Anti-fibrinolytic use for minimising perioperative allogeneic blood transfusion

Changes in Practices After Implementation of a Patient Blood Management Program in French Surgical Departments: The National Multicenter Observational PERIOPES Study

BACKGROUND

Patient blood management (PBM) is an evidence-based approach recommended to improve patient outcomes. Change in practices is often challenging. We report here data from French surgical departments before and after a standardized implementation of a PBM program.

METHODS

This was a national, multicenter, observational study in surgical centers ("expert" centers with an already established protocol for preoperative anemia or "pilot" centers). Data from consecutive surgical patients of different specialties were retrieved before and after the implementation of a PBM program. Primary outcome variables (preoperative anemia treatment rates, transfusion rates, and length of hospital stay) before and after the implementation of a PBM program were analyzed with segmented regression adjusted on confounders (American Society of Anesthesiologists [ASA] scores and centers).

RESULTS

A total of 1618 patients (ASA physical status III and IV, 38% in the first period and 45% in the second period) were included in expert (N = 454) or pilot (N = 1164) centers during the first period (January 2017-August 2022) and 1542 (N = 440 and N = 1102, respectively) during the second period (January 2020-February 2023). After implementation of the PBM program, the rate of preoperative anemia treatment increased (odds ratio, 2.37; 95% confidence interval [CI], 1.20-4.74; P = .0136) and length of hospital stay in days decreased (estimate, -0.11; 95% CI, -0.21 to -0.02; P = .0186). Transfusion rate significantly decreased only in expert centers (odds ratio, 0.17; 95% CI, 0.03-0.88; P = .0354).

CONCLUSIONS

PBM practices in various surgical specialties improved significantly after the implementation of a PBM program. However, too many patients with preoperative anemia remained untreated.

Does Tranexamic Acid Reduce the Blood Loss in Various Surgeries? An Umbrella Review of State-of-the-Art Meta-Analysis

Background: Tranexamic acid (TXA) has been applied in various types of surgery for hemostasis purposes. The efficacy and safety of TXA are still controversial in different surgeries. Guidelines for clinical application of TXA are needed. Materials and method: We systematically searched multiple medical databases for meta-analyses examining the efficacy and safety of TXA. Types of surgery included joint replacement surgery, other orthopedic surgeries, cardiac surgery, cerebral surgery, etc. Outcomes were blood loss, blood transfusion, adverse events, re-operation rate, operative time and length of hospital stay, hemoglobin (Hb) level, and coagulation function. Assessing the methodological quality of systematic reviews 2 (AMSTAR 2) and Grading of Recommendations, Assessment, Development and Evaluation (GRADE) were used for quality assessment of the included meta-analyses. Overlapping reviews were evaluated by calculating the corrected covered area (CCA). Result: In all, we identified 47 meta-analyses, of which 44 of them were of "high" quality. A total of 319 outcomes were evaluated, in which 58 outcomes were assessed as "high" quality. TXA demonstrates significant hemostatic effects in various surgeries, with lower rates of blood transfusion and re-operation, shorter operative time and length of stay, and higher Hb levels. Besides, TXA does not increase the risk of death and vascular adverse events, but it is a risk factor for seizure (a neurological event) in cardiac surgery. Conclusion: Our study demonstrates that TXA has a general hemostatic effect with very few adverse events, which indicates TXA is the recommended medication to prevent excessive bleeding and reduce the blood transfusion rate. We also recommend different dosages of TXA for different types of adult surgery. However, we could not recommend a unified dosage for different surgeries due to the heterogeneity of the experimental design. Systematic Review Registration: clinicaltrials.gov/, identifier CRD42021240303.

Can prospective systematic reviews of animal studies improve clinical translation?

Systematic reviews are powerful tools with the potential to generate high quality evidence. Their application to animal studies has been instrumental in exposing the poor quality of these studies, as well as a catalyst for improvements in study design, conduct and reporting. It has been suggested that prospective systematic reviews of animal studies (i.e. systematic reviews conducted prior to clinical trials) would allow scrutiny of the preclinical evidence, providing valuable information on safety and efficacy, and helping to determine whether clinical trials should proceed. However, while prospective systematic reviews allow valuable scrutiny of the preclinical animal data, they are not necessarily able to reliably predict the safety and efficacy of an intervention when trialled in humans. Consequently, they may not reliably safeguard humans participating in clinical trials and might potentially result in lost opportunities for beneficial clinical treatments. Furthermore, animal and human studies are often conducted concurrently, which not only makes prospective systematic reviews of animal studies impossible, but suggests that animal studies do not inform human studies in the manner presumed. We suggest that this points to a confused attitude regarding animal studies, whereby tradition demands that they precede human studies but practice indicates that their findings are often ignored. We argue that it is time to assess the relative contributions of animal and human research in order to better understand how clinical knowledge is actually produced.

Epsilon-aminocaproic acid versus tranexamic acid in total knee arthroplasty: a meta-analysis study

Introduction

Total knee arthroplasty (TKA) surgery can be associated with significant blood loss. Among the problems associated with such blood loss is the need for transfusions of banked blood [1]. Transfusions not only have a financial consequence but also carry a small risk of disease transmission to the patient. Antifibrinolytics have been successfully used to reduce transfusion requirements in elective arthroplasty patients. The objective of this meta-analysis is to determine which of tranexamic acid (TXA) and epsilon-aminocaproic acid (EACA) is more effective for reducing peri-operative blood loss, and lessening the need for blood transfusion following knee arthroplasty surgery.

Materials and methods

MEDLINE, Embase and CINAHL databases were searched for relevant articles published between January 1980 to January 2018 for the purpose of identifying studies comparing TXA and EACA for TKA surgery. A double-extraction technique was used, and included studies were assessed regarding their methodological quality prior to analysis. Outcomes analysed included blood loss, pre- and post-operative haemoglobin, number of patients requiring transfusion, number of units transfused, operative and tourniquet time, and complications associated with antifibrinolytics.

Results

Three studies contributed to the quantitative analysis of 1691 patients, with 743 patients included in the TXA group and 948 in the EACA group. Estimated blood loss was similar between the two groups [95% confidence interval (CI) −0.50, 0.04; Z = 1.69; P = 0.09]. There were no differences between the two groups regarding the percentage of patients requiring transfusion (95% CI 0.14, 4.13; Z = 0.31; P = 0.76). There was no difference in the pre- and post-operative haemoglobin difference between the two groups (95% CI −0.36, 0.24; Z = 0.38; P = 0.70). There was no difference in the average number of transfused units (95% CI −0.53, 0.25; Z = 0.71; P = 0.48). There was no difference in the operative (95% CI −0.35, 0.36; Z = 0.04; P = 0.97) or tourniquet time (95% CI −0.16, 0.34; Z = 0.72; P = 0.47). Similarly, there was no difference in the percentage of venous thromboembolism between the two groups (95% CI 0.17, 2.80; Z = 0.51; P = 0.61).

Conclusions

This study did not demonstrate TXA to be superior to EACA. In fact, both antifibrinolytic therapies demonstrated similar efficacy in terms of intra-operative blood loss, transfusion requirements and complication rates. Currently EACA has a lower cost, which makes it an appealing alternative to TXA for TKA surgery.

Level of evidence

3.

