Blood conservation with tranexamic acid in total hip arthroplasty: a randomized, double-blind study in 40 primary operations

[Pharmacological reduction of bleeding during hip endoprosthetic replacement]

INTRODUCTION

Endoprosthetic replacement of the large joints is accompanied by major bleeding. During the last few years several authors reported the perioperative administration of tranexamic acid and its beneficial effect on reducing the blood loss.

OBJECTIVES

In the present study, the author studied the effect of intravenously administered tranexamic acid in patients undergoing primary total hip arthroplasty in order to examine whether this treatment could reduce postoperative blood loss, the amount of transfused packed red cells, and the cost of the blood saving and/or transfusion.

METHODS

The author compared retrospectively the data of 104 patients undergoing primary total hip arthroplasty between April, 2010 and December, 2011. 54 patients were administered tranexamic acid (Group 1) and 50 patients were treated without tranexamic acid (Group 2). The amount of postoperative bleeding, haemoglobin, hematocrit, red blood cell count, and the number of units of the transfused packed red cells were recorded. Cost effectiveness of treatment with tranexamic acid was calculated.

RESULTS

Postoperative blood loss in Group 1 was 732 ml (210-1280 ml), and in Group 2 1092 ml (420-2640 ml). Ten of the 54 patients in Group 1 had to be transfused, and the all-over need was 20 units of packed red cells. 49 of the 50 patients in Group 2 received 98 units of allogenic blood. Thromboembolic complication was not observed in connection with the use of tranexamic acid. The reduction of blood loss with the application of tranexamic acid and the transfused packed red cells cost in average 5,180 HUF per patient in Group 1 and 15,850 HUF in Group 2.

CONCLUSIONS

Intravenous administration of tranexamic acid reduces effectively the transfusion rate and the blood loss in the postoperative period in patients undergoing primary total hip arthroplasty. More than 1.5 million HUF and 240 units of packed red cells could be yearly saved with the introduction of this simple, safe and cheap method of drug administered blood conservation.

Efficacy of tranexamic acid on blood loss after primary cementless total hip replacement with rivaroxaban thromboprophylaxis: A case-control study in 70 patients

INTRODUCTION

Perioperative blood loss is a frequent cause of complications in total hip replacement (THR). The present prospective study assessed the efficacy of tranexamic acid (Exacyl(®)) in reducing blood loss in primary THR associated to rivaroxaban (Xarelto(®)) thromboprophylaxis.

HYPOTHESIS

Tranexamic acid associated to rivaroxaban reduces blood loss.

MATERIAL AND METHOD

A prospective case-control study included 70 primary cementless THRs performed by a single surgeon on a standardized technique, between September 2009 and September 2010. Thirty-seven patients received perioperative tranexamic acid; all patients received rivaroxaban thromboprophylaxis.

RESULTS

There was no significant difference between the two groups in terms of peroperative blood-loss volume or rates of thromboembolic or ischemic events or hematoma. Postoperative blood loss, D0-5 differential hemoglobinemia and real blood loss (in mL 100% hematocrit) were significantly lower in the tranexamic acid group. No transfusions were required in the tranexamic acid group, versus four in the control group.

DISCUSSION

Tranexamic acid associated to direct anti-Xa (antithrombin-independent) oral anticoagulants was effective in reducing postoperative blood loss, improving hemoglobinemia at 5 days and reducing transfusion rates. The results also confirmed the efficacy of and tolerance for rivaroxaban thromboprophylaxis in primary THR, with no clinical thrombotic events induced by the association of tranexamic acid with rivaroxaban.

CONCLUSIONS

Tranexamic acid is a simple means of reducing postoperative blood loss in THR, without increased risk of thromboembolism when associated to rivaroxaban thromboprophylaxis.

LEVEL OF EVIDENCE

Level III prospective case-control study.

Tranexamic acid: a review of its use in the treatment of hyperfibrinolysis

Tranexamic acid, a synthetic derivative of the amino acid lysine, is an antifibrinolytic agent that acts by binding to plasminogen and blocking the interaction of plasmin(ogen) with fibrin, thereby preventing dissolution of the fibrin clot. Tranexamic acid (Transamin®) is indicated in Japan for use in certain conditions with abnormal bleeding or bleeding tendencies in which local or systemic hyperfibrinolysis is considered to be involved. This article reviews the efficacy and tolerability of tranexamic acid in conditions amenable to antifibrinolytic therapy and briefly overviews the pharmacological properties of the drug. In large, randomized controlled trials, tranexamic acid generally significantly reduced perioperative blood loss compared with placebo in a variety of surgical procedures, including cardiac surgery with or without cardiopulmonary bypass, total hip and knee replacement and prostatectomy. In many instances, tranexamic acid also reduced transfusion requirements associated with surgery. It also reduced blood loss in gynaecological bleeding disorders, such as heavy menstrual bleeding, postpartum haemorrhage and bleeding irregularities caused by contraceptive implants. Tranexamic acid significantly reduced all-cause mortality and death due to bleeding in trauma patients with significant bleeding, particularly when administered early after injury. It was also effective in traumatic hyphaema, gastrointestinal bleeding and hereditary angioneurotic oedema. While it reduces rebleeding in subarachnoid haemorrhage, it may increase ischaemic complications. Pharmacoeconomic analyses predicted that tranexamic acid use in surgery and trauma would be very cost effective and potentially life saving. In direct comparisons with other marketed agents, tranexamic acid was at least as effective as ε-aminocaproic acid and more effective than desmopressin in surgical procedures. It was more effective than desmopressin, etamsylate, flurbiprofen, mefenamic acid and norethisterone, but less effective than the levonorgestrel-releasing intra-uterine device in heavy menstrual bleeding and was as effective as prednisolone in traumatic hyphaema. Tranexamic acid was generally well tolerated. Most adverse events in clinical trials were of mild or moderate severity; severe or serious events were rare. Therefore, while high-quality published evidence is limited for some approved indications, tranexamic acid is an effective and well tolerated antifibrinolytic agent.

