Use of tranexamic acid for an effective blood conservation strategy after total knee arthroplasty

Most effective regimen of tranexamic acid in knee arthroplasty: a prospective randomized controlled study in 240 patients

BACKGROUND

The antifibrinolytic tranexamic acid reduces surgical blood loss, but studies have not identified an optimal regimen.

QUESTIONS/PURPOSES

We studied different dosages, timings, and modes of administration to identify the most effective regimen of tranexamic acid in achieving maximum reduction of blood loss in TKA.

METHODS

We prospectively studied five regimens (four intravenous, one local; 40 patients each) with a control group (no tranexamic acid). The four intravenous (10-mg/kg dose) regimens included (1) intraoperative dose (IO) given before tourniquet deflation, (2) additional preoperative dose (POIO), (3) additional postoperative dose (IOPO), and (4) all three doses (POIOPO). The fifth regimen was a single local application (LA). Two independent parameters of drain loss and total blood loss, calculated by the hemoglobin balance method, were evaluated statistically.

RESULTS

Both parameters were reduced in all five regimens as against the control. A significant reduction in drain loss was seen in the POIO, IOPO, and POIOPO groups whereas total blood loss was significantly reduced in the POIO, POIOPO, and LA groups. The POIOPO group had the least drain loss (303 mL) and least total blood loss (688 mL). The IO group had the greatest drain loss and the IOPO group the greatest total blood loss.

CONCLUSIONS

Single-dose tranexamic acid did not give effective results. The two-dose regimen of POIO was the least amount necessary for effective results. When compared against the control, this regimen produced reduction of drain loss and total blood loss, whereas the IOPO regimen did not. The three-dose regimen of POIOPO produced maximum effective reduction of drain loss and total blood loss.

Temporary clamping of drain combined with tranexamic acid reduce blood loss after total knee arthroplasty: a prospective randomized controlled trial

Background

Total knee arthroplasty (TKA) is associated with a significant blood loss. Several methods have been reported to reduce postoperative blood loss and avoid homologous blood transfusions. In this study, we investigated the efficacy of temporary clamping of the drain either or not in combination with tranexamic acid administration for controlling blood loss after TKA.

Methods

The prospective, randomized, and double-blinded study was conducted in our institute. Total of 240 patients, who diagnosed primary osteoarthritis and scheduled to undergo a primary TKA,,were randomized into one of the four groups: Group A or control group, the drain was not clamped and the patient received a placebo; Group B, the drain was not clamped and the patient received tranexamic acid; Group C, the drain was clamped and the patient received a placebo; and Group D, the drain was clamped and the patient received tranexamic acid. The volume of drained blood at 48 hours postoperatively, the decreasing of hemoglobin (Hb) level at 12 hours postoperatively and the number of patients requiring blood transfusion were recorded and compared.

Results

The mean postoperative volumes of drained blood and the amount of blood transfusion in the three study groups (group B, C and D) were significantly lower than those in the control group (p < 0.05), which group D had the lowest values. Furthermore, group B and D could maintain the Hb level better than group A and C (p < 0.001). In terms of blood transfusions rate, although the patients in group D required transfusion less than group A and C (p < 0.05), there was no significant difference between group D and B. The relative risks for transfusion requirement were 4.4 for group A, 1.4 for group B and 3.0 for group C when compared to group D.

Conclusions

The clamping of drain combined with tranexamic acid administration could reduce postoperative blood loss and blood transfusion after TKA, significantly greater than using tranexamic acid or drain clamping alone.

Trial registration

ClinicalTrials.gov NCT01449552

The blood-saving effect of tranexamic acid in minimally invasive total knee replacement

Tranexamic acid (TEA), an inhibitor of fibrinolysis, reduces blood loss after routine total knee replacement (TKR). However, controversy persists regarding the dosage and timing of administration of this drug during surgery. We performed a prospective randomised controlled study to examine the optimum blood-saving effect of TEA in minimally invasive TKR.