Tranexamic acid for treatment and prophylaxis of bleeding and hyperfibrinolysis

Uncontrolled massive bleeding with subsequent derangement of the coagulation system is a major challenge in the management of both surgical and seriously injured patients. Under physiological conditions activators and inhibitors of coagulation regulate the sensitive balance between clot formation and fibrinolysis. In some cases, excessive and diffuse bleeding is caused by systemic activation of fibrinolysis, i. e. hyperfibrinolysis (HF). Uncontrolled HF is associated with a high mortality. Polytrauma patients and those undergoing surgical procedures involving organs rich in plasminogen proactivators (e. g. liver, kidney, pancreas, uterus and prostate gland) are at a high risk for HF. Antifibrinolytics, such as tranexamic acid (TXA) are used for prophylaxis and treatment of bleeding caused by a local or generalized HF as well as other hemorrhagic conditions. TXA is a synthetic lysine analogue that has been available in Austria since 1966. TXA is of utmost importance in the prevention and treatment of traumatic and perioperative bleeding due to the resulting reduction in perioperative blood loss and blood transfusion requirements. The following article presents the different fields of application of TXA with particular respect to indications and dosages, based on a literature search and on current guidelines.

Safety and Efficacy of Tranexamic Acid in Total Knee Arthroplasty

Background

The prevalence of total knee arthroplasty (TKA) is increasing, which is one of the most frequent operations in orthopedic practice. To further investigate the safe and effective role of using tranexamic acid (TA) in reducing transfusion rate and blood loss in total knee arthroplasty.

Material/Methods

This meta-analysis was conducted according to the Cochrane methodology. Twenty-eight superior quality and well designed randomized controlled trials (RCT) were collected to analyze for this study. Patients who had undergone primary unilateral TKA were chosen. The software, RevMan 5.2, was used to analyze collected data.

Results

Finally, 28 RCTs were collected to analyze for this study. Total blood loss was dramatically decreased via the application of TA, by a mean of 420 ml [95% CI: −514 to −327]. A significant reduction about blood transfusion rate was also found in patients who received TA. [RD: −0.26, 95%CI: −0.33 to −0.19]. Moreover, no significant differences were found between TA and control groups in incidence of deep vein thrombosis (DVT) and pulmonary embolism (PE).

Conclusions

This meta-analysis demonstrates that the application of TA in TKA could decrease total blood loss and transfusion rate. On the other hand, the application of TA is not associated with high incidence of DVT or other adverse events. TA should be taken into account in routine use in primary knee arthroplasty to benefit the patients.

Exploring redundant research into the effect of tranexamic acid on surgical bleeding: further analysis of a systematic review of randomised controlled trials

OBJECTIVES

We examined whether apparent redundancy in a cumulative meta-analysis of trials is justified by concern about bias, random error or generalisability of the results.

DESIGN

Cumulative meta-analysis, risk of bias assessment, trial sequential analysis, description of study participants over time and a review of rationales for conducting trials.

DATA SOURCE

126 randomised trials included in a systematic review assessing of tranexamic acid on blood transfusion in surgery.

RESULTS

The cumulative meta-analysis including all trials shows that the pooled estimate first reached statistical significance after the second trial in 1993. When the analysis was limited to the 38 high-quality trials and adjusted to account for potential systematic and random errors, the uncertainty was resolved after the 22nd trial in 2008. When the analysis was restricted to the two high-quality, prospectively registered trials, the cumulative z-curve crossed p=0.05 but not the monitoring boundary, suggesting an early potentially spurious statistically significant result. As precision of the pooled estimate increased, the number of trials initiated increased, although trial activity appeared to move to other surgery types. Most (62%) reports cited at least one systematic review. Of 118 reports examined, concern about generalisability was the reason for initiating the trial in 60%. Other reasons were to address a question other than the effect on bleeding (26%) and to confirm previously observed results (4%). Unawareness of previous research was apparent in 4% trials, while the rationale was unclear in 3%.

CONCLUSIONS

Our results indicate that poor quality is a more important cause of redundant research than the failure to review existing evidence. Concerns about generalisability of results is the main motivation for new trials. Contrary to previous claims, our results suggest that systematic reviews showing treatment effects can stimulate an increase in trial activity rather than reduce it.

Low-, medium- and high-dose steroids with or without aminocaproic acid in adult hematopoietic SCT patients with diffuse alveolar hemorrhage

Diffuse alveolar hemorrhage (DAH) is a poorly understood complication of transplantation carrying a high mortality. Patients commonly deteriorate and require intensive care unit (ICU) admission. Treatment with high-dose steroids and aminocaproic acid (ACA) has been suggested. The current study examined 119 critically ill adult hematopoietic transplant patients treated for DAH. Patients were subdivided into low-, medium- and high-dose steroid groups with or without ACA. All groups had similar baseline characteristics and severity of illness scores. Primary objectives were 30, 60, 100 day, ICU and hospital mortality. Overall mortality (n=119) on day 100 was high at 85%. In the steroids and ACA cohort (n=82), there were no significant differences in 30, 60, 100, day, ICU and hospital mortality between the dosing groups. In the steroids only cohort (n=37), the low-dose steroid group had a lower ICU and hospital mortality (P=0.02). Adjunctive treatment with ACA did not produce differences in outcomes. In the multivariate analysis, medium- and high-dose steroids were associated with a higher ICU mortality (P=0.01) as compared with the low-dose group. Our data suggest that treatment strategies may need to be reanalyzed to avoid potentially unnecessary and potentially harmful therapies.

Meta-analysis of the effect of automated contrast injection devices versus manual injection and contrast volume on risk of contrast-induced nephropathy

Contrast-sparing devices have been slowly adopted into routine patient care. Randomized trial evidence of automated contrast injectors (ACIs) has not been analyzed to evaluate the true reduction in contrast volume during coronary angiography and intervention. It has been thought that reducing the amount of contrast exposure will result in a simultaneous reduction in the risk of contrast-induced nephropathy (CIN). Therefore, we sought to synthesize published evidence on contrast-sparing devices, contrast volume, and the incidence of CIN. We searched Medline, the Cochrane Library, and Clinicaltrials.gov. The search criteria included ACIs versus manual injection, contrast media volume, and the incidence of CIN. Data were extracted by 2 independent reviewers. The weighted mean difference of contrast volume was calculated using random effects models in RevMan, version 5.4.1, software to derive a summary estimate. A total of 79,694 patients from 10 studies were included (ACI arm, n = 20,099; manual injection arm, n = 59,595). On average, ACIs reduced contrast volume delivery by 45 ml/case (p <0.001, 95% confidence interval -54 to -35). The CIN incidence was significantly reduced by 15%, with an odds ratio of 0.85 (p <0.001, 95% confidence interval 0.78 to 0.93) for those using ACIs compared with manual injection. In conclusion, the use of ACIs in angiography significantly reduces the volume of contrast delivered to the patient and the incidence of CIN.

Hemostatic strategies for traumatic and surgical bleeding

Wide interest in new hemostatic approaches has stemmed from unmet needs in the hospital and on the battlefield. Many current commercial hemostatic agents fail to fulfill the design requirements of safety, efficacy, cost, and storage. Academic focus has led to the improvement of existing strategies as well as new developments. This review will identify and discuss the three major classes of hemostatic approaches: biologically derived materials, synthetically derived materials, and intravenously administered hemostatic agents. The general class is first discussed, then specific approaches discussed in detail, including the hemostatic mechanisms and the advancement of the method. As hemostatic strategies evolve and synthetic-biologic interactions are more fully understood, current clinical methodologies will be replaced.