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.

Reduction of blood loss in primary hip arthroplasty with tranexamic acid or fibrin spray

BACKGROUND AND PURPOSE

Previous studies have shown that either fibrin spray or tranexamic acid can reduce blood loss at total hip replacement, but the 2 treatments have not been directly compared. We therefore conducted a randomized, controlled trial.

PATIENTS AND METHODS

In this randomized controlled trial we compared the effect of tranexamic acid and fibrin spray on blood loss in cemented total hip arthroplasty. 66 patients were randomized to 1 of 3 parallel groups receiving (1) a 10 mg/kg bolus of tranexamic acid prior to surgery, (2) 10 mL of fibrin spray during surgery, or (3) neither. All participants except the surgeon were blinded as to treatment group until data analysis was complete. Blood loss was calculated from preoperative and postoperative hematocrit.

RESULTS

Neither active treatment was found to be superior to the other in terms of overall blood loss. Losses were lower than those in the control group, when using either tranexamic acid (22% lower, p = 0.02) or fibrin spray (32% lower, p = 0.02).

INTERPRETATION

We found that the use of tranexamic acid at induction, or topical fibrin spray intraoperatively, reduced blood loss compared to the control group. Blood loss was similar in the fibrin spray group and in the tranexamic acid group. ClinicalTrials.gov identifier: NCT00378872. EudraCT identifier: 2006-001299-19. Regional Ethics Committee approval: 06/S0703/55, granted June 6, 2006.

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.

Systematic review and meta-analysis of the use of tranexamic acid in total hip replacement

We report a systematic review and meta-analysis of published randomised controlled trials evaluating the efficacy of tranexamic acid (TXA) in reducing blood loss and transfusion in total hip replacement (THR). The data were evaluated using the generic evaluation tool designed by the Cochrane Bone, Joint and Muscle Trauma Group. We identified 11 clinical trials which were suitable for detailed extraction of data. There were no trials that used TXA in revision THR. A total of seven studies (comprising 350 patients) were eligible for the blood loss outcome data. The use of TXA reduced intra-operative blood loss by a mean of 104 ml (95% confidence interval (CI) -164 to -44, p = 0.0006, heterogeneity I(2) 0%), postoperative blood loss by a mean of 172 ml (95% CI -263 to -81, p = 0.0002, heterogeneity I(2) 63%) and total blood loss by a mean of 289 ml (95% CI -440 to -138, p < 0.0002, heterogeneity I(2) 54%). TXA led to a significant reduction in the proportion of patients requiring allogeneic blood transfusion (risk difference -0.20, 95% CI -0.29 to -0.11, p < 0.00001, I(2) 15%). There were no significant differences in deep-vein thrombosis, pulmonary embolism, infection rates or other complications among the study groups.

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.

Effects of tranexamic acid on blood loss during total hip arthroplasty

PURPOSE

To assess the effects of tranexamic acid (TA) in patients undergoing total hip arthroplasty (THA) for osteoarthritis.

METHODS

42 patients underwent primary THA for osteoarthritis by a single surgeon. 10 men and 11 women who did not receive TA were controls, whereas 9 men and 12 women who received TA constituted the treatment group. Both groups were matched for age, gender, body mass index, and American Society of Anesthesiologists grading. The type of prosthesis used (cemented or uncemented) was based on the surgeon's preference and patient age, activity level and demands. No hybrid prosthesis was used. 10 minutes prior to incision, a single dose of intravenous TA (10 mg per kg body weight) was given to patients in the treatment group. Comparison was made between both groups with regard to intra-operative blood loss, postoperative reduction in haemoglobin and haematocrit levels, blood transfusion, incidence of deep vein thrombosis, and the length of hospital stay.

RESULTS

The mean intra-operative blood loss (489 [SD, 281] vs. 339 [SD, 184] ml, p = 0.048) and the decrease in haemoglobin level (38 [SD, 12] vs. 29 [SD, 10] g/l, p=0.014) were significantly higher in the control than the treatment group. Two patients among the controls received a transfusion, compared to none in the TA group (p = 0.49, Fisher's exact test). The 2 patients who needed blood transfusion had blood losses of 600 and 690 ml, compared to a mean of 489 ml in the whole group. No patient in either group developed deep vein thrombosis or pulmonary embolism up to 3 months.

CONCLUSION

A single dose of intravenous TA (10 mg per kg body weight) given 10 minutes prior to THA is a cost-effective and safe means of minimising blood loss and reduction in haemoglobin concentrations as well as the need for allogenic blood transfusion, without increasing the risk of thromboembolic events.