We randomly assigned 151 patients who underwent unilateral minimally invasive TKR to three groups: 1) a placebo group (50 patients); 2) a one-dose TEA group (52 patients), who received one injection of TEA (10 mg/kg) intra-operatively on deflation of the tourniquet; and 3) a two-dose TEA group (49 patients), who received two injections of TEA (10 mg/kg) given pre-operatively and intra-operatively. Total blood loss was calculated from the maximum loss of haemoglobin. All patients were followed clinically for the presence of venous thromboembolism (VTE).

The mean total blood loss was significantly higher in the placebo group than in the other two groups (1222 ml (845 to 2043) versus 1035 ml (397 to 1934) and 986 ml (542 to 1811), respectively (both p < 0.0001)). The mean blood loss was not significantly different between the one- and two-TEA groups (p = 0.148). The mean transfusion rate was higher in the placebo group than in the other two groups (22% versus 3.8% (p = 0.006) and 6.1% (p = 0.041), respectively) and there was no statistically significant difference in the mean transfusion rate between the one- and two-TEA groups (p = 0.672). Only one patient, in the two-dose group, had a radiologically confirmed deep venous thrombosis.

Our prospective randomised controlled study showed that one intra-operative injection of TEA is effective for blood conservation after minimally invasive TKR.

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.

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

We conducted a systematic review and meta-analysis of randomised controlled trials evaluating the effect of tranexamic acid (TXA) upon blood loss and transfusion in primary total knee replacement. The review used the generic evaluation tool designed by the Cochrane Bone, Joint and Muscle Trauma Group. A total of 19 trials were eligible: 18 used intravenous administration, one also evaluated oral dosing and one trial evaluated topical use. TXA led to a significant reduction in the proportion of patients requiring blood transfusion (risk ratio (RR) 2.56, 95% confidence interval (CI) 2.1 to 3.1, p < 0.001; heterogeneity I(2) = 75%; 14 trials, 824 patients). Using TXA also reduced total blood loss by a mean of 591 ml (95% CI 536 to 647, p < 0.001; I(2) = 78%; nine trials, 763 patients). The clinical interpretation of these findings is limited by substantial heterogeneity. However, subgroup analysis of high-dose (> 4 g) TXA showed a plausible consistent reduction in blood transfusion requirements (RR 5.33; 95% CI 2.44 to 11.65, p < 0.001; I(2) = 0%), a finding that should be confirmed by a further well-designed trial. The current evidence from trials does not support an increased risk of deep-vein thrombosis (13 trials, 801 patients) or pulmonary embolism (18 trials, 971 patients) due to TXA administration.

Tranexamic acid reduces blood loss and blood transfusion after TKA: a prospective randomized controlled trial

BACKGROUND

TKA may be associated with considerable blood loss, and transfusion carries substantial risk of immunologic reaction and disease transmission. Blood transfusion also involves additional cost, therefore a reduction in its use is important. Several methods reportedly reduce postoperative blood loss and avoid homologous blood transfusion with traditional TKA approaches, but it is unclear these reductions apply to a minimally invasive technique.

QUESTIONS/PURPOSES

We asked whether tranexamic acid administration could reduce blood loss and blood transfusion requirements after TKA.

PATIENTS AND METHODS

Between March 2008 and May 2008, we enrolled 100 patients with primary osteoarthritis undergoing a unilateral cemented TKA in a prospective, randomized, double-blind study. Patients were randomized into one of two groups: the control group received a placebo and the study group received tranexamic acid intravenously (10 mg/kg) 10 minutes before inflation of the tourniquet and 3 hours postoperatively and orally (250 mg/capsule; two capsules three times daily) for 5 days. We measured volume of drained blood 48 hours postoperatively, decrease in hemoglobin levels 12 hours postoperatively, amount of blood transfused, and number of patients requiring allogenic blood transfusion. The minimum followup was 6 months (mean, 10.4 months; range, 6-12 months).

RESULTS

Mean (± SD) postoperative volume of drained blood was lower in the group receiving tranexamic acid (727.50 ± 234 mL) than in control subjects (1208.77 ± 421 mL). The mean hemoglobin decrease 12 hours postoperatively was lower in patients receiving tranexamic acid (2.12 ± 0.64 g/dL) than in control subjects (3.33 ± 0.88 g/dL). The amount of blood transfused and number of patients requiring blood transfusion were lower in patients receiving tranexamic acid than in control subjects.

