Effect of tranexamic acid on surgical bleeding: systematic review and cumulative meta-analysis

Aminocaproic acid use in hospitalized patients with hematological malignancy: a case series

The antifibrinolytic aminocaproic acid is widely used in surgical settings to prevent blood loss and decrease transfusion requirements, and small observational studies have suggested that aminocaproic acid may be useful in the setting of malignancy-related bleeding. At our institution, aminocaproic acid is sometimes prescribed to patients with hematological malignancy who experience refractory thrombocytopenia with or without bleeding. We performed a 5-year retrospective review of 54 adult patients with 13 types of hematological malignancy who received aminocaproic acid at our institution. Indications for use included 31 (57.4%) for refractory thrombocytopenia with bleeding, 16 (29.6%) for refractory thrombocytopenia without bleeding, and 7 (13%) for bleeding alone. Patients received both oral and intravenous formulations. Administered doses ranged broadly and median duration of use was 6 days. Three patients (5.7%) developed deep venous thrombosis but none of the thrombotic events were clearly related to administration of aminocaproic acid. We conclude that aminocaproic acid may be a relatively safe and cost-effective adjunct treatment in the setting of bleeding related to the diagnosis and treatment of hematological malignancy. Prospective trials as well as formalized protocols for the use of aminocaproic acid may be indicated. Copyright © 2015 John Wiley & Sons, Ltd.

Damage control resuscitation

The early recognition and management of hemorrhage shock are among the most difficult tasks challenging the clinician during primary assessment of the acutely bleeding patient. Often with little time, within a chaotic setting, and without sufficient clinical data, a decision must be reached to begin transfusion of blood components in massive amounts. The practice of massive transfusion has advanced considerably and is now a more complete and, arguably, more effective process. This new therapeutic paradigm, referred to as damage control resuscitation (DCR), differs considerably in many important respects from previous management strategies for catastrophic blood loss. We review several important elements of DCR including immediate correction of specific coagulopathies induced by hemorrhage and management of several extreme homeostatic imbalances that may appear in the aftermath of resuscitation. We also emphasize that the foremost objective in managing exsanguinating hemorrhage is always expedient and definitive control of the source of bleeding.

Risk factors for surgical site infections after pediatric spine operations

STUDY DESIGN

Matched case-control study.

OBJECTIVE

To identify modifiable risk factors for surgical site infections (SSIs) after pediatric spinal fusion.

SUMMARY OF BACKGROUND DATA

The number of SSIs after pediatric spinal fusions increased.

METHODS

Between July 2001 and July 2010, 22 of 598 pediatric patients who underwent spinal fusion at a university hospital acquired SSIs. Each patient with an SSI was matched with 2 controls by procedure date. Bivariable and multivariable analyses were used to identify risk factors for SSIs and outcomes of SSIs.

RESULTS

Gram-negative organisms caused more than 50% of the SSIs. By multivariable analysis, neuromuscular scoliosis (odds ratio [OR] = 20.8; 95% confidence interval [CI], 3.1-889.5; P < 0.0001) and weight-for-age at the 95th percentile or higher (OR = 8.6; 95% CI, 1.2-124.9; P = 0.02) were preoperative factors associated with SSIs. Blood loss (OR = 1.0; 95% CI, 1.0-1.0; P = 0.039) and allografts and allografts in combination with other grafts were operative risk factors for SSIs. The final overall risk model for SSIs was weight-for-age at the 95th percentile or higher (OR = 4.0; 95% CI, 1.4-∞; P = 0.037), American Society of Anesthesiologists score 3 or more (OR = 3.8; 95% CI, 1.6-∞; P = 0.01), and prolonged operation duration (OR = 1.0/min increase; 95% CI, 1.0-1.0; P = 0.004). SSIs were associated with 2.8 days of additional postoperative length of stay (P = 0.02). Neuromuscular scoliosis was the only factor significantly associated with hospital readmission (OR = 23.6; 95% CI, 3.8-147.3; P = 0.0007).