Transfusion of intra-operative autologous whole blood: influence on complement activation and interleukin formation

BACKGROUND AND OBJECTIVES

Transfusion of autologous whole blood is one available method to reduce the need for allogenic blood transfusion. The objective of this study was to investigate the safety of transfusion of intra-operative autologous whole blood by monitoring plasma concentration of laboratory variables and adverse events after transfusion with the Sangvia(®) system.

MATERIALS AND METHODS

The clinical trial was designed as an open, prospective, multi-centre study, and a total of 20 patients undergoing primary hip arthroplasty were included. Systemic blood samples were taken and analysed preoperatively, at transfusion start and end and at 3, 6, 24 and 48 h after the transfusion.

RESULTS

Elevated values of complement activation and pro-inflammatory cytokines were seen in the intra-operatively collected blood but the impact on systemic levels were limited with low peak levels, systemic elevations before transfusion and normalization during the study period. Elevated levels of free haemoglobin and potassium were also detected in the intra-operatively collected blood, but systemic values were within reference values after the transfusion. No clinically relevant adverse event occurred during the study.

CONCLUSION

Inflammatory mediators and plasma haemoglobin were increased in intra-operatively salvaged and filtered blood compared to circulatory levels. Intra-operative retransfusion of autologous whole blood caused a transient systemic increase that normalized in the early postoperative period. There were no significant adverse events reported in the study. These data suggest that the Sangvia(®) system can be used for intra-operative collection and retransfusion of salvaged blood.

Limit the bleeding, limit the pain in total hip and knee arthroplasty

Patients undergoing total hip or knee arthroplasty often sustain significant decreases in hemoglobin and hematocrit, despite modern techniques and shorter operating times. Reasons for the blood loss include raw bony surfaces, vascular inflammatory tissue, and fragile vessels in elderly patients. Acute postoperative anemia has numerous deleterious effects on patients, including delayed rehabilitation, exposure to allogeneic blood transfusions, higher complication rates, and increased pain. The ability to limit the amount of postoperative bleeding may reduce the amount of postoperative pain that patients experience, ultimately resulting in greater patient satisfaction and smoother postoperative rehabilitation. This article focuses on intraoperative techniques available to limit bleeding, thereby minimizing pain and the need for postoperative transfusion.

Adverse drug events associated with disorders of coagulation

Disorders of coagulation are common adverse drug events encountered in critically ill patients and present a serious concern for intensive care unit (ICU) clinicians. Dosing strategies for medications used in the ICU are typically developed for use in noncritically ill patients and, therefore, do not account for the altered pharmacokinetic and pharmacodynamic properties encountered in the critically ill as well as the increased potential for drug-drug interactions, given the far greater number of medications ordered. This substantially increases the risk for coagulation-related adverse reactions, such as a bleeding or prothrombotic events. Although many medications used in the ICU have the potential to cause coagulation disorders, the exact incidence will vary based on the specific medication, dose, concomitant drug therapy, ICU setting, and patient-specific comorbidities. Clinicians must strongly consider these factors when evaluating the risk/benefit ratio for a particular therapy. This review surveys recent literature documenting the risk for adverse drug reactions specific to bleeding and/or clotting with commonly used medications in the ICU.

Giving tranexamic acid to reduce surgical bleeding in sub-Saharan Africa: an economic evaluation

BACKGROUND

The identification of safe and effective alternatives to blood transfusion is a public health priority. In sub-Saharan Africa, blood shortage is a cause of mortality and morbidity. Blood transfusion can also transmit viral infections. Giving tranexamic acid (TXA) to bleeding surgical patients has been shown to reduce both the number of blood transfusions and the volume of blood transfused. The objective of this study is to investigate whether routinely administering TXA to bleeding elective surgical patients is cost effective by both averting deaths occurring from the shortage of blood, and by preventing infections from blood transfusions.

METHODS

A decision tree was constructed to evaluate the cost-effectiveness of providing TXA compared with no TXA in patients with surgical bleeding in four African countries with different human immunodeficiency virus (HIV) prevalence and blood donation rates (Kenya, South Africa, Tanzania and Botswana). The principal outcome measures were cost per life saved and cost per infection averted (HIV, Hepatitis B, Hepatitis C) averted in 2007 International dollars ($). The probability of receiving a blood transfusion with and without TXA and the risk of blood borne viral infection were estimated. The impact of uncertainty in model parameters was explored using one-way deterministic sensitivity analyses. Probabilistic sensitivity analysis was performed using Monte Carlo simulation.

RESULTS

The incremental cost per life saved is $87 for Kenya and $93 for Tanzania. In Botswana and South Africa, TXA administration is not life saving but is highly cost saving since fewer units of blood are transfused. Further, in Botswana the administration of TXA averts one case of HIV and four cases of Hepatitis B (HBV) per 1,000 surgical patients. In South Africa, one case of HBV is averted per 1,000 surgical patients. Probabilistic sensitivity analyses confirmed the robustness of the model.

CONCLUSION

An economic argument can be made for giving TXA to bleeding elective surgical patients. In countries where there is a blood shortage, TXA would be a cost effective way to reduce mortality. In countries where there is no blood shortage, TXA would reduce healthcare costs and avert blood borne infections.