CONCLUSIONS

Tranexamic acid reduced postoperative blood loss after TKA, as reflected in reduction in the number of blood transfusions. We did not observe any change in symptomatic thromboembolic phenomenon.

LEVEL OF EVIDENCE

Level 1, therapeutic study. See the Guidelines for Authors for a complete description of levels of evidence.

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.

Blood loss control with two doses of tranexamic Acid in a multimodal protocol for total knee arthroplasty

Average blood loss after total knee arthroplasty (TKA) usually ranges from 1500 to 1900 cc, including both the postoperative drain and hidden blood loss. This represents about 46% of TKA patients requiring postoperative blood transfusion. Not only the risks of disease transmission but also those of ABO incompatibility, infection due to immunosupression, increased procedure costs, and increased length of hospital stay, are potential problems that foster blood saving strategies. In this study, 71 unilateral TKAs using a multimodal protocol to decrease blood loss were compared to 61 historical cases. Patients in both groups underwent cemented TKA with the same system, surgical technique, and multimodal protocol (MIS approach, plug in the femoral canal, tourniquet removal after wound closure and compressive bandage, analgesic periarticular infiltration with vasoconstrictor, postoperative drain at atmospheric pressure, opened 2 hours after the end of the surgical procedure and removed after 24 hours). The study series incorporated intravenous tranexamic acid (TXA) infusion in 2 doses of 10-15 mg/kg, 15 minutes before tourniquet release and 3 hours later. Results showed no transfusion requirements in the TXA series (0%), with 23/61 (37.7%) transfusions in the control, with an average cost decrease of 240 euros per patient. Visible bleeding in 24h significantly decreased from 553.36 cc (range 50-1500) to 169.72 cc (range 10-480) in the TXA series. As a conclusion, implementing a TXA-based multimodal protocol produced significant decrease in the transfusion rate, visible blood loss, and cost per patient, thus proving effectiveness and efficiency in the surgical management of TKA.

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.

Tranexamic acid for control of blood loss in bilateral total knee replacement in a single stage

BACKGROUND

Tranexamic acid (TEA) reduces blood loss and red cell transfusions in patients undergoing unilateral total knee arthroplasty (TKA). However, there is not much literature regarding the use of TEA in patients undergoing bilateral TKA in a single stage and the protocols for administration of TEA in such patients are ill-defined.

MATERIALS AND METHODS

We carried out a case control study evaluating the effect of TEA on postoperative hemoglobin (Hb), total drain output, and number of blood units transfused in 52 patients undergoing bilateral TKA in a single stage, and compared it with 56 matched controls who did not receive TEA. Two doses of TEA were administered in doses of 10 mg / kg each (slow intravenous (IV) infusion), with the first dose given just before tourniquet release of the first knee and the second dose three hours after the first one.

RESULTS

A statistically significant reduction in the total drain output and requirement of allogenic blood transfusion in cases who received TEA, as compared to the controls was observed. The postoperative Hb and Hb at the time of discharge were found to be lower in the control group, and this result was found to be statistically significant.

CONCLUSION

TEA administered in patients undergoing single stage bilateral TKA helped reduce total blood loss and decreased allogenic blood transfusion requirements. This might be particularly relevant, where facilities such as autologous reinfusion might not be available.

Tranexamic acid to reduce blood loss after bilateral total knee arthroplasty: a prospective, randomized double blind study

The effects of 2-dosage regimens of tranexamic acid (10 mg/kg and 15 mg/kg) on blood loss and transfusion requirement were compared to saline placebo in 60 patients undergoing concurrent bilateral total knee arthroplasty, with additional reinfusion autotransfusion from intraarticular drains. Mean blood loss was 462 mL in 15 mL/kg group, 678 mL in 10 mg/kg group, and 918 mL in controls (P < .01 vs 15 mg/kg). Blood available for autotransfusion was greatest in controls and least in 15 mg/kg group. Combined autologous and allogenic transfusion volumes were similar in the treatment groups and significantly less than controls (P < .01). With use of an autologous reinfusion strategy, the lower dose is sufficient to lead to a lesser allogenic transfusion requirement.