Plasmin Activation of Glial Cells through Protease-Activated Receptor 1

The objective of this study was to determine whether plasmin could induce morphological changes in human glial cells via PAR1. Human glioblastoma A172 cells were cultured in the presence of plasmin or the PAR1 specific activating hexapeptide, SFLLRN. Cells were monitored by flow cytometry to detect proteolytic activation of PAR1 receptor. Morphological changes were recorded by photomicroscopy and apoptosis was measured by annexinV staining. Plasmin cleaved the PAR1 receptor on glial cells at 5 minutes (P = 0.02). After 30 minutes, cellular processes had begun to retract from the basal substratum and by 4 hours glial cells had become detached. Similar results were obtained by generating plasmin de novo from plasminogen. Morphological transformation was blocked by plasmin inhibitors aprotinin or epsilon-aminocaproic acid (P = 0.03). Cell viability was unimpaired during early morphological changes, but by 24 hours following plasmin treatment 22% of glial cells were apoptotic. PAR1 activating peptide SFLLRN (but not inactive isomer FSLLRN) promoted analogous glial cell detachment (P = 0.03), proving the role for PAR1 in this process. This study has identified a plasmin/PAR1 axis of glial cell activation, linked to changes in glial cell morophology. This adds to our understanding of pathophysiological disease mechanisms of plasmin and the plasminogen system in neuroinjury.

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

OBJECTIVE

To assess the effect of tranexamic acid on blood transfusion, thromboembolic events, and mortality in surgical patients.

DESIGN

Systematic review and meta-analysis.

DATA SOURCES

Cochrane central register of controlled trials, Medline, and Embase, from inception to September 2011, the World Health Organization International Clinical Trials Registry Platform, and the reference lists of relevant articles.

STUDY SELECTION

Randomised controlled trials comparing tranexamic acid with no tranexamic acid or placebo in surgical patients. Outcome measures of interest were the number of patients receiving a blood transfusion; the number of patients with a thromboembolic event (myocardial infarction, stroke, deep vein thrombosis, and pulmonary embolism); and the number of deaths. Trials were included irrespective of language or publication status.

RESULTS

129 trials, totalling 10,488 patients, carried out between 1972 and 2011 were included. Tranexamic acid reduced the probability of receiving a blood transfusion by a third (risk ratio 0.62, 95% confidence interval 0.58 to 0.65; P<0.001). This effect remained when the analysis was restricted to trials using adequate allocation concealment (0.68, 0.62 to 0.74; P<0.001). The effect of tranexamic acid on myocardial infarction (0.68, 0.43 to 1.09; P = 0.11), stroke (1.14, 0.65 to 2.00; P = 0.65), deep vein thrombosis (0.86, 0.53 to 1.39; P = 0.54), and pulmonary embolism (0.61, 0.25 to 1.47; P=0.27) was uncertain. Fewer deaths occurred in the tranexamic acid group (0.61, 0.38 to 0.98; P = 0.04), although when the analysis was restricted to trials using adequate concealment there was considerable uncertainty (0.67, 0.33 to 1.34; P = 0.25). Cumulative meta-analysis showed that reliable evidence that tranexamic acid reduces the need for transfusion has been available for over 10 years.

CONCLUSIONS

Strong evidence that tranexamic acid reduces blood transfusion in surgery has been available for many years. Further trials on the effect of tranexamic acid on blood transfusion are unlikely to add useful new information. However, the effect of tranexamic acid on thromboembolic events and mortality remains uncertain. Surgical patients should be made aware of this evidence so that they can make an informed choice.

Case report: The management of advanced oral cancer in a Jehovah's Witness using the Ultracision Harmonic Scalpel

We present the first case of a head and neck oncological procedure accomplished in a Jehovah's Witness using the Ultracision Harmonic Scalpel (Ethicon, Cincinnati, OH). Jehovah's Witnesses present a serious challenge to the head and neck cancer surgeon due to their refusal to accept transfusion of any blood products. However, our experience reinforces the view that surgical management of head and neck cancer is possible in these patients. We show the Harmonic Scalpel, an ultrasonic tissue dissector, to be a useful surgical tool in obviating the need for blood transfusion. Preoperative optimisation, intra-operative surgical and anaesthetic techniques are also fully discussed.

[The "Seville" Consensus Document on Alternatives to Allogenic Blood Transfusion. Sociedades españolas de Anestesiología (SEDAR), Medicina Intensiva (SEMICYUC), Hematología y Hemoterapia (AEHH), Transfusión sanguínea (SETS) Trombosis y Hemostasia (SETH)]

The Consensus Document on Alternatives to Allogenic Blood Transfusion (AABT) has been drawn up by a panel of experts from 5 scientific societies. The Spanish Societies of Anesthesiology (SEDAR), Critical Care Medicine and Coronary Units (SEMICYUC), Hematology and Hemotherapy (AEHH), Blood Transfusion (SETS) and Thrombosis and Hemostasis (SETH) have sponsored and participated in this Consensus Document. Alternatives to blood transfusion have been divided into pharmacological and non-pharmacological, with 4 modules and 12 topics. The main objective variable was the reduction of allogenic blood transfusions and/or the number of transfused patients. The extent to which this objective was achieved by each AABT was evaluated using the Delphi method, which classifies the grade of recommendation from A (supported by controlled studies) to E (non-controlled studies and expert opinion). The experts concluded that most of the indications for AABT were based on middle or low grades of recommendation, "C", "D", or "E", thus indicating the need for further controlled studies.

Anti-fibrinolytic use for minimising perioperative allogeneic blood transfusion

BACKGROUND

Concerns regarding the safety of transfused blood have led to the development of a range of interventions to minimise blood loss during major surgery. Anti-fibrinolytic drugs are widely used, particularly in cardiac surgery, and previous reviews have found them to be effective in reducing blood loss, the need for transfusion, and the need for re-operation due to continued or recurrent bleeding. In the last few years questions have been raised regarding the comparative performance of the drugs. The safety of the most popular agent, aprotinin, has been challenged, and it was withdrawn from world markets in May 2008 because of concerns that it increased the risk of cardiovascular complications and death.

OBJECTIVES

To assess the comparative effects of the anti-fibrinolytic drugs aprotinin, tranexamic acid (TXA), and epsilon aminocaproic acid (EACA) on blood loss during surgery, the need for red blood cell (RBC) transfusion, and adverse events, particularly vascular occlusion, renal dysfunction, and death.

SEARCH STRATEGY

We searched: the Cochrane Injuries Group's Specialised Register (July 2010), Cochrane Central Register of Controlled Trials (The Cochrane Library 2010, Issue 3), MEDLINE (Ovid SP) 1950 to July 2010, EMBASE (Ovid SP) 1980 to July 2010. References in identified trials and review articles were checked and trial authors were contacted to identify any additional studies. The searches were last updated in July 2010.

SELECTION CRITERIA

Randomised controlled trials (RCTs) of anti-fibrinolytic drugs in adults scheduled for non-urgent surgery. Eligible trials compared anti-fibrinolytic drugs with placebo (or no treatment), or with each other.

DATA COLLECTION AND ANALYSIS

Two authors independently assessed trial quality and extracted data. This version of the review includes a sensitivity analysis excluding trials authored by Prof. Joachim Boldt.

