on-pump and off-pump surgeries. Topical application didn't reduce the need for transfusion requirement, while intravenous delivery no matter as bolus injection alone or bolus plus continuous infusion were effective. Intravenous high-dose TXA didn't further decrease transfusion rate compared with low-dose regimen, and increased the risk of seizure by 4.83 times. No patients in the low-dose group had seizure attack.

CONCLUSIONS

TXA was effective in reducing transfusion requirement in all kinds of cardiac surgeries. Low-dose intravenous infusion was the most preferable delivery method which was as effective as high-dose regimen in reducing transfusion rate without increasing the risk of seizure.

Safety of a High-Dose Tranexamic Acid Protocol in Complex Adult Spinal Deformity: Analysis of 100 Consecutive Cases

STUDY DESIGN

Retrospective review of high-dose tranexamic acid (TXA) use in consecutive patients.

OBJECTIVE

To determine the safety profile of a high-dose TXA protocol in complex adult spinal deformity patients.

SUMMARY OF BACKGROUND DATA

Adult spinal deformity (ASD) surgery may involve significant amounts of blood loss, especially when various osteotomy techniques are used. Antifibrinolytic agents such as TXA have been used to reduce intraoperative blood loss. However, there is no universally accepted dosing protocol for its use during complex ASD surgery.

METHODS

Consecutive patients undergoing spinal deformity correction over a 14-month period at a single institution were identified. Inclusion criteria were adults (age ≥18 years) who underwent posterior spinal fusion of at least 5 levels and use of our standard TXA protocol of 50 mg/kg intravenous loading dose followed by a 5-mg/kg/h infusion until skin closure. Patient demographics, estimated blood loss (EBL), operative time, transfusion rates, complications, and other procedure-specific information were recorded.

RESULTS

A total of 100 adult patients were included. All operative procedures were performed by the senior surgeon. The mean age was 47.3 years, and 71% of patients were female. Average body mass index was 24.9. The average fusion length was 14 levels; 33/100 patients had fusion constructs of 17 levels or more. Pedicle subtraction osteotomy was performed in 9 patients and vertebral column resections were performed in 14 patients. There were 45/100 patients who had a primary procedure, whereas the rest were revisions. Mean EBL was 1,336 mL (98 mL/level, 31% estimated blood volume). There were three thromboembolic complications, including one pulmonary embolism and two deep vein thromboses (DVTs), which were all treated successfully with anticoagulation. There were no cases of myocardial infarction, seizure, stroke, or acute renal failure.

CONCLUSIONS

This is the first study to demonstrate the use of high-dose TXA in a complex ASD population. Larger prospective studies are needed to assess the efficacy and safety of high-dose TXA in ASD.

LEVEL OF EVIDENCE

Level IV, therapeutic.

Tranexamic acid reduces perioperative blood loss of posterior lumbar surgery for stenosis or spondylolisthesis: A randomized trial

BACKGROUND

A prospective, randomized, double-blind, placebo-controlled study was performed. The routine usage of TA in spinal surgery is controversial. Only a few studies have focused on patients undergoing posterior lumbar surgery for stenosis or spondylolisthesis, although a large clinical cohort exists in the population. This study aimed to evaluate the effect and safety of TA in reducing perioperative blood loss in posterior lumbar surgery for stenosis or spondylolisthesis.

METHODS

100 eligible patients out of 126 were randomized to receive either a bolus dose of 30 mg/kg TA i.v, a maintenance dosage of 2 mg/kg/h TA, or an equivalent volume of normal saline. The pedicle screw system was used for fixing in all the patients, followed by decompression and posterior lumbar interbody fusion. The primary outcomes were intraoperative estimated blood loss and total blood loss. The secondary outcomes were receiving packed red blood cells and postoperative hemoglobin and hematocrit levels.

RESULTS

In total, 4 patients were excluded from the analyses, 50 patients were in the TA group, and 46 in the placebo group. The demographic and baseline data between the groups were not statistically different. The intraoperative estimated blood loss and the total blood loss were 33% and 41% lower in the TA group than the placebo group, respectively. The blood transfusion rate did not vary significantly (P = 0.191). Except a patient with a dural tear in the placebo group, no other complications were observed.

CONCLUSION

TA significantly reduced the perioperative blood loss in patients undergoing posterior lumbar surgery for stenosis or spondylolisthesis.

Combined Administration of Systemic and Topical Tranexamic Acid for Total Knee Arthroplasty: Can It Be a Better Regimen and Yet Safe? A Randomized Controlled Trial

BACKGROUND

Total knee arthroplasty (TKA) is associated with substantial blood loss in postoperative period. Tranexamic acid (TXA) is potent antifibrinolytic agent, routinely administered by intravenous (IV) and topical route, which can possibly interrupt cascade of events due to hemostatic irregularities close to source of bleeding. However, scientific evidence of combined administration of TXA in TKA is still meagre. The present study aimed to compare efficacy of combined IV and topical TXA with IV use alone in terms of blood loss, transfusion rate, and incidence of deep vein thrombosis and thromboembolism.

PATIENTS AND METHODS

119 patients undergoing unilateral TKA were randomized into IV alone and combined group. Patients assigned to IV group were given IV TXA as a preoperative and postoperative dose given 3 and 6 hours after surgery, whereas in combined group, topical TXA solution was applied intraarticularly about 5 minutes before closure of arthrotomy in addition to IV doses.

RESULTS

Combined use of IV and topical TXA provided better results than IV use alone with mean calculated total blood loss (590.69±191.1 vs 385.68±182.5, P<.001), blood transfusion rate (6.6% vs 1.6%, P = .364), hemoglobin drop (1.82±0.6 vs 1.14±0.5, P<.001). No case of DVT or TE was noted among the 2 study groups.

CONCLUSION

Combined use of IV and intraarticular TXA provided significantly better results compared with IV use alone with respect to all variables related to postoperative blood loss in TKA. Moreover, TXA use is safe in terms of incidence of symptomatic DVT and TE.