CONCLUSION

Our results suggest that pediatric patients undergoing spinal fusion might benefit from antimicrobial prophylaxis that covers gram-negative organisms. Surgical duration, graft implantation, and blood loss are potentially modifiable operative risk factors. Neuromuscular scoliosis, high weight-for-age, and American Society of Anesthesiologists scores 3 or more may help surgical teams identify patients at high risk for SSI.

Lower limb joint replacement in patients with a history of venous thromboembolism

Although patients with a history of venous thromboembolism (VTE) who undergo lower limb joint replacement are thought to be at high risk of further VTE, the actual rate of recurrence has not been reported. The purpose of this study was to identify the recurrence rate of VTE in patients who had undergone lower limb joint replacement, and to compare it with that of patients who had undergone a joint replacement without a history of VTE. From a pool of 6646 arthroplasty procedures (3344 TKR, 2907 THR, 243 revision THR, 152 revision TKR) in 5967 patients (68% female, mean age 67.7; 21 to 96) carried out between 2009 and 2011, we retrospectively identified 118 consecutive treatment episodes in 106 patients (65% female, mean age 70; 51 to 88,) who had suffered a previous VTE. Despite mechanical prophylaxis and anticoagulation with warfarin, we had four recurrences by three months (3.4% of 118) and six by one year (5.1% of 118). In comparison, in all our other joint replacements the rate of VTE was 0.54% (35/6528). The relative risk of a VTE by 90 days in patients who had undergone a joint replacement with a history of VTE compared with those with a joint replacement and no history of VTE was 6.3 (95% confidence interval, 2.3 to 17.5). There were five complications in the previous VTE group related to bleeding or over-anticoagulation.

Platelet transfusion goals in oncology patients

Despite the advances in platelet component preparation and transfusion support over the years, platelet products remain a limited resource due to their short (5 day) shelf life, and therefore their optimal use in the non-bleeding thrombocytopenic patient continue to draw much attention. There have been a number of national and international guidelines for platelet transfusion therapy in patients with hematologic diseases, some within the last 1-2 years that have incorporated key randomized controlled trials (RCTs) which address issues, such as the optimal platelet dose, the most appropriate threshold for prophylactic platelet transfusions, and whether prophylactic platelet transfusions are superior to therapeutic-only platelet transfusion practices for the prevention life-threatening bleeding in patients with hypoproliferative thrombocytopenia. This review highlights key RCTs and recent systematic reviews focused on optimal platelet transfusion therapy in adult and pediatric patients with hypoproliferative thrombocytopenia secondary to chemotherapy or hematopoietic stem cell transplant (HSCT), discuss how recent innovations in platelet component processing may affect transfusion efficiency, and introduce renewed concepts on adjuvant therapies to prevent bleeding in the hypoproliferative thrombocytopenic patient.

Viscoelastic guidance of resuscitation

PURPOSE OF REVIEW

Bleeding in trauma carries a high mortality and is increased in case of coagulopathy. Our understanding of hemostasis and coagulopathy has improved, leading to a change in the protocols for hemostatic monitoring. This review describes the current state of evidence supporting the use of viscoelastic hemostatic assays to guide trauma resuscitation.

RECENT FINDINGS

Viscoelastic hemostatic assays such as thrombelastography and rotational thrombelastometry have shown to reduce bleeding, transfusion of fresh frozen plasma and platelets, and possibly mortality in different surgical populations. In trauma care, viscoelastic hemostatic assays allows for rapid and timely identification of coagulopathy and individualized, goal-directed transfusion therapy. As part of the resuscitation concept, viscoelastic hemostatic assays seem to improve outcome also in trauma; however, there is a need for randomized clinical trials to confirm this.

SUMMARY

We are moving toward avoiding coagulopathy by individualized, goal-directed transfusion therapy, using viscoelastic hemostatic assays to guide ongoing resuscitation of actively bleeding patients in a goal-directed manner.

HALT-IT--tranexamic acid for the treatment of gastrointestinal bleeding: study protocol for a randomised controlled trial

Background

Gastrointestinal bleeding is a common emergency that causes substantial mortality worldwide. Acute upper and lower gastrointestinal bleeding accounts for about 75,000 hospital admissions each year in the UK and causes the death of about 10% of these patients.