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.

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.

[Effectiveness of tranexamic acid in routine performance of total knee replacement surgery]

OBJECTIVES

To evaluate the effectiveness of treatment with tranexamic acid, compared to absence of antifibrinolytic treatment, in reducing transfusion rates and the number of units of packed red blood cells required in patients undergoing total knee replacement surgery.

MATERIAL AND METHODS

We reviewed the medical records of all patients who underwent total knee replacement surgery in a general hospital in 2006. Information was recorded on treatment with tranexamic acid, use of other antifibrinolytic drugs, hemoglobin and hematocrit levels before surgery and 3 days after surgery, patients requiring transfusions, units of packed red blood cells administered, and whether or not drains were clamped within 4 hours. Complications attributable to tranexamic acid (thromboembolic or systemic complications) and preoperative treatment with erythropoietin were also recorded.

RESULTS

Data for 166 patients were analyzed. Of these, 120 (72.3%) received tranexamic acid, 15 (9%) received epsilon-aminocaproic acid, and 31 (18.7%) received no antifibrinolytic treatment. Transfusions were given to 17 patients, of whom 6 (5.0%) had received tranexamic acid, 2 (133%) had received epsilon-aminocaproic acid, and 9 (29.0%) had received no antifibrinolytic treatment. The mean numbers of packed red blood cell units transfused in each group were as follows: 0.075 in the tranexamic acid group, 0.200 in the epsilon-aminocaproic acid group, and 0.645 in the group with no antifibrinolytic treatment (P < .001). The mean decrease in hemoglobin levels 5 days after surgery was 3.04 g/dL in the tranexamic acid group, 3.55 g/dL in the epsilon-aminocaproic acid group and 3.76 g/dL in the group with no antifibrinolytic treatment (P < .001).

CONCLUSIONS

Tranexamic acid is effective in reducing the percentage of patients requiring transfusions and in the number of units of packed red blood cells required in total knee replacement surgery. No complications attributable to this treatment were found.

Effectiveness and safety of tranexamic acid administration during total knee arthroplasty

BACKGROUND

The administration of tranexamic acid (TA) is associated with a decrease in the number of red blood cell (RBC) units transfused. However, concerns about its safety have hindered its broader use.

STUDY DESIGN AND METHODS

We evaluated the effect of TA on RBC transfusion and thromboembolic complications in total knee arthroplasty. We retrospectively studied 414 patients, 215 immediately before introducing TA treatment (control group) and after, in 199 patients without history of thromboembolic diseases (TA group). In a subgroup of patients, a lower extremities contrast venography was performed.

RESULTS

Fifty-four per cent of control group patients were transfused with RBC while only 17.6% of TA group patients received RBCs. In the TA that group, those transfused received less units (2.83 vs. 1.89), showed smaller mean calculated perioperative blood loss and haemoglobin values at discharge were higher compared to control group (10.1 vs. 9.3 g/dl). Thromboembolic complications were diagnosed in 2.8% of the patients in the control group and in 1.5% in the TA group. Asymptomatic distal deep venous thrombosis was found in 54 (14.8%) of TA group patients and 54 (30.1%) of control patients. TA administration reduced the expenditure for RBC transfusion plus the cost of TA from 148.94 to 33.87 euro per patient.

CONCLUSION

Routine administration of TA during total knee arthroplasty to patients without history of thromboembolic disease is associated with a 67% reduction in RBC transfusions and, in those transfused, with a reduction in the number of units administered. TA treatment was not associated with an increase in thromboembolic complications. Transfusion costs are significantly reduced.

Tranexamic acid combined with recombinant factor VIII increases clot resistance to accelerated fibrinolysis in severe hemophilia A

BACKGROUND

Most patients with severe hemophilia A suffer from a profoundly compromised hemostatic response. In addition to both the delayed and slow development of a clot, previous studies have documented that severe hemophilia A is also associated with reduced clot stability.

OBJECTIVES

We examined whether the clot stability in hemophiliacs could be improved by treatment with tranexamic acid (TXA) in combination with recombinant factor VIII (rFVIII).

