Natural and synthetic antifibrinolytics: inert, poisonous or therapeutic agents?

Efficacy of oral tranexamic acid on blood loss in primary total hip arthroplasty using a direct anterior approach: a prospective randomized controlled trial

BACKGROUND

Tranexamic acid (TXA), delivered intravenously or topically, has been shown to reduce blood loss, the need for transfusion, and relevant healthcare costs when administered in primary standard total hip arthroplasty (THA). Whether the same is true of oral TXA is unclear, the purpose of this study was to determine if oral tranexamic acid is equivalent to intravenous TXA in the case of patients undergoing THA via the direct anterior approach.

METHODS

In this prospective randomized controlled trial, 120 patients undergoing primary THA by the direct anterior approach were randomized to receive oral TXA (two doses of 20 mg/kg), intravenous TXA (two doses of 15 mg/kg), or no TXA. Primary outcomes were haemoglobin drop, haematocrit levels, total blood loss, intra-operative blood loss, need for transfusion, and volume transfused. Secondary outcomes included thromboembolic events, wound complications, the length of post-operative hospital stay, and 30-day readmission.

RESULTS

Demographic characteristics were similar among the three patient groups (p > 0.05, n = 40 per group). Haemoglobin drop, haematocrit levels, total blood loss, and intra-operative blood loss were similar in the oral and intravenous groups (p > 0.05), and significantly smaller than in the control group (p < 0.05). Transfusions were given to significantly fewer patients in the oral group (3%) and intravenous group (6%) than in the control group (27%, p = 0.01). Costs of TXA and transfusions were significantly lower in the oral group than the intravenous group (p < 0.05). The three groups were similar in thromboembolic events, wound complications, the length of post-operative hospital stay, and 30-day readmission (p > 0.05).

CONCLUSION

Oral TXA shows similar efficacy and safety as intravenous TXA for reducing haemoglobin drop, haematocrit levels, total blood loss, and transfusion rate following THA by the direct anterior approach. Therefore, the much less-expensive oral formulation may be superior to the intravenous form.

Effect of knee flexion position and combined application of tranexamic acid on blood loss following primary total knee arthroplasty: a prospective randomized controlled trial

PURPOSE

The aim of this study was to demonstrate the association between tranexamic acid (TXA)-combined application and knee flexion in the first 24 hour post-operatively that could reduce total blood loss and transfusion need in patients undergoing total knee arthroplasty (TKA), without sacrificing safety.

METHODS

Ninety TKA patients were divided into three groups randomly: the flexion group: the knee was in 90° flexion position for the first 12 hour post-surgery and kept at 60°for the next 12 hour, combined with 1 g TXA topical and 1 g TXA intravenous application. The extension group: the knee was in fully extension position post-operatively, combined with topical and intravenous TXA application. The controlled group: the knee was in fully extension position post-operatively combined with single intravenous TXA application. The primary outcomes included blood loss variables and transfusion values. The secondary outcomes included post-operative hospital stay, knee flexion degree, complication rate, and hospital charge.

RESULTS

The total blood loss and transfusion needs in the flexion group were significantly reduced in comparison with that in the extension group and controlled group. The post-operative knee flexion motion was significant higher in the flexion group than the other two groups. There was no difference among the three groups with regard to the rates of complications.

CONCLUSIONS

Keeping the knee in flexion position combined with topical and intravenous TXA application in patients undergoing primary unilateral TKA significantly reduced post-operative bleeding and the transfusion rate compared with what was found after treatment with extension knee position or single intravenous TXA application.

LEVEL OF EVIDENCE

Therapeutic Level I.

Intravenous Combined with Topical Administration of Tranexamic Acid in Primary Total Hip Arthroplasty: A Randomized Controlled Trial

OBJECTIVE

Although there are still some controversies, large previous studies have confirmed that intravenous (i.v.) tranexamic acid (TXA) can effectively reduce blood loss and transfusions in total hip arthroplasty (THA) without increasing the risk of deep venous thrombosis. However, few studies have investigated the combination of i.v. and topical application of TXA in primary THA. The purpose of our current study is to examine whether i.v. combined with topical administration of TXA decreases postoperative blood loss and transfusion rates after THA.