Tranexamic acid in hip fracture surgery: a randomized controlled trial

BACKGROUND

Hip fracture surgery may be associated with substantial blood loss. This study was designed to assess the efficacy and safety of the use of tranexamic acid in hip fracture surgery for the reduction of erythrocyte transfusion.

METHODS

The study pertains to a randomized double-blind study with blinded adjudication of outcomes. Patients requiring surgery for an isolated hip fracture of less than 48 h received saline or tranexamic acid 15 mg kg(-1) given at skin incision and 3 h later. Primary efficacy outcome was erythrocyte transfusion from surgery up to day 8. Transfusion was administered according to a standardized protocol (Hb<9 g dl(-1)). Safety criterion was a composite of symptomatic and asymptomatic vascular events up to 6 weeks.

RESULTS

Fifty-seven patients were randomized to tranexamic acid and 53 to placebo. The rate of erythrocyte transfusion was 42% with tranexamic acid and 60% with placebo (P=0.06). Preoperative haemoglobin value, age, and type of surgery were risk factors for erythrocyte transfusion independent of treatment group. The probability of vascular events at 6 weeks was 16% in the tranexamic acid group and 6% in the placebo group (P=0.10). A meta-analysis combining this study with previous trials showed that tranexamic acid significantly reduced erythrocyte transfusion in hip fracture surgery although efficacy was lower than that observed in hip or knee arthroplasty.

CONCLUSIONS

In hip fracture surgery, tranexamic acid reduces erythrocyte transfusion but may promote a hypercoagulable state. Thus, further evaluation of safety is required before recommending the off-label use of tranexamic acid.

The effect of tranexamic acid on reducing blood loss in cementless total hip arthroplasty under epidural anesthesia

Total hip arthroplasty (THA) is associated with high intraoperative and postoperative blood loss. Antifibrinolytic drugs have been used to minimize the potential risks of bleeding and blood transfusion. Studies on the effect of tranexamic acid on decreasing blood loss in THA have revealed interesting results, but most have focused on cemented THA. Yet its benefits in THA, especially in cementless THA, have not been proved. We conducted a prospective double-blind randomized controlled study on 64 patients who were candidates for cementless THA under epidural anesthesia between 2006 and 2008. Patients were randomly assigned into study and control groups. Patients in both groups were well matched regarding preoperative characteristics. Five minutes preoperatively 32 patients of the study and control groups received 15 mg/kg tranexamic acid or normal saline intravenously respectively. Our findings showed a significantly smaller decrease in 6- and 24-hour postoperative hemoglobin levels, less intraoperative and postoperative bleeding, and less need for allogenic blood transfusion in the tranexamic acid group. Our results also revealed a higher mean of 6- and 24-hour hematocrit level and shorter hospital stay in the tranexamic acid group compared to the control group, which were not statistically meaningful. In our study no thromboembolic event was seen; except 1 patient in the control group. Our study showed that administering tranexamic acid before the start of cementless THA under epidural anesthesia can reduce intraoperative and postoperative bleeding as well as need for blood transfusion.

Tranexamic acid reduces blood loss and blood transfusions in primary total hip arthroplastyA prospective randomized double-blind study in 40 patients

INTRODUCTION

We performed a prospective, randomized, double-blind study on 40 patients scheduled for primary total hip arthroplasty due to arthrosis or osteonecrosis to determine the effect of tranexamic acid on per- and postoperative blood losses and on the number of blood transfusions needed.

PATIENTS AND METHODS

40 patients were randomized to tranexamic acid (10 mg/kg given as a bolus intravenous injection, followed by a continuous infusion of 1 mg/kg/hour for 10 hours) or placebo (20 mL saline given intravenously) 15 minutes before the incision. We recorded the peroperative and postoperative blood losses at removal of the drain 24 hours after the operation and the number of blood transfusions.

RESULTS

Patients receiving tranexamic acid had a mean peroperative blood loss of 480 mL versus 622 mL in patients receiving placebo (p = 0.3), a postoperative blood loss of 334 mL versus 609 mL (p = 0.001), a total blood loss of 814 mL versus 1231 mL (p = 0.001) and a total need for 4 blood transfusions versus 25 (p = 0.04). No patient in either group had symptoms of deep venous thrombosis, pulmonary embolism or prolonged wound drainage.

INTERPRETATION

Transemic acid is effective in reducing the postoperative blood loss, the total blood loss and the need for blood transfusion in primary total hip arthroplasty.

The effect of an intravenous bolus of tranexamic acid on blood loss in total hip replacement

Tranexamic acid is a fibrinolytic inhibitor which reduces blood loss in total knee replacement. We examined the effect on blood loss of a standardised intravenous bolus dose of 1 g of tranexamic acid, given at the induction of anaesthesia in patients undergoing total hip replacement and tested the potential prothrombotic effect by undertaking routine venography. In all, 36 patients received 1 g of tranexamic acid, and 37 no tranexamic acid. Blood loss was measured directly per-operatively and indirectly post-operatively.

Tranexamic acid reduced the early post-operative blood loss and total blood loss (p = 0.03 and p = 0.008, respectively) but not the intraoperative blood loss. The tranexamic acid group required fewer transfusions (p = 0.03) and had no increased incidence of deep-vein thrombosis. The reduction in early post-operative blood loss was more marked in women (p = 0.05), in whom this effect was dose-related (r = −0.793).

