The safety of aprotinin and lysine-derived antifibrinolytic drugs in cardiac surgery: a meta-analysis

Antifibrinolytic and Adjunct Hemostatic Agents: The Pediatric Extracorporeal Membrane Oxygenation Anticoagulation CollaborativE Consensus Conference

OBJECTIVES

To derive systematic-review informed, modified Delphi consensus regarding antifibrinolytic and adjunct hemostatic agents in neonates and children supported with extracorporeal membrane oxygenation (ECMO) for the Pediatric ECMO Anticoagulation CollaborativE consensus conference.

DATA SOURCES

A structured literature search was performed using PubMed, EMBASE, and Cochrane Library (CENTRAL) databases from January 1988 to May 2021.

STUDY SELECTION

Use of antifibrinolytics (epsilon-aminocaproic acid [EACA] or tranexamic acid), recombinant factor VII activated (rFVIIa), or topical hemostatic agents (THAs).

DATA EXTRACTION

Two authors reviewed all citations independently, with a third independent reviewer resolving conflicts. Eleven references were used for data extraction and informed recommendations. Evidence tables were constructed using a standardized data extraction form.

MEASUREMENTS AND MAIN RESULTS

Risk of bias was assessed using the Quality in Prognosis Studies tool. The evidence was evaluated using the Grading of Recommendations Assessment, Development, and Evaluation system. Forty-eight experts met over 2 years to develop evidence-based recommendations and, when evidence was lacking, expert-based consensus statements for the management of bleeding and thrombotic complications in pediatric ECMO patients. A web-based modified Delphi process was used to build consensus via the Research And Development/University of California Appropriateness Method. Consensus was defined as greater than 80% agreement. One weak recommendation and three consensus statements are presented.

CONCLUSIONS

Evidence supporting recommendations for administration of antifibrinolytics (EACA or tranexamic acid), rFVIIa, and THAs were sparse and inconclusive. Much work remains to determine effective and safe usage strategies.

Use of Aprotinin versus Tranexamic Acid in Cardiac Surgery Patients with High-Risk for Excessive Bleeding (APACHE) trial: a multicentre retrospective comparative non-randomized historical study

OBJECTIVES

Following the reintroduction of aprotinin into the European market, the French Society of Cardiovascular and Thoracic Anaesthesiologists recommended its prophylactic use at half-dose for high-risk cardiac surgery patients. We examined whether the use of aprotinin instead of tranexamic acid could significantly reduce severe perioperative bleeding.

METHODS

This multicentre, retrospective, historical study included cardiac surgery patients treated with aprotinin or tranexamic acid between December 2017 and September 2020. The primary efficacy end point was the severe or massive perioperative bleeding (class 3-4 of the universal definition of perioperative bleeding). The safety secondary end points included the occurrence of thromboembolic events and all-cause mortality within 30 days after surgery.

RESULTS

Among the 693 patients included in the study, 347 received aprotinin and 346 took tranexamic acid. The percentage of patients with severe or massive bleeding was similar in the 2 groups (42.1% vs 43.6%, Adjusted odds ratio [ORadj] = 0.87, 95% confidence interval: 0.62-1.23, P = 0.44), as was the perioperative need for blood products (81.0% vs 83.2%, ORadj = 0.75, 95% confidence interval: 0.48-1.17, P = 0.20). However, the median (Interquartile range) 12 h postoperative blood loss was significantly lower in the aprotinin group (383 ml [241-625] vs 450 ml [290-730], P < 0.01). Compared to tranexamic acid, the intraoperative use of aprotinin was associated with increased risk for thromboembolic events (adjusted Hazard ratio 2.30 [95% Cl: 1.06-5.30]; P = 0.04).

CONCLUSIONS

Given the modest reduction in blood loss at the expense of a significant increase in thromboembolic adverse events, aprotinin use in high-risk cardiac surgery patients should be based on a carefully considered benefit-risk assessment.

Optimizing Blood Loss and Management in Craniosynostosis Surgery: A Systematic Review of Outcomes Over the Last 40 Years

Surgical correction of craniosynostosis can involve significant blood loss. Rates of allogenic blood transfusion have been reported to approach 100%. Multiple interventions have been described to reduce blood loss and transfusion requirements. The aim of this study was to analyze various approaches over the last 4 decades to optimize blood loss and management during craniosynostosis surgery.

PRISMA guidelines for systematic reviews were followed. PubMed and Cochrane database searches identified studies analyzing approaches to minimizing blood loss or transfusion rate in craniosynostosis surgery.

Primary outcomes included rate or amount of allogenic or autologous blood transfusion, estimated blood loss (EBL), postoperative hemoglobin (Hg), or hematocrit (Hct) levels. Secondary outcomes were examined when reported.

Fifty-two studies met inclusion criteria. There was marked heterogeneity regarding design, inclusion criteria, surgical intervention, and endpoints. The majority of the studies were nonrandomized and noncomparative. Four studies analyzed erythropoietin (EPO), 6 analyzed various cell-saver (CS) technologies, 18 analyzed antifibrinolytics (tranexamic acid [TXA], aminocaproic acid [ACA], and aprotinin [APO]), 8 analyzed various alternatives, and 16 analyzed multimodal pathways & protocols. Some studies analyzed multiple approaches.

Although the majority of studies reviewed represent level III/IV evidence, several high-quality level I studies were identified and included. Level I evidence supported an improvement in blood outcomes by utilizing EPO, CS, and TXA, individually or in concert with one another. Thus, this review suggests that a multi-prong approach may be the most effective means to optimize blood loss and transfusion outcomes in craniosynostosis surgery.

Drugs to reduce bleeding and transfusion in major open vascular or endovascular surgery: a systematic review and network meta-analysis

BACKGROUND

Vascular surgery may be followed by internal bleeding due to inadequate surgical haemostasis, abnormal clotting, or surgical complications. Bleeding ranges from minor, with no transfusion requirement, to massive, requiring multiple blood product transfusions. There are a number of drugs, given systemically or applied locally, which may reduce the need for blood transfusion.

OBJECTIVES

To assess the effectiveness and safety of anti-fibrinolytic and haemostatic drugs and agents in reducing bleeding and the need for blood transfusion in people undergoing major vascular surgery or vascular procedures with a risk of moderate or severe (> 500 mL) blood loss.

SEARCH METHODS

We searched: Cochrane Central Register of Controlled Trials; MEDLINE; Embase; CINAHL, and Transfusion Evidence Library. We also searched the WHO ICTRP and ClinicalTrials.gov trial registries for ongoing and unpublished trials. Searches used a combination of MeSH and free text terms from database inception to 31 March 2022, without restriction on language or publication status.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) in adults of drug treatments to reduce bleeding due to major vascular surgery or vascular procedures with a risk of moderate or severe blood loss, which used placebo, usual care or another drug regimen as control.

DATA COLLECTION AND ANALYSIS

We used standard Cochrane methods. Our primary outcomes were units of red cells transfused and all-cause mortality. Our secondary outcomes included risk of receiving an allogeneic blood product, risk of reoperation or repeat procedure due to bleeding, risk of a thromboembolic event, risk of a serious adverse event and length of hospital stay. We used GRADE to assess certainty of evidence.