MAIN RESULTS

This review summarises data from 252 RCTs that recruited over 25,000 participants. Data from the head-to-head trials suggest an advantage of aprotinin over the lysine analogues TXA and EACA in terms of reducing perioperative blood loss, but the differences were small. Compared to control, aprotinin reduced the probability of requiring RBC transfusion by a relative 34% (relative risk [RR] 0.66, 95% confidence interval [CI] 0.60 to 0.72). The RR for RBC transfusion with TXA was 0.61 (95% CI 0.53 to 0.70) and was 0.81 (95% CI 0.67 to 0.99) with EACA. When the pooled estimates from the head-to-head trials of the two lysine analogues were combined and compared to aprotinin alone, aprotinin appeared more effective in reducing the need for RBC transfusion (RR 0.90; 95% CI 0.81 to 0.99).Aprotinin reduced the need for re-operation due to bleeding by a relative 54% (RR 0.46, 95% CI 0.34 to 0.62). This translates into an absolute risk reduction of 2% and a number needed-to-treat (NNT) of 50 (95% CI 33 to 100). A similar trend was seen with EACA (RR 0.32, 95% CI 0.11 to 0.99) but not TXA (RR 0.80, 95% CI 0.55 to 1.17). The blood transfusion data were heterogeneous and funnel plots indicate that trials of aprotinin and the lysine analogues may be subject to publication bias.When compared with no treatment aprotinin did not increase the risk of myocardial infarction (RR 0.87, 95% CI 0.69 to 1.11), stroke (RR 0.82, 95% CI 0.44 to 1.52), renal dysfunction (RR 1.10, 95% CI 0.79 to 1.54) or overall mortality (RR 0.81, 95% CI 0.63 to 1.06). Similar trends were seen with the lysine analogues, but data were sparse. These data conflict with the results of recently published non-randomised studies, which found increased risk of cardiovascular complications and death with aprotinin. There are concerns about the adequacy of reporting of uncommon events in the small clinical trials included in this review.When aprotinin was compared directly with either, or both, of the two lysine analogues it resulted in a significant increase in the risk of death (RR 1.39, 95% CI 1.02, 1.89), and a non-significant increase in the risk of myocardial infarction (RR 1.11 95% CI 0.82, 1.50). Most of the data contributing to this added risk came from a single study - the BART trial (2008).

AUTHORS' CONCLUSIONS

Anti-fibrinolytic drugs provide worthwhile reductions in blood loss and the receipt of allogeneic red cell transfusion. Aprotinin appears to be slightly more effective than the lysine analogues in reducing blood loss and the receipt of blood transfusion. However, head to head comparisons show a lower risk of death with lysine analogues when compared with aprotinin. The lysine analogues are effective in reducing blood loss during and after surgery, and appear to be free of serious adverse effects.

The challenges of meeting the blood transfusion requirements in Sub-Saharan Africa: the need for the development of alternatives to allogenic blood

As a resource, allogenic blood has never been more in demand than it is today. Escalating elective surgery, shortages arising from a fall in supply, a lack of national blood transfusion services, policies, appropriate infrastructure, trained personnel, and financial resources to support the running of a voluntary nonremunerated donor transfusion service, and old and emerging threats of transfusion-transmitted infection, have all conspired to ensure that allogenic blood remains very much a vital but limited asset to healthcare delivery particularly in Sub-Saharan Africa. This is further aggravated by the predominance of family replacement and commercially remunerated blood donors, rather than regular benevolent, nonremunerated donors who give blood out of altruism. The demand for blood transfusion is high in Sub-Saharan Africa because of the high prevalence of anemia especially due to malaria and pregnancy-related complications. All stakeholders in blood transfusion have a significant challenge to apply the best available evidenced-based medical practices to the world-class management of this precious product in a bid to using blood more appropriately. Physicians in Sub-Saharan Africa must always keep in mind that the first and foremost strategy to avoid transfusion of allogenic blood is their thorough understanding of the pathophysiologic mechanisms involved in anemia and coagulopathy, and their thoughtful adherence to the evidenced-based good practices used in the developed world in a bid to potentially reduce the likelihood of allogenic blood transfusion in many patient groups. There is an urgent need to develop innovative ways to recruit and retain voluntary low-risk blood donors. Concerns about adverse effects of allogenic blood transfusion should prompt a review of transfusion practices and justify the need to search for transfusion alternatives to decrease or avoid the use of allogenic blood. These strategies should include the correction of anemia using pharmacological measures (use of antifibrinolytics to prevent bleeding and the use of erythropoietin and oral and intravenous iron to treat anemia) use of nonpharmacologic measures (preoperative autologous blood transfusion, perioperative red blood cell salvage and normothermia to reduce blood loss in surgical patients). All these strategies will help optimize the use of the limited blood stocks.

Anti-fibrinolytic use for minimising perioperative allogeneic blood transfusion

BACKGROUND

Concerns regarding the safety of transfused blood have led to the development of a range of interventions to minimise blood loss during major surgery. Anti-fibrinolytic drugs are widely used, particularly in cardiac surgery, and previous reviews have found them to be effective in reducing blood loss, the need for transfusion, and the need for re-operation due to continued or recurrent bleeding. In the last few years questions have been raised regarding the comparative performance of the drugs. The safety of the most popular agent, aprotinin, has been challenged, and it was withdrawn from world markets in May 2008 because of concerns that it increased the risk of cardiovascular complications and death.

OBJECTIVES

To assess the comparative effects of the anti-fibrinolytic drugs aprotinin, tranexamic acid (TXA), and epsilon aminocaproic acid (EACA) on blood loss during surgery, the need for red blood cell (RBC) transfusion, and adverse events, particularly vascular occlusion, renal dysfunction, and death.

SEARCH STRATEGY

We searched: the Cochrane Injuries Group's Specialised Register (July 2010), Cochrane Central Register of Controlled Trials (The Cochrane Library 2010, Issue 3), MEDLINE (Ovid SP) 1950 to July 2010, EMBASE (Ovid SP) 1980 to July 2010. References in identified trials and review articles were checked and trial authors were contacted to identify any additional studies. The searches were last updated in July 2010.

SELECTION CRITERIA

Randomised controlled trials (RCTs) of anti-fibrinolytic drugs in adults scheduled for non-urgent surgery. Eligible trials compared anti-fibrinolytic drugs with placebo (or no treatment), or with each other.

DATA COLLECTION AND ANALYSIS

Two authors independently assessed trial quality and extracted data.

MAIN RESULTS

This review summarises data from 252 RCTs that recruited over 25,000 participants. Data from the head-to-head trials suggest an advantage of aprotinin over the lysine analogues TXA and EACA in terms of reducing perioperative blood loss, but the differences were small. Compared to control, aprotinin reduced the probability of requiring RBC transfusion by a relative 34% (relative risk [RR] 0.66, 95% confidence interval [CI] 0.60 to 0.72). The RR for RBC transfusion with TXA was 0.61 (95% CI 0.53 to 0.70) and was 0.81 (95% CI 0.67 to 0.99) with EACA. When the pooled estimates from the head-to-head trials of the two lysine analogues were combined and compared to aprotinin alone, aprotinin appeared more effective in reducing the need for RBC transfusion (RR 0.90; 95% CI 0.81 to 0.99).Aprotinin reduced the need for re-operation due to bleeding by a relative 54% (RR 0.46, 95% CI 0.34 to 0.62). This translates into an absolute risk reduction of 2% and a number needed-to-treat (NNT) of 50 (95% CI 33 to 100). A similar trend was seen with EACA (RR 0.32, 95% CI 0.11 to 0.99) but not TXA (RR 0.80, 95% CI 0.55 to 1.17). The blood transfusion data were heterogeneous and funnel plots indicate that trials of aprotinin and the lysine analogues may be subject to publication bias.When compared with no treatment aprotinin did not increase the risk of myocardial infarction (RR 0.87, 95% CI 0.69 to 1.11), stroke (RR 0.82, 95% CI 0.44 to 1.52), renal dysfunction (RR 1.10, 95% CI 0.79 to 1.54) or overall mortality (RR 0.81, 95% CI 0.63 to 1.06). Similar trends were seen with the lysine analogues, but data were sparse. These data conflict with the results of recently published non-randomised studies, which found increased risk of cardiovascular complications and death with aprotinin. There are concerns about the adequacy of reporting of uncommon events in the small clinical trials included in this review.When aprotinin was compared directly with either, or both, of the two lysine analogues it resulted in a significant increase in the risk of death (RR 1.39, 95% CI 1.02, 1.89), and a non-significant increase in the risk of myocardial infarction (RR 1.11 95% CI 0.82, 1.50). Most of the data contributing to this added risk came from a single study - the BART trial (2008).

