Aprotinin reduces red blood cell transfusion in orthotopic liver transplantation: a prospective, randomized, double-blind study

Comparison of Postoperative Hemorrhage Risk After Partial Liver Transplantation Versus Whole Liver Transplantation: A Single-Center Experience

BACKGROUND

We aimed to identify risk factors associated with reoperation for postoperative intraperitoneal hemorrhage (PIH) after orthotopic liver transplantation and investigate if partial liver transplantation (PLT) increases the risk of PIH.

METHODS

We retrospectively analyzed the medical records of 304 consecutive recipients who underwent orthotopic liver transplantation at the Affiliated Lihuili Hospital, Ningbo University, from January 2016 to July 2022. Data were compared between recipients who experienced PIH requiring reoperation and those who did not. Subgroup propensity score matching analysis was performed to assess the impact of PLT on PIH risk. Neither prisoners nor participants who were coerced or paid were used in the study.

RESULTS

Among the 304 recipients, 22 (7.2%) underwent reoperation for PIH. Multivariate analysis revealed that the recipient Model for End-Stage Liver Disease (MELD) score (odds ratio = 1.066, 95% CI [1.025-1.109], P = .001) and volume of intraoperative packed red blood cell transfusion (odds ratio = 1.089, 95% CI [1.032-1.481], P = .002) were independent risk factors for PIH. No significant differences were observed in the risk of PIH between PLT and whole liver transplantation.

CONCLUSION

Preoperative MELD score and intraoperative packed red blood cell transfusion should be carefully considered to manage the risk of PIH in liver transplantation recipients. Partial liver transplantation, a crucial approach for addressing donor shortages, does not increase the risk of reoperation for PIH in recipients.

Swine model in transplant research: Review of anaesthesia and perioperative management

Pigs are one of most common animal species to be used in biomedical models due to their many anatomical visceral similarities with humans, particularly with regards to transplantation. Despite this use, in many of the researches in which pigs are selected for transplantation, the anaesthesia used is an adaptation of human anaesthesia and presents some limitations such as a reduced analgesia a limited control in perioperative period. In this review we show some of the most important conditions in the preanaesthetic management and of swine as well as we review of anaesthetic protocols for the most common types of swine model of transplantation.

[Coagulation management in patients with liver disease]

BACKGROUND

End-stage liver disease is associated with complex alterations in hemostasis. Whereas prognosis is essentially affected by life-threatening bleeding complications in some patients, others, especially those with cholestatic liver diseases, suffer from thromboembolic complications. Standard laboratory values (SLVS; prothrombin time, activated partial thrombin time, platelet count) cannot sufficiently reflect the altered balance of pro- and anticoagulatory factors. Moreover, a couple of studies indicated that SLVS are not able to predict bleeding complications in patients with acute liver failure or decompensated liver cirrhosis.

DIAGNOSIS AND THERAPY

Use of bed-side coagulation diagnostics such as thrombelastometry/-graphy, detection of thrombocyte function by multiple electrode aggregometry and selective measurement of single factors allows a targeted and causal therapy of hepatic coagulopathies especially in the context of bleeding complications or surgical interventions. In recent years, coagulation management guided by these new devices has contributed to a reduction in transfusion of allogenic blood products, which may be associated with undesirable side effects.

DISCUSSION

The current review summarizes the complex pathophysiological alterations of hemostasis associated with advanced liver insufficiency and discusses recent upcoming diagnostics and coagulation management in this patient cohort.

Aminocaproic Acid (amicar) as an alternative to aprotinin (trasylol) in liver transplantation

INTRODUCTION

This study compared clinical outcomes for a large number of liver transplant patients receiving intraoperative epsilon-aminocaproic acid (EACA), aprotinin, or no antifibrinolytic agent over an 8-year period.

PATIENTS AND METHODS

Records for deceased donor liver transplants were reviewed. Data included antifibrinolytic agent, blood loss, early graft function, and postoperative complications. Study groups included low-dose aprotinin, high-dose aprotinin, EACA (25 mg/kg, 1-hour infusion), or no antifibrinolytic agent.