MAIN RESULTS

We included 22 RCTs with 3393 participants analysed, of which one RCT with 69 participants was reported only in abstract form, with no usable data. Seven RCTs evaluated systemic drug treatments (three aprotinin, two desmopressin, two tranexamic acid) and 15 RCTs evaluated topical drug treatments (drug-containing bioabsorbable dressings or glues), including fibrin, thrombin, collagen, gelatin, synthetic sealants and one investigational new agent. Most trials were conducted in high-income countries and the majority of the trials only included participants undergoing elective surgery. We also identified two ongoing RCTs. We were unable to perform the planned network meta-analysis due to the sparse reporting of outcomes relevant to this review. Systemic drug treatments We identified seven trials of three systemic drugs: aprotinin, desmopressin and tranexamic acid, all with placebo controls. The trials of aprotinin and desmopressin were small with very low-certainty evidence for all of our outcomes. Tranexamic acid versus placebo was the systemic drug comparison with the largest number of participants (2 trials; 1460 participants), both at low risk of bias. The largest of these included a total of 9535 individuals undergoing a number of different higher risk surgeries and reported limited information on the vascular subgroup (1399 participants). Neither trial reported the number of units of red cells transfused per participant up to 30 days. Three outcomes were associated with very low-certainty evidence due to the very wide confidence intervals (CIs) resulting from small study sizes and low number of events. These were: all-cause mortality up to 30 days; number of participants requiring an allogeneic blood transfusion up to 30 days; and risk of requiring a repeat procedure or operation due to bleeding. Tranexamic acid may have no effect on the risk of thromboembolic events up to 30 days (risk ratio (RR) 1.10, 95% CI 0.88 to 1.36; 1 trial, 1360 participants; low-certainty evidence due to imprecision). There is one large ongoing trial (8320 participants) comparing tranexamic acid versus placebo in people undergoing non-cardiac surgery who are at high risk of requiring a red cell transfusion. This aims to complete recruitment in April 2023. This trial has primary outcomes of proportion of participants transfused with red blood cells and incidence of venous thromboembolism (DVT or PE). Topical drug treatments Most trials of topical drug treatments were at high risk of bias due to their open-label design (compared with usual care, or liquids were compared with sponges). All of the trials were small, most were very small, and few reported clinically relevant outcomes in the postoperative period. Fibrin sealant versus usual care was the topical drug comparison with the largest number of participants (5 trials, 784 participants). The five trials that compared fibrin sealant with usual care were all at high risk of bias, due to the open-label trial design with no measures put in place to minimise reporting bias. All of the trials were funded by pharmaceutical companies. None of the five trials reported the number of red cells transfused per participant up to 30 days or the number of participants requiring an allogeneic blood transfusion up to 30 days. The other three outcomes were associated with very low-certainty evidence with wide confidence intervals due to small sample sizes and the low number of events, these were: all-cause mortality up to 30 days; risk of requiring a repeat procedure due to bleeding; and risk of thromboembolic disease up to 30 days. We identified one large trial (500 participants) comparing fibrin sealant versus usual care in participants undergoing abdominal aortic aneurysm repair, which has not yet started recruitment. This trial lists death due to arterial disease and reintervention rates as primary outcomes.

AUTHORS' CONCLUSIONS

Because of a lack of data, we are uncertain whether any systemic or topical treatments used to reduce bleeding due to major vascular surgery have an effect on: all-cause mortality up to 30 days; risk of requiring a repeat procedure or operation due to bleeding; number of red cells transfused per participant up to 30 days or the number of participants requiring an allogeneic blood transfusion up to 30 days. There may be no effect of tranexamic acid on the risk of thromboembolic events up to 30 days, this is important as there has been concern that this risk may be increased. Trials with sample size targets of thousands of participants and clinically relevant outcomes are needed, and we look forward to seeing the results of the ongoing trials in the future.

The effect of tranexamic acid on myocardial injury in cardiac surgical patients: a systematic review and meta-analysis

Tranexamic acid (TXA) is one of the most commonly used antifibrinolytic agents for surgical patients. However, the effect of TXA on myocardial injury remains controversial. We systemically reviewed literature regarding the effectiveness of TXA on myocardial injury in patients who have undergone a cardiac surgery. We included all randomized controlled trials (RCTs) comparing TXA and control (saline) in cardiac surgical patients. Relevant studies were identified by a comprehensive electronic literature search from database inception to 15 August 2021. A standardized data extraction form was used to collect methodological and outcome variables from each eligible study. We conducted a meta-analysis to estimate the pooled effect size of TXA administration on myocardial injury. In total, eight RCTs were identified, with 292 patients in the TXA group, and 241 patients in saline or control group. The meta-analysis demonstrated that patients in the TXA group had lower levels of CK-MB and cTnI within 24 h postoperatively (CK-MB: P  = 0.005; cTnI: P  = 0.01), compared with the saline group. No significant difference was found with respect to AST level ( P  = 0.71) between TXA and saline groups within 24 h postoperatively. TXA administration was found to be associated with less myocardial injury among patients who have undergone cardiac surgery. High-quality randomized controlled trials are warranted to further examine the cardioprotective effects of TXA.

The role of tranexamic acid in the management of postpartum haemorrhage

In the last decades, tranexamic acid (TXA) has emerged as an essential tool in blood loss management in obstetrics. TXA prophylaxis for postpartum haemorrhage (PPH) has been studied in double-blind, placebo-controlled, randomized clinical trials (RCTs). Given the small observed preventive effect, the systematic use of TXA for vaginal and/or caesarean deliveries remains controversial. The result of a pharmacokinetic modelling suggests that relative to intravenous administration, intramuscular administration may be an equally effective alternative route for preventing PPH and may enable access to this drug in low-resource countries. Prophylaxis is currently studied in high-risk populations, such as women with prepartum anaemia or placenta previa. TXA effectively reduces blood loss and PPH-related morbidity and mortality during active PPH, as demonstrated by high-grade evidence from large RCTs. The drug has a good safety profile: in most cases, only mild gastrointestinal or visual adverse events may be observed. TXA use does not increase the risk of serious adverse events, such as venous or arterial thromboembolism, seizures, or acute kidney injury. The TRACES in vivo analysis of biomarkers of TXA's antifibrinolytic effect have suggested that a dose of at least 1 g is required for the treatment of PPH. The TRACES pharmacokinetic model suggests that because TXA can be lost in the haemorrhaged blood, a second dose should be administered if the PPH continues or if severe coagulopathy occurs. Future pharmacodynamic analyses will focus on the appropriateness of TXA dosing regimens with regard to the intensity of fibrinolysis in catastrophic obstetric events.

Efficacy and safety of aprotinin in paediatric cardiac surgery: A systematic review and meta-analysis

BACKGROUND

The relicensing of aprotinin in Europe and Canada has stimulated discussions on its usefulness in paediatric cardiac surgery.

OBJECTIVE

To systematically evaluate the available evidence on the efficacy and safety of aprotinin in paediatric cardiac surgery.

DESIGN

Systematic review of all randomised and observational studies comparing aprotinin with tranexamic acid, epsilon aminocaproic acid, placebo or no drug in paediatric cardiac surgery. Meta-analyses were performed on efficacy and safety outcomes.

DATA SOURCES

PubMed, Cochrane Central Register of Controlled Trials, Web of Science and Embase were searched from January 2000 to March 2021.