AUTHORS' CONCLUSIONS

Anti-fibrinolytic drugs provide worthwhile reductions in blood loss and the receipt of allogeneic red cell transfusion. Aprotinin appears to be slightly more effective than the lysine analogues in reducing blood loss and the receipt of blood transfusion. However, head to head comparisons show a lower risk of death with lysine analogues when compared with aprotinin. The lysine analogues are effective in reducing blood loss during and after surgery, and appear to be free of serious adverse effects.

Management of bleeding following major trauma: an updated European guideline

INTRODUCTION

Evidence-based recommendations are needed to guide the acute management of the bleeding trauma patient, which when implemented may improve patient outcomes.

METHODS

The multidisciplinary Task Force for Advanced Bleeding Care in Trauma was formed in 2005 with the aim of developing a guideline for the management of bleeding following severe injury. This document presents an updated version of the guideline published by the group in 2007. Recommendations were formulated using a nominal group process, the Grading of Recommendations Assessment, Development and Evaluation (GRADE) hierarchy of evidence and based on a systematic review of published literature.

RESULTS

Key changes encompassed in this version of the guideline include new recommendations on coagulation support and monitoring and the appropriate use of local haemostatic measures, tourniquets, calcium and desmopressin in the bleeding trauma patient. The remaining recommendations have been reevaluated and graded based on literature published since the last edition of the guideline. Consideration was also given to changes in clinical practice that have taken place during this time period as a result of both new evidence and changes in the general availability of relevant agents and technologies.

CONCLUSIONS

This guideline provides an evidence-based multidisciplinary approach to the management of critically injured bleeding trauma patients.

Sodium bicarbonate plus N-acetylcysteine prophylaxis: a meta-analysis

OBJECTIVES

We sought to conduct a meta-analysis to compare N-acetylcysteine (NAC) in combination with sodium bicarbonate (NaHCO(3)) for the prevention of contrast-induced acute kidney injury (AKI).

BACKGROUND

Contrast-induced AKI is a serious consequence of cardiac catheterizations and percutaneous coronary interventions (PCI). Despite recent supporting evidence for combination therapy, not enough has been done to prevent the occurrence of contrast-induced AKI prophylactically.

METHODS

Published randomized controlled trial data were collected from OVID/PubMed, Web of Science, and conference abstracts. The outcome of interest was contrast-induced AKI, defined as a >or=25% or >or=0.5 mg/dl increase in serum creatinine from baseline. Secondary outcome was renal failure requiring dialysis.

RESULTS

Ten randomized controlled trials met our criteria. Combination treatment of NAC with intravenous NaHCO(3) reduced contrast-induced AKI by 35% (relative risk: 0.65; 95% confidence interval: 0.40 to 1.05). However, the combination of N-acetylcysteine plus NaHCO(3) did not significantly reduce renal failure requiring dialysis (relative risk: 0.47; 95% confidence interval: 0.16 to 1.41).

CONCLUSIONS

Combination prophylaxis with NAC and NaHCO(3) substantially reduced the occurrence of contrast-induced AKI overall but not dialysis-dependent renal failure. Combination prophylaxis should be incorporated for all high-risk patients (emergent cases or patients with chronic kidney disease) and should be strongly considered for all interventional radio-contrast procedures.

Effect of epsilon aminocaproic acid on red-cell transfusion requirements in major spinal surgery

STUDY DESIGN

: Randomized, placebo-controlled trial.

OBJECTIVE

: To evaluate the efficacy of epsilon aminocaproic acid (EACA) to reduce the number of red-cell (RBC) transfusions in adult patients undergoing major spinal surgery.

SUMMARY OF BACKGROUND DATA

: Reconstructive spinal surgery is associated with significant blood loss. The number of studies evaluating the efficacy of EACA in adult patients undergoing spinal surgery remains scarce and limited.

METHODS

: EACA (100 mg/kg) or placebo was administered to 182 adult patients after the induction of anesthesia followed by an infusion that was continued for 8 hours after surgery. Primary end points included total allogeneic RBC transfusions through postoperative day 8 and postoperative allogeneic plus autologus RBC transfusions through postoperative day 8.

RESULTS

: Mean total allogeneic RBC transfusions were not statistically different between the groups (5.9 units EACA vs. 6.9 units placebo; P = 0.17). Mean postoperative RBC transfusions in the EACA group was less (2.0 units vs. 2.8 units placebo; P = 0.03). There was no significantdifference in mean estimated intraoperative estimated-blood loss (2938 cc EACA vs. 3273 cc placebo; P = 0.32). Mean intensive care unit length of stay was decreased (EACA: 1.8 days vs. 2.8 days placebo; P = 0.04). The incidence of thromboembolic complications was similar (2.2% EACA vs. 6.6% placebo; P = 0.15).

CONCLUSION

: The difference in total allogeneic RBC transfusions between the groups was not statistically significant. EACA was associated with a 30% (0.8 units) reduction in postoperative RBC transfusions and a 1-day reduction in ICU LOS, without an increased incidence of thromboembolic events. EACA may be considered for patients undergoing major spinal surgery. Larger studies are needed to evaluate the relationship between EACA and total RBC requirements.

Can trial sequential monitoring boundaries reduce spurious inferences from meta-analyses?

BACKGROUND

Results from apparently conclusive meta-analyses may be false. A limited number of events from a few small trials and the associated random error may be under-recognized sources of spurious findings. The information size (IS, i.e. number of participants) required for a reliable and conclusive meta-analysis should be no less rigorous than the sample size of a single, optimally powered randomized clinical trial. If a meta-analysis is conducted before a sufficient IS is reached, it should be evaluated in a manner that accounts for the increased risk that the result might represent a chance finding (i.e. applying trial sequential monitoring boundaries).

METHODS

We analysed 33 meta-analyses with a sufficient IS to detect a treatment effect of 15% relative risk reduction (RRR). We successively monitored the results of the meta-analyses by generating interim cumulative meta-analyses after each included trial and evaluated their results using a conventional statistical criterion (alpha = 0.05) and two-sided Lan-DeMets monitoring boundaries. We examined the proportion of false positive results and important inaccuracies in estimates of treatment effects that resulted from the two approaches.

RESULTS

Using the random-effects model and final data, 12 of the meta-analyses yielded P > alpha = 0.05, and 21 yielded P </= alpha = 0.05. False positive interim results were observed in 3 out of 12 meta-analyses with P > alpha = 0.05. The monitoring boundaries eliminated all false positives. Important inaccuracies in estimates were observed in 6 out of 21 meta-analyses using the conventional P </= alpha = 0.05 and 0 out of 21 using the monitoring boundaries.

CONCLUSIONS

Evaluating statistical inference with trial sequential monitoring boundaries when meta-analyses fall short of a required IS may reduce the risk of false positive results and important inaccurate effect estimates.