PATIENTS/METHODS

Baseline blood samples were obtained from eight males with severe hemophilia A. Thereafter, a bolus injection of rFVIII was administered to increase the functional level of FVIII to approximately 50%. After 10 min, blood was collected followed by an intravenous injection of TXA. A third blood sample was obtained after a further 10 min. Whole blood clotting profiles were determined by thrombelastography using minimal tissue factor activation. Clot formation was assessed by both clot initiation and clot propagation. At clot termination, the maximum clot firmness and area under the elasticity curve were used to illustrate clot stability. Tissue-plasminogen activator was included in those experiments designed to assess clot stability.

RESULTS

As expected, rFVIII increased clot formation, whereas TXA had no effect upon this parameter. Assays including tissue-plasminogen activator revealed that rFVIII increased the maximum clot firmness 3-fold; whereas the presence of TXA induced an additional 4-fold increase. The area under the elasticity curve increased 5-fold after rFVIII and 24-fold after addition of TXA.

CONCLUSIONS

The study demonstrates that simultaneous treatment with TXA and rFVIII significantly improves the clot stability in patients with hemophilia A.

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.

Efficacy of aminocaproic, tranexamic acids in the control of bleeding during total knee replacement: a randomized clinical trial

BACKGROUND

Risks and costs of allogeneic blood transfusions mandate strategies to reduce blood loss in surgery. The objective of this study was to assess the efficacy of antifibrinolytic treatment in reducing perioperative blood loss during total knee replacement.

METHODS

A double-blind, randomized and placebo-controlled clinical trial was carried out on 127 patients undergoing total knee replacement. Patients in the study group received tranexamic acid 10 mg kg(-1) i.v. just before the tourniquet was deflated and 3 h later, or epsilon-aminocaproic acid 100 mg kg(-1) before tourniquet deflation followed by continuous perfusion (1 g h(-1)) during 3 h. External perioperative blood loss was measured and total blood loss was calculated. The number of patients transfused and number of packed red cell (PRC) units transfused was recorded and possible postoperative thromboembolic complications were investigated.

RESULTS

Total blood loss [mean (sd)] was 1099 ml (535) in the group that received antifibrinolytic agents and 1784 ml (660) in the control group (P<0.001). Five patients (7.5%) in the study group and 23 (38.3%) in the control group (P<0.001) received blood transfusions; the first group received a mean of 0.10 PRC unit per patient and the second, 0.58 (P<0.001). Mean reduction in haemoglobin levels (g dl(-1)) between preoperative and fifth day postoperative readings was 2.5 (0.9) in the study group and 3.4 (1.2) in the control group (P<0.001). Clinical assessment did not reveal any thromboembolic complications.

CONCLUSIONS

Antifibrinolytic agents produce a significant decrease in blood loss in patients undergoing total knee replacement, reflected in a reduction in the number of blood transfusions required.

Tranexamic acid for hemostasis in the surgical treatment of metastatic tumors of the spine

STUDY DESIGN

This is a retrospective study of sequential cohorts.

OBJECTIVE

To assess the efficacy of tranexamic acid in decreasing operative blood loss and the need for intraoperative transfusion in metastatic spine surgery.

SUMMARY OF BACKGROUND DATA

Significant published data have established the efficacy of antifibrinolytic drugs in limiting surgical bleeding during heart surgery and total joint replacement. One study in scoliosis suggested benefit in spine surgery as well.

METHODS

During a 6-month trial period, 14 patients with spine cancer undergoing palliative intralesional tumor excision and concomitant instrumentation to stabilize the spine in the hands of a single surgeon were administered tranexamic acid intraoperatively in the attempt to minimize operative blood loss. They were then compared to the immediately preceding 14 patients.

RESULTS

Estimated operative blood loss was 1385 mL in the study group treated with tranexamic acid and 1815 mL in controls not receiving the drug, and was not found to be significantly decreased in this study.

CONCLUSIONS

Control of operative bleeding in metastatic spine surgery can be problematical. Optimum protocol might include routine preoperative angiographic tumor embolization to decrease lesion vascularity in all cases, but angiography is not without risk. Noninvasive prophylaxis of tumor bleeding would have obvious desirable advantages but was, unfortunately, not achieved in this study.