ELIGIBILITY CRITERIA

Studies that enrolled children under 18 years undergoing cardiac surgery with cardiopulmonary bypass.

RESULTS

Thirty-two studies enrolling a total of 63 894 paediatric cardiac procedures were included. Aprotinin significantly reduced total blood loss [mean difference -4.70 ml kg-1, 95% confidence interval (CI), -7.88 to -1.53; P = 0.004], postoperative transfusion requirements and the incidence of surgical re-exploration for bleeding [odds ratio (OR) 0.74, 95% CI, 0.56 to 0.97; P = 0.03]. Aprotinin had no effects on 30-day mortality (OR 1.02, 95% CI, 0.93 to 1.11; P = 0.73) and on other safety outcomes, except for the incidence of renal replacement therapy (RRT), which was significantly increased in patients given aprotinin (OR 1.29, 95% CI, 1.08 to 1.54; P = 0.006). Findings from observational and randomised controlled trials did not largely differ. A sub-group analysis in neonates showed that aprotinin significantly reduced packed red blood cell transfusions and the incidence of postoperative surgical re-exploration for bleeding and/or tamponade. When compared with lysine analogues, aprotinin was more effective at reducing bleeding and transfusion without increasing the risk of side effects.

CONCLUSION

This meta-analysis suggests that aprotinin is effective and well tolerated in paediatric cardiac surgery. Given the large heterogeneity of the results and the risk of selection bias in observational studies, large randomised controlled trials are warranted.

Antifibrinolytic Drugs for the Prevention of Bleeding in Pediatric Cardiac Surgery on Cardiopulmonary Bypass: A Systematic Review and Meta-analysis

BACKGROUND

Bleeding is one of the commonest complications affecting children undergoing cardiac surgery on cardiopulmonary bypass. Antifibrinolytic drugs are part of a multifaceted approach aimed at reducing bleeding, though sufficiently sized pediatric studies are sparse, and dosing algorithms are heterogeneous. Our objective was to evaluate the efficacy and safety of antifibrinolytic agents as well as the effectiveness of different dosing regimens in pediatric cardiac surgery using cardiopulmonary bypass.

METHODS

We performed a systematic review and meta-analysis evaluating randomized controlled trials published between 1980 and 2019, identified by searching the databases MEDLINE, EMBASE, PubMed, and CENTRAL. All studies investigating patients <18 years of age without underlying hematological disorders were included. The primary outcome was postoperative bleeding; secondary end points included blood product transfusion, mortality, and safety (thromboses, anaphylaxis, renal or neurological dysfunction, and seizures). Different dosing regimens were compared. Studies were dual appraised, outcomes were reported descriptively and, if appropriate, quantitatively using the Review Manager 5 (REVMAN 5) software (The Cochrane Collaboration).

RESULTS

Thirty of 209 articles were included, evaluating the following drugs versus control: aprotinin n = 14, tranexamic acid (TXA) n = 12, and epsilon-aminocaproic acid (EACA) n = 4. The number of participants per intervention group ranged from 11 to 100 (median, 25; interquartile range [IQR], 20.5) with a wide age span (mean, 13 days to 5.8 years) and weight range (mean, 3.1-26.3 kg). Methodological quality was low to moderate.All agents reduced mean 24-hour blood loss compared to control: aprotinin by 6.0 mL/kg (95% confidence interval [CI], -9.1 to -3.0; P = .0001), TXA by 9.0 mL/kg (95% CI, -11.3 to -6.8; P < .00001), and EACA by 10.5 mL/kg (95% CI, -21.1 to 0.0; P = .05). Heterogeneity was low for TXA (I2 = 29%; P = .19), moderate for aprotinin (I2 = 41%; P = .11), and high for EACA (I2 = 95%; P = <.00001). All agents also reduced 24-hour blood product transfusion. There was no clear dose-response effect for TXA nor aprotinin. Studies were underpowered to detect significant differences in mortality, thromboses, anaphylaxis, and renal or neurological dysfunction.

CONCLUSIONS

The available data demonstrate efficacy for all 3 antifibrinolytic drugs. Therefore, the agent with the most favorable safety profile should be used. As sufficient data are lacking, large comparative trials are warranted to assess the relative safety and appropriate dosing regimens in pediatrics.

Tranexamic acid for the prevention and treatment of bleeding in surgery, trauma and bleeding disorders: a narrative review

OBJECTIVES

We review the evidence for tranexamic acid (TXA) for the treatment and prevention of bleeding caused by surgery, trauma and bleeding disorders. We highlight therapeutic areas where evidence is lacking and discuss safety issues, particularly the concern regarding thrombotic complications.

METHODS

An electronic search was performed in PubMed and the Cochrane Library to identify clinical trials, safety reports and review articles.

FINDINGS

TXA reduces bleeding in patients with menorrhagia, and in patients undergoing caesarian section, myomectomy, hysterectomy, orthopedic surgery, cardiac surgery, orthognathic surgery, rhinoplasty, and prostate surgery. For dental extractions in patients with bleeding disorders or taking antithrombotic drugs, as well as in cases of idiopathic epistaxis, tonsillectomy, liver transplantation and resection, nephrolithotomy, skin cancer surgery, burn wounds and skin grafting, there is moderate evidence that TXA is effective for reducing bleeding. TXA was not effective in reducing bleeding in traumatic brain injury and upper and lower gastrointestinal bleeding. TXA reduces mortality in patients suffering from trauma and postpartum hemorrhage. For many of these indications, there is no consensus about the optimal TXA dose. With certain dosages and with certain indications TXA can cause harm, such as an increased risk of seizures after high TXA doses with brain injury and cardiac surgery, and an increased mortality after delayed administration of TXA for trauma events or postpartum hemorrhage. Whereas most trials did not signal an increased risk for thrombotic events, some trials reported an increased rate of thrombotic complications with the use of TXA for gastro-intestinal bleeding and trauma.

CONCLUSIONS

TXA has well-documented beneficial effects in many clinical indications. Identifying these indications and the optimal dose and timing to minimize risk of seizures or thromboembolic events is work in progress.

First Comparative Study of the Effectiveness of the Use of Tranexamic Acid against ε-Aminocapróic Acid via the Oral Route for the Reduction of Postoperative Bleeding in TKA: A Clinical Trial

Total primary knee replacement results in significant postoperative bleeding. There are reports that 20 to 50% of the patients require a blood transfusion, which has been related to many complications, resulting in the search for strategies to reduce bleeding. The use of oral antifibrinolytics is becoming a low cost and safe way of achieving this goal. The hypothesis of this study was that the use of oral aminocaproic acid could provide similar results to the use of oral tranexamic acid (TXA). The purpose was to compare the effects of oral aminocaproic acid as a hemostatic agent versus the use of oral TXA administered in multiple doses pre and postsurgery in patients undergoing total primary knee replacement. We enrolled 92 patients that were randomly divided into two groups: received three doses of aminocaproic acid (2,000 mg per dose) or three doses of oral TXA (1,300 mg per dose). The drugs were administered according to the following schedule: 2 hours before surgery and 6 and 12 hours after surgery. The variables that were analyzed to compare the effectiveness of the hemostatic agents were total blood loss; hidden blood loss; external blood loss; transfusion rate; intraoperative blood loss; decreases in hemoglobin and hematocrit values; surgical drainage output; visual analogue scale; and surgical complications. There were no significant differences between any of the study variables for the group receiving oral aminocaproic acid and the group receiving oral TXA (p > 0.05), with the exception of patients who received TXA, who presented with more adverse events (p = 0.04). Our study showed that the use of oral aminocaproic acid was similar to its counterpart TXA regarding the evaluated parameters. Although patients who received TXA presented an average of 140 mL less blood loss than patients in the ε-ACA group, the difference did not appear to be clinically important, the transfusion rate was very low, and there were no between-group differences in postoperative complications.