RESULTS

Data were included for 1170 consecutive transplants. Groups included low-dose aprotinin (n = 324 [28%]), high-dose aprotinin (n = 308 [26%]), EACA (n = 216 [18%]), or no antifibrinolytic (n = 322 [28%]). EACA had the lowest intraoperative blood loss and required the fewest transfusions of plasma. Patients receiving no agent required the most blood transfusions. Early graft loss was lowest in the EACA group, and 90-day and 1-year patient survival rates were significantly higher for the low-dose aprotinin and EACA groups according to Cox regression. Complications were similar, but there were more episodes of deep vein thrombosis in patients receiving EACA.

CONCLUSIONS

These results suggest that transitioning from aprotinin to EACA did not result in worse outcomes. In addition to decreased intraoperative blood loss, a trend toward improved graft and patient survival was seen in patients receiving EACA.

Delicate balance of bleeding and thrombosis in end-stage liver disease and liver transplantation

Liver transplantation in cirrhotic patients is accompanied by severe bleeding. Indeed, the first 100 recipients of liver allografts transplanted by Thomas E. Starzl died mainly by uncontrolled bleeding. Since then, much progress has been made as to the understanding of the pathophysiology and the treatment of hemostatic disorders in cirrhotic patients. The aim of this review is to provide a state-of-the-art overview on recent developments and treatment options for hemostatic disorder in cirrhotic patients. Patients with end-stage-liver disease (ESLD) do not suffer only from procoagulant deficiency; there is also a lack of natural anticoagulants (i.e. proteins C and S) and profibrinolytics. Conventional laboratory methods such as the determination of the international normalized ratio or the activated partial thromboplastin time cannot predict bleeding complications in these patients. Progressive diagnostic techniques reveal that cirrhotic patients have the same capacity to produce thrombin like healthy volunteers. Moreover, cirrhotic patients--and particularly those with primary biliary cirrhosis or primary sclerosing cholangitis-- are at a higher risk for developing thrombosis as compared with healthy controls. Hemostatic alterations are common in cirrhotic patients; they involve both the pro- and the anticoagulant pathways. However, this is a very delicate balance, which may be shifted to either of these pathways by different treatments thereby causing bleeding or thrombosis, respectively.

Hemostasis in liver disease: implications of new concepts for perioperative management

The hemostatic profile of patients with liver diseases is frequently profoundly different from that of healthy individuals. These complex alterations lead to abnormal results from routine laboratory tests, but because of the nature of these assays, they fail to accurately represent the patient's hemostatic state. Nevertheless, based on abnormal laboratory coagulation values, it has long been assumed that patients with liver disease have a natural bleeding tendency and are protected from thrombosis. This assumption is false; the average patient with liver disease is actually in a state of "rebalanced hemostasis" that can relatively easily be tipped toward both bleeding and thrombosis. The new paradigm of rebalanced hemostasis has strong implications for the clinic, which are presented in this review. There is no evidence that prophylactic transfusion of plasma helps to prevent procedure-related bleeding. In addition, the presence of independent risk factors such as poor kidney status or infections should be carefully assessed before invasive procedures. Furthermore, central venous pressure plays an important role in the risk of bleeding in patients with liver diseases, so during procedures, a restrictive infusion policy should be applied. Finally, thrombosis prophylaxis should not be withheld from patients with cirrhosis or acute liver failure, and clinicians should be alert to the possibility of thrombosis occurring in these patients.

Blood loss, predictors of bleeding, transfusion practice and strategies of blood cell salvaging during liver transplantation

Blood loss during liver transplantation (OLTx) is a common consequence of pre-existing abnormalities of the hemostatic system, portal hypertension with multiple collateral vessels, portal vein thrombosis, previous abdominal surgery, splenomegaly, and poor “functional” recovery of the new liver. The intrinsic coagulopathic features of end stage cirrhosis along with surgical technical difficulties make transfusion-free liver transplantation a major challenge, and, despite the improvements in understanding of intraoperative coagulation profiles and strategies to control blood loss, the requirements for blood or blood products remains high. The impact of blood transfusion has been shown to be significant and independent of other well-known predictors of posttransplant-outcome. Negative effects on immunomodulation and an increased risk of postoperative complications and mortality have been repeatedly demonstrated. Isovolemic hemodilution, the extensive utilization of thromboelastogram and the use of autotransfusion devices are among the commonly adopted procedures to limit the amount of blood transfusion. The use of intraoperative blood salvage and autologous blood transfusion should still be considered an important method to reduce the need for allogenic blood and the associated complications. In this article we report on the common preoperative and intraoperative factors contributing to blood loss, intraoperative transfusion practices, anesthesiologic and surgical strategies to prevent blood loss, and on intraoperative blood salvaging techniques and autologous blood transfusion. Even though the advances in surgical technique and anesthetic management, as well as a better understanding of the risk factors, have resulted in a steady decrease in intraoperative bleeding, most patients still bleed extensively. Blood transfusion therapy is still a critical feature during OLTx and various studies have shown a large variability in the use of blood products among different centers and even among individual anesthesiologists within the same center. Unfortunately, despite the large number of OLTx performed each year, there is still paucity of large randomized, multicentre, and controlled studies which indicate how to prevent bleeding, the transfusion needs and thresholds, and the “evidence based” perioperative strategies to reduce the amount of transfusion.