A comparison of high-dose and low-dose tranexamic acid antifibrinolytic protocols for primary coronary artery bypass surgery

BACKGROUND AND AIMS

Tranexamic acid (TA) is used for prophylactic antifibrinolysis in coronary artery bypass surgeries to reduce bleeding. We evaluated the efficacy of two different doses of TA for prophylactic antifibrinolysis in patients undergoing primary coronary artery bypass grafting (CABG) surgery in this retrospective cohort study at a tertiary care referral centre.

METHODS

One-hundred eighty-four patients who underwent primary CABG with cardiopulmonary bypass (CPB) via sternotomy between January 2009 and June 2011 were evaluated. Pre-operative patient characteristics, intraoperative data, post-operative bleeding, transfusions, organ dysfunction and 30-day mortality were compared between high-dose TA (30 mg/kg loading dose followed by infusion of 15 mg/kg/h until the end of surgery along with 2 mg/kg priming dose in the bypass circuit) and low-dose TA (15 mg/kg loading dose followed by infusion of 6 mg/kg/h until the end of surgery along with 1 mg/kg priming dose in the bypass circuit) groups. Univariate comparative analysis of all categorical and continuous variables was performed between the two groups by appropriate statistical tests. Linear and logistic regression analyses were performed to control for the effect of confounding on the outcome variables.

RESULTS

Chest tube output, perioperative transfusion of blood products and incidence of re-exploration for bleeding did not differ significantly (P> 0.05) between groups. Post-operative complications and 30-day mortality were comparable between the groups. The presence of cardiogenic shock and increased pre-operative creatinine were found to be associated with increased chest tube output on the post-operative day 2 by multivariable linear regression model.

CONCLUSIONS

Low-dose TA protocol is as effective as high-dose protocol for antifibrinolysis in patients undergoing primary CABG with CPB.

Perioperative blood conservation strategies for major spine surgery

BACKGROUND

Orthopedic surgery, especially spine and spinal deformity surgery, may be associated with high perioperative blood loss. In order to reduce the risk of excessive blood loss and unnecessary blood transfusions, strategies such as Patient Blood Management including goal-directed coagulation management have been developed.

RECENT FINDINGS

Adverse effects of allogeneic blood transfusions have been shown for most surgical fields including orthopedic surgery. Several efforts have been made to increase the preoperative red blood cell (RBC) mass, to reduce the intraoperative blood loss, and to use restrictive transfusion triggers in order to minimize or avoid RBC transfusions. Measures to reduce intraoperative blood loss include new surgical techniques, use of cell salvage where possible, bedside coagulation management with point-of-care devices, substitution of coagulation factors, antifibrinolytic agents, and desmopressin, induced hypotension, and avoidance of hypothermia.

SUMMARY

Blood conservation in spinal surgery is a multidisciplinary approach and the efficacy of most single measures has been shown. Cost-effectiveness and the benefits of long-term patient outcomes are the subjects of current and future research.

Tranexamic acid evokes pain by modulating neuronal excitability in the spinal dorsal horn

Tranexamic acid (TXA) is an antifibrinolytic agent widely used to reduce blood loss during surgery. However, a serious adverse effect of TXA is seizure due to inhibition of γ-aminobutyric acid (GABA) and glycine receptors in cortical neurons. These receptors are also present in the spinal cord, and antagonism of these receptors in spinal dorsal horn neurons produces pain-related phenomena, such as allodynia and hyperalgesia, in experimental animals. Moreover, some patients who are injected intrathecally with TXA develop severe back pain. However, the effect of TXA on spinal dorsal horn neurons remain poorly understood. Here, we investigated the effects of TXA by using behavioral measures in rats and found that TXA produces behaviors indicative of spontaneous pain and mechanical allodynia. We then performed whole-cell patch-clamp experiments that showed that TXA inhibits GABA_A and glycine receptors in spinal dorsal horn neurons. Finally, we also showed that TXA facilitates activation of the extracellular signal-regulated kinase in the spinal cord. These results indicated that TXA produces pain by inhibiting GABA_A and glycine receptors in the spinal dorsal horn.

Preliminary investigation of high-dose tranexamic acid for controlling intraoperative blood loss in patients undergoing spine correction surgery

BACKGROUND CONTEXT

With a significant increase in the number and complexity of spinal deformity corrective surgeries, blood loss, often requiring massive intraoperative transfusions, becomes a major limiting factor during surgery. This scenario is particularly during posterior vertebral column resection (PVCR), where extensive intraoperative blood loss may pose a major risk to the patient, preventing smooth execution of the procedure. Tranexamic Acid (TXA) has been used in cardiac and orthopedic surgeries, including major spinal surgeries, to reduce blood loss and transfusion requirements for decades.

PURPOSE

To assess the efficacy and safety of high doses of TXA in posterior spinal deformity corrective surgery, including PVCR procedures.

STUDY DESIGN

A retrospective study from a single institution.

PATIENT SAMPLE

Fifty-nine patients (age range 7 to 46 years old) with spinal deformities undergoing spinal corrective surgeries were included. The patients were divided into two groups: the TXA group (total of 26 patients, including 8 PVCR patients) and the control group (total of 33 patients, including 9 PVCR patients).

OUTCOME MEASURES

The analyzed outcome measures included estimated intraoperative blood loss, real blood loss (RBL; blood loss/blood volume×100%), blood transfusion requirements, coagulation parameters, complete blood count, liver function, and renal function. Lower limb vein thrombus, symptomatic pulmonary embolism, symptomatic myocardial infarction, seizures, and acute renal failure were also recorded.