Effectiveness of Tranexamic Acid in Reducing Postoperative Blood Loss in Patients Undergoing Off-Pump Coronary Artery Bypass Grafting

Background Off-pump coronary artery bypass grafting (OP-CABG) is an accepted surgical option in treating ischemic heart disease and has proven safer than traditional on-pump CABG in terms of reducing perioperative bleeding, coagulopathy, avoiding cardiopulmonary bypass machine and its related morbidity. However, there is evidence that shows the risk of bleeding in OP-CABG due to surgical trauma, heart manipulations, and heparin-protamine exposure. We aim to evaluate the effectiveness of tranexamic acid (TxA) in reducing blood loss and related perioperative complications in patients undergoing OP-CABG. Method An individual matched cohort study was conducted at a cardiac centre over a period of one year. We enrolled a total of 60 patients undergoing OPCABG in our study. The basic strategy was to enroll every possible intervention patient until the desired sample size (30 in each group) was achieved and then to select and enroll controls, using a prospective individual matching strategy. Preoperative cardiac risk evaluation was done using the European System for Cardiac Operative Risk Evaluation II (EuroSCORE II) in both groups. The intervention group (I) received TxA 10 mg/kg over 10 minutes at the time of induction while the control group (C) did not receive any TxA. Postoperative blood loss was measured by observing chest drain output 24 hourly till the chest drain tube was removed. Perioperative complications were also recorded. Results Demographics and baseline characteristics were comparable among groups (p > 0.05). The mean volume of postoperative blood loss in the I group at 24 hours and 48 hours were 352.67 ml and 86.83 ml, respectively. On the other hand, in the C group, the mean volume of postoperative blood loss was 602.00 ml and 166.3 ml. The data showed a statistically significant difference in the postoperative chest drainage output between the groups (unpaired t-test, p < 0.05) and exhibiting a significant reduction in postoperative blood loss in the I group. However, there was no significant difference in blood transfusion requirements in both of the groups (Mann Whitney U test, p > 0.05). The mean duration of postoperative complications, inotropic support, intermittent positive pressure ventilation, intensive care, and hospital stay were also comparable depicting no significant effect of TxA on reducing the perioperative morbidity. Conclusion This study showed the significance of TxA in reducing bleeding in the postoperative period in patients undergoing OP-CABG.

Impact of multidisciplinary engagement in a quality improvement blood conservation protocol for craniosynostosis

OBJECTIVE

Patients undergoing open cranial vault remodeling for craniosynostosis frequently experience substantial blood loss requiring blood transfusion. Multiple reports in the literature have evaluated the impact of individual blood conservation techniques on blood transfusion rates during craniosynostosis surgery. The authors engaged a multidisciplinary team and assessed the impact of input from multiple stakeholders on the evolution of a comprehensive quality improvement protocol aimed at reducing or eliminating blood transfusion in patients undergoing open surgery for craniosynostosis.

METHODS

Over a 4-year period from 2012 to 2016, 39 nonsyndromic patients were operated on by a single craniofacial plastic surgeon. Initially, no clear blood conservation protocol existed, and specific interventions were individually driven. In 2014, a new pediatric neurosurgeon joined the craniofacial team, and additional stakeholders in anesthesiology, transfusion medicine, critical care, and hematology were brought together to evaluate opportunities for developing a comprehensive blood conservation protocol. The initial version of the protocol involved the standardized administration of intraoperative aminocaproic acid (ACA) and the use of a cell saver. In the second version of the protocol, the team implemented the preoperative use of erythropoietin (EPO). In addition, intraoperative and postoperative resuscitation and transfusion guidelines were more clearly defined. The primary outcomes of estimated blood loss (EBL), transfusion rate, and intraoperative transfusion volume were analyzed. The secondary impact of multidisciplinary stakeholder input was inferred by trends in the data obtained with the implementation of the partial and full protocols.

RESULTS

Implementing the full quality improvement protocol resulted in a 66% transfusion-free rate at the time of discharge compared to 0% without any conservation protocol and 27% with the intermediate protocol. The administration of EPO significantly increased starting hemoglobin/hematocrit (11.1 g/dl/31.8% to 14.7 g/dl/45.6%, p < 0.05). The group of patients receiving ACA had lower intraoperative EBL than those not receiving ACA, and trends in the final-protocol cohort, which had received both preoperative EPO and intraoperative ACA, demonstrated decreasing transfusion volumes, though the decrease did not reach statistical significance.

CONCLUSIONS

Patients undergoing open calvarial vault remodeling procedures benefit from the input of a multidisciplinary stakeholder group in blood conservation protocols. Further research into comprehensive protocols for blood conservation may benefit from input from the full surgical team (plastic surgery, neurosurgery, anesthesiology) as well as additional pediatric subspecialty stakeholders including transfusion medicine, critical care, and hematology.

Effect of Tranexamic Acid for Traumatic Brain Injury: A Case Report

Traumatic brain injury (TBI) often results in coagulopathy, which increases mortality risk. The Clinical Randomization of an Antifibrinolytic in Significant Head injury (CRASH)-2 and CRASH-3 trials confirmed that tranexamic acid (TXA) was effective after trauma. Herein, we report a unique coagulation change in a patient with TBI given TXA after point-of-care assessment. Coagulation functions were impaired on admission. At 1 hour after TXA administration, clotting time was further prolonged in the extrinsic coagulation pathway but shortened in the intrinsic coagulation system. The results of a test of the total thrombus-formation analysis system showed improved blood clot formation ability. Intrinsic coagulation and clot formation improved after TXA administration in a TBI patient with coagulopathy.

Introduction of a standardised protocol, including systematic use of tranexamic acid, for management of severe adult trauma patients in a low-resource setting: the MSF experience from Port-au-Prince, Haiti

BACKGROUND

Bleeding is an important cause of death in trauma victims. In 2010, the CRASH-2 study, a multicentre randomized control trial on the effect of tranexamic acid (TXA) administration to trauma patients with suspected significant bleeding, reported a decreased mortality in randomized patients compared to placebo. Currently, no evidence on the use of TXA in humanitarian, low-resource settings is available. We aimed to measure the hospital outcomes of adult patients with severe traumatic bleeding in the Médecins Sans Frontières Tabarre Trauma Centre in Port-au-Prince, Haiti, before and after the implementation of a Massive Haemorrhage protocol including systematic early administration of TXA.

METHODS

Patients admitted over comparable periods of four months (December2015- March2016 and December2016 - March2017) before and after the implementation of the Massive Haemorrhage protocol were investigated. Included patients had blunt or penetrating trauma, a South Africa Triage Score ≥ 7, were aged 18-65 years and were admitted within 3 h from the traumatic event. Measured outcomes were hospital mortality and early mortality rates, in-hospital time to discharge and time to discharge from intensive care unit.