METHODS

From December 2013 to May 2014, all adult patients undergoing primary THA at our arthroplasty center were considered for inclusion in the present study. Included patients were randomly assigned to two groups by computer-generated list number: a TXA group and a placebo group. Patients in the TXA group received i.v. (15 mg/kg) combined with topical administration (1.0 g) of TXA during the THA procedure, and patients in the other group received the same dosage of normal saline both i.v. and topically. Our primary outcome measures were total blood loss (calculated using Gross's equation), hemoglobin, hematocrit and platelet concentration changes on the third postoperative day, the amount of drainage, the amount of intraoperative blood loss, the frequency of transfusion, and the number of blood units transfused. Secondary outcome measures were the length of postoperative stay, range of hip motion (measured by goniometer), Harris hip scores (HHS), and any perioperative complications or events such as infection, DVT or PE. Range of motion and HHS were measured at 3 week follow-up and compared with preoperative values.

RESULTS

This trial included 100 patients (50 in each group). Patients in the TXA group had significantly higher postoperative hemoglobin (103 vs 87.7 g/dL, P < 0.01), lower hemoglobin changes (32.2 vs 44.9 g/dL, P < 0.01), higher postoperative hematocrit (0.32 vs 0.27 L/L, P < 0.01), lower hematocrit changes (0.1 vs 0.14 L/L, P < 0.01), lower total blood loss (822 vs 1100 mL, P = 0.004), lower drainage (117.8 vs 242.4 mL, P < 0.01), lower intraoperative blood loss (193.8 vs 288.2 mL, P < 0.01), and lower transfusion rate (2% vs 34%, P < 0.01) compared with those in the placebo group. No statistical difference was found in postoperative platelets between the two groups. There were no differences in perioperative complications or venous thromboembolism (VTE) events.

CONCLUSIONS

The combined administration of i.v. and topical TXA resulted in a clinically relevant reduction in blood loss, compared with placebo group. No thromboembolic complications were observed. This randomized controlled trial supports the combined i.v. and topical administration of TXA in primary THA.

Tranexamic Acid Administration in Primary Total Hip Arthroplasty: A Randomized Controlled Trial of Intravenous Combined with Topical Versus Single-Dose Intravenous Administration

BACKGROUND

The use of tranexamic acid (TXA) in primary total hip arthroplasty is well documented. However, considering the potential side effects, including deep vein thrombosis and pulmonary embolism, the ideal method of providing TXA to patients undergoing total hip arthroplasty remains controversial. The objective of this trial was to assess the efficacy and safety of intravenous (IV) administration combined with topical administration of TXA regarding postoperative blood loss and transfusion rates in patients treated with primary unilateral total hip arthroplasty.

METHODS

In this prospective, randomized controlled trial, 150 patients were divided into three groups: the combined group (IV administration of 15 mg/kg of TXA combined with topical administration of 1 g/100 mL of TXA), the single IV group (IV administration of 15 mg/kg of TXA), and the placebo group. The primary outcomes included blood-loss variables (total, intraoperative, and drainage blood loss; changes in hemoglobin, hematocrit, and platelet concentration; and amount of IV transfusion fluid) and transfusion values (frequency of transfusion and number of transfused blood units). The secondary outcomes included the length of the hospital stay, range of hip motion, Harris hip score, and prevalences of deep vein thrombosis and pulmonary embolism.

RESULTS

The total blood loss in the combined group (mean and standard deviation, 835.49 ± 343.50 mL) was significantly reduced (p < 0.05) in comparison with that in the single IV group (1002.62 ± 366.85 mL) and placebo group (1221.11 ± 386.25 mL). The combined group also had fewer transfusions in comparison with the single IV and placebo groups (1, 8, and 19, respectively; p < 0.05). There was no difference among the 3 groups with regard to the rates of deep vein thrombosis or pulmonary embolism.