Methods to decrease blood loss and transfusion requirements for liver transplantation

BACKGROUND

Excessive blood loss and increased blood transfusion requirements may have significant impact on the short-term and long-term outcomes after liver transplantation.

OBJECTIVES

To compare the potential benefits and harms of different methods of decreasing blood loss and blood transfusion requirements during liver transplantation.

SEARCH METHODS

We searched The Cochrane Central Register of Controlled Trials in The Cochrane Library, MEDLINE, EMBASE, Science Citation Index Expanded, and metaRegister of Controlled Trials until September 2011.

SELECTION CRITERIA

We included all randomised clinical trials that were performed to compare various methods of decreasing blood loss and blood transfusion requirements during liver transplantation.

DATA COLLECTION AND ANALYSIS

Two authors independently identified the trials and extracted the data. We analysed the data with both the fixed-effect and the random-effects model using RevMan Analysis. For each outcome we calculated the risk ratio (RR), mean difference (MD), or standardised mean difference (SMD) with 95% confidence intervals (CI) based on available data analysis. We also conducted network meta-analysis.

MAIN RESULTS

We included 33 trials involving 1913 patients. The sample size in the trials varied from 8 to 209 participants. The interventions included pharmacological interventions (aprotinin, tranexamic acid, epsilon amino caproic acid, antithrombin 3, recombinant factor (rFvIIa), oestrogen, prostaglandin, epinephrine), blood substitutes (blood components rather than whole blood, hydroxy-ethyl starch, thromboelastography), and cardiovascular interventions (low central venous pressure). All the trials were of high risk of bias. Primary outcomes were reported in at least two trials for the following comparisons: aprotinin versus control, tranexamic acid versus control, recombinant factor VIIa (rFVIIa) versus control, and tranexamic acid versus aprotinin. There were no significant differences in the 60-day mortality (3 trials; 6/161 (3.7%) in the aprotinin group versus 8/119 (6.7%) in the control group; RR 0.52; 95% CI 0.18 to 1.45), primary graft non-function (2 trials; 0/128 (0.0%) in the aprotinin group versus 4/89 (4.5%) in the control group; RR 0.15; 95% CI 0.02 to 1.25), retransplantation (3 trials; 2/256 (0.8%) in the aprotinin group versus 12/178 (6.7%) in the control group; RR 0.21; 95% CI 0.02 to 1.79), or thromboembolic episodes (3 trials; 4/161 (2.5%) in the aprotinin group versus 5/119 (4.2%) in the control group; RR 0.59; 95% CI 0.19 to 1.84) between the aprotinin and control groups. There were no significant differences in the 60-day mortality (3 trials; 4/83 (4.8%) in the tranexamic acid group versus 5/56 (8.9%) in the control group; RR 0.55; 95% CI 0.17 to 1.76), retransplantation (2 trials; 3/41 (7.3%) in the tranexamic acid group versus 3/36 (8.3%) in the control group; RR 0.79; 95% CI 0.18 to 3.48), or thromboembolic episodes (5 trials; 5/103 (4.9%) in the tranexamic acid group versus 1/76 (1.3%) in the control group; RR 2.20; 95% CI 0.38 to 12.64) between the tranexamic acid and control groups. There were no significant differences in the 60-day mortality (3 trials; 8/195 (4.1%) in the recombinant factor VIIa (rFVIIa) group versus 2/91 (2.2%) in the control group; RR 1.51; 95% CI 0.33 to 6.95), thromboembolic episodes (2 trials; 24/185 (13.0%) in the rFVIIa group versus 8/81 (9.9%) in the control group; RR 1.38; 95% CI 0.65 to 2.91), or serious adverse events (2 trials; 90/185 (48.6%) in the rFVIIa group versus 30/81 (37.0%) in the control group; RR 1.30; 95% CI 0.94 to 1.78) between the rFVIIa and control groups. There were no significant differences in the 60-day mortality (2 trials; 6/91 (6.6%) in the tranexamic acid group versus 1/87 (1.1%) in the aprotinin group; RR 4.12; 95% CI 0.71 to 23.76) or thromboembolic episodes (2 trials; 4/91 (4.4%) in the tranexamic acid group versus 2/87 (2.3%) in the aprotinin group; RR 1.97; 95% CI 0.37 to 10.37) between the tranexamic acid and aprotinin groups. The remaining outcomes in the above comparisons and the remaining comparisons included only only trial under the primary outcome or the outcome was not reported at all in the trials. There were no significant differences in the mortality, primary graft non-function, graft failure, retransplantation, thromboembolic episodes, or serious adverse events in any of these comparisons. However, the confidence intervals were wide, and it is not possible to reach any conclusion on the safety of the interventions. None of the trials reported the quality of life in patients.Secondary outcomes were reported in at least two trials for the following comparisons - aprotinin versus control, tranexamic acid versus control, rFVIIa versus control, thromboelastography versus control, and tranexamic acid versus aprotinin. There was significantly lower allogeneic blood transfusion requirements in the aprotinin group than the control group (8 trials; 185 patients in aprotinin group and 190 patients in control group; SMD -0.61; 95% CI -0.82 to -0.40). There were no significant differences in the allogeneic blood transfusion requirements between the tranexamic acid and control groups (4 trials; 93 patients in tranexamic acid group and 66 patients in control group; SMD -0.27; 95% CI -0.59 to 0.06); rFVIIa and control groups (2 trials; 141 patients in rFVIIa group and 80 patients in control group; SMD -0.05; 95% CI -0.32 to 0.23); thromboelastography and control groups (2 trials; 31 patients in thromboelastography group and 31 patients in control group; SMD -0.73; 95% CI -1.69 to 0.24); or between the tranexamic acid and aprotinin groups (3 trials; 101 patients in tranexamic acid group and 97 patients in aprotinin group; SMD -0.09; 95% CI -0.36 to 0.19). The remaining outcomes in the above comparisons and the remaining comparisons included only only trial under the primary outcome or the outcome was not reported at all in the trials. There were no significant differences in the blood loss, transfusion requirements, hospital stay, or intensive care unit stay in most of the comparisons.