Urinary aprotinin as a predictor of acute kidney injury after cardiac surgery in children receiving aprotinin therapy

Proteomic analysis has revealed potential early biomarkers of acute kidney injury (AKI) in children undergoing cardiopulmonary bypass (CPB), the most prominent one with a mass-to-charge ratio of 6.4 kDa. The objective of this study was to identify this protein and test its utility as a biomarker of AKI. Trypsin-digested protein bands were analyzed by tandem mass spectrometry (MS/MS) to identify the protein in urine samples. Surface-enhanced laser desorption/ionization time-of-flight analysis and a functional activity assay were performed to quantify urinary levels in a pilot study of 106 pediatric patients undergoing CPB. The protein was identified as aprotinin. Urinary aprotinin levels 2 h after initiation of CPB were predictive of AKI (for functional assay: 92% sensitivity, 96% specificity, area under the curve of 0.98). By multivariate analysis, the urinary aprotinin level 2 h after CPB was an independent predictor of AKI (beta = 0.001, P < 0.0001). The 2 h urinary aprotinin level correlated with serum creatinine, duration of AKI, and length of hospital stay. We concluded that urinary aprotinin levels 2 h after initiation of CPB predict the development of AKI and adverse clinical outcomes.

A benefit-risk review of systemic haemostatic agents: part 1: in major surgery

Systemic haemostatic agents play an important role in the management of blood loss during major surgery where significant blood loss is likely and their use has increased in recent times as a consequence of demand for blood products outstripping supply and the risks associated with transfusions. Their main application is as prophylaxis to reduce bleeding in major surgery, including cardiac and orthopaedic surgery and orthotopic liver transplantation. Aprotinin has been the predominant agent used in this setting; of the other antifibrinolytic agents that have been studied, tranexamic acid is the most effective and epsilon-aminocaproic acid may also have a role. Eptacog alfa (recombinant factor VIIa) has also shown promise. Tranexamic acid, epsilon-aminocaproic acid and eptacog alfa are generally well tolerated; however, when considering the methods to reduce or prevent blood loss intra- and postoperatively, the benefits of these agents need to be weighed against the risk of adverse events. Recently, concerns have been raised about the safety of aprotinin after an association between increased renal dysfunction and mortality was shown in retrospective observational studies and an increase in all-cause mortality with aprotinin relative to tranexamic acid or epsilon-aminocaproic acid was seen after a pre-planned periodic analysis of the large BART (Blood conservation using Antifibrinolytics in a Randomized Trial) study. The latter finding resulted in the trial being halted, and aprotinin has subsequently been withdrawn from the market pending detailed analysis of efficacy and safety results from the study. Part 1 of this benefit-risk review examines the efficacy and adverse effect profiles of systemic haemostatic agents commonly used in surgery, and provides individual benefit-risk profiles that may assist clinicians in selecting appropriate pharmacological therapy in this setting.

Transfusion-related acute lung injury: past, present, and future

Noncardiogenic pulmonary edema caused by transfusion has been observed for almost 60 years. Today, we know this entity as transfusion-related acute lung injury (TRALI). TRALI is an uncommon but potentially fatal adverse reaction to transfusion of plasma-containing blood components. It is typified by dyspnea, cough, hypoxemia, and pulmonary edema within 6 hours of transfusion. Most commonly, it is caused by donor HLA antibodies that react with recipient antigens. It may also be caused by biologically active compounds accumulated during storage of blood products, which are capable of priming neutrophils. Without a "gold standard," the diagnosis of TRALI relies on a high index of suspicion and on excluding other types of transfusion reactions. Although current definitions of TRALI depend on symptoms, laboratory parameters can aid in the diagnosis and frequently identify the causative donor unit. As our understanding of TRALI deepens, risk reduction or prevention may become possible.

Anti-fibrinolytic use for minimising perioperative allogeneic blood transfusion

BACKGROUND

Concerns regarding the safety of transfused blood have led to the development of a range of interventions to minimise blood loss during major surgery. Anti-fibrinolytic drugs are widely used, particularly in cardiac surgery and previous reviews have found them to be effective in reducing blood loss and the need for transfusion. Recently, questions have been raised regarding the comparative performance of the drugs and the safety of the most popular agent, aprotinin.

OBJECTIVES

To assess the comparative effects of the anti-fibrinolytic drugs aprotinin, tranexamic acid (TXA), and epsilon aminocaproic acid (EACA) on blood loss during surgery, the need for red blood (RBC) transfusion, and adverse events, particularly vascular occlusion, renal dysfunction, and death.

SEARCH STRATEGY

We searched CENTRAL, MEDLINE, EMBASE, and the internet. References in identified trials and review articles were checked and trial authors were contacted to identify any additional studies. The searches were last updated in July 2006.

SELECTION CRITERIA

Randomised controlled trials (RCTs) of anti-fibrinolytic drugs in adults scheduled for non-urgent surgery. Eligible trials compared anti-fibrinolytic drugs with placebo (or no treatment), or with each other.

DATA COLLECTION AND ANALYSIS

Two authors independently assessed trial quality and extracted data.

MAIN RESULTS

This review summarises data from 211 RCTs that recruited 20,781 participants. Data from placebo/inactive controlled trials, and from head-to-head trials suggest an advantage of aprotinin over the lysine analogues TXA and EACA in terms of operative blood loss, but the differences were small. Aprotinin reduced the probability of requiring RBC transfusion by a relative 34% (relative risk [RR] 0.66, 95% confidence interval [CI] 0.61 to 0.71). The RR for RBC transfusion with TXA was 0.61 (95% CI 0.54 to 0.69) and it was 0.75 (95% CI 0.58 to 0.96) with EACA. When the pooled estimates from the head-to-head trials of the two lysine analogues were combined and compared to aprotinin alone, aprotinin appeared superior in reducing the need for RBC transfusion: RR 0.83 (95% CI 0.69 to 0.99). Aprotinin reduced the need for re-operation due to bleeding: RR 0.48 (95% CI 0.35 to 0.68). This translates into an absolute risk reduction of just under 3% and a number needed-to-treat (NNT) of 37 (95% CI 27 to 56). Similar trends were seen with TXA and EACA, but the data were sparse and the differences failed to reach statistical significance. The blood transfusion data were heterogeneous and funnel plots indicate that trials of aprotinin and the lysine analogues may be subject to publication bias. Evidence of publication bias was not observed in trials reporting re-operation rates. Adjustment for these effects reduced the magnitude of estimated benefits but did not negate treatment effects. However, the apparent advantage of aprotinin over the lysine analogues was small and may be explained by publication bias and non-equivalent drug doses. Aprotinin did not increase the risk of myocardial infarction (RR 0.92, 95% CI 0.72 to 1.18), stroke (RR 0.76, 95% CI 0.35 to 1.64) renal dysfunction (RR 1.16, 95% CI 0.79 to 1.70) or overall mortality (RR 0.90, 95% CI 0.67 to 1.20). The analyses of myocardial infarction and death included data from the majority of subjects recruited into the clinical trials of aprotinin. However, under-reporting of renal events could explain the lack of effect seen with aprotinin. Similar trends were seen with the lysine analogues but data were sparse. These results conflict with the results of recently published non-randomised studies.