CONCLUSIONS

Intravenous combined with topical administration of TXA in patients undergoing a primary unilateral total hip arthroplasty significantly reduced postoperative bleeding and the transfusion rate. Studies with more patients and longer follow-up are needed to confirm whether this promising combined strategy is safe with regard to thromboembolic complications.

LEVEL OF EVIDENCE

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

The beneficial effect of Batroxobin on blood loss reduction in spinal fusion surgery: a prospective, randomized, double-blind, placebo-controlled study

OBJECTIVE

Our objective was to evaluate the efficacy and safety of Batroxobin on blood loss during spinal operations.

METHODS

After obtaining approval from the ethics committee at the hospital along with informed written consent, we performed a double-blind, randomized, placebo-controlled study with 100 patients who were randomized equally into 2 groups (Batroxobin and placebo). Patients received either 2 ku IV 15 min before surgery and followed 1 ku IM of Batroxobin following surgery, or an equivalent volume of placebo (normal saline). Cost of Batroxobin treatment is amounted to 84.75 euros. The primary outcomes were intraoperative, 24 h postoperative, and total perioperative blood loss. Secondary outcomes were hemoglobin (Hb), red blood cell count (RBC), the volume of blood/fluid transfusion intraoperatively, and 24 h postoperatively. Safety evaluation parameters were the incidence of venous thrombosis in the lower extremities, active partial thromboplastin time, prothrombin time, thrombin time, and fibrinogen. The data were analyzed using the Statistical Package for the Social Science Version 12.0. The results were presented as mean ± SEM. The Mann-Whitney test and Independent Student t test, when appropriate, were used to compare the 2 groups, and differences were considered significant if the P value was <0.05.

RESULTS

88 patients were included in the analysis while 12 patients were withdrawn from the study due to extended surgical duration, change of surgical procedure, or after the patients' request. The total perioperative blood loss was approximately 31% lower in patients given Batroxobin versus placebo (700.5 ± 45.81 vs 485.7 ± 30.01 mL, P = 0.001). The Batroxobin group had significantly less intraoperative blood loss (326.1 ± 24.16) compared to the placebo group (556.0 ± 43.58), but there was no difference in the amount of blood/fluid transfused, postoperatively Hb, or RBC between the two groups. After the operation, coagulation parameters were not significantly different between the 2 groups at the days 1 or 3 postoperatively. No adverse events related to the use of Batroxobin were recorded. There were no cases of superficial wound infection. None of the subjects died during the study.

CONCLUSIONS

In this study, prophylactic use of Batroxobin provided an effective and cheap method for reducing blood loss without coagulopathy during or after operations. The use of Batroxobin for patients undergoing one-level PLIF surgery safely and effectively reduced the total amount of perioperative blood loss.

Efficacy of tranexamic acid on surgical bleeding in spine surgery: a meta-analysis

BACKGROUND CONTEXT

Spine surgery is usually associated with large amount of blood loss, necessitating blood transfusions. Blood loss-associated morbidity can be because of direct risks, such as hypotension and organ damage, or as a result of blood transfusions. The antifibrinolytic, tranexamic acid (TXA), is a lysine analog that inhibits activation of plasminogen and has shown to be beneficial in reducing surgical blood loss.

PURPOSE

To consolidate the findings of randomized controlled trials (RCTs) investigating the use of TXA on surgical bleeding in spine surgery.

STUDY DESIGN

A metaanalysis.

STUDY SAMPLE

Randomized controlled trials investigating the effectiveness of intravenous TXA in reducing blood loss in spine surgery, compared with a placebo/no treatment group.

METHODS

MEDLINE, Embase, Cochrane controlled trials register, and Google Scholar were used to identify RCTs published before January 2014 that examined the effectiveness of intravenous TXA on reduction of blood loss and blood transfusions, compared with a placebo/no treatment group in spine surgery. Metaanalysis was performed using RevMan 5. Weighted mean difference with 95% confidence intervals was used to summarize the findings across the trials for continuous outcomes. Dichotomous data were expressed as risk ratios with 95% confidence intervals. A p<.05 was considered statistically significant.