Tranexamic acid has been shown to reduce the need for blood transfusion in surgical patients and to reduce mortality in bleeding trauma patients, with no apparent increase in thromboembolic events.

A systematic review of clinical trials of upper gastrointestinal bleeding shows a reduction in the risk of death with tranexamic acid but the quality of the trials was poor and the estimates are imprecise. The trials were also too small to assess the effect of tranexamic acid on thromboembolic events.

Methods

HALT-IT is a pragmatic, randomised, double-blind, placebo-controlled trial which will determine the effect of tranexamic acid on mortality, morbidity (re-bleeding, non-fatal vascular events), blood transfusion, surgical intervention, and health status in patients with acute gastrointestinal bleeding. Eight thousand adult patients who fulfil the eligibility criteria will be randomised to receive tranexamic acid or placebo.

Adults with significant acute upper or lower gastrointestinal bleeding can be included if the responsible doctor is substantially uncertain as to whether or not to use tranexamic acid in that particular patient.

Trial treatment consists of a loading dose of tranexamic acid (1 g by intravenous injection) or placebo (sodium chloride 0.9%) given as soon as possible after randomisation, followed by an intravenous infusion of 3 g tranexamic acid or placebo (sodium chloride 0.9%) over 24 hours.

The main analyses will compare those allocated tranexamic acid with those allocated placebo, on an intention-to-treat basis. Results will be presented as effect estimates with a measure of precision (95% confidence intervals). Subgroup analyses for the primary outcome will be based on time to treatment, source of bleeding (upper versus lower), suspected variceal bleeding and severity of bleeding. A study with 8,000 patients will have over 90% power to detect a 25% reduction in mortality from 10% to 7.5%.

Trial registration

Current Controlled Trials ISRCTN11225767 (registration date: 3 July 2012); Clinicaltrials.gov NCT01658124 (registration date: 26 July 2012).

Electronic supplementary material

The online version of this article (doi:10.1186/1745-6215-15-450) contains supplementary material, which is available to authorized users.

[Efficacy and safety of tranexamic acid administration for the prevention and/or the treatment of post-partum haemorrhage: a systematic review with meta-analysis]

OBJECTIVE(S)

Assess the efficacy and safety of tranexamic acid administration for the prevention and/or the treatment of postpartum haemorrhage.

STUDY DESIGN

Systematic review with meta-analysis.

MATERIAL AND METHODS

Systematic review of the literature with the aim of identifying prospective, randomised, controlled trials that assessed the effect of tranexamic acid on peripartum blood loss and transfusion requirement in three clinical contexts: (i) prevention of post-partum haemorrhage in case of elective caesarean section, (ii) prevention of post-partum haemorrhage in case of vaginal delivery, (iii) treatment of post-partum haemorrhage.

RESULTS

Prophylactic administration of tranexamic acid reduced blood loss (mean difference for intraoperative blood loss: -177.9mL, IC 95%: -189.51 to -166.35, total blood loss: -183.94, IC 95%: -198.29 to -169.60), and the incidence of severe post-partum haemorrhage (OR: 0.49, IC 95%: 0.33 to 0.74). None of the published trials assessed the effect of tranexamic acid on blood products administration or transfusion requirement. Only one study assessed and reported the efficacy of tranexamic acid when administered as a treatment for postpartum haemorrhage. A significant reduction in blood loss was reported within 30 minutes after randomisation (P=0.03) and confirmed after 6 hours (median: 170mL (58-323) vs 221mL (110-543), P=0.04). None of the included studies adequately studied the incidence of side effects after tranexamic acid administration.

CONCLUSION

Although tranexamic acid administration seemed to significantly reduce blood loss and the incidence of severe post-partum haemorrhage, further prospective trials are needed to confirm the efficacy and safety of tranexamic administration in the treatment of postpartum haemorrhage. Those studies should assess the pharmacokinetic profile and the safety of this drug in pregnant women.