AUTHORS' CONCLUSIONS

Aprotinin, recombinant factor VIIa, and thromboelastography groups may potentially reduce blood loss and transfusion requirements. However, risks of systematic errors (bias) and risks of random errors (play of chance) hamper the confidence in this conclusion. We need further well-designed randomised trials with low risk of systematic error and low risk of random errors before these interventions can be supported or refuted.

Detrimental effect of aprotinin ban on amount of blood loss during liver transplantation: single-center experience

BACKGROUND

Aprotinin, a plasmin inhibitor, had been used for reduction of intraoperative bleeding caused by hyperfibrinolysis during extensive surgery. Prophylaxis with aprotinin to limit blood loss during orthotopic liver transplantation (OLT) had been widely applied until the drug was weaned off the therapeutic list for severe complications. We compared the need for blood and blood products transfusion in patients undergoing OLT with and without the use of aprotinin.

MATERIALS AND METHODS

A retrospective analysis was performed on 150 patients, who underwent OLT between March 2004 and August 2008 and were divided into 2 groups: the APRO group (n = 111) after induction of anesthesia was given a bolus of 500 kIU of aprotinin in a 30-minutes infusion followed by 140 kIU/h till the end of the OLT in which aprotinin was not administered, and the NON-APRO group (n = 39).

RESULTS

Patients from the NON-APRO group needed significantly more units of packed red blood cells (PRBC) than the APRO group (5.53 ± 4.89 vs 3.99 ± 3.58 units; P = .037). Avoidance of aprotinin administration (β = 1.408), Child-Pugh score (β = 0.519), and duration of anhepatic phase (β = 0.03) affected the volume of transfused blood according to multiple regression analysis (P < .05).

CONCLUSIONS

Our study confirmed the important prophylactic role aprotinin used to have during OLT in limiting the need for blood transfusions. Further research and progress in methods of blood loss minimization and monitoring of hemostasis are needed to warrant safe liver transplantation.

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

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

Aprotinin versus tranexamic acid during liver transplantation: impact on blood product requirements and survival

BACKGROUND

Historically, orthotopic liver transplantation (OLT) has been associated with major blood loss and the need for blood product transfusions. Activation of the fibrinolytic system can contribute significantly to bleeding. Prophylactic administration of antifibrinolytic agents was found to reduce blood loss.

METHODS

The efficacy of two antifibrinolytic compounds--aprotinin (AP) and tranexamic acid (TA)--was compared in OLT. Four hundred consecutive OLTs were studied: 300 patients received AP and 100 received TA. Multivariate logistic regression analysis was used to identify independent predictors of intraoperative transfusion requirement and 1-year patient mortality.

RESULTS

There was no intergroup difference in intraoperative blood loss (1082±1056 vs. 1007±790 mL), red blood cell transfusion per patient (0.5±1.4 vs. 0.5±1.0), final hemoglobin (Hb) concentration (93±20 g/L vs. 95±22 g/L), the percentage of OLT cases requiring no blood product administration (80% vs. 82%), and 1-year survival (85.1% vs. 87.4%). Serum creatinine concentrations were also the same (116±55 vs. 119±36 μmol/L) 1 year after surgery. Two variables, starting Hb and phlebotomy, correlated with the two primary outcome measures (transfusion and 1-year survival).

CONCLUSIONS

In our experience, administration of AP was not superior to TA with regards to blood loss and blood product transfusion requirement during OLT. In addition, we found no difference between the groups in the 1-year survival rate and renal function. Furthermore, we suggest that starting Hb concentration should be considered when prioritizing patients on the waiting list and planning perioperative care for OLT recipients.

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.

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.

Liver donor's age and recipient's serum creatinine predict blood component use during liver transplantation

BACKGROUND

Excessive use of blood components during liver transplantation should be avoided because it has been associated with poor outcomes and it may stress blood bank resources.

STUDY DESIGN AND METHODS

To determine preoperative predictors of excessive transfusion requirements in patients undergoing liver transplantation, the clinical records of 126 consecutive adult patients undergoing primary liver transplantation were retrospectively reviewed. Outcome variables included number of red blood cells (RBCs), plasma, and plateletpheresis components intraoperatively transfused. Univariate analyses of the following predictor variables were performed: recipient age, sex, ethnicity, height/weight, Model for End Stage Liver Disease score, year of transplant, previous abdominal surgery, hepatoma, wait-list time, standard recipient laboratory values obtained immediately before transplantation, cold ischemia time, donor age, sex, and height/weight. Multivariate analysis using logistic regression was used to build a model that best predicted how many blood components should be available before transplant.

RESULTS

Donor age of more than 50 years old (odds ratio [OR], 2.8 95% confidence interval [CI], 1.3-6.0), and recipient serum creatinine (SCr) level of more than 1.3 mg/dL (OR, 3.8 95% CI, 1.6-8.9) were the only variables found to be predictive of RBC use in multivariate analysis. This model accurately predicted the use of more than 10 units of RBCs 79% of cases. Having both adverse factors present resulted in using more than one box in 80% of cases as compared to 44% of cases where only one or no adverse factor was present (p = 0.002). Further analyses showed a direct correlation between the number of RBCs transfused and plasma (r = 0.93) and plateletpheresis components (r = 0.74) transfused. [Corrections added after online publication 22-Jul-2009: OR updated from 3.8 to 2.8; CI from 1.6-8.9 to 1.3-6.0; OR from 2.8-3.8.]

CONCLUSION

Liver donor's age and recipient's SCr are important in preoperatively predicting blood use during liver transplantation.

Aprotinin and the risk of thrombotic complications after liver transplantation: a retrospective analysis of 1492 patients

Aprotinin is an antifibrinolytic drug that reduces blood loss during orthotopic liver transplantation (OLT). Case reports have suggested that aprotinin may be associated with an increased risk of thromboembolic complications. Recent studies in cardiac surgery also have suggested a higher risk of renal failure and postoperative mortality. Despite these concerns, no large-scale safety assessment has been performed in OLT. In a retrospective observational study involving 1492 liver transplants, we studied the occurrence of postoperative thromboembolic or thrombotic events and mortality in patients who received aprotinin (n = 907) and patients who did not (n = 585). The overall incidence of hepatic artery thrombosis and central venous complications (pulmonary embolism or inferior vena cava thrombosis) was 3.2% and 0.9%, respectively. In propensity score-adjusted analyses (C-index = 0.79), aprotinin was not associated with an increased risk of hepatic artery thrombosis [odds ratio (OR) = 1.00, 95% confidence interval (CI) = 0.50-2.01, P = 0.86]. Although central venous complications were found more frequently in patients receiving aprotinin, the difference was not statistically significant (OR = 2.95, 95% CI = 0.54-16.23, P = 0.32). In addition, no significant differences were found in 1-year mortality (OR = 1.21, 95% CI = 0.86-1.71, P = 0.32). In conclusion, this study did not demonstrate an increased risk of thrombotic complications or mortality when aprotinin is used during OLT.

Requirements for transfusion and postoperative outcomes in orthotopic liver transplantation: A meta-analysis on aprotinin

AIM: To study the effect of aprotinin used in orthotopic liver transplantation (OLT) on the intraoperative requirement for blood products and on the incidence of laparotomy for bleeding, thrombotic events and mortality.

METHODS: A systematic review of the literature in the electronic database Medline and the Clinic Trials Registry Database was performed. Literature that did not fit our study were excluded. Patients in the reviewed studies were divided into two groups; one group used aprotinin (aprotinin group) while the other did not (control group). The data in the literature that fit our requirements were recorded. Weighted mean differences (WMD) in the requirements for blood products between the aprotinin group and the control group were tested using a fixed effect model. A Z test was performed to examine their reliability; the Fleiss method of fixed effect model was used to analyze data on postoperative events, and odds ratios (ORs) were tested and merged.

RESULTS: Seven citations were examined in our study. Among them, a requirement for blood products was reported in 4 studies including 321 patients, while postoperative events were reported in 5 studies including 477 patients. The requirement for red blood cells and fresh frozen plasma in the aprotinin group was statistically lower than that in the control group (WMD = -1.80 units, 95% CI, -3.38 to -0.22; WMD = -3.99 units, 95% CI, -6.47 to -1.50, respectively). However, no significant difference was indicated in the incidence of laparotomy for bleeding, thrombotic events and mortality between the two groups. Analysis on blood loss, anaphylactic reactions and renal function was not performed in this study due to a lack of sufficient information.

CONCLUSION: Aprotinin can reduce the intraoperative requirement for blood products in OLT, and has no significant effect on the incidence of laparotomy for bleeding, thrombotic events and mortality.

Predictors of blood product use in orthotopic liver transplantation using the piggyback hepatectomy technique

Orthotopic liver transplantation (OLT) has historically been associated with massive blood loss and hemodynamic instability related to the coexistence of varices, coagulopathy, thrombocytopenia, and portal hypertension. Piggyback hepatectomy (PGB) is a technique increasingly utilized in OLT to avoid veno-venous bypass and vena cava clamping. This study evaluated the factors associated with blood loss and blood product requirement in PGB.

METHODS

This study is a retrospective review of the anesthesia preoperative and operative notes and computerized lab values for all adult cadaveric liver transplants over a 42-month period. These data were combined with the liver transplant database for analysis. Approximately 98% of the transplants were performed using a standard piggyback approach with no use of veno-venous bypass.

RESULTS

Data were included for all 526 transplants performed during this time period. Estimated blood loss (EBL) was 1000 cc. Median transfusion requirement was 3 units packed red blood cells, 7 units fresh frozen plasma, and 6 units platelets. Multivariate linear regression demonstrated that predictors of EBL were age, MELD score, preoperative hemoglobin, initial fibrinogen, initial central venous pressure, and total anesthesia time. Predictors of PRBC useage were age, MELD score, preoperative hemoglobin, initial fibrinogen, and anesthesia time. Postoperatively increased transfusion requirement was associated with increased length of hospital stay and lower 90-day and 1-year graft and patient survivals.

CONCLUSION

These results demonstrate that PGB can be safely accomplished in nearly all liver transplant patients without venovenous bypass or vena cava clamping and with less warm ischemia, which may ultimately be associated with less perioperative morbidity and improved outcomes.

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.

[Systemic hemostatic drugs]

Understanding the haemostatic changes is crucial in developing strategies for the management of haemorrhage syndroma. In recent years, the revised model of coagulation ("cell based" model) provided a much more authentic description of the coagulation process. Pharmacological intervention, especially desmopresin, antifibrinolytics (synthetics and nature) and increasingly recombinant activated factor VII are being used in prevention and therapeutically to control bleeding of variety etiologies. Skillfull surgery combined with blood saving methods and careful management of blood coagulation will all help in sucessfull haemorrhage prevention and treatment, and reduce unnecessary blood loss and transfusion requirements and its attendant risks. Among the all avalaible tests, the use of thromboelastography has allowed for more detailed dynamic assessment of the various steps of hemostasis.

Evaluation of cell salvage autotransfusion utility during liver transplantation

BACKGROUND

Orthotopic liver transplantation (OLT) may be associated with massive blood loss and the need for allogenic blood product transfusions. Cell salvage autotransfusion (CS) is an attractive alternative to allogenic red blood cell (RBC) transfusion. However, controversy surrounds its usefulness during OLT; some studies stated that CS decreased transfusions of allogenic blood products and others stated that blood loss was increased. The aim of this study was to evaluate the efficiency of the CS during OLT.

PATIENTS AND METHODS

After approval by the institutional ethics committee, a prospective survey was undertaken. A total of 150 consecutive OLTs were included in the study. Two groups of patients were formed. Period 1 included patients 1-75 with no CS use. Period 2 comprised patients 76-150 with systematic CS use.

RESULTS

Patients from both periods were comparable. CS was used in all cases in period 2, and there was enough salvaged blood to retransfuse 65% of these OLTs. The mean volume of retransfused blood was 338+/-339 ml. The transfusion rate did not change from period 1 to period 2. The mean number of RBC units transfused per patient was 0.4+/-0.9 vs 0.4+/-1.2 with 78.7% vs 81.3% of cases not receiving transfusion of any blood product. The threshold for RBC transfusions was the same. The length of surgery and blood loss were greater in period 2 than in period 1 (associated with the arrival of two junior surgeons), but the hemoglobin (Hb) value was also higher at the end of surgery (93.8+/-19.3 g/L vs 85.2+/-17.8 g/L, p<0.0001).

CONCLUSION

Despite increased blood loss in period 2, CS saved 21 g/L of Hb per patient or two RBC unit transfusions. As long as we cannot predict with accuracy which patients will bleed, we will continue to use the CS for all OLTs.

Efficacy and safety of antifibrinolytic drugs in liver transplantation: a systematic review and meta-analysis

Although several randomized controlled trials (RCTs) have shown the efficacy of antifibrinolytic drugs in liver transplantation, their use remains debated due to concern for thromboembolic complications. None of the reported RCTs has shown a higher incidence of these complications in treated patients; however, none of the individual studies has been large enough to elucidate this issue completely. We therefore performed a systematic review and meta-analysis of efficacy and safety endpoints in all published controlled clinical trials on the use of antifibrinolytic drugs in liver transplantation. Studies were included if antifibrinolytic drugs (epsilon-aminocaproic acid, tranexamic acid (TA) or aprotinin) were compared with each other or with controls/placebo. Intraoperative red blood cell and fresh frozen plasma requirements, the perioperative incidence of hepatic artery thrombosis, venous thromboembolic events and mortality were analyzed. We identified 23 studies with a total of 1407 patients which met the inclusion criteria. Aprotinin and TA both reduced transfusion requirements compared with controls. No increased risk for hepatic artery thrombosis, venous thromboembolic events or perioperative mortality was observed for any of the investigated drugs. This systematic review and meta-analysis does not provide evidence for an increased risk of thromboembolic events associated with antifibrinolytic drugs in liver transplantation.

Effect of aprotinin on postoperative blood loss in off-pump coronary artery bypass surgery

BACKGROUND AND AIM OF THE STUDY

Off-pump coronary artery bypass (OPCAB) enables a reduction in postoperative complications, particularly bleeding and transfusion. Nevertheless, a significant percentage of patients still needs transfusion. The effect of antifibrinolytic therapy on postoperative bleeding as part of OPCAB is still not widely described. The purpose of this study was to investigate the potential benefit of aprotinin in OPCAB.

METHODS

We conducted a retrospective comparative study with a historical control group. Consecutive patients undergoing off-pump coronary bypass were divided in two groups: 40 patients were operated without any antifibinolytic drug (group C); 40 patients received aprotinin (group A) during surgery. Patients in group A received a bolus of 2 x 10(6) KIU during 30 minutes, followed by a continuous infusion of 0