RESULTS

One-hundred and sixteen patients met inclusion criteria. Patients treated after the introduction of the Massive Haemorrhage protocol had about 70% less chance of death during hospitalization compared to the group "before" (adjusted odds ratio 0.3, 95%confidence interval 0.1-0.8). They also had a significantly shorter hospital length of stay (p = 0.02).

CONCLUSIONS

Implementing a Massive Haemorrhage protocol including early administration of TXA was associated with the reduced mortality and hospital stay of severe adult blunt and penetrating trauma patients in a context with poor resources and limited availability of blood products.

The safety and efficiency of intravenous administration of tranexamic acid in coronary artery bypass grafting (CABG): a meta-analysis of 28 randomized controlled trials

Background

The safety and efficiency of intravenous administration of tranexamic acid (TXA) in coronary artery bypass grafting (CABG) remains unconfirmed. Therefore, we conducted a meta-analysis on this topic.

Methods

We searched the Cochrane Central Register of Controlled Trials (CENTRAL), PUBMED and EMBASE for randomized controlled trials on the topic. The results of this work are synthetized and reported in accordance with the PRISMA statement.

Results

Twenty-eight studies met our inclusion criteria. TXA reduced the incidence of postoperative reoperation of bleeding (relative risk [RR], 0.46; 95% confidence interval [CI]; 0.31–0.68), the frequency of any allogeneic transfusion (RR, 0.64; 95% CI, 0.52–0.78) and the postoperative chest tube drainage in the first 24 h by 206 ml (95% CI − 248.23 to − 164.15). TXA did not significantly affect the incidence of postoperative cerebrovascular accident (RR, 0.93; 95%CI, 0.62–1.39), mortality (RR, 0.82; 95%CI, 0.53–1.28), myocardial infarction (RR, 0.90; 95%CI, 0.78–1.05), acute renal insufficiency (RR, 1.01; 95%CI, 0.77–1.32). However, it may increase the incidence of postoperative seizures (RR, 6.67; 95%CI, 1.77–25.20). Moreover, the subgroup analyses in on-pump and off-pump CABG, the sensitivity analyses in trials randomized more than 99 participants and sensitivity analyses that excluded the study with the largest number of participants further strengthened the above results.

Conclusions

TXA is effective to reduce reoperation for bleeding, blood loss and the need for allogeneic blood products in patients undergoing CABG without increasing prothrombotic complication. However, it may increase the risk of postoperative seizures.

Electronic supplementary material

The online version of this article (10.1186/s12871-019-0761-3) contains supplementary material, which is available to authorized users.

Decreasing Postoperative Blood Loss by Topical vs. Intravenous Tranexamic Acid in Open Cardiac Surgery (DEPOSITION) study: Results of a pilot study

BACKGROUND

Cardiac surgery patients are at high risk for postoperative bleeding. Intravenous (IV) tranexamic acid (TxA) is a commonly used antifibrinolytic drug, but is associated with postoperative seizures. We conducted this pilot randomized controlled trial (RCT) to determine the feasibility of a larger trial that will be designed to investigate the impact of TxA administration route, intrapericardial (IP) vs IV, on postoperative bleeding and seizures.

METHODS

In this single-center, double-blinded, pilot RCT we enrolled adult patients undergoing nonemergent on-pump cardiac operations through a median sternotomy. Participants were randomized to IP or IV TxA groups. The primary outcomes were cumulative chest tube drainage, transfusion requirements, and incidence of postoperative seizures.

RESULTS

A total of 97 participants were randomized to the intervention and control groups. Baseline characteristics were similar in both groups. Most participants underwent a CABG and/or aortic valve replacement. There was no statistical difference. The IP TxA group was found to have a tendency for less chest tube drainage in comparison to the IV TxA group, 500.5 (370.0-700.0) and 540.0 (420.0-700.0) mL, respectively, which was not statistically significant (P = 0.2854). Fewer participants in the IP TxA group with cardiac tamponade and/or required a reoperation for bleeding and fewer packed red blood cell transfusions. None of the IP TxA group developed seizure vs one from the IV TxA group.

CONCLUSION

This is the first known pilot RCT to investigate the role of TxA route of administration in open cardiac surgery. Intrapericardial TxA shows promising results with decreased bleeding, transfusion requirements, reoperations, and postoperative seizures. A larger RCT is needed to confirm these results and lead to a change in practice.

Effects of restrictive red blood cell transfusion on the prognoses of adult patients undergoing cardiac surgery: a meta-analysis of randomized controlled trials

PURPOSE

Restrictive red blood cell transfusion strategies remain controversial in patients undergoing cardiac surgery. We performed a meta-analysis to assess the prognostic benefits of restrictive red blood cell transfusion strategies in patients undergoing cardiac surgery.

METHODS

We identified randomized clinical trials through the 9th of December 2017 that investigated a restrictive red blood cell transfusion strategy versus a liberal transfusion strategy in patients undergoing cardiac surgery. Individual patient data from each study were collected. Meta-analyses were performed for the primary and secondary outcomes. The risk of bias was assessed using the Cochrane Risk of Bias Tool. A trial sequential analysis (TSA)-adjusted random-effects model was used to pool the results from the included studies for the primary outcomes.

RESULTS

Seven trials involving a total of 8886 patients were included. The TSA evaluations suggested that this meta-analysis could draw firm negative results, and the data were sufficient. There was no evidence that the risk of 30-day mortality differed between the patients assigned to a restrictive blood cell transfusion strategy and a liberal transfusion strategy (odds ratio (OR) 0.98; 95% confidence interval (CI) 0.77 to 1.24; p = 0.87). Furthermore, the study suggested that the restrictive transfusion strategy was not associated with significant increases in pulmonary morbidity (OR 1.09; 95% CI 0.88 to 1.34; p = 0.44), postoperative infection (OR 1.11; 95% CI 0.95 to 1.3; p = 0.58), acute kidney injury (OR 1.03; 95% CI 0.92 to 1.14; p = 0.71), acute myocardial infarction (OR 1.01; 95% CI 0.80 to 1.27; p = 0.78), or cerebrovascular accidents (OR 0.97; 95% CI 0.72 to 1.30; p = 0.66).

CONCLUSIONS

Our meta-analysis demonstrates that the restrictive red blood cell transfusion strategy was not inferior to the liberal strategy with respect to 30-day mortality, pulmonary morbidity, postoperative infection, cerebrovascular accidents, acute kidney injury, or acute myocardial infarction, and fewer red blood cells were transfused.

Effects of restrictive red blood cell transfusion on the prognoses of adult patients undergoing cardiac surgery: a meta-analysis of randomized controlled trials

PURPOSE

Restrictive red blood cell transfusion strategies remain controversial in patients undergoing cardiac surgery. We performed a meta-analysis to assess the prognostic benefits of restrictive red blood cell transfusion strategies in patients undergoing cardiac surgery.