Tranexamic acid reduces early post-operative blood loss after total knee arthroplasty: a prospective randomised controlled trial of 29 patients

INTRODUCTION

Extensive blood loss related to knee arthroplasty is quite normal and many patients require blood transfusions. Surgery and the use of pneumatic tourniquets lead to an increase in the activity of the fibrinolytic system, which in turn may accentuate the blood loss. Drugs that inhibit the fibrinolytic system may thus be used to reduce blood loss. Tranexamic acid (TA) acts by binding to one of the enzymes at the start of the coagulation cascade, so inhibiting the fibrinolytic system. A concern is that this inhibition may have the side effect of increasing thromboembolic disease, a common complication of joint replacement surgery. We aimed to confirm the reductions in blood loss and to assess the impact of TA usage on clinical and sub-clinical DVT.

METHOD

We performed a prospective, randomised, double blind, controlled trial, using patients due to undergo primary unilateral total knee arthroplasty. Patients were randomised to receive either 15 mg/kg of tranexamic acid or a similar volume of normal saline at the time of cementing of the prosthesis. Perioperative blood loss was recorded and patients were screened for DVT with duplex ultrasound assessment of both legs on the fifth post-operative day.

RESULTS

A statistically significant (p=0.006) decrease in blood loss in the early post-operative period was noted in the group receiving tranexamic acid. This was not associated with a significant difference in total blood loss (p=0.55) or in transfusion requirements. There was no of evidence in DVT in either group on duplex ultrasound screening of the lower limbs.

INTERPRETATION

One injection of 15 mg/kg of tranexamic given at the time of cementing the prosthesis in total knee arthroplasty, before deflation of the tourniquet, significantly decreases the amount of blood loss in the early post-operative period. The treatment was not associated with an increase in thromboembolic complications.

Resource utilization and costs of blood management services associated with knee and hip surgeries in US hospitals

This article assesses the use and costs of blood transfusion during knee and hip surgery through a retrospective observational study of 92,223 discharged inpatients who had undergone knee or hip surgery from July 1, 2003, through June 30, 2004; a sample of US hospitals that participated in the Perspective Comparative Database (Premier Inc., Charlotte, NC) was used. Descriptive and multivariate analyses were performed to determine the use and costs of allogeneic blood transfusion (ABT). The average cost of ABT per user ranged from $387 (SD=$952) for red blood cells to $6585 (SD=$11,162) for cryoprecipitate. Utilization rates in the sample were as follows: antifibrinolytics, 0.14%; topical sealants, 3.24%; volume expanders, 3.89%; erythropoietin agents, 5.08%; and hypotensive anesthesia, 22.28%. Patients who were given volume expanders ($133.73, SD=$23.00, P<.01) or erythropoietin ($177.72, SD=$34.61, P<.01) had higher costs associated with ABT than did those who did not use volume expanders or erythropoietin. Patients who received hypotensive anesthesia (odds ratio [OR]=1.96; 95% confidence interval [CI], 1.87-2.06), a volume expander (OR=1.71; 95% CI, 1.57- 1.85), a topical sealant (OR=1.61; 95% CI, 1.45-1.79), or an erythropoietic agent (OR=2.30; 95% CI, 2.06-2.57) had a greater likelihood of ABT. Investigators concluded that most transfusion reduction techniques are underused, or they do not reduce the burden of ABT associated with knee or hip surgery.

Management of bleeding emergencies: when to use recombinant activated Factor VII

Recombinant activated Factor VII (rVIIa) was originally released as a clotting factor, with use limited to a select group of patients who had few other treatment options. Due to the apparent ability of rVIIa to stop bleeding, no matter what the underlying cause, there is great interest in use of rVIIa in a wide range of bleeding patients. This article discusses rVIIa and its uses in a variety of patients, especially liver disease and trauma patients, and makes suggestions for appropriate use. Although most of the reports on rVIIa are anecdotes and case series, there is increasing data for clinical trials to help guide usage.