METHODS

Before skin incision, the patients in the TXA group received an intravenous loading dose of 100 mg/Kg over a 20-minute period, followed by a maintenance infusion of 10 mg/Kg/h until skin closure was completed. The patients in the control group received saline infusion of a similar volume. Statistics included estimated intraoperative blood loss, RBL, blood transfusion requirements, coagulation parameters, complete blood count, liver function, and renal function. All patients in this study were also carefully monitored for consciousness level, breathing status, chest tightness or pain, and urine output after surgery. These were done to detect the presence or absence of pulmonary embolism, myocardial infarction, seizures, and acute renal failure. Patients treated with TXA were examined via vascular ultrasound before and after surgery.

RESULTS

There were no significant differences in the demographic or surgical traits between the two groups. The blood loss of the patients in the TXA group was 2,441±1,666 mL, whereas that of the control group patients was 4,789±4,719 mL. The difference was statistically significant (p<.05). The average RBL of the patients in the TXA group was 80.6%±49.6% versus 160.8%±163.1% in the control group (p<.05). The blood transfusion requirements for the patients in the TXA group were significantly less than that in the control group (p<.05). Blood loss, RBL, and blood transfusion requirements were all significantly lower in the TXA group, compared with the control group among both PVCR patients and non-PVCR patients. In the TXA group, there was an average of 57.4% reduced blood loss in patients who received PVCR and 39.8% in patients not receiving PVCR. There were no differences in liver and renal functions between the TXA and control groups. There was no lower limb vein thrombus, symptomatic myocardial infarction, symptomatic pulmonary embolism, seizures, or acute renal failure reported in the TXA group.

CONCLUSIONS

In our study, high doses of TXA have been shown to effectively control blood loss and reduce the transfusion requirement. This effect was more apparent in patients receiving PVCR. No adverse drug reaction was recorded in the study. In the future, prospective randomized controlled trials to validate our results will be necessary. Future studies conducted on older patient cohort may also be necessary to confirm the safety of extending the use of TXA to the older patients.

Usefulness of intraoperative continuous infusion of tranexamic acid during emergency surgery for type A acute aortic dissection

PURPOSE

We investigated the influence of intraoperative continuous tranexamic acid (TA) infusion on the amount of blood transfusion required in emergency surgery for type A acute aortic dissection.

METHODS

The study was based on the data of 55 consecutive patients who underwent surgery for type A acute aortic dissection. The patients were divided into 2 groups for comparison: Group T, consisting of 26 patients who received intraoperative continuous infusion of TA, and Group N, consisting of 29 patients who did not receive TA infusion during the surgery.

RESULTS

The mean amounts of blood transfusion required during and after surgery were compared between the 2 groups: they were 10.5 ± 8.7 and 16.2 ± 10.0 units of mannitol-adenine-phosphate-added red cell concentrate, 9.3 ± 8.6 and 17.1 ± 10.0 units of fresh frozen plasma, and 20.4 ± 12.2 and 29.7 ± 14.9 units of platelet concentrate, respectively, in Groups T and N. Thus, the amount of each of these blood products required was significantly reduced in Group T.

CONCLUSIONS

During emergency surgery for type A acute aortic dissection, continuous infusion of TA resulted in a significant reduction in the amount of blood transfusion required.

Tranexamic Acid Impairs γ-Aminobutyric Acid Receptor Type A–mediated Synaptic Transmission in the Murine Amygdala

Background:

Tranexamic acid (TXA) is commonly used to reduce blood loss in cardiac surgery and in trauma patients. High-dose application of TXA is associated with an increased risk of postoperative seizures. The neuronal mechanisms underlying this proconvulsant action of TXA are not fully understood. In this study, the authors investigated the effects of TXA on neuronal excitability and synaptic transmission in the basolateral amygdala.

Methods:

Patch clamp recordings and voltage-sensitive dye imaging were performed in acute murine brain slices. Currents through N-methyl-d-aspartate, α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid, and γ-aminobutyric acid receptor type A (GABAA) receptors were recorded. GABAA receptor–mediated currents were evoked upon electrical stimulation or upon photolysis of caged GABA. TXA was applied at different concentrations.

Results:

Voltage-sensitive dye imaging demonstrates that TXA (1 mM) reversibly enhances propagation of neuronal excitation (mean ± SEM, 129 ± 6% of control; n = 5). TXA at concentrations of 0.1, 0.3, 1, 5, or 10 mM led to a dose-dependent reduction of GABAA receptor–mediated currents in patch clamp recordings. There was no difference in the half-maximal inhibitory concentration for electrically (0.76 mM) and photolytically (0.84 mM) evoked currents (n = 5 to 9 for each concentration), and TXA did not affect the paired-pulse ratio of GABAA receptor–mediated currents. TXA did not impact glutamatergic synaptic transmission.

Conclusions:

This study clearly demonstrates that TXA enhances neuronal excitation by antagonizing inhibitory GABAergic neurotransmission. The results provide evidence that this effect is mediated via postsynaptic mechanisms. Because GABAA receptor antagonists are known to promote epileptiform activity, this effect might explain the proconvulsant action of TXA.

Comparison of Two Doses of Tranexamic Acid in Adults Undergoing Cardiac Surgery with Cardiopulmonary Bypass

Background:

The optimal dose of tranexamic acid (TA) is still an issue. The authors compared two doses of TA during cardiac surgery in a multicenter, double-blinded, randomized study.

Methods:

Patients were stratified according to transfusion risk, then randomized to two TA doses: 10 mg/kg bolus followed by 1 mg·kg−1·h−1 infusion (low dose) until the end of surgery or 30 mg/kg bolus followed by 16 mg·kg−1·h−1 infusion (high dose). The primary endpoint was the incidence of blood product transfusion up to day 7. Secondary ones were incidences of transfusion for each type of blood product and amounts transfused, blood loss, repeat surgery, TA-related adverse events, and mortality.