How I treat patients with massive hemorrhage

Massive hemorrhage is associated with coagulopathy and high mortality. The transfusion guidelines up to 2006 recommended that resuscitation of massive hemorrhage should occur in successive steps using crystalloids, colloids, and red blood cells (RBCs) in the early phase and plasma and platelets in the late phase. With the introduction of the cell-based model of hemostasis in the mid-1990s, our understanding of the hemostatic process and of coagulopathy has improved. This has contributed to a change in resuscitation strategy and transfusion therapy of massive hemorrhage along with an acceptance of the adequacy of whole blood hemostatic tests to monitor these patients. Thus, in 2005, a strategy aiming at avoiding coagulopathy by proactive resuscitation with blood products in a balanced ratio of RBC:plasma:platelets was introduced, and this has been reported to be associated with reduced mortality in observational studies. Concurrently, whole blood viscoelastic hemostatic assays have gained acceptance by allowing a rapid and timely identification of coagulopathy along with enabling an individualized, goal-directed transfusion therapy. These strategies joined together seem beneficial for patient outcome, although final evidence on outcome from randomized controlled trials are lacking. We present how we in Copenhagen and Houston, today, manage patients with massive hemorrhage.

Applying results from clinical trials: tranexamic acid in trauma patients

This paper considers how results from clinical trials should be applied in the care of patients, using the results of the Clinical Randomisation of an Antifibrinolytic in Significant Haemorrhage (CRASH-2) trial of tranexamic acid in bleeding trauma patients as a case study. We explain why an understanding of the mechanisms of action of the trial treatment, and insight into the factors that might be relevant to this mechanism, is critical in order to properly apply (generalise) trial results and why it is not necessary that the trial population is representative of the population in which the medicine will be used. We explain why cause (mechanism)-specific mortality is more generalizable than all-cause mortality and why the risk ratio is the generalizable measure of the effect of the treatment. Overall, we argue that a biological insight into how the treatment works is more relevant when applying research results to patient care than the application of statistical reasoning.

Efficacy and safety of tranexamic acid versus ϵ-aminocaproic acid in cardiovascular surgery

BACKGROUND

Blood conservation is a major concern in the management of surgical patients because of transfusion-related complications, limited supply, and health care costs. Tranexamic acid (TXA) and ϵ-aminocaproic acid (ϵACA) are lysine analogue antifibrinolytics used to reduce surgical bleeding and transfusions.

OBJECTIVE

To evaluate the efficacy and safety of TXA compared with ϵACA in the management of cardiovascular surgical bleeding at an academic medical center.

METHODS

This single-center, retrospective, observational cohort study included 120 patients undergoing cardiovascular surgery with or without cardiopulmonary bypass, who received at least 1 dose of perioperative TXA or ϵACA. The efficacy outcome-massive perioperative bleeding-was a composite end point of chest tube drainage >1500 mL in any 8-hour period after surgery, perioperative transfusion of 10 or more units of packed red blood cells, reoperation for bleeding, or death from hemorrhage within 30 days. The safety outcomes were incidence of thromboembolic events, postoperative renal dysfunction, seizure, and 30-day all-cause mortality.

RESULTS

The primary end point-massive perioperative bleeding-occurred in 10 patients (16.7%) in the TXA group compared with 5 patients (8.3%) in the ϵACA group (P = 0.17). There were no significant differences in the secondary end points of 30-day all-cause mortality, thromboembolic events, renal dysfunction, and seizure.

CONCLUSIONS

There were no differences in the efficacy and safety outcomes between TXA and ϵACA in the management of cardiovascular surgical bleeding at our institution. Considering the substantial cost difference and comparable efficacy and safety, ϵACA may have better value over TXA for reducing cardiovascular surgical bleeding.

Tranexamic acid use and postoperative outcomes in patients undergoing total hip or knee arthroplasty in the United States: retrospective analysis of effectiveness and safety

OBJECTIVE

To determine the effectiveness and safety of perioperative tranexamic acid use in patients undergoing total hip or knee arthroplasty in the United States.