METHODS

We identified randomized clinical trials through the 9th of December 2017 that investigated a restrictive red blood cell transfusion strategy versus a liberal transfusion strategy in patients undergoing cardiac surgery. Individual patient data from each study were collected. Meta-analyses were performed for the primary and secondary outcomes. The risk of bias was assessed using the Cochrane Risk of Bias Tool. A trial sequential analysis (TSA)-adjusted random-effects model was used to pool the results from the included studies for the primary outcomes.

RESULTS

Seven trials involving a total of 8886 patients were included. The TSA evaluations suggested that this meta-analysis could draw firm negative results, and the data were sufficient. There was no evidence that the risk of 30-day mortality differed between the patients assigned to a restrictive blood cell transfusion strategy and a liberal transfusion strategy (odds ratio (OR) 0.98; 95% confidence interval (CI) 0.77 to 1.24; p = 0.87). Furthermore, the study suggested that the restrictive transfusion strategy was not associated with significant increases in pulmonary morbidity (OR 1.09; 95% CI 0.88 to 1.34; p = 0.44), postoperative infection (OR 1.11; 95% CI 0.95 to 1.3; p = 0.58), acute kidney injury (OR 1.03; 95% CI 0.92 to 1.14; p = 0.71), acute myocardial infarction (OR 1.01; 95% CI 0.80 to 1.27; p = 0.78), or cerebrovascular accidents (OR 0.97; 95% CI 0.72 to 1.30; p = 0.66).

CONCLUSIONS

Our meta-analysis demonstrates that the restrictive red blood cell transfusion strategy was not inferior to the liberal strategy with respect to 30-day mortality, pulmonary morbidity, postoperative infection, cerebrovascular accidents, acute kidney injury, or acute myocardial infarction, and fewer red blood cells were transfused.

Treatment of individuals who cannot receive blood products for religious or other reasons

By virtue of their religious principles, Jehovah's Witnesses (JWs) generally object to receiving blood products, raising numerous ethical, legal, and medical challenges for providers who care for these patients, especially in the emergent setting. In this review, we discuss several areas relevant to the care of JWs, including the current literature on "bloodless" medical care in the setting of perioperative and intraoperative management, acute blood loss, trauma, pregnancy, and malignancy. We have found that medical and administrative efforts in the form of bloodless medicine and surgery programs can be instrumental in helping to reduce risks of morbidity and mortality in these patients. Planning prior to an anticipated event associated with blood loss or anemia (such as elective surgery, pregnancy, and chemotherapy) is critical. Specifically, bloodless medicine programs should prioritize vigilant early screening and management of anemias, early establishment of patient wishes regarding transfusion, and the incorporation of those wishes into multidisciplinary medical and surgical care. Although there are now a variety of human-based and nonhuman-based products available as transfusion alternatives, the degree and quality of evidence to support their use varies significantly between products and is also largely dependent on the clinical setting.

Blood Conservation Using Tranexamic Acid Is Not Superior to Epsilon-Aminocaproic Acid After Total Knee Arthroplasty

BACKGROUND

Epsilon-aminocaproic acid (EACA) and tranexamic acid (TXA) are synthetic amino acid derivatives that interfere with fibrinolysis, promoting hemostasis by pharmacological means. Although both drugs have been shown to decrease blood loss with a minimal risk of thromboembolic adverse events following cardiac and vascular surgery, we are aware of only 1 published trial that directly compared the antifibrinolytic effects of EACA with those of TXA after total knee arthroplasty (TKA). The primary aim of this prospective, randomized, controlled trial was to determine whether TXA provides superior blood conservation following TKA compared with that provided by EACA.

METHODS

A total of 194 patients scheduled to undergo a primary unilateral TKA in the same community-based hospital were prospectively randomized to receive intravenous EACA (n = 96) or TXA (n = 98). Both the patients and the operating surgeons were blinded to the treatment assignments. Primary outcome measures included transfusions, estimated blood loss, and the drop in the hemoglobin (Hgb) level. Secondary outcomes measures included the change in the serum creatinine level, postoperative complications, and length of hospital stay.

RESULTS

Although the patients who received TXA averaged less estimated blood loss than the patients who received EACA (t185 = 2.18, p = 0.031; mean difference = 144.2 mL, 95% confidence interval = 13.62 to 274.78 mL), no transfusions were required in either group. We observed no statistically significant or clinically relevant between-group differences in the change in Hgb or serum creatinine level, postoperative complications, or length of hospital stay.

CONCLUSIONS

Although the estimated blood loss was significantly greater in the EACA group, no transfusions were required and no significant between-group differences were observed for any other outcomes measured. We concluded that EACA may be an acceptable alternative to TXA for blood conservation following TKA, although replication of our results in noninferiority trials is necessary.

LEVEL OF EVIDENCE

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

Association between CK-MB Area Under the Curve and Tranexamic Acid Utilization in Patients Undergoing Coronary Artery Bypass Surgery

Myonecrosis after coronary artery bypass graft (CABG) surgery is associated with excess mortality. Tranexamic acid (TA), an anti-fibrinolytic agent, has been shown to reduce peri-operative blood loss without increasing the risk of myocardial infarction (MI); however, no large study has examined the association between TA treatment and post-CABG myonecrosis. In the MC-1 to Eliminate Necrosis and Damage in Coronary Artery Bypass Graft Surgery II trial, inverse probability weighting of the propensity to receive TA was used to test for differences among the 656 patients receiving and 770 patients not receiving TA. The primary outcome was creatine kinase MB (CK-MB) area under the curve (AUC) through 24 h. The secondary outcome was 30-day cardiovascular death or MI. Patients who received TA were more frequently female, had a previous MI, heart failure, low molecular weight heparin therapy, on-pump CABG, valvular surgery, and saphenous vein or radial grafts. The median 24-h CK-MB AUC was higher in TA-treated patients [301.9 (IQR 196.7-495.6) vs 253.5 (153.4-432.5) ng h/mL, p < 0.001]. No differences in the 30-day incidence of cardiovascular death or MI were observed (8.7 vs 8.3%, adjusted OR 0.99; 95% CI 0.67-1.45, p = 0.948). In patients undergoing CABG, TA use was associated with a higher risk of myonecrosis; however, no differences were observed in death or MI. Future larger studies should be directed at examining the pathophysiology of TA myonecrosis, and its association with subsequent clinical outcomes.

Meta-analysis of Intravenous Tranexamic Acid in Primary Total Hip Arthroplasty

Previous meta-analyses established that tranexamic acid confers benefits when used during total hip arthroplasty (THA). However, 2 of these meta-analyses included a variety of routes of administration of tranexamic acid in THA (topical, intravenous, oral, and intra-articular), another meta-analysis included a variety of antifibrinolytic drugs (not restricted to a single drug), and the final meta-analysis included nonrandomized controlled trials. This meta-analysis focused on a single medication, tranexamic acid, administered in a specific way, intravenously in patients undergoing primary THA, using data reported only in randomized controlled studies. Outcomes were restricted to blood loss, allogeneic transfusion rates, and complications. Other outcomes, such as return to function or clinical scores, could not be evaluated because of lack of consistent reporting. To better understand the effects of intravenous tranexamic acid in THA on clinical outcomes, such as recovery, return to function, and patient-reported outcome measures, it would be helpful to have more controlled trials examining these measures in a standardized manner. Intravenous tranexamic acid was beneficial for blood loss intraoperatively, blood loss through drains, and total blood loss during hospitalization, in addition to reducing allogeneic transfusion rates. No difference between intravenous tranexamic acid and placebo was found for most complications, except deep venous thrombosis, which showed favorable results with placebo. [Orthopedics.2016; 39(5):e883-e892.].