Our study showed that the administration of a standardised pre-operative bolus of 1 g of tranexamic acid was cost-effective in reducing the blood loss and transfusion requirements after total hip replacement, especially in women.

Use of antifibrinolytic therapy to reduce transfusion in patients undergoing orthopedic surgery: a systematic review of randomized trials

BACKGROUND

Minimizing bleeding and transfusion is desirable given its cost, complexity and potential for adverse events. Concerns have been heightened by recent data demonstrating that bleeding events may predict worse outcomes and by warnings about the safety of erythropoietic stimulating agents. Prior small studies suggest that antifibrinolytic agents may reduce bleeding and transfusion need in patients undergoing total hip replacement (THR) or total knee arthroplasty (TKA). However, no single study has been large enough to definitively determine if these agents are safe and effective. To address this issue we performed a systematic review of randomized trials describing the use of tranexamic acid, epsilon aminocaproic acid, or aprotinin administration in the perioperative setting.

METHODS

MEDLINE, EMBASE, CINAHL and the Cochrane databases were searched for relevant trials. Two independent reviewers abstracted total blood loss, transfusion requirements, and venous thromboembolism (VTE) rates. Data were combined using the Mantel-Haenszel method and dichotomous data expressed as relative risk (RR) with 95% confidence intervals (CI).

RESULTS

Patients receiving antifibrinolytic agents had reduced transfusion need (RR 0.52; 95% CI, 0.42 to 0.64; P<0.00001), reduced blood loss and no increase in the risk of VTE (RR 0.95% CI, 0.80 to 1.10, I(2)=0%, P=0.531).

CONCLUSIONS

We conclude that antifibrinolytic agents may reduce bleeding and transfusion in patients undergoing THR or TKA who receive appropriate antithrombotic prophylaxis. There is a need for a large, adequately powered prospective study to carefully examine the safety and efficacy of these agents.

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.

Intravenous tranexamic acid use in myomectomy: a prospective randomized double-blind placebo controlled study

OBJECTIVE

To define the effect of tranexamic acid use on perioperative and postoperative bleeding and blood transfusion requirements in women undergoing myomectomy.

STUDY DESIGN

Among the patients that underwent myomectomy a total of 100 cases were included in the study. The patients (n=50) randomized to receive tranexamic acid were defined as Group I and those receiving saline were defined as Group II. Perioperative blood loss was calculated by measuring the volume in the suction apparatus and weighing the swabs. Postoperative blood loss was defined as the blood volume found in the subfascial suction drain. The two groups were compared for age, body mass index, basal hemoglobin and hematocrit, basal parameters of coagulation, the number and the volume of myomas removed, peri- and postoperative and total blood loss, duration of surgery and blood transfusion requirements.

RESULTS

No significant difference was found between the two groups when compared age, body mass index, preoperative blood analysis, the number and volume of myomas removed. Statistically significant differences were found between the two groups when compared for postoperative and total blood loss and duration of surgery (p<0.01, p=0.03 and p=0.03, respectively). Perioperative blood loss and blood transfusion requirements were similar between the two groups (p=0.12 and p=0.25, respectively). There were no complications in either group.

CONCLUSION

Our study is the first in the literature evaluating the effectiveness of tranexamic acid use on peri- and postoperative bleeding in gynecological surgery. No additional benefit of intravenous infusion of tranexamic acid was found. Tranexamic acid does not seem to be a useful adjunct in myomectomy if given according to the described protocol in this study.

The use of antifibrinolytic agents in total hip arthroplasty: a meta-analysis

Total hip arthroplasty is associated with significant blood loss that often requires allogenic blood transfusions. Tranexamic acid and aprotinin have been shown to reduce blood loss and transfusions in clinical trials with variable results. This meta-analysis evaluates whether tranexamic acid and aprotinin significantly reduces blood loss and transfusion requirements in total hip arthroplasty. Thirteen clinical trials were identified. Combined, these agents were significant across all outcome measures in reducing blood loss and transfusions. Separately, only aprotinin was found to be significant. The data also showed that aprotinin (tranexamic acid is inconclusive) is only beneficial in revision total hip arthroplasty. Therefore, only aprotinin is effective in reducing both blood loss and transfusion requirements without an increase in thromboembolic complications in patients undergoing revision total hip arthroplasty.

Tranexamic acid reduces blood loss in cemented hip arthroplasty: a randomized, double-blind study of 39 patients with osteoarthritis

BACKGROUND

Tranexamic acid has been found to reduce blood loss and the need for blood transfusions in knee arthroplasty. In hip arthroplasty, the benefit of tranexamic acid is not as clear.

PATIENTS AND METHODS

In a randomized, double-blind study, 39 patients with primary cemented hip arthroplasty for osteoarthritis were divided into two groups; one receiving tranexamic acid and the other not receiving it. Tranexamic acid was given in a dose of 10 mg/kg before the operation and twice thereafter, at 8-hour intervals.

RESULTS AND INTERPRETATION

Total blood loss was smaller in the tranexamic acid group than in the control group. No thromboembolic complications were noticed. Tranexamic acid appears to be an effective and economic drug for reduction of blood loss in cemented primary hip arthroplasty for osteoarthritis.