DESIGN

Retrospective cohort study; multilevel multivariable logistic regression models measured the association between tranexamic acid use in the perioperative period and outcomes.

SETTING

510 US hospitals from the claims based Premier Perspective database for 2006-12.

PARTICIPANTS

872,416 patients who had total hip or knee arthroplasty.

INTERVENTION

Perioperative intravenous tranexamic acid use by dose categories (none, ≤ 1000 mg, 2000 mg, and ≥ 3000 mg).

MAIN OUTCOME MEASURES

Allogeneic or autologous transfusion, thromboembolic complications (pulmonary embolism, deep venous thrombosis), acute renal failure, and combined complications (thromboembolic complications, acute renal failure, cerebrovascular events, myocardial infarction, in-hospital mortality).

RESULTS

While comparable regarding average age and comorbidity index, patients receiving tranexamic acid (versus those who did not) showed lower rates of allogeneic or autologous transfusion (7.7% v 20.1%), thromboembolic complications (0.6% v 0.8%), acute renal failure (1.2% v 1.6%), and combined complications (1.9% v 2.6%); all P<0.01. In the multilevel models, tranexamic acid dose categories (versus no tranexamic acid use) were associated with significantly (P<0.001) decreased odds for allogeneic or autologous blood transfusions (odds ratio 0.31 to 0.38 by dose category) and no significantly increased risk for complications: thromboembolic complications (odds ratio 0.85 to 1.02), acute renal failure (0.70 to 1.11), and combined complications (0.75 to 0.98).

CONCLUSIONS

Tranexamic acid was effective in reducing the need for blood transfusions while not increasing the risk of complications, including thromboembolic events and renal failure. Thus our data provide incremental evidence of the potential effectiveness and safety of tranexamic acid in patients requiring orthopedic surgery.

Accumulating research: a systematic account of how cumulative meta-analyses would have provided knowledge, improved health, reduced harm and saved resources

Background

“Cumulative meta-analysis” describes a statistical procedure to calculate, retrospectively, summary estimates from the results of similar trials every time the results of a further trial in the series had become available. In the early 1990s, comparisons of cumulative meta-analyses of treatments for myocardial infarction with advice promulgated through medical textbooks showed that research had continued long after robust estimates of treatment effects had accumulated, and that medical textbooks had overlooked strong, existing evidence from trials. Cumulative meta-analyses have subsequently been used to assess what could have been known had new studies been informed by systematic reviews of relevant existing evidence and how waste might have been reduced.

Methods and Findings

We used a systematic approach to identify and summarise the findings of cumulative meta-analyses of studies of the effects of clinical interventions, published from 1992 to 2012. Searches were done of PubMed, MEDLINE, EMBASE, the Cochrane Methodology Register and Science Citation Index. A total of 50 eligible reports were identified, including more than 1,500 cumulative meta-analyses. A variety of themes are illustrated with specific examples. The studies showed that initially positive results became null or negative in meta-analyses as more trials were done; that early null or negative results were over-turned; that stable results (beneficial, harmful and neutral) would have been seen had a meta-analysis been done before the new trial; and that additional trials had been much too small to resolve the remaining uncertainties.

Conclusions

This large, unique collection of cumulative meta-analyses highlights how a review of the existing evidence might have helped researchers, practitioners, patients and funders make more informed decisions and choices about new trials over decades of research. This would have led to earlier uptake of effective interventions in practice, less exposure of trial participants to less effective treatments, and reduced waste resulting from unjustified research.

Tranexamic acid – a useful drug in ENT surgery?

Background:

Tranexamic acid is a synthetic antifibrinolytic drug. It has been widely available for over 40 years, but only recently has it started to be used routinely in many surgical disciplines. For ENT surgeons, epistaxis and post-tonsillectomy bleeding contribute a significant proportion of the morbidity and emergency workload in a general ENT department. Published evidence indicates a potentially helpful role for tranexamic acid in managing epistaxis.