AUTHORS' CONCLUSIONS

Anti-fibrinolytic drugs provide worthwhile reductions in blood loss and the need for allogeneic red cell transfusion. Based on the results of randomised trials their efficacy does not appear to be offset by serious adverse effects. In most circumstances the lysine analogues are probably as effective as aprotinin and are cheaper; the evidence is stronger for tranexamic acid than for aminocaproic acid. In high risk cardiac surgery, where there is a substantial probability of serious blood loss, aprotinin may be preferred over tranexamic acid. Aprotinin does not appear to be associated with an increased risk of vascular occlusion and death, but the data do not exclude an increased risk of renal failure. There is no need for further placebo-controlled trials of aprotinin or lysine analogues in cardiac surgery. The principal need is for large comparative trials to assess the relative efficacy, safety and cost-effectiveness of anti-fibrinolytic drugs in different surgical procedures.

[Procedure for critical nonsurgical bleeding]

The improvement of surgical and nonsurgical approaches to control bleeding offers new strategies for overcoming coagulopathy. Massive hemorrhage is usually caused by a combination of surgical and coagulopathic bleeding. Coagulopathy is multifactorial and results from the dilution and consumption of both platelets and coagulation factors and dysfunction of the coagulation system. Blood component therapy continues to be a mainstay for this coagulopathy-related bleeding. However, the transfusion of red blood cells has been shown to be associated with post-injury infection and multiple organ failure. Therefore it is crucial to develop a clear strategy for correcting coagulopathy, preventing exsanguination, and minimizing the need for blood transfusion.

Topical use of tranexamic acid to control perioperative local bleeding in gynaecology patients with clotting disorders: two cases

Operating on patients with abnormal coagulation is a challenge frequently faced by surgeons. Achieving haemostasis perioperatively can involve bleeding points that would not ordinarily present a problem with intact clotting function. Here we present two women with localised wound bleeding following a gynaecological surgery in the presence of a clotting disorder. Haemostasis was successfully achieved with tropical use of tranexamic acid. These two cases illustrate a novel use for this antifibrinolytic agent. We suggest that there is a role for topical use of tranexamic acid in perioperative haemostasis in patients with clotting disorders.

Management of bleeding following major trauma: a European guideline

INTRODUCTION

Evidence-based recommendations can be made with respect to many aspects of the acute management of the bleeding trauma patient, which when implemented may lead to improved patient outcomes.

METHODS

The multidisciplinary Task Force for Advanced Bleeding Care in Trauma was formed in 2005 with the aim of developing guidelines for the management of bleeding following severe injury. Recommendations were formulated using a nominal group process and the GRADE (Grading of Recommendations Assessment, Development, and Evaluation) hierarchy of evidence and were based on a systematic review of published literature.

RESULTS

Key recommendations include the following: The time elapsed between injury and operation should be minimised for patients in need of urgent surgical bleeding control, and patients presenting with haemorrhagic shock and an identified source of bleeding should undergo immediate surgical bleeding control unless initial resuscitation measures are successful. A damage control surgical approach is essential in the severely injured patient. Pelvic ring disruptions should be closed and stabilised, followed by appropriate angiographic embolisation or surgical bleeding control, including packing. Patients presenting with haemorrhagic shock and an unidentified source of bleeding should undergo immediate further assessment as appropriate using focused sonography, computed tomography, serum lactate, and/or base deficit measurements. This guideline also reviews appropriate physiological targets and suggested use and dosing of blood products, pharmacological agents, and coagulation factor replacement in the bleeding trauma patient.

CONCLUSION

A multidisciplinary approach to the management of the bleeding trauma patient will help create circumstances in which optimal care can be provided. By their very nature, these guidelines reflect the current state-of-the-art and will need to be updated and revised as important new evidence becomes available.

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

Background

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

Methods

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

Results

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

Conclusion

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

Transfusion-related acute lung injury: a literature review

Transfusion-related acute lung injury (TRALI) is a serious and potentially fatal complication of transfusion of blood and blood components. TRALI is under-diagnosed and under-reported because of a lack of awareness. A number of models have been proposed to explain the pathogenesis of TRALI: an antibody mediated model; a two-event biologically active mediator model; and a combined model. TRALI can occur with any type of blood product and can occur with as little as one unit. Its presentation is similar to other forms of acute lung injury and management is predominantly supportive. The main strategy in combating TRALI is prevention both through manipulation of the donor pool and through clinical strategies directed at reducing transfusion of blood products including, but not limited to, evidence-based lower transfusion thresholds. This article presents a review of TRALI and addresses the definition, pathology, pathogenesis, clinical manifestations, treatment and prevention of the syndrome.

Haemostatic drug therapies for acute primary intracerebral haemorrhage

BACKGROUND

Because primary intracerebral haemorrhage (PICH) volume influences its outcome and a third of PICHs enlarge by a third within 24 hours of onset, early haemostatic drug therapy might improve outcome.

OBJECTIVES

To examine the clinical effectiveness and safety of haemostatic drug therapies for acute PICH in a randomised controlled trial (RCT) design.

SEARCH STRATEGY

We searched the Cochrane Stroke Group Trials Register (last searched May 2006), the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library Issue 2, 2006), MEDLINE (1966 to August 2005) and EMBASE (1980 to August 2005). In an effort to identify further published, ongoing and unpublished studies we scanned bibliographies of relevant articles, searched international registers of clinical trials and research, and contacted authors and pharmaceutical companies.

SELECTION CRITERIA

We sought RCTs of any haemostatic drug therapy for acute PICH, compared against placebo or open control, with relevant clinical outcome measures.

DATA COLLECTION AND ANALYSIS

Two review authors independently applied the inclusion criteria, reviewed the relevant studies, and extracted data from them.

MAIN RESULTS

We found four phase II RCTs, involving adults aged 18 years or over, within four hours of PICH: 116 received placebo and 373 participants received haemostatic drugs (two received epsilon-aminocaproic acid (EACA) and 371 received recombinant activated factor VII (rFVIIa)). Haemostatic drugs appeared to reduce the risk of death or dependence on the modified Rankin Scale (grades 4 to 6) within 90 days of PICH (risk reduction 0.79 (95% confidence intervals (CI) 0.67 to 0.93)), but not when assessed by the extended Glasgow Outcome Scale (risk reduction 0.90 (95%CI 0.81 to 1.01)). There was a statistically significant excess of arterial thromboembolism at 160 mcg/kg rFVIIa.

AUTHORS' CONCLUSIONS

Current evidence for the use of haemostatic drugs in the treatment of acute PICH cannot provide clear guidelines for clinical practice. Adults with acute PICH may benefit from haemostatic therapy with rFVIIa, but the evidence on major clinical outcomes is neither robust nor precise. Large phase III RCTs of rFVIIa - and other less costly drugs - are necessary.

Are antifibrinolytic drugs equivalent in reducing blood loss and transfusion in cardiac surgery? A meta-analysis of randomized head-to-head trials

BACKGROUND

Aprotinin has been shown to be effective in reducing peri-operative blood loss and the need for re-operation due to continued bleeding in cardiac surgery. The lysine analogues tranexamic acid (TXA) and epsilon aminocaproic acid (EACA) are cheaper, but it is not known if they are as effective as aprotinin.

METHODS

Studies were identified by searching electronic databases and bibliographies of published articles. Data from head-to-head trials were pooled using a conventional (Cochrane) meta-analytic approach and a Bayesian approach which estimated the posterior probability of TXA and EACA being equivalent to aprotinin; we used as a non-inferiority boundary a 20% increase in the rates of transfusion or re-operation because of bleeding.