Results:

The low-dose group comprised 284 patients and the high-dose one 285. The primary endpoint was not significantly different between TA doses (63% for low dose vs. 60% for high dose; P = 0.3). With the high dose, a lower incidence of frozen plasma (18 vs. 26%; P = 0.03) and platelet concentrate (15 vs. 23%; P = 0.02) transfusions, lower amounts of blood products (2.5 ± 0.38 vs. 4.1 ± 0.39; P = 0.02), fresh frozen plasma (0.49 ± 0.14 vs.1.07 ± 0.14; P = 0.02), and platelet concentrates transfused (0.50 ± 0.15 vs. 1.13 ± 0.15; P = 0.02), lower blood loss (590 ± 50.4 vs. 820 ± 50.7; P = 0.01), and less repeat surgery (2.5 vs. 6%; P = 0.01) were observed. These results are more marked in patients with a high risk for transfusion.

Conclusions:

A high dose of TA does not reduce incidence of blood product transfusion up to day 7, but is more effective than a low dose to decrease transfusion needs, blood loss, and repeat surgery.

Efficacy and safety of using antifibrinolytic agents in spine surgery: a meta-analysis

PURPOSE

Spine surgery, particularly reconstructive surgery, can be associated with significant blood loss, and blood transfusion. Antifibrinolytic agents are used routinely to reduce bleeding in cardiac, orthopaedic, and hepatic surgery. The purpose of this study was to assess the efficacy and safety of using antifibrinolytic agents in reducing blood loss and blood transfusions in spine surgery.

METHODS

A systematic search of all related studies written in English published by October 2012 was conducted using the MEDLINE, EMBASE and the Cochrane Library databases. Randomized controlled trials that reported the drug dosage, total blood loss, blood transfusion and incidence of deep vein thrombosis as the primary outcome were included.

RESULTS

Nine studies involving 482 patients were identified. Patients receiving antifibrinolytic agents had reduced blood loss (WMD =-288.8, 95 % CI - 46.49, - 110.19; P = 0.002), reduced blood transfusion (WMD =-242.7, 95 % CI - 422.57, - 62.95; P = 0.008), reduced blood transfusion rate (RR 0.73, 95% CI 0.58, 0.93; p = 0.010) and no increase (RR 0.25, 95 % CI 0.03, 2.22; P = 0.21) in the risk of deep vein thrombosis.

CONCLUSIONS

We conclude that antifibrinolytic agents significantly decrease blood loss, blood transfusion, and there is no increase in the risk of deep vein thrombosisfor transfusion requirements in spine surgery.

Repeat-dose intravenous tranexamic acid further decreases blood loss in total knee arthroplasty

PURPOSE

Tranexamic acid (TXA) reduces blood loss in patients undergoing total knee arthroplasty (TKA). However, few studies have reported the optimum timing and dosage for administration of TXA. The purpose of this study was to evaluate the effect of repeat-dose TXA on blood loss during TKA and the necessity of autologous blood donation or postoperative autotransfusion.

METHODS

We enrolled 78 patients with primary osteoarthritis undergoing cemented TKAs. Consecutive patients were divided into three groups, as follows: control group (n = 31), single-TXA group (n = 21) in whom TXA (1,000 mg) was intravenously administered 10 min before deflation of the tourniquet, and twice-TXA group (n = 26) in whom TXA (1,000 mg) was intravenously administered 10 min before deflation of the tourniquet and 3 h after the operation. We measured the volume of drained blood after the operation. Haemoglobin (Hb) levels were measured at days 1, 4 and 7 postoperation. Venous thromboembolic events (VTE) were screened using compression ultrasonography at enrollment and 1 and 7 days after operation.

RESULTS

The mean volume of drained blood after the operation was lower in the twice-TXA group than in the single-TXA (p < 0.001) and control (p < 0.0001) groups. No significant differences were observed in the incidence of VTE between these groups.

CONCLUSION

Administration of TXA twice reduced postoperative blood loss after TKA, and TXA was not associated with the risk of deep-vein thrombosis (DVT) or pulmonary embolism (PE). Further, administration of TXA twice may eliminate the need for blood transfusion during TKA.

[Haemorrhage and morbidity associated with the use of tranexamic acid in cardiac surgery: a retrospective, multicentre cohort study]

INTRODUCTION

Postoperative bleeding is common complication, affecting up to 20% of patients, after cardiac bypass surgery. Fibrinolysis is one of the causes of this excessive bleeding, and for this reason the use of tranexamic acid is recommended. The problem with using this is that there are numerous guidelines and differences in the dose to be administered. Our aim was to evaluate whether there were any differences in postoperative bleeding and morbidity after cardiac surgery with the administering of different tranexamic acid doses in three university hospitals.

MATERIAL AND METHODS

A retrospective, multicentre cohort study was conducted. A total of 146 patients who were subjected to elective cardiac bypass surgery according to the anaesthetic-surgical protocol of each hospital were included in the study. The clinical histories were reviewed, and they were divided into two groups according to the tranexamic acid dose: Group A (high doses), initial dose of 20mg/kg and continuous infusion of 4 mg/kg/hour until closure of the sternotomy. A further 100mg was added to prime the bypass machine. Group B (low doses), initial dose of 10mg/kg followed by a continuous infusion of 2mg/kg/hour until closure of the sternotomy. A further 50mg was added to prime the bypass machine. Variables, such as age, sex, weight, height, type of surgical procedure (valvular, coronary or mixed), haematocrit, INR, and preoperative platelet count, time and temperature of the bypass machine, and haematocrit on sternum closure, were recorded. Among the post-operative variables collected were: debit due to drainage at 6, 12 and 24 hours after surgery, number and type of blood products transfused in the first 24 hours, need for further surgery due to haemorrhage, CVA, TIA, or a new acute myocardial infarction, convulsions, and mortality.

RESULTS

The incidence of increased bleeding (patients in the 90 percentile) was higher in Group B at all the study evaluation times (P<.05). The incidence of further surgery due to bleeding, and the need for transfusion of ≥ 3 units of packed red cells was lower in Group A (5.56%) than in Group B (13.89%). There were no significant differences in the requirements for blood products transfusions between the groups. As regards associated morbidity, there was one isolated case of convulsion and a perioperative AMI in another case in Group A, and three cases of perioperative AMI in Group B.