Results and conclusion:

To date, the benefits of tranexamic acid as a prophylactic treatment to reduce the rate and severity of post-tonsillectomy bleeding are less certain. Two recently published pilot studies looking at primary haemorrhage in children and secondary haemorrhage in adults following tonsillectomy suggest that further large, randomised trials should explore the efficacy of tranexamic acid in routine ENT surgery. There are potential reductions in patient morbidity and cost savings if tranexamic acid is found to be efficacious in larger trials.

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.

Hypoxia, haemorrhage and hypotension: the interface between emergency medicine and intensive care medicine

This subjective review is based on a presentation made at the College of Emergency Medicine Scientific Conference in September 2013. My theme was that there are certain features of the critically ill which cause understandable anxiety, namely hypoxia, haemorrhage and hypotension. So, I have selected papers relevant to the management of these frightening situations.

Intraoperative tranexamic acid in pediatric bloodless cardiac surgery

OBJECTIVE

The aim of this study was to evaluate the clinical effects of intraoperative tranexamic acid administration in cardiac surgery without blood transfusion (bloodless cardiac surgery) in children.

METHODS

Seventy-one consecutive patients weighing less than 20 kg, who underwent bloodless cardiac surgery for simple atrial or ventricular septal defects at Kobe Children's Hospital from January 2011 to June 2013, were enrolled in this retrospective study. Tranexamic acid was administered during surgery from January 2012 (TXA group; n = 31), whereas it was not administered before January 2012 (control group; n = 40). Perioperative variables were compared between the TXA and control groups.

RESULTS

There were no significant differences in patient characteristics or preoperative data between the 2 groups. Serial changes in perioperative hemoglobin and hematocrit levels, mixed venous oxygen saturation, and regional cerebral oxygenation during cardiopulmonary bypass were significantly higher in the TXA group compared to the control group. There were significant reductions in operative time, dopamine dose, peak serum lactate level, intubation time, chest tube drainage and duration, and hospital stay in the TXA group.

CONCLUSIONS

Intraoperative tranexamic acid administration was effective for blood conservation, and improved postoperative clinical outcomes in pediatric bloodless cardiac surgery.

Classifying types of disseminated intravascular coagulation: clinical and animal models

Disseminated intravascular coagulation (DIC) has a common pathogenesis in terms of persistent widespread activation of coagulation in the presence of underlying disease, but the degree of fibrinolytic activation often differs by DIC type. DIC with suppressed fibrinolysis is a DIC type usually seen in sepsis. Coagulation activation is severe, but fibrinolytic activation is mild. DIC with enhanced fibrinolysis is a DIC type usually seen in acute promyelocytic leukemia (APL). Both coagulation activation and fibrinolytic activation are severe. DIC with balanced fibrinolysis is a DIC type usually seen in solid tumors, with an intermediate pathogenesis between the above two types. In animal DIC models, lipopolysaccharide (LPS)-induced models are similar to suppressed-fibrinolytic-type DIC, whereas tissue factor (TF)-induced models are similar to enhanced fibrinolytic/balanced fibrinolytic DIC. Appropriate diagnosis and treatment may also differ depending on the DIC type.

Single-dose tranexamic acid in advanced ovarian cancer surgery reduces blood loss and transfusions: double-blind placebo-controlled randomized multicenter study

OBJECTIVE

To determine whether single-dose tranexamic acid given intravenously immediately before surgery for presumed advanced ovarian cancer reduces perioperative blood loss and blood transfusions.

DESIGN

A randomized double-blind, placebo-controlled multicenter study.

SETTING

Two university hospitals and two central hospitals in the southeast health region of Sweden.

POPULATION

One hundred women with presumed advanced ovarian cancer scheduled for radical debulking surgery between March 2008 and May 2012 who complied with inclusion/exclusion criteria were randomized; 50 were allocated to receive tranexamic acid and 50 to receive placebo. Analysis was performed according to intention-to-treat principles.

METHODS

The volume of tranexamic acid (15 mg/kg body weight, 100 mg/mL tranexamic acid) or the same volume of placebo (0.9% NaCl) was added to a 100-mL saline solution plastic bag. The study medication was given immediately before the start of surgery. Data were analyzed by means of non-parametric statistics and multivariate models adjusted for confounding factors.