RESULTS

Peri-operative blood loss was significantly greater with TXA and EACA than with aprotinin: weighted mean differences were 106 mls (95% CI 37 to 227 mls) and 185 mls (95% CI 134 to 235 mls) respectively. The pooled relative risks (RR) of receiving an allogeneic red blood cell (RBC) transfusion with TXA and EACA, compared with aprotinin, were 1.08 (95% CI 0.88 to 1.32) and 1.14 (95% CI 0.84 to 1.55) respectively. The equivalent Bayesian posterior mean relative risks were 1.15 (95% Bayesian Credible Interval [BCI] 0.90 to 1.68) and 1.21 (95% BCI 0.79 to 1.82) respectively. For transfusion, using a 20% non-inferiority boundary, the posterior probabilities of TXA and EACA being non-inferior to aprotinin were 0.82 and 0.76 respectively. For re-operation the Cochrane RR for TXA vs. aprotinin was 0.98 (95% CI 0.51 to 1.88), compared with a posterior mean Bayesian RR of 0.63 (95% BCI 0.16 to 1.46). The posterior probability of TXA being non-inferior to aprotinin was 0.92, but this was sensitive to the inclusion of one small trial.

CONCLUSION

The available data are conflicting regarding the equivalence of lysine analogues and aprotinin in reducing peri-operative bleeding, transfusion and the need for re-operation. Decisions are sensitive to the choice of clinical outcome and non-inferiority boundary. The data are an uncertain basis for replacing aprotinin with the cheaper lysine analogues in clinical practice. Progress has been hampered by small trials and failure to study clinically relevant outcomes.

Antifibrinolytic agents in traumatic haemorrhage

Among trauma patients who survive to reach hospital, exsanguination is a common cause of death. Could anti fibrinolytics reduce the death rate? Only a large randomized controlled trial can answer the question

What is the evidence for using hemostatic agents in surgery?

The pharmacological methods used to achieve systemic hemostasis have generated much discussion due to concerns of serious adverse effects (e.g., thromboembolic complications) and costs of therapy in addition to efficacy considerations. There are a limited number of well-controlled trials involving pharmacological hemostasis for spine surgery. In the largest double-blinded randomized controlled trial to date involving spine surgery, there was a trend toward reduced homologous transfusion in patients receiving aprotinin, but the only statistically significant result ( p<0.001) was a reduction in autologous red cell donations. The findings of this trial are important, since the investigators used a number of restrictive transfusion strategies (e.g., autologous donation, low hematocrit trigger for transfusion, blood-salvaging procedures with the exception of no cell saver) that were not always employed in earlier trials involving hemostatic agents. Smaller studies involving antifibrinolytic agents other than aprotinin have demonstrated reductions in blood loss and transfusion requirements in patients undergoing spine surgery, although the results were not always statistically significant. A very large randomized trial would be required to address comparative medication- and transfusion-related adverse events; such a trial involving patients undergoing cardiac surgery is currently being performed. Additionally, cost-effectiveness analyses are needed to help define the role of these agents based on the data that is available.

An overview of blood-sparing techniques used in spine surgery during the perioperative period

The problems linked to blood loss and blood-sparing techniques in spine surgery have been less studied than in other fields of orthopedics, such as joint-replacement procedures. Decreasing bleeding is not only important for keeping the patient's hemodynamic equilibrium but also for allowing a better view of the surgical field. In spine surgery the latter aspect is especially important because of the vicinity of major and highly fragile neurologic structures. The techniques and agents used for hemostasis and blood sparing in spinal procedures are mostly similar to those used elsewhere in surgery. Their use is modulated by the specific aspects of spinal approach and its relation to the contents of the spinal canal. Blood-sparing techniques can be divided into two categories based on their goals: either they are aimed at decreasing the bleeding itself, or they are aimed at decreasing the need for homologous transfusion. Various hemodynamic techniques, as well as systemic and local drugs and agents, can be used separately or in combination, and their use in the field of spine surgery is reported. The level of evidence for the efficacy of many of those methods in surgery as a whole is limited, and there is a lack of evidence for most of them in spine surgery. However, several blood-saving procedures and drugs, as well as promising new agents, appear to be efficient, although their efficacy has yet to be assessed by proper randomized controlled trials.

Pre-operative autologous donation for minimising perioperative allogeneic blood transfusion

BACKGROUND

Public concerns regarding the safety of transfused blood have prompted re-consideration of the indications for the transfusion of allogeneic red cells (blood from an unrelated donor), and a range of techniques designed to minimise transfusion requirements.

OBJECTIVES

To examine the evidence for the efficacy of pre-operative autologous blood donation (PAD) in reducing the need for peri-operative allogeneic red blood cell (RBC) transfusion.

SEARCH STRATEGY

Articles were identified by: computer searches of OVID MEDLINE, EMBASE, and Current Contents (to March 2001) and web sites of international health technology assessment agencies (to January 2001). References in the identified trials were checked and authors contacted to identify additional studies.

SELECTION CRITERIA

Randomised controlled trials with a concurrent control group in which adult patients, scheduled for non-urgent surgery, were randomised to PAD, or to a control group who did not receive the intervention.

DATA COLLECTION AND ANALYSIS

Trial quality was assessed using criteria proposed by Schulz et al (1995) and Jadad et al (1996). The principle outcomes were: the number of patients exposed to allogeneic red blood cells, and the amount of blood transfused. Other clinical outcomes are detailed in the review.

MAIN RESULTS

Overall PAD reduced the risk of receiving an allogeneic blood transfusion by a relative 63% (RR=0.37: 95%CI:0.26,0.54). The absolute reduction in risk of allogeneic transfusion was 43.8% (RD=-0.438: 95%CI: -0.607,-0.268). In contrast the results show that the risk of receiving any blood transfusion (allogeneic and/or autologous) is actually increased by pre-operative autologous blood donation (RR=1.29: 95%CI: 1.12,1.48). Trials were unblinded and allocation concealment was not described in 87.5% of the trials.

REVIEWER'S CONCLUSIONS

Although the trials of PAD showed a reduction in the need for allogeneic blood the methodological quality of the trials was poor and the overall transfusion rates (allogeneic and/or autologous) in these trials were high, and were increased by recruitment into the PAD arms of the trials. This raises questions about the true benefit of PAD. In the absence of large, high quality trials using clinical endpoints, it is not possible to say whether the benefits of PAD outweigh the harms.

Utilization of technologies to reduce allogeneic blood transfusion in the United States

Concern over safety of the blood supply has led to the use of technologies to reduce allogeneic blood transfusion. The objective of this research was to determine the utilization of these technologies in the United States. We evaluated the following techniques: preoperative autologous donation (PAD), cell salvage (CS) and acute normovolemic haemodilution (ANH); and the following pharmaceuticals: aprotinin (APR), epsilon-aminocaproic acid (EACA), tranexamic acid (TXA), desmopressin (DDAVP) and recombinant human erythropoietin (EPO). In 1997, we conducted a cross-sectional mail survey of service chiefs at 1000 US hospitals randomly selected and stratified by status as a provider of open-heart surgery, geographical location and hospital bed size. Sixty-nine per cent (690) of hospitals responded to at least one of the four surveys sent to each hospital. Hospitals reported use of techniques more than pharmaceuticals (P < 0.001); PAD (83%, n = 206) and CS (82% n = 420) were used most frequently. Lack of familiarity was the most common reason cited for infrequent use of pharmaceuticals. Organizational characteristics (e.g. provision of open-heart surgery, size, geographical location, teaching status and type of hospital) were differentially associated with technology use. There is greater use of techniques than pharmaceuticals in US hospitals to reduce the need for allogeneic blood in the peri-operative setting. Providing open-heart surgery is strongly associated with the utilization of these technologies.