CONCLUSIONS

Elevated doses of tranexamic acid in cardiac bypass surgery appear to significantly reduce bleeding in the first hours after surgery compared to low doses. However, this decrease did not lead to a reduction in the needs for blood products.

Tranexamic acid reduces blood transfusions in elderly patients undergoing combined aortic valve and coronary artery bypass graft surgery: a randomized controlled trial

OBJECTIVE

To evaluate the effects of tranexamic acid on postoperative blood loss and transfusion requirements in elderly patients undergoing combined aortic valve replacement and coronary artery bypass graft surgery (CABG).

DESIGN

A prospective, randomized, double-blinded, placebo-controlled, parallel-group trial.

SETTING

A university hospital (single institution).

PARTICIPANTS

Sixty-four patients 70 years or older undergoing combined aortic valve replacement and CABG surgery were included. One patient was withdrawn from the study after randomization by the attending surgeon because of a change in the surgical procedure. The remaining 63 patients were analyzed as intention to treat.

INTERVENTIONS

The included patients were randomized to treatment with either tranexamic acid, 10 mg/kg, as a bolus injection before surgery followed by 1 mg/kg/h as an infusion during surgery, or a corresponding volume of 0.9% sodium chloride.

MEASUREMENTS AND MAIN RESULTS

Postoperative blood loss was recorded for 16 hours. The transfusion of blood products was recorded during the entire hospital stay. The number of packed red cell transfusions given to the patients was significantly lower in the tranexamic acid group compared with the placebo group (median, 3.0 [interquartile range, 2-5] v 5.0 [3-7], p = 0.049).

CONCLUSION

Tranexamic acid reduced the number of packed red cell transfusions given to patients 70 years or older undergoing combined aortic valve replacement and CABG surgery.

Safety and effectiveness of two treatment regimes with tranexamic acid to minimize inflammatory response in elective cardiopulmonary bypass patients: a randomized double-blind, dose-dependent, phase IV clinical trial

BACKGROUND

In cardiopulmonary bypass (CPB) patients, fibrinolysis may enhance postoperative inflammatory response. We aimed to determine whether an additional postoperative dose of antifibrinolytic tranexamic acid (TA) reduced CPB-mediated inflammatory response (IR).

METHODS

We performed a randomized, double-blind, dose-dependent, parallel-groups study of elective CPB patients receiving TA. Patients were randomly assigned to either the single-dose group (40 mg/Kg TA before CPB and placebo after CPB) or the double-dose group (40 mg/Kg TA before and after CPB).

RESULTS

160 patients were included, 80 in each group. The incident rate of IR was significantly lower in the double-dose-group TA2 (7.5% vs. 18.8% in the single-dose group TA1; P = 0.030). After adjusting for hypertension, total protamine dose and temperature after CPB, TA2 showed a lower risk of IR compared with TA1 [OR: 0.29 (95% CI: 0.10-0.83), (P = 0.013)]. Relative risk for IR was 2.5 for TA1 (95% CI: 1.02 to 6.12). The double-dose group had significantly lower chest tube bleeding at 24 hours [671 (95% CI 549-793 vs. 826 (95% CI 704-949) mL; P = 0.01 corrected-P significant] and lower D-dimer levels at 24 hours [489 (95% CI 437-540) vs. 621(95% CI: 563-679) ng/mL; P = 0.01 corrected-P significant]. TA2 required lower levels of norepinephrine at 24 h [0.06 (95% CI: 0.03-0.09) vs. 0.20(95 CI: 0.05-0.35) after adjusting for dobutamine [F = 6.6; P = 0.014 corrected-P significant]. We found a significant direct relationship between IL-6 and temperature (rho = 0.26; P < 0.01), D-dimer (rho = 0.24; P < 0.01), norepinephrine (rho = 0.33; P < 0.01), troponin I (rho = 0.37; P < 0.01), Creatine-Kinase (rho = 0.37; P < 0.01), Creatine Kinase-MB (rho = 0.33; P < 0.01) and lactic acid (rho = 0.46; P < 0.01) at ICU arrival. Two patients (1.3%) had seizure, 3 patients (1.9%) had stroke, 14 (8.8%) had acute kidney failure, 7 (4.4%) needed dialysis, 3 (1.9%) suffered myocardial infarction and 9 (5.6%) patients died. We found no significant differences between groups regarding these events.

CONCLUSIONS

Prolonged inhibition of fibrinolysis, using an additional postoperative dose of tranexamic acid reduces inflammatory response and postoperative bleeding (but not transfusion requirements) in CPB patients. A question which remains unanswered is whether the dose used was ideal in terms of safety, but not in terms of effectiveness.

High-dose tranexamic acid reduces blood loss in postpartum haemorrhage

Introduction

Our purpose in conducting this study was to determine whether administration of high-dose tranexamic acid (TA) at the time of diagnosis of postpartum haemorrhage (PPH) could reduce blood loss.

Methods

This was a randomised, controlled, multicentred, open-label trial. Women with PPH >800 mL following vaginal delivery were randomly assigned to receive TA (loading dose 4 g over 1 hour, then infusion of 1 g/hour over 6 hours) or not. In both groups, packed red blood cells (PRBCs) and colloids could be used according to French guidelines. The use of additional procoagulant treatments was permitted only in cases involving intractable bleeding. The primary objective was to assess the efficacy of TA in the reduction of blood loss in women with PPH, and the secondary objectives were the effect of TA on PPH duration, anaemia, transfusion and the need for invasive procedures.