Benefits of Limited Use of a Tourniquet Combined With Intravenous Tranexamic Acid During Total Knee Arthroplasty

BACKGROUND

Blood loss during total knee arthroplasty (TKA) may require blood transfusions that are associated with increased risk, morbidity, and cost. Multiple techniques exist to reduce blood loss in TKA, including the use of a tourniquet and tranexamic acid (TXA). While multiple studies suggest that TXA is effective in reducing blood loss, the use of a tourniquet is more controversial. We studied the combined effect of TXA with a limited-use tourniquet on blood loss and complications in the setting of primary TKA.

METHODS

A retrospective review of a prospectively gathered arthroplasty database from a single institution was performed. We compared our limited-use cohort data with the published results of randomized controlled trials evaluating the effectiveness of tourniquets used during the entire TKA procedure.

RESULTS

Fifty-one procedures from our institution's database met the inclusion criteria. TXA (administered in a single 15-mg/kg dose) with limited tourniquet use (a mean duration of 26.3 minutes) resulted in an average intraoperative estimated blood loss of 94.7 mL. The mean decrease in hemoglobin from the preprocedure baseline to postoperative day 1 was 2.6 ± 0.9 g/dL (P<0.001), and only 2 of the 51 procedures required a blood transfusion. When compared to recent randomized controlled trials, the 51 procedures demonstrated lower levels of blood loss, similar operative time, and no increase in morbidity or mortality.

CONCLUSION

Our study results suggest that using TXA in combination with a tourniquet during the cementation portion only of a TKA provides a reasonable operative time and low intraoperative blood loss without increasing perioperative morbidity or complications.

Efficacy and Safety of Antifibrinolytic Agents in Reducing Perioperative Blood Loss and Transfusion Requirements in Scoliosis Surgery: A Systematic Review and Meta-Analysis

Background

Routine use of antifibrinolytic agents in spine surgery is still an issue of debate.

Objective

To gather scientific evidence for the efficacy and safety of antifibrinolytic agents including aprotinin, tranexamic acid (TXA) and epsilon aminocaproic acid (EACA, traditionally known as Amicar) in reducing perioperative blood loss and transfusion requirements in scoliosis surgery.

Methods

We conducted a systematic review and meta-analysis for randomized controlled trials (RCTs), retrospective case-control studies, and retrospective cohort studies on the use of antifibrinolytic agents in scoliosis surgery by searching in the MEDLINE and EMBASE databases and the Cochrane Database of Systematic Reviews and Controlled Trials of papers published from January 1980 through July 2014. Safety of the antifibrinolytic agents was evaluated in all included studies, while efficacy was evaluated in RCTs.

Results

Eighteen papers with a total of 1,158 patients were eligible for inclusion in this study. Among them, 8 RCTs with 450 patients were included for evaluation of pharmacologic efficacy (1 RCT was excluded because of a lack of standard deviation data). Mean blood loss was reduced in patients with perioperative use of antifibrinolytic agents by 409.25 ml intraoperatively (95% confidence interval [CI], 196.57–621.94 ml), 250.30 ml postoperatively (95% CI, 35.31–465.30), and 601.40 ml overall (95% CI, 306.64–896.16 ml). The mean volume of blood transfusion was reduced by 474.98 ml (95% CI, 195.30–754.67 ml). The transfusion rate was 44.6% (108/242) in the patients with antifibrinolytic agents and 68.3% (142/208) in the patients with placebo. (OR 0.38; 95% CI; 0.25–0.58; P<0.00001, I² = 9%). All studies were included for evaluation of safety, with a total of 8 adverse events reported overall (4 in the experimental group and 4 in the control group).

Conclusion

The systematic review and meta-analysis indicated that aprotinin, TXA, and EACA all significantly reduced perioperative blood loss and transfusion requirements in scoliosis surgery. There was no evidence that the use of antifibrinolytic agents was a risk factor for adverse events, especially thromboembolism, in scoliosis surgery.

Intra-articular administration of tranexamic acid in total hip arthroplasty

PURPOSE

To evaluate the effectiveness of intraarticular tranexamic acid (TXA) in reducing blood loss and the need for blood transfusion during total hip arthroplasty (THA).

METHODS

Records of 19 men and 31 women aged 46 to 83 (mean, 62) years who underwent primary THA with intra-articular administration of TXA were reviewed. They were compared with a matched cohort of 17 men and 33 women aged 40 to 87 (mean, 62) years who underwent the same procedure by the same surgeon without use of TXA. Postoperatively, a standard thromboembolic prophylaxis protocol was followed. A serum haemoglobin level of <80 g/l was the trigger for blood transfusion.

RESULTS

The 2 groups were comparable in terms of age, gender, body mass index, side involved, and anaesthesia method. No patient developed infection, wound haematoma, symptomatic deep vein thrombosis, or pulmonary embolism within 30 days. Compared with controls, patients in the TXA group had a higher median postoperative serum haemoglobin level (103 vs. 112 g/l, p=0.013), lower median drop in serum haemoglobin level (31 vs. 20 g/l, p<0.001), lower median total blood loss (900 vs. 575 ml, p<0.001), and lower transfusion rate (32% vs. 10%, p=0.007). The TXA treatment cost S$19.50 per patient, whereas one unit of allogenic blood cost S$123 per patient. Respectively in the control and TXA groups, the mean cost per patient was S$39.36 and S$31.80, indicating a 19% difference.

CONCLUSION

Intra-articular administration of TXA is a cost-effective and safe means to reduce blood loss and the need for blood transfusion during THA, without increasing the risk of thromboembolic events.

Structure of BbKI, a disulfide-free plasma kallikrein inhibitor

A serine protease inhibitor from Bauhinia bauhinioides (BbKI) belongs to the Kunitz family of plant inhibitors, which are common in plant seeds. BbKI does not contain any disulfides, unlike most other members of this family. It is a potent inhibitor of plasma kallikrein, in addition to other serine proteases, and thus exhibits antithrombotic activity. A high-resolution crystal structure of recombinantly expressed BbKI was determined (at 1.4 Å resolution) and was compared with the structures of other members of the family. Modeling of a complex of BbKI with plasma kallikrein indicates that changes in the local structure of the reactive loop that includes the specificity-determining Arg64 are necessary in order to explain the tight binding. An R64A mutant of BbKI was found to be a weaker inhibitor of plasma kallikrein, but was much more potent against plasmin, suggesting that this mutant may be useful for preventing the breakup of fibrin and maintaining clot stability, thus preventing excessive bleeding.

Effects of intravenous administration of tranexamic acid on hematological, hemostatic, and thromboelastographic analytes in healthy adult dogs

OBJECTIVE

To assess the effects of tranexamic acid (TA) on hematological, hemostatic, and thromboelastographic analytes in healthy adult dogs.

DESIGN

Prospective study.

SETTING

University teaching hospital.

ANIMALS

Eleven healthy, staff-owned, adult dogs.