MAIN OUTCOME MEASURES

Blood loss and red blood cell transfusions.

RESULTS

The total blood loss volume and transfusion rate were significantly lower in the tranexamic acid group compared with the placebo group. Median total blood loss was 520 and 730 mL, respectively (p = 0.03). Fifteen (30%) and 22 (44%), respectively received transfusions (odds ratio 0.44; upper 95% CI 0.97; p = 0.02).

CONCLUSION

A single dose of tranexamic acid given immediately before surgery reduces blood loss and transfusion rates significantly in advanced ovarian cancer surgery. Tranexamic acid may be recommended as standard prophylactic treatment in advanced ovarian cancer surgery.

How to increase value and reduce waste when research priorities are set

The increase in annual global investment in biomedical research--reaching US$240 billion in 2010--has resulted in important health dividends for patients and the public. However, much research does not lead to worthwhile achievements, partly because some studies are done to improve understanding of basic mechanisms that might not have relevance for human health. Additionally, good research ideas often do not yield the anticipated results. As long as the way in which these ideas are prioritised for research is transparent and warranted, these disappointments should not be deemed wasteful; they are simply an inevitable feature of the way science works. However, some sources of waste cannot be justified. In this report, we discuss how avoidable waste can be considered when research priorities are set. We have four recommendations. First, ways to improve the yield from basic research should be investigated. Second, the transparency of processes by which funders prioritise important uncertainties should be increased, making clear how they take account of the needs of potential users of research. Third, investment in additional research should always be preceded by systematic assessment of existing evidence. Fourth, sources of information about research that is in progress should be strengthened and developed and used by researchers. Research funders have primary responsibility for reductions in waste resulting from decisions about what research to do.

Single tranexamic acid dose to reduce perioperative morbidity in primary total hip replacement: a randomised clinical trial

INTRODUCTION

Although prophylactic tranexamic acid (TXA) is a safe, low-cost option to reduce bleeding in patients undergoing total hip replacement (THR), its optimal dose and duration is unknown. We compared the safety and effectiveness of TXA given as either a single injection or continuous infusion in THR patients, hypothesising that a second TXA dose would not offer any clinical advantages over the single injection.

MATERIALS AND METHODS

One hundred and sixty-four patients undergoing unilateral THR were randomised. Exclusion criteria were history of thromboembolic events (TE), epilepsy, thrombophilia, and severe chronic renal failure. Patients received either a single dose of 30 mg/kg TXA on induction of surgery (one shot [OS] group), or a loading dose of 10 mg/kg TXA followed two hours later by a continuous infusion of 2 mg/kg per hour for 20 hours (one day [OD] group). The primary outcome was blood loss (BL) calculated from haematocrit levels. Secondary outcomes were mortality and TE events within 90 days postoperatively.

RESULTS

All patients completed treatment, with none lost to follow-up. Mean BL was 1107 ± 508 ml in Group OS and 1047 ± 442 ml in Group OD (p = 0.43). No patients were transfused prior to Day 10 postoperatively. At final follow-up, no patients had died, and there were no occurrences of major TE.

CONCLUSION

The 30 mg/kg TXA single shot was as safe as continuous infusion. As it is also less cumbersome, we recommend it as part of routine care in THR patients.

Efficacy of low-dose intra-articular tranexamic acid in total knee replacement; a prospective triple-blinded randomized controlled trial

BACKGROUND

Recently, a number of studies using intra-articular application of tranexamic acid (IA-TXA), with different dosage and techniques, successfully reduced postoperative blood loss in total knee replacement (TKR). However, best of our knowledge, the very low dose of IA-TXA with drain clamping technique in conventional TKR has not been yet studied. This study aimed to evaluate the effectiveness and dose-response effect of two low-dose IA-TXA regimens in conventional TKR on blood loss and blood transfusion reduction.