Results

A total of 144 women fully completed the protocol (72 in each group). Blood loss between enrolment and 6 hours later was significantly lower in the TA group than in the control group (median, 173 mL; first to third quartiles, 59 to 377) than in controls (221 mL; first to third quartiles 105 to 564) (P = 0.041). In the TA group, bleeding duration was shorter and progression to severe PPH and PRBC transfusion was less frequent than in controls (P < 0.03). Invasive procedures were performed in four women in the TA group and in seven controls (P = NS). PPH stopped after only uterotonics and PRBC transfusion in 93% of women in the TA group versus 79% of controls (P = 0.016). Mild, transient adverse manifestations occurred more often in the TA group than in the control group (P = 0.03).

Conclusions

This study is the first to demonstrate that high-dose TA can reduce blood loss and maternal morbidity in women with PPH. Although the study was not adequately powered to address safety issues, the observed side effects were mild and transient. A larger international study is needed to investigate whether TA can decrease the need for invasive procedures and reduce maternal morbidity in women with PPH.

Trial registration

Controlled Trials ISRCTN09968140.

High-dose tranexamic acid is related to increased risk of generalized seizures after aortic valve replacement

OBJECTIVE

To investigate the incidence of postoperative generalized seizures in patients undergoing aortic valve replacement (AVR) under extracorporeal circulation, who received either high-dose tranexamic acid (TXA) or epsilon aminocaproic acid (EACA) as an antifibrinolytic agent.

METHODS

This retrospective analysis comprised 682 consecutive patients undergoing AVR with or without simultaneous coronary artery bypass surgery. Patients operated on before March 2008 were treated intra-operatively with TXA (100 mg kg⁻¹; n = 341), patients operated on after March 2008 received EACA (50 mg kg⁻¹ loading dose, followed by 25 mg kg⁻¹ h⁻¹, and an additional 5 g in the extracorporeal circuit; n = 341).

RESULTS

Clinically diagnosed generalized seizures were observed within the first 24h postoperatively, more frequently in patients receiving TXA compared with EACA (6.4% vs 0.6%, p < 0.001, difference = 5.8%, 95% confidence interval 3.1-8.5%). Besides the antifibrinolytic agent, three other variables differed significantly between patients with and without postoperative seizures: age (mean (SD), 77.0 (5.9) years vs 73.2 (9.0) years, p = 0.039), preoperative creatinine clearance (55.4 (16.5)ml min⁻¹ vs 72.6 (28.5)ml min⁻¹, p = 0.002), and administration of recombinant activated factor VIIa (3 out of 24 patients (12.5%) vs 8 out of 658 patients (1.2%), p = 0.005). Logistic regression analysis demonstrated a significant impact of the antifibrinolytic drug, creatinine clearance, and the application of recombinant activated factor VIIa on the occurrence of generalized seizures.

CONCLUSIONS

Our results indicate that high-dose TXA is associated with an increased incidence of postoperative generalized seizures in patients undergoing AVR compared with EACA, especially when suffering from renal impairment. A possible association between recombinant activated factor VIIa and the occurrence of postoperative seizures needs further investigation.

Lessons learned in antifibrinolytic therapy: The BART trial

Despite nearly 2 decades of published reports and clinical trials demonstrating the relative safety and efficacy of aprotinin in adult cardiac surgical patients at increased risk of bleeding-culminating in an official endorsement of the usage of aprotinin in such patients from both cardiac surgery and anesthesiology subspecialty committees-several more recent studies have raised profound concerns regarding the safety of aprotinin in these same patients. These studies and the implications thereof have ultimately resulted in the withdrawal of aprotinin from clinical usage internationally. This article will briefly review these developments with the hope of understanding how this abrupt turnabout took place and will attempt to understand how such events can be avoided in the future.

A comparison of aprotinin and lysine analogues in high-risk cardiac surgery

BACKGROUND

Antifibrinolytic agents are commonly used during cardiac surgery to minimize bleeding and to reduce exposure to blood products. We sought to determine whether aprotinin was superior to either tranexamic acid or aminocaproic acid in decreasing massive postoperative bleeding and other clinically important consequences.

METHODS

In this multicenter, blinded trial, we randomly assigned 2331 high-risk cardiac surgical patients to one of three groups: 781 received aprotinin, 770 received tranexamic acid, and 780 received aminocaproic acid. The primary outcome was massive postoperative bleeding. Secondary outcomes included death from any cause at 30 days.

RESULTS

The trial was terminated early because of a higher rate of death in patients receiving aprotinin. A total of 74 patients (9.5%) in the aprotinin group had massive bleeding, as compared with 93 (12.1%) in the tranexamic acid group and 94 (12.1%) in the aminocaproic acid group (relative risk in the aprotinin group for both comparisons, 0.79; 95% confidence interval [CI], 0.59 to 1.05). At 30 days, the rate of death from any cause was 6.0% in the aprotinin group, as compared with 3.9% in the tranexamic acid group (relative risk, 1.55; 95% CI, 0.99 to 2.42) and 4.0% in the aminocaproic acid group (relative risk, 1.52; 95% CI, 0.98 to 2.36). The relative risk of death in the aprotinin group, as compared with that in both groups receiving lysine analogues, was 1.53 (95% CI, 1.06 to 2.22).

CONCLUSIONS

Despite the possibility of a modest reduction in the risk of massive bleeding, the strong and consistent negative mortality trend associated with aprotinin, as compared with the lysine analogues, precludes its use in high-risk cardiac surgery. (Current Controlled Trials number, ISRCTN15166455 [controlled-trials.com].).

Tranexamic acid diminishes intraoperative blood loss and transfusion in spinal fusions for duchenne muscular dystrophy scoliosis

STUDY DESIGN

Retrospective review of intraoperative blood loss and blood replacement.

OBJECTIVE

We compared intraoperative blood loss and blood replacement during spinal fusion surgery for scoliosis in Duchenne muscular dystrophy (DMD) performed with and without the synthetic antifibrinolytic agent tranexamic acid (TXA).