MEASUREMENTS AND MAIN RESULTS

Dogs were administered TA as an IV bolus, followed by a 3-hour constant rate infusion (CRI). Complete blood count, prothrombin time, activated partial thromboplastin time, D-dimer, antithrombin, fibrinogen, and thromboelastography (TEG) were measured prior to, and immediately after TA administration. Vomiting occurred transiently in the first 2 treated dogs, immediately after 20 and 15 mg/kg IV boluses, but not during the CRI. In all other dogs the TA IV bolus dose was reduced to 10 mg/kg, and administered slower, and vomiting did not occur. All measured hemostatic and hematological analytes remained within their reference intervals, however, following TA treatment, significant decreases were recorded in prothrombin time, TEG R and A30 values, Hct, and hemoglobin concentration, while the TEG LY30 significantly increased.

CONCLUSIONS

Administration of TA as a slow IV bolus at 10 mg/kg, followed by a 10 mg/kg/h CRI over 3 hours to healthy dogs is safe; however, its effect on TEG A30, A60, LY30, and LY60 values was inconsistent with its expected anti-fibrinolytic properties.

Evaluation of differences in patient and physician perception of benefit and risks of aspirin and antifibrinolytic therapy in cardiac surgery

It is unclear whether physicians and patients have similar concerns and preferences when considering benefit and risks of aspirin and antifibrinolytic therapy for cardiac surgery. We surveyed both groups to ascertain their perceptions and preferences for treatment in this setting. Both preoperative and postoperative cardiac surgical patients and the physician craft groups caring for them (cardiology, surgery, anaesthesia/critical care), were provided with estimates of benefits and risks of aspirin and antifibrinolytic therapy. All study participants were asked to stipulate the minimal absolute risk reduction required for them to agree to such therapy. When compared with the cardiac surgical patients they treat, physicians required a smaller thrombotic risk reduction with aspirin whilst accepting its known increased risk of bleeding. This was significantly different in a high-risk stroke setting (incidence 5%) where the required relative risk reduction with aspirin use for physicians was 20% versus patients 40% (P <0.001); and for myocardial infarction, physicians 20% versus patients 36% (P=0.051). For antifibrinolytic therapy, the tolerated increased relative risk of stroke for physicians was 20% versus patients 10% (P=0.004), and for myocardial infarction, physicians 16.7% versus patients 4.2% (P <0.001). The three physician craft groups had comparable tolerances of thrombotic risk. Patient and physician preferences for perioperative aspirin and antifibrinolytic therapy sometimes differ based on risk benefit analysis.

Tranexamic acid in pediatric trauma: why not?

Trauma is a leading cause of death in pediatrics. Currently, no medical treatment exists to reduce mortality in the setting of pediatric trauma; however, this evidence does exist in adults. Bleeding and coagulopathy after trauma increases mortality in both adults and children. Clinical research has demonstrated a reduction in mortality with early use of tranexamic acid in adult trauma patients in both civilian and military settings. Tranexamic acid used in the perioperative setting safely reduces transfusion requirements in children. This article compares the hematologic response to trauma between children and adults, and explores the potential use of tranexamic acid in pediatric hemorrhagic trauma.

Aprotinin and transfusion requirements in pediatric craniofacial surgery

OBJECTIVE

To evaluate transfusion requirements in children receiving aprotinin during craniofacial surgery.

BACKGROUND

Pediatric craniofacial procedures may involve massive blood loss. Aprotinin may decrease perioperative blood loss and transfusion requirements.

METHODS

Patients (aged 1 month to 3 years) who had major reconstructive craniofacial surgery received intraoperative aprotinin (13 patients) or placebo (13 patients). Administered colloids and blood products were recorded.

RESULTS

Patients in the aprotinin and placebo groups had similar mean age, body weight, body surface area, operative time, and length of hospital stay. Mean volumes of total colloids (aprotinin group: 70 ± 40 ml; and placebo group: 120 ± 80 ml; P ≤ 0.05) and packed red blood cells (aprotinin group: 380 ± 90 ml; and placebo group: 550 ± 200 ml; P ≤ 0.004) were less in the aprotinin group than in the placebo group. Mean urine output during surgery was greater in the aprotinin group than in the placebo group (320 ± 200 ml vs 150 ± 70 ml, respectively; P ≤ 0.003). Mean blood urea nitrogen and serum creatinine values after surgery were similar between the groups. Complications of aprotinin included anaphylaxis (one patient) and rash (one patient); no deaths occurred.

CONCLUSIONS

Aprotinin was associated with decreased packed red blood cell transfusion requirements in children undergoing craniofacial surgery, with no renal toxicity or death. Aprotinin is no longer available for clinical use in the USA because of adverse effects in adults; re-evaluation of aprotinin is warranted for children scheduled to undergo surgery involving potentially high blood loss.

The effect of tranexamic acid on transfusion rate in primary total hip arthroplasty

Total hip arthroplasty (THA) may produce blood loss requiring allogenic blood transfusion. Recently several authors have reported success decreasing their transfusion rate with tranexamic acid (TXA). We retrospectively reviewed our last 1595 primary THA in 1494 patients looking at whether the patients received TXA via IV infusion, topical application, or neither, and the need for a blood transfusion. Infusion of TXA acid produced a statistically significant difference in transfusion rate (p<0.001) while topical TXA failed to reach statistical significance (P=0.15). The transfusion rate without TXA was 19.86%, 4.39% with TXA infusion (odds ratio=5.36), and 12.86% (odds ratio=1.67) with topical TXA.

Topical (intra-articular) tranexamic acid reduces blood loss and transfusion rates following total hip replacement: a randomized controlled trial (TRANX-H)

BACKGROUND

Approximately one-third of patients undergoing total hip replacement surgery require one to three units of blood postoperatively. Tranexamic acid is a synthetic antifibrinolytic agent that has been successfully used intravenously to control bleeding after total hip replacement. A topical application is easy to administer, provides a maximum concentration of tranexamic acid at the bleeding site, and is associated with little or no systemic absorption of the tranexamic acid.

METHODS

A double-blind, randomized controlled trial of 161 patients undergoing unilateral primary total hip replacement investigated the effect of topical (intra-articular) application of tranexamic acid on blood loss. The primary outcome was the blood transfusion rate. Secondary outcomes included the drain blood loss, hemoglobin concentration drop, generic quality of life (EuroQol), Oxford Hip Score, length of stay, a cost analysis, and complications.

RESULTS

Tranexamic acid reduced the absolute risk of blood transfusion by 19.6% (95% confidence interval [CI], 6.9% to 32.1%; p = 0.004), from 32.1% to 12.5%, and reduced blood loss by 129 mL (95% CI, 47 to 211 mL; p = 0.002), the hemoglobin concentration drop by 0.84 g/dL (95% CI, 0.41 to 1.27; p &lt; 0.0001), the length of stay by 1.0 days (95% CI, -0.2 to 2.3 days; p = 0.109), and the cost per episode by £305 (95% CI, £0 to £610; p = 0.05). (In 2010, £1 = 1.5 U.S. dollars.) Oxford Hip Scores and EuroQol scores were similar at three months.

CONCLUSIONS

Topically applied tranexamic acid was effective in reducing blood loss and the need for blood transfusion following total hip replacement, avoiding the potential complications of intravenous tranexamic acid administration.

LEVEL OF EVIDENCE

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