Tranexamic acid reduces allogeneic red cell transfusions in patients undergoing total knee arthroplasty: results of a meta-analysis of randomized controlled trials

BACKGROUND

The delayed bleeding associated with total knee arthroplasty (TKA) may be a result of a tourniquet-induced imbalance of the procoagulant and fibrinolytic systems. There are conflicting results in the literature about tranexamic acid (TA) infusion in reducing postoperative blood loss and the number of transfused red cells (RBC) units. A meta-analysis was performed to summarize the results of different research studies.

STUDY DESIGN AND METHODS

Randomized controlled trials reported through October 2004 were retrieved, and nine studies met the criteria for meta-analysis. Summary odds ratio (OR) of allogeneic transfusion and a weighted mean difference (WMD) of transfusions per patient in TA-treated group versus placebo group were calculated across studies.

RESULTS

The use of TA significantly reduced the proportion of patients requiring blood transfusion (summary OR, 0.10; 95% CI, 0.06-0.18; p < 0.00001) and the number of RBC transfusions per patient (WMD, -1.72; 95% CI, -2.11 to -1.33; p < 0.00001) when compared with patients who received placebo.

CONCLUSION

Our meta-analysis shows that the use of TA for patients undergoing TKA is effective in reducing the requirements of allogeneic blood transfusion.

Use of activated recombinant coagulation factor VII in patients undergoing reconstruction surgery for traumatic fracture of pelvis or pelvis and acetabulum: a double-blind, randomized, placebo-controlled trial † †This article is accompanied by the Editorial. ‡ ‡Declaration of interest. R. M. Grounds has worked in the past as a consultant for Novo Nordisk and has lectured at symposiums organized by Novo Nordisk. Novo Nordisk has given an unrestricted educational grant to St George’s Hospital Special Trustee’s. The trial was funded by Novo Nordisk, UK

BACKGROUND

Activated recombinant coagulation factor VII (rFVIIa) effectively prevents and controls bleeding in patients with coagulopathy. Data show that rFVIIa may reduce blood loss and eliminate the need for transfusion in patients with normal haemostasis undergoing major surgery. We assessed the efficacy of rFVIIa in patients with normal haemostasis undergoing repair surgery of major traumatic fracture of the pelvis or the pelvis and acetabulum, who were expected to have a large volume of blood loss.

METHODS

We performed a double-blind, randomized, placebo-controlled trial involving 48 patients undergoing major pelvic-acetabular surgery. Patients were randomized to receive an i.v. bolus injection of rFVIIa 90 microg kg(-1) or placebo as add-on therapy at the time of the first skin incision. All patients also received intraoperative salvaged red blood cells (RBC).

RESULTS

There was no significant difference in the total volume of perioperative blood loss, the primary outcome variable, between the rFVIIa and placebo groups. In addition, there were no differences between the two groups in the total volume of blood components, including salvaged RBC transfused, number of patients requiring allogeneic blood components, total volume of fluids infused, total operating time, time taken after entry to the intensive care unit to reach normal body temperature and acid-base status, and time spent in hospital. No adverse events, in particular thromboembolic events, were reported in either group.

CONCLUSIONS

In patients with normal haemostasis undergoing repair surgery of traumatic pelvic-acetabular fracture, the prophylactic use of rFVIIa does not decrease the volume of perioperative blood loss.

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.

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.

Tranexamic acid given intraoperatively reduces blood loss after total knee replacement: a randomized, controlled study

BACKGROUND

Extensive blood loss in total knee replacement (TKR) surgery is well known and is associated with a high transfusion rate of allogenic blood. Tranexamic acid (TXA) has been shown to reduce blood loss by 50% in this patient group, but only in cases with a perioperative loss of 1400-1800 ml. This study was performed to see if TXA offers any advantages in knee replacement surgery with blood loss at 800 ml.

METHODS

Thirty consecutive patients scheduled for TKR in spinal anesthesia with the use of a tourniquet, were randomized to TXA or non-TXA. Tranexamic acid 10 mg kg-1 was given at conclusion of surgery and again 3 h later. Blood loss was registered.

RESULTS

Total blood loss was at all times significantly lower in the TXA group compared to the non-TXA group (409.7+/-174.9 ml vs. 761.7+/-313.1 ml; P<0.001). There were no differences in coagulation parameters. No patients in the TXA group had a blood transfusion vs. 13% in the non-TXA group (NS). No complications were registered in the two groups.