SUMMARY OF BACKGROUND DATA

High levels of intraoperative blood loss are widely documented in DMD patients undergoing posterior spinal fusion for scoliosis. The effect of the antifibrinolytic agent tranexamic acid on decreasing the blood loss has not been studied in a large group of DMD patients.

METHODS

All 56 DMD patients underwent posterior spinal fusion with the same technique using 2 rods and multiple sublaminar wires. TXA was not used in 36 patients and was used in 20. In the respective groups, the age at surgery (14 vs. 13.9 years), the preoperative deformity (45 degrees vs. 51 degrees ), the mean number of levels fused (14.3 vs. 14.7), and the mean surgical times (446 minutes vs. 459 minutes) were similar. TXA dose was 100 mg/kg in solution over 15 minutes before incision followed by an infusion of 10 mg/kg per hour during surgery. Standardized measurements of intraoperative blood loss were used and calculated to compare total amount of blood loss in milliliters per patient and blood loss as a percentage in relation to estimated blood volume [estimated blood loss (EBL)/estimated blood volume (EBV) x 100]. The EBV was calculated to be 70 mL/kg (body weight).

RESULTS

Mean blood loss with TXA was 1944 +/- 789 mL (range, 760-4000 mL) and without TXA was 3382 +/- 1795 mL (range, 600-9580 mL) (P < 0.001). Blood loss with TXA decreased by 42% compared with those not treated with TXA. Accounting for patient weight and estimated blood volume, mean % blood loss with and without TXA was 47% +/- 28% versus 112% +/- 67% (P < 0.001). This physiologic indicator shows that blood loss with TXA decreased by 58% compared with those patients not treated with TXA. TXA was also found to reduce blood loss after accounting for surgical time. No hypercoagulation or other complications from TXA therapy were observed. The reduced blood loss in TXA-treated patients translated into decreased blood transfusions. Transfusion of homologous whole blood and packed red blood cells in the TXA group was decreased by 46% compared with the no TXA group (mean levels, 512 +/- 470 mL vs. 955 +/- 718 mL), and transfusion of autologous cell saver blood was decreased by 42% in the TXA group (mean levels, 419 +/- 235 mL vs. 728 +/- 416 mL).

CONCLUSION

TXA significantly reduces both intraoperative blood loss and the need for homologous transfusion of whole blood and packed red blood cells in DMD patients undergoing posterior spinal fusion for scoliosis.

The impact of administration of tranexamic acid in reducing the use of red blood cells and other blood products in cardiac surgery

Background

To study the effect of administration of tranexamic acid on the use of blood and blood products, return to theatre for post-operative bleeding and the length of intensive care stay after primary cardiac surgery, data for 4191 patients, of all priorities, who underwent primary cardiac operation during the period between 30/10/00 and 21/09/04 were analysed.

Methods

Retrospective analysis of data collected prospectively during the study period. The main outcome measures were whether or not patients were transfused with red blood cells, fresh frozen plasma or any blood product, the proportion of patients returned to theatre for investigation for post-operative bleeding and length of stay in the intensive care unit. We performed univariate analysis to identify the factors influencing the outcome measures and multivariate analysis to identify the effect of administration of tranexamic acid on the outcome measures.

Results

Administration of tranexamic acid was an independent factor affecting the transfusion of red blood cells, fresh frozen plasma or any blood product. It was also an independent factor influencing the rate of return to theatre for exploration of bleeding. The odds of receiving a transfusion or returning to theatre for bleeding were significantly lower in patients receiving tranexamic acid. The administration of tranexamic acid also significantly decreased blood loss. We did not find any association between the administration of tranexamic acid and the length of intensive care stay.

Conclusion

Based on the analysis of 4191 patients who underwent a primary cardiac operation, administration of tranexamic acid decreased the number of patients exposed to a transfusion or returned to theatre for bleeding in our institute.

Does fast-track treatment lead to a decrease of intensive care unit and hospital length of stay in coronary artery bypass patients? A meta-regression of randomized clinical trials*

OBJECTIVE

Evaluation of randomized, controlled clinical trials studying fast-track treatment in low-risk coronary artery bypass grafting patients.

DESIGN

Meta-regression.

PATIENTS

Low-risk coronary artery bypass grafting patients.

INTERVENTIONS

Fast-track treatments including (high or low) anesthetic dose, normothermia vs. hypothermia, and extubation protocol (within or after 8 hrs).

MEASUREMENTS

Number of hours of intensive care unit stay, number of days of hospital stay, prevalence of myocardial infarction, and death. Furthermore, quality of life and cost evaluations were evaluated. The epidemiologic and economic qualities of the different trials were also assessed.

MAIN RESULTS

A total of 27 studies evaluating fast-track treatment were identified, of which 12 studies were with major and 15 were without major differences in extubation protocol or anesthetic treatment or both. The use of an early extubation protocol (p=.000) but not the use of a low anesthetic dose (p=.394) or normothermic temperature management (p=.552) resulted in a decrease of the total intensive care unit stay of low-risk coronary artery bypass grafting patients. Early extubation was found to be an important determinant of the total hospital stay for these patients. An influence of the type of fast-track treatment on mortality or the prevalence of postoperative myocardial infarction was not observed. In general, the epidemiologic and economic qualities of included studies were moderate.

CONCLUSIONS

Although fast-track anesthetics and normothermic temperature management facilitate early extubation, the introduction of an early extubation protocol seems essential to decrease intensive care unit and hospital stay in low-risk coronary artery bypass grafting patients.

Tranexamic acid and early saphenous vein graft patency in conventional coronary artery bypass graft surgery: a prospective randomized controlled clinical trial

OBJECTIVE

Use of antifibrinolytic agents reduces the risk of bleeding and decreases the need for blood product use in patients undergoing cardiac surgery. The purpose of this study was to determine whether perioperative use of tranexamic acid decreases the rate of saphenous vein graft patency in the early postoperative period after conventional coronary artery bypass grafting surgery.