Tranexamic Acid Does Not Prevent Rebleeding in an Uncontrolled Hemorrhage Porcine Model

BACKGROUND

Fluid resuscitation after uncontrolled hemorrhage might promote rebleeding and irreversible shock. Tranexamic acid is a procoagulant drug that limits blood loss after surgery of the hip, knee, and heart. We hypothesized that pretreatment with tranexamic acid reduces the rebleeding in uncontrolled hemorrhage and thereby allows safe administration of crystalloid fluid resuscitation.

METHODS

A 120-minute intravenous infusion of 100 mL/kg of Ringer's solution was given to 24 pigs (mean weight, 20 kg) 10 minutes after lacerating the infrarenal aorta. The animals were randomized to receive an intravenous injection of 15 mg/kg of tranexamic acid or placebo just before starting the resuscitation. Rebleeding events were monitored by two ultrasonic probes positioned proximal and distal to the laceration.

RESULTS

Tranexamic acid had no effect on the number of rebleeding events, bled volume, or mortality. The initial bleeding stopped within 4 minutes after the injury. The five animals that died suffered from 4.4 rebleeding events on average, which tripled the total blood loss, whereas the survivors had only 1.3 such events during fluid resuscitation (p < 0.02). At autopsy, death was associated with a larger total hemorrhage; the blood recovered from the abdomen weighed 1.4 kg (median) in nonsurvivors and 0.6 kg in survivors (p < 0.001), with the difference being attributable to rebleeding.

CONCLUSION

Rebleeding events increased the amount of blood lost and the mortality in uncontrolled aortic hemorrhage. Tranexamic acid offered no benefit.

Tranexamic acid reduces postoperative blood loss in cementless total hip arthroplasty

BACKGROUND

Tranexamic acid, an inhibitor of fibrinolysis that blocks the lysine-binding site of plasminogen to fibrin, has been reported to reduce intraoperative and postoperative blood loss in patients undergoing total hip arthroplasty with cement. However, there have been few reports describing the effects of tranexamic acid on blood loss during and following total hip arthroplasty without cement.

METHODS

We investigated the effects of tranexamic acid in twenty-one patients who underwent staged bilateral total hip arthroplasty without cement for the treatment of osteoarthritis of the hip. The average interval between the two procedures was 16 +/- 16 months. On one side, 1000 mg of tranexamic acid was administered intravenously five minutes before the skin incision. On the other side, tranexamic acid was not administered. Baseline hemoglobin and hematocrit values were obtained three weeks before each arthroplasty. The volume of postoperative blood loss was recorded at two-hour intervals for the first twelve hours and then again at twenty-four hours, and the values were compared between the two groups.

RESULTS

The total intraoperative blood loss in the tranexamic acid group (607 +/- 298 mL) was similar to that in the control group (633 +/- 220 mL). The postoperative blood loss in the tranexamic acid group was significantly lower than that in the control group at all time-points during the first twenty-four hours (p < 0.001 for all comparisons). The greatest reduction in blood loss was observed during the first four hours after surgery in the tranexamic acid group (p < 0.01).

CONCLUSIONS

In patients undergoing total hip arthroplasty without cement, preoperative administration of tranexamic acid is associated with decreased postoperative blood loss during the first twenty-four hours, especially during the first four hours after surgery.

Perioperative systemic haemostatic agents

Skilful surgery combined with blood-saving methods and careful management of blood coagulation will all help reduce unnecessary blood loss and transfusion requirements. Excessive surgical bleeding causes hypovolaemia, haemodynamic instability, anaemia and reduced oxygen delivery to tissues, with a subsequent increase in postoperative morbidity and mortality. The role of anaesthetists in managing surgical blood loss has increased greatly in the last decade. Position of the patient during surgery and the provision of a hypotensive anaesthetic regimen were once considered the most important contributions of the anaesthetist to decreasing blood loss. Now, several pharmacological haemostatic agents are being used by anaesthetists as blood-saving agents. After a brief discussion of the physiology of haemostasis, this article will review the evidence for the role of such agents in reducing perioperative blood loss and transfusion requirements.

Intraoperative blood management in joint replacement surgery

Interest is growing in blood conservation and avoidance of transfusion in patients undergoing orthopedic surgery, especially in the field of joint replacement. Several methods have proven successful in reducing intraoperative blood loss, which can translate into lessened allogeneic and autologous transfusion requirements. Available techniques include acute normovolemic hemodilution, hypotensive anesthesia, intraoperative blood salvage, specialized cautery, topical hemostatic agents, and pharmacologic agents given in the perioperative period. The greatest potential benefit arises in operations with greater expected blood loss or in special situations such as in patients with religious issues, bilateral joint replacement, coagulation disorders, or significant preoperative anemia.

Evaluation of hemorrhage depressors on blood loss during orthognathic surgery: a retrospective study

PURPOSE

Correction of dentofacial deformities by orthognathic surgery may cause significant bleeding and therefore hypotensive anesthesia is often used to reduce the blood loss. The main objective of the present clinical study was to determine whether the addition of hemorrhage depressors to other medication during orthognathic surgery would further reduce the blood loss.

PATIENTS AND METHODS

Thirty patients, consecutively operated on with standardized Le Fort I osteotomies in 1998 (n = 15, control group) and 1999 (n = 15, treatment group), were included in the study. Both groups received hypotension anesthesia during surgery and the treatment group received additional hemorrhage depressors; tranexamic acid and desmopressin.