METHODS

Between 2010 and 2011, a triple-blinded randomized controlled study was conducted in 135 patients undergoing conventional TKR. The patients were allocated into three groups according to intra-articular solution received: Control group (physiologic saline), TXA-250 group (TXA 250 mg), and TXA-500 group (TXA 500 mg). The solution was injected after wound closure followed by drain clamping for 2 hours. Blood loss and transfusion were recorded. Duplex ultrasound was performed. Functional outcome and complication were followed for one year.

RESULTS

There were forty-five patients per groups. The mean total hemoglobin loss was 2.9 g/dL in control group compared with 2.2 g/dL in both TXA groups (p > 0.001). Ten patients (22%, control), six patients (13%, TXA-250) and none (TXA-500) required transfusion (p = 0.005). Thromboembolic events were detected in 7 patients (4 controls, 1 TXA-250, and 2 TXA-500). Functional outcome was non-significant difference between groups.

CONCLUSIONS

Combined low-dose IA-TXA, as 500 mg, with 2-hour clamp drain is effective for reducing postoperative blood loss and transfusion in conventional TKR without significant difference in postoperative knee function or complication.

TRIAL REGISTRATION

ClinicalTrials.gov NCT01850394.

How we manage the haematological aspects of major obstetric haemorrhage

Major obstetric haemorrhage (MOH) remains an important medical challenge worldwide, contributing to significant maternal morbidity and mortality. Prompt and appropriate management is essential if we are to improve outcomes and reduce substandard care that may result in adverse consequences. This review describes the current understanding of the pathophysiological aspects of MOH together with the principles of transfusion and haemostatic therapy, with emphasis on a coordinated multidisciplinary approach. We also highlight the current lack of evidence available from randomized controlled trials to inform best practice and the need to prioritize research in this key clinical area.

Topical tranexamic acid in total knee replacement: a systematic review and meta-analysis

BACKGROUND

To examine the safety and efficacy of topical use of tranexamic acid (TA) in total knee arthroplasty (TKA).

METHODS

An electronic literature search of PubMed Medline; Ovid Medline; Embase; and the Cochrane Library was performed, identifying studies published in any language from 1966 to February 2013. The studies enrolled adults undergoing a primary TKA, where topical TA was used. Inverse variance statistical method and either a fixed or random effect model, depending on the absence or presence of statistical heterogeneity were used; subgroup analysis was performed when possible.

RESULTS

We identified a total of seven eligible reports for analysis. Our meta-analysis indicated that when compared with the control group, topical application of TA limited significantly postoperative drain output (mean difference: -268.36ml), total blood loss (mean difference=-220.08ml), Hb drop (mean difference=-0.94g/dL) and lowered the risk of transfusion requirements (risk ratio=0.47, 95CI=0.26-0.84), without increased risk of thromboembolic events. Sub-group analysis indicated that a higher dose of topical TA (>2g) significantly reduced transfusion requirements.

CONCLUSIONS

Although the present meta-analysis proved a statistically significant reduction of postoperative blood loss and transfusion requirements with topical use of TA in TKA, the clinical importance of the respective estimates of effect size should be interpreted with caution.

LEVEL OF EVIDENCE

I, II.

Topical tranexamic acid reduces blood loss and transfusion rates in total hip and total knee arthroplasty

The objective of this study was to determine if tranexamic acid (TXA) applied topically reduced postoperative bleeding and transfusion rates after primary total hip arthroplasty (THA) and primary total knee arthroplasty (TKA). Two hundred and ninety consecutive patients from a single surgeon were enrolled. In TKA, TXA solution was injected into the knee after closure of the arthrotomy. In THA, the joint was bathed in TXA solution at three points during the procedure. In both THA and TKA the TXA solution was at a concentration of 3 g TXA per 100 mL saline. The mean blood loss was significantly higher in the non-TXA patients in both TKA and THA groups. Postoperative transfusions decreased dramatically with TXA, dropping from 10% to 0%, and from 15% to 1%, in the TKA and THA groups, respectively. Topical application of TXA significantly reduces postoperative blood loss and transfusion risk in TKA and THA.