RESULTS

Eleven RCTs were included for TXA (644 total patients). Tranexamic acid reduced intraoperative, postoperative, and total blood loss by an average of 219 mL ([-322, -116], p<.05), 119 mL ([-141, -98], p<.05), and 202 mL ([-299, -105], p<.05), respectively. Tranexamic acid led to a reduction in proportion of patients who received a blood transfusion (risk ratio 0.67 [0.54, 0.83], p<.05) relative to placebo. There was one myocardial infarction (MI) in the TXA group and one deep vein thrombosis (DVT) in placebo.

CONCLUSIONS

Tranexamic acid reduces surgical bleeding and transfusion requirements in patients undergoing spine surgery. Tranexamic acid does not appear to be associated with an increased incidence of pulmonary embolism, DVT, or MI.

Reduced blood loss after intra-articular tranexamic acid injection during total knee arthroplasty: a meta-analysis of the literature

PURPOSE

The purpose of the study is to conduct a meta-analysis of randomized, controlled trials evaluating the efficacy and safety of intra-articular injection of tranexamic acid (TXA) for reducing blood loss and transfusion in patients undergoing total knee arthroplasty (TKA).

METHODS

A meta-analysis was conducted of RCTs published before March 2013, identified from the PubMed, EMBase, Cochrane library, ScienceDirect, and other databases. Two independent reviewers assessed the methodological quality of the studies and performed data extraction. Mean difference in blood loss and blood transfusions, risk ratios of transfusion rates, and deep vein thrombosis (DVT) incidence in the TXA-treated group versus placebo group were pooled from the included studies. Data were analysed using Stata 11.0 software.

RESULTS

Six studies were included, with a total sample size of 647 patients. The use of TXA significantly reduced total blood loss (mean difference: -344.96; 95% confidence interval (CI) -401.20 to -239.68; P < 0.01) and the proportion of patients requiring blood transfusions (risk ratios, 0.28; 95% CI: 0.19-0.42; P < 0.01). There were no significant differences in the incidence of DVT, pulmonary embolism, or other complications between the study groups.

CONCLUSIONS

The present meta-analysis indicated that intra-articular injection of TXA in patients undergoing TKA may reduce total blood loss and the need for blood transfusions, particularly when a high dosage of TXA is used (≥30 mg/ml), without any increase in the risk of post-operative DVT.

LEVEL OF EVIDENCE

II.

The use of tranexamic acid to reduce blood loss and transfusion in major orthopedic surgery: a meta-analysis

BACKGROUND

Conflicting reports have been published regarding the effect of tranexamic acid (TXA) on reducing blood loss and transfusion in patients undergoing orthopedic surgery. We performed a meta-analysis to evaluate the effectiveness and safety of TXA treatment in reducing blood loss and transfusion in major orthopedic surgery.

MATERIALS AND METHODS

MEDLINE, PubMed, EMBASE, and Cochrane databases were searched for relevant studies. Only randomized controlled trials were eligible for this study. The weighted mean difference in blood loss, number of transfusions per patient, and the summary risk ratio of transfusion and deep vein thrombosis (DVT) were calculated in the TXA-treated group and the control group.

RESULTS

A total of 46 randomized controlled trials involving 2925 patients were included. The use of TXA reduced total blood loss by a mean of 408.33 mL (95% confidence interval [CI], -505.69 to -310.77), intraoperative blood loss by a mean of 125.65 mL (95% CI, -182.58 to -68.72), postoperative blood loss by a mean of 214.58 mL (95% CI, -274.63 to -154.52), the number of blood transfusions per patient by 0.78 U (95% CI, -0.19 to -0.37), and the volumes of blood transfusions per patient by 205.33 mL (95% CI, -301.37 to -109.28). TXA led to a significant reduction in transfusion requirements (relative risk, 0.51; 95% CI, 0.46-0.56), and no increase in the risk of DVT (relative risk, 1.11; 95% CI, 0.69-1.79).

CONCLUSIONS

TXA significantly reduced blood loss and blood transfusion requirements in patients undergoing orthopedic surgery, and did not appear to increase the risk of DVT.