RESULTS

The mean blood loss was 740 +/- 410 mL (11.3 mL/kg) in the control group and 400 +/- 210 mL (5.7 mL/kg) in the treatment group. The results showed a statistically significant reduction of blood loss in the treatment group (P <.01).

CONCLUSIONS

This study shows that blood loss during orthognathic surgery under hypotensive anesthesia can be significantly reduced when a combination of tranexamic acid and desmopressin is added.

Blood management in patients with deep prosthetic hip and knee infections

Patients undergoing treatment for infected hip and knee replacements often have significant blood loss and require allogeneic blood transfusions. In the setting of sepsis, traditional methods of blood management such as preoperative blood donations, cell savers, and reinfusion drains are contraindicated. Pharmacologic agents can minimize transfusion requirements by increasing erythropoiesis, or minimize perioperative blood loss. This article reviews the use of these agents in the management of patients with deep prosthetic hip and knee infections.

Bone bleeding during total hip arthroplasty after administration of tranexamic acid

Numerous methods of controlling bleeding during total hip arthroplasty have been used. Thromboplastic agents have been used with some success, but the resultant fibrin layer interposed between the bone and cement weakens the interface. Topical freezing saline and hypotensive anesthesia have proved to be the most effective to date. The goal of this randomized, double blind, controlled study is to determine the effect of a single bolus dose of tranexamic acid, administered at the time of anesthesia, on bleeding during primary total hip arthroplasty. Fifty patients were randomized to receive either 10 mg/kg of tranexamic acid or a similar volume of normal saline as a preoperative bolus. Patients were not given pharmacologic thrombotic prophylaxis until 48 hours after surgery. The goal was to measure blood loss from the femoral canal at the time of surgery. An estimate of the internal and external blood loss during and after surgery was performed, and the transfusion requirement was recorded. No significant difference was found between the groups in terms of blood loss from the femoral canal, the perioperative bleeding, and postoperative hemoglobin. In the group that received tranexamic acid, a greater number of patients required transfusion than in the placebo group. The results of this study do not support the routine use of tranexamic acid in primary total hip arthroplasty.

Tranexamic acid reduces the need for allogenic red blood cell transfusions in patients undergoing total hip replacement

PURPOSE

This prospective randomized double-blind trial evaluates the efficacy of tranexamic acid (TA) to decrease blood losses and red blood cell transfusions in patients undergoing primary unilateral total hip replacement (THR).

METHODS

Forty ASA class I to III patients received either iv TA 10 mg.kg(-1) bolus before surgery plus a 1 mg.kg(-1).hr(-1) infusion until wound closure (Group TA) or a placebo (Group P). Red blood cell transfusions were administered according to a standardized protocol.

RESULTS

One patient of Group P was excluded because of an erroneous diagnosis at enrollment. Total measured blood losses (Group TA: 1308 +/- 462 mL vs Group P: 1469 +/- 405 mL), preoperative hemoglobin levels (Group TA: 130.4 +/- 12.5 g.L(-1) vs Group P: 131.4 +/- 12.8 vs g.L(-1)), and seven-day postoperative hemoglobin values (Group TA: 97.8 +/- 11.8 g.L(-1) vs Group P: 102.9 +/- 12.2 g.L(-1)) were similar. Autologous whole blood was available in five patients of Group P and seven patients of Group TA. Fewer patients in Group TA required red blood cells (Group TA: 6/20 vs Group P: 13/19; P = 0.026) and allogenic red blood cell transfusions (Group TA: 0/20 vs Group P: 8/19; P = 0.0012). The median number of transfused unit per patient was also significantly less in patients of Group TA (0 unit) than in Group P (2 units; P = 0.03).

CONCLUSION

TA did not change measured blood losses but reduced red blood cell transfusion requirements in patients undergoing primary unilateral THR.

The use of tranexamic acid to reduce blood loss during total knee arthroplasty

HYPOTHESIS

The fall in haemoglobin following unilateral total knee arthroplasty is reduced by tranexamic acid administration.

METHODS

60 patients were studied in total, 30 received tranexamic acid 10 mg/kg on induction and a further dose shortly before the release of the tourniquet. Surgery was performed by the senior author in a standardised fashion using the Freeman Samuelson cemented total knee replacement. Haemoglobin levels were measured 2 weeks pre and 3 days post operatively. Any complications were noted. A control group was matched using the Bone and Joint Research Unit database for age, sex, disease and pre-operative haemoglobin level. This group had been monitored in the same way as the group treated with tranexamic acid.

RESULTS

In the group receiving no tranexamic acid the mean fall in haemoglobin was 2.8 g/dl (95% CI of mean 2.5-3.2) and in the group treated with tranexamic acid 1.7 g/dl (95% CI of mean 1.3-2) P<0.01. There were no complications in either group.

CONCLUSIONS

The administration of tranexamic acid is an effective method of reducing the haemoglobin fall following knee arthroplasty.

Tranexamic acid decreases external blood loss but not hidden blood loss in total knee replacement

BACKGROUND

Total knee arthroplasty (TKA) is often carried out using a tourniquet and shed blood is collected in drains. Tranexamic acid decreases the external blood loss. Some blood loss may be concealed, and the overall effect of tranexamic acid on the haemoglobin (Hb) balance is not known.