METHODS

A total of 312 patients scheduled for elective coronary artery bypass grafting surgery with cardiopulmonary bypass were randomized to receive either tranexamic acid 100 mg/kg (n = 147) or placebo (n = 165) in a double-blinded fashion before the initiation of cardiopulmonary bypass. Saphenous vein graft patency was assessed with magnetic resonance imaging 5 to 30 days after surgery.

RESULTS

Both groups were comparable with respect to baseline demographic data and surgical characteristics. A total of 237 (76%) patients underwent magnetic resonance imaging assessment. A total of 297 saphenous vein grafts were performed and 253 (85.2%; 95% confidence interval, 83.5%-86.9%) were seen in the tranexamic acid group, and 265 saphenous vein grafts were performed and 231 (87.2%; 95% confidence interval, 85.5%-88.9%) were seen in the placebo group (P = .4969). The blood loss and blood product transfusion rates in the tranexamic acid group were significantly lower than in the placebo group. There was no difference between groups with respect to postoperative morbidity and mortality.

CONCLUSIONS

The administration of tranexamic acid before cardiopulmonary bypass did not seem to compromise early venous graft patency rates but reduced perioperative blood product transfusion rates. Consequently, tranexamic acid could be advocated for routine use in patients undergoing conventional coronary artery bypass grafting surgery.

The effects of aprotinin and tranexamic acid on thrombin generation and fibrinolytic response after cardiac surgery

BACKGROUND

Thrombin formation during cardiac surgery could result in disordered hemostasis and thrombosis. The aim of the study was to examine the effects of aprotinin and tranexamic acid on thrombin generation and fibrinolytic activity in patients undergoing cardiac surgery.

METHODS

Data were collected prospectively from 60 patients undergoing coronary artery bypass grafting using cardiopulmonary bypass (CPB). In a randomized sequence, 20 patients received aprotinin, 20 patients received tranexamic acid, and in 20 patients placebo was used.

RESULTS

Significant thrombin activity was found in all the studied patients. Thrombin generation was less in the aprotinin group than in the tranexamic acid and the placebo group (thrombin/anti-thrombin III complexes 33.7 +/- 3.6, 53.6 +/- 7.0 and 44.2 +/- 5.3 microg/l 2 h after CPB and F1 + 2 fragment 1.50 +/- 0.10, 2.37 +/- 0.37 and 2.04 +/- 0.20 nmol/l 6 h after surgery, respectively). The inhibition of fibrinolysis was significant with both anti-fibrinolytic drugs (D-dimers 0.427 +/- 0.032, 0.394 +/- 0.039 and 2.808 +/- 0.037 mg/l 2 h after CPB, respectively). The generation of d-dimers was inhibited until 16 h after CPB in the aprotinin group. The plasminogen activation was significantly less in the aprotinin group (plasmin/anti-plasmin complexes 0.884 +/- 0.095, 2.764 +/- 0.254 and 1.574 +/- 0.185 mg/l 2 h after CPB, respectively).

CONCLUSION

Thrombin formation is inevitable in coronary artery bypass surgery when CPB is used. The suppression of fibrinolytic activity, either with aprotinin or with tranexamic acid interferes with the hemostatic balance as evaluated by biochemical markers. Further investigations are needed to define the role of hemostatic activation in ischemic complications associated with cardiac surgery.

A pilot trial evaluating the clinical effects of prolonged storage of red cells

The clinical consequences of prolonged storage of red cells have not been established. In this pilot study, we evaluated whether it would be feasible to provide a continuous supply of red cells stored <8 days. In addition, we examined the potential benefits attributed to "fresh" as compared to standard red cells in 66 critically ill and cardiac surgical patients. Nine patients were issued red cells but were not transfused. From the 57 remaining patients, the number of units transfused averaged 5.5 +/- 8.43 red cell units in the experimental group compared to 3.3 +/- 3.27 red cell units in the standard group (P = 0.25). The median storage time was 4 days in the experimental group compared to 19 days in the standard group (difference of 15 days; interquartile range of 12-16 days; P < 0.001). Overall, 73% of patients received red cells with storage times that corresponded to the treatment allocation more than 90% of the time. The group receiving red cells <8 days old tended to be older on average (68 +/- 8.54 yr versus 63 +/- 15.30 yr; P = 0.13) and have more comorbid illnesses (85% versus 65%; P = 0.09). In total, 27% of patients in the experimental group died or had a life-threatening complication as compared to 13% in the standard group (P = 0.31). There were no differences in prolonged respiratory, cardiovascular, or renal support after randomization (P > 0.05). A large clinical trial comparing red cell storage times is feasible and warranted given the limited available evidence.

Tranexamic acid in aortic valve replacement

OBJECTIVE

To assess the relative efficacy of tranexamic acid compared with a control group to decrease bleeding and transfusion requirements in a uniform population undergoing aortic valve replacement.

DESIGN

Prospective, randomized, double-blind study.

SETTINGS

University hospital.

PARTICIPANTS

Adult cardiac surgery patients (n = 300).

INTERVENTIONS

Patients were randomized into 2 groups to receive either a total of 5 g of tranexamic acid or a saline solution. Bleeding in the postoperative period, transfusions of bank blood products, coagulation profile, intensive care unit stay, and hospital length of stay were recorded.

MEASUREMENTS AND MAIN RESULTS

Postoperative bleeding in patients treated with tranexamic acid was significantly lower compared with the control group (p < 0.0001). Packed red blood cells and fresh frozen plasma usage were reduced in the tranexamic acid group compared with the control group (p = 0.0095 and p < 0.0001). Only 24.5% of tranexamic acid patients received blood products versus 45% of control patients (p < 0.01). There was no significant difference in hematologic and coagulation profiles after the operation between the groups.

CONCLUSIONS

Tranexamic acid reduces postoperative blood loss and transfusion requirements in elective aortic valve replacement.