Systematic review and meta-analysis of perioperative intravenous tranexamic acid use in spinal surgery

BACKGROUND

Tranexamic acid (TXA) is well-established as a versatile oral, intramuscular, and intravenous (IV) antifibrinolytic agent. However, the efficacy of IV TXA in reducing perioperative blood transfusion in spinal surgery is poorly documented.

METHODOLOGY

We conducted a meta-analysis of randomized controlled trials (RCTs) and quasi-randomized (qi-RCTs) trials that included patients for various spinal surgeries, such as adolescent scoliosis surgery administered with perioperative IV TXA according to Cochrane Collaboration guidelines using electronic PubMed, Cochrane Central Register of Controlled Trials, and Embase databases. Additional journal articles and conference proceedings were manually located by two independent researchers.

RESULTS

Totally, nine studies were included, with a total sample size of 581 patients. Mean blood loss was decreased in patients treated with perioperative IV TXA by 128.28 ml intraoperatively (ranging from 33.84 to 222.73 ml), 98.49 ml postoperatively (ranging from 83.22 to 113.77 ml), and 389.21 ml combined (ranging from 177.83 to 600.60 ml). The mean volume of transfused packed cells were reduced by 134.55 ml (ranging 51.64 to 217.46) (95% CI; P = 0.0001). Overall, the number of patients treated with TXA who required blood transfusions was lower by 35% than that of patients treated with the comparator and who required blood transfusions (RR 0.65; 95% CI; 0.53 to 0.85; P<0.0001, I(2) = 0%). A dose-independent beneficial effect of TXA was observed, and confirmed in subgroup and sensitivity analyses. A total of seven studies reported DVT data. The study containing only a single DVT case was not combined.

CONCLUSIONS

The blood loss was reduced in spinal surgery patients with perioperative IV TXA treatment. Also the percentage of spinal surgery patients who required blood transfusion was significantly decreased. Further evaluation is required to confirm our findings before TXA can be safely used in patients undergoing spine surgery.

The association of epsilon-aminocaproic acid with postoperative decrease in creatinine clearance in 1502 coronary bypass patients

Renal dysfunction is a common serious complication after cardiac surgery. Reports of proteinuria and hyperkalemia after cardiac surgery with epsilon-aminocaproic acid (EACA) have therefore raised concerns for renal safety. Since EACA renders these markers unreliable, we used perioperative change in creatinine clearance (DCrCl) to test the hypothesis that EACA is associated with greater reductions in creatinine clearance after heart surgery, particularly for patients with renal disease. We evaluated data from all elective primary coronary bypass patients during EACA introduction at our institution (July 1, 1991-December 31, 1992; 10 g iv bolus pre-cardiopulmonary bypass, then 1 g/h for 5 h). DCrCl was calculated using preoperative (CrPre) and postoperative peak serum creatinine values, using the Cockroft-Gault equation. Patients with CrPre > or = 133 micromol/L were also separately analyzed. Evaluated patients (n = 1502, +/-EACA; 581/905, 16 exclusions) included 233 with CrPre > or = 133 micromol/L (+/-EACA; 98/135). Multivariate analyses confirmed several known risk factors, but no association between DCrCl and EACA in all patients (P: = 0.66), and the subgroup with CrPre > or = 133 micromol/L (P: = 0.42).

IMPLICATIONS

In a large population of primary Coronary Artery Bypass Graft including a subset with preoperative renal dysfunction, there were no postoperative reductions in creatinine clearance attributable to epsilon-aminocaproic (EACA) administration. This retrospective study suggests that moderate epsilon-aminocaproic acid dosing during cardiac surgery is safe for the kidney; however, this inference is based on a single marker of renal dysfunction and requires prospective confirmation using a variety of tests of renal function.

Efficacy of epsilon-aminocaproic acid in children undergoing cardiac surgery

OBJECTIVE

To compare coagulation test results, blood loss, and blood product transfusions between patients receiving prophylactic epsilon-aminocaproic acid (EACA) and a control group matched for age, resternotomy, and surgery in children undergoing cardiac surgery.

DESIGN

Nested case-control study.

SETTING

University-affiliated, pediatric medical center.