METHODS

Patients with osteoarthrosis had unilateral cemented TKA using spinal anaesthesia. In a double-blind fashion, they received either placebo (n=24) or tranexamic acid 10 mg kg(-1) (n=27) i.v. just before tourniquet release and 3 h later. The decrease in circulating Hb on the fifth day after surgery, after correction for Hb transfused, was used to calculate the loss of Hb in grams. This value was then expressed as ml of blood loss.

RESULTS

The groups had similar characteristics. The median volume of drainage fluid after placebo was 845 (interquartile range 523-990) ml and after tranexamic acid was 385 (331-586) ml (P<0.001). Placebo patients received 2 (0-2) units and tranexamic acid patients 0 (0-0) units of packed red cells (P<0.001). The estimated blood loss was 1426 (1135-1977) ml and 1045 (792-1292) ml, respectively (P<0.001). The hidden loss of blood (calculated as loss minus drainage volume) was 618 (330-1347) ml and 524 (330-9620) ml, respectively (P=0.41). Two patients in each group developed deep vein thrombosis.

CONCLUSIONS

Tranexamic acid decreased total blood loss by nearly 30%, drainage volume by approximately 50% and drastically reduced transfusion. However, concealed loss was only marginally influenced by tranexamic acid and was at least as large as the drainage volume.

Pharmacological strategies to decrease transfusion requirements in patients undergoing surgery

Surgical procedures are inevitably associated with bleeding. The amount of blood loss may vary widely between different surgical procedures and depends on surgical as well as non-surgical factors. Whereas adequate surgical haemostasis may suffice in most patients, pro-haemostatic pharmacological agents may be of additional benefit in patients with (diffuse) surgical bleeding or in patients with a specific underlying haemostatic defect. In general, surgical haemostasis and pharmacological therapies can be complementary in controlling blood loss. The use of pharmacological therapies to reduce blood loss and blood transfusions in surgery has historically been restricted to a few drugs. Antifibrinolytic agents (aprotinin, tranexamic acid and aminocaproic acid) have the best evidence supporting their use, especially in cardiac surgery, liver transplantation and some orthopaedic surgical procedures. Meta-analyses of randomised, controlled trials in cardiac patients have suggested a slight benefit of aprotinin, compared with the other antifibrinolytics. Desmopressin is the treatment of choice in patients with mild haemophilia A and von Willebrand disease. It has also been shown to be effective in patients undergoing cardiac surgery who received aspirin up to the time of operation. However, overall evidence does not support a beneficial effect of desmopressin in patients without pre-existing coagulopathy undergoing elective surgical procedures. Topical agents, such as fibrin sealants have been successfully used in a variety of surgical procedures. However, only very few controlled clinical trials have been performed and scientific evidence supporting their use is still limited. Novel drugs, like recombinant factor VIIa (eptacog alfa), are currently under clinical investigation. Recombinant factor VIIa has been introduced for the treatment of haemophilia patients with inhibitors, either in surgical or non-surgical situations. Preliminary data indicate that it may also be effective in surgical patients without pre-existing coagulation abnormalities. More clinical trials are warranted before definitive conclusions can be drawn about the safety and the exact role of this new drug in surgical patients. Only adequately powered and properly designed randomised, clinical trials will allow us to define the most effective and the safest pharmacological therapies for reducing blood loss and transfusion requirements in surgical patients. Future trials should also consider cost-effectiveness because of considerable differences in the costs of the available pro-haemostatic pharmacological agents.

Pharmacological approaches to reducing allogeneic blood exposure

This article discusses evidence for the role of pharmacological interventions such as the protease inhibitor aprotinin (Trasylol), lysine analogue anti-fibrinolytics [tranexamic acid (Cyclokapron) and epsilon aminocaproic acid (Amicar)], DDAVP (Desmopressin) and recombinant Factor VIIa (NovoSeven), in preventing the need for blood and blood-component therapies after major (cardiac, hepatic and orthopaedic/trauma) surgery. The data show that aprotinin is consistently effective in reducing globally the transfusion burden in cardiac and hepatic surgical procedures. However, there are little data to support its use in routine elective orthopaedic surgery. Multiple studies have failed to show an increased risk for myocardial ischaemia or infarction with aprotinin, and there may even be a reduced incidence of perioperative stroke in patients undergoing cardiac surgery. An increased probability of a hypersensitivity reaction when the drug is readministered within a 6-month period remains a significant issue. The data for the lysine analogue anti-fibrinolytics show no evidence of efficacy in reducing the transfusion burden for epsilon aminocaproic acid and inconsistent results with tranexamic acid in cardiac and hepatic surgery. As with aprotinin therapy, there is a paucity of data to support their use in routine elective orthopaedic surgery. There are no data to support the routine use of DDAVP to reduce the transfusion burden. Limited data suggest that this drug may be effective when a defect in platelet function is demonstrated. This aspect deserves further investigation. Recombinant activated Factor VII (rFVIIa) has proven benefit for its licensed indication to reduce bleeding in haemophiliacs with inhibitors to Factors VIII and IX. Reports of benefit in other instances are largely anecdotal. Hence, at this time it is therefore speculative and premature to suggest whether there is a place for this agent in routine clinical practice. No adequately powered, placebo-controlled prospective studies are available to investigate the safety of the lysine analogues, DDAVP or rFVIIa in cardiac, hepatic or orthopaedic surgery.