CONCLUSION

We conclude that TXA significantly reduces blood loss after total knee replacement surgery.

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

We performed a randomized, double-blind study on the effect of tranexamic acid on blood loss and blood transfusions in 40 primary total hip arthroplasties. Tranexamic acid, 10 mg/kg body weight, or placebo, was given intravenously just before the operation. Blood loss during the operation and postoperatively into the drains was recorded, as also were blood hemoglobin concentrations. Ultrasound examination 1 week postoperatively was done to estimate the blood loss due to remaining hematomas. Total (operation + drain) blood loss was 0.76 (95 CI 0.63-0.89) L in the tranexamic acid group as compared to 1.0 (CI 0.81-1.2) L in the placebo group (p = 0.03). The number of blood transfusions during the day of operation was 2 vs. 10 (p = 0.07) and the total number during the hospital stay was 5 vs. 13 (p = 0.2). 1 patient in each group had a pulmonary embolism.

Systemic hemostatic medications for reducing surgical blood loss

OBJECTIVE

To review randomized trials involving the use of systemic hemostatic medications for reducing surgical blood loss.

DATA SOURCES

Articles were obtained through searches of MEDLINE (1966-September 2000). The bibliographies of retrieved publications were reviewed for additional references.

STUDY SELECTION

All randomized studies and pharmacoeconomic evaluations that involved medications used for systemic hemostasis in the perioperative period were included.

DATA EXTRACTION

Randomized studies involving conjugated estrogens, aminocaproic acid, tranexamic acid, desmopressin, and aprotinin for systemic hemostasis were extracted. Studies of proton-pump inhibitors for upper gastrointestinal bleeding and octreotide for variceal bleeding were excluded, as were trials involving the use of any hemostatic agent for cardiovascular surgery. The primary outcome under review was a reduction in bleeding as defined by reduced transfusion requirements.

DATA SYNTHESIS

There is limited efficacy and toxicity information concerning the use of conjugated estrogens for reducing surgery-related bleeding. Similarly, there are a limited number of randomized studies involving aminocaproic acid and tranexamic acid, and with the exception of tranexamic acid for reducing transfusion requirements with knee surgery, the study results are either conflicting or negative. For desmopressin, evidence from a substantial number of randomized trials documents its lack of efficacy. Aprotinin has reduced bleeding and transfusion requirements in a number of randomized studies involving patients undergoing orthopedic surgery, but cost-effectiveness studies are needed to better define its therapeutic role. Trials of aprotinin during hepatic surgery have yielded conflicting results.

CONCLUSIONS

Most hemostatic medications used for reducing surgery-related bleeding have limited or contradictory evidence of efficacy.

Regional hemostatic status and blood requirements after total knee arthroplasty with and without tranexamic acid or aprotinin

Antifibrinolytics seem to reduce postoperative blood loss after total knee arthroplasty. Few studies have shown the impact of these drugs on the mechanisms of coagulation. The purpose of this study was to examine coagulation/fibrinolysis variables as well as blood loss after total knee arthroplasty with and without antifibrinolytics in the operated limb on a regional level. Thirty-six patients were randomized into one of three groups to receive aprotinin, tranexamic acid, or no medication. We took blood samples of the femoral vein before deflating the tourniquet and after 5, 10, 30, 60, 120 min and on the first postoperative day. The implantation of a knee prosthesis in artificial ischemia caused a significant activation of coagulation and fibrinolysis in the regional circulation. Tranexamic acid and aprotinin did not cause a significant modulation of fibrinolysis variables or a significant reduction of postoperative bleeding and transfusion requirements. One of the differences in comparison to other studies was the decreased total blood loss. The use of bone cement as well as surgical hemostasis before wound closure may be regarded as reasons for this. Therefore, primarily these methods should be used because there is no increased risk of adverse drug effects.

IMPLICATIONS

After total knee arthroplasty total blood loss may be kept in a low range if methods such as cemented knee prosthesis and surgical hemostasis are used. In this case aprotinin and tranexamic acid did not cause a significant modulation of fibrinolysis variables or a significant reduction of postoperative bleeding.