PARTICIPANTS

Same study period; 70 patients in EACA group and 70 patients in control group.

INTERVENTIONS

Prophylactic EACA administered intravenously (load, 150 mg/kg, infusion; 30 mg/kg/h) to 70 patients at increased risk for bleeding (reoperation or Ross procedure).

MEASUREMENTS AND MAIN RESULTS

Coagulation test values were measured before, during, and after cardiopulmonary bypass (CPB). Intraoperative blood loss, postoperative chest tube output, and allogenic blood product transfusions were recorded. Comparison of demographic and surgical data indicated close matching of the EACA and control groups. The EACA group ([median, 25th to 75th quartile] 15.6 mL/kg; 9.2 to 26.3 mL/kg) had less intraoperative blood loss than the control group (22.2 mL/kg; 14.3 to 36.3 mL/kg; p = 0.02). Postoperative chest tube output at 6 hours (p = 0.08), 12 hours (p = 0.07), and 24 hours (p = 0.08) was not significantly different between groups. Fewer EACA group patients required reexploration for bleeding (p < 0.05). There was no difference between groups in blood products transfused (in milliliters per kilogram or allogenic exposure per patient). Thromboelastography values (maximum amplitude [MA], whole blood clot lysis index at 30 minutes after MA) during CPB were better preserved in the EACA group.

CONCLUSION

EACA reduced intraoperative blood loss but did not significantly decrease blood product transfusions. Lack of efficacy may be related to relative underdosing and should be further studied.

Tranexamic acid: a review of its use in surgery and other indications

Tranexamic acid is a synthetic derivative of the amino acid lysine that exerts its antifibrinolytic effect through the reversible blockade of lysine binding sites on plasminogen molecules. Intravenously administered tranexamic acid (most commonly 10 mg/kg followed by infusion of 1 mg/kg/hour) caused reductions relative to placebo of 29 to 54% in postoperative blood losses in patients undergoing cardiac surgery with cardiopulmonary bypass (CPB), with statistically significant reductions in transfusion requirements in some studies. Tranexamic acid had similar efficacy to aprotinin 2 x 10(6) kallikrein inhibitory units (KIU) and was superior to dipyridamole in the reduction of postoperative blood losses. Transfusion requirements were reduced significantly by 43% with tranexamic acid and by 60% with aprotinin in 1 study. Meta-analysis of 60 trials showed tranexamic acid and aprotinin, unlike epsilon-aminocaproic acid (EACA) and desmopressin, to reduce significantly the number of patients requiring allogeneic blood transfusions after cardiac surgery with CPB. Tranexamic acid was associated with reductions relative to placebo in mortality of 5 to 54% in patients with upper gastrointestinal bleeding. Meta-analysis indicated a reduction of 40%. Reductions of 34 to 57.9% versus placebo or control in mean menstrual blood loss occurred during tranexamic acid therapy in women with menorrhagia; the drug has also been used to good effect in placental bleeding, postpartum haemorrhage and conisation of the cervix. Tranexamic acid significantly reduced mean blood losses after oral surgery in patients with haemophilia and was effective as a mouthwash in dental patients receiving oral anticoagulants. Reductions in blood loss were also obtained with the use of the drug in patients undergoing orthotopic liver transplantation or transurethral prostatic surgery, and rates of rebleeding were reduced in patients with traumatic hyphaema. Clinical benefit has also been reported with tranexamic acid in patients with hereditary angioneurotic oedema. Tranexamic acid is well tolerated; nausea and diarrhoea are the most common adverse events. Increased risk of thrombosis with the drug has not been demonstrated in clinical trials.

CONCLUSIONS

Tranexamic acid is useful in a wide range of haemorrhagic conditions. The drug reduces postoperative blood losses and transfusion requirements in a number of types of surgery, with potential cost and tolerability advantages over aprotinin, and appears to reduce rates of mortality and urgent surgery in patients with upper gastrointestinal haemorrhage. Tranexamic acid reduces menstrual blood loss and is a possible alternative to surgery in menorrhagia, and has been used successfully to control bleeding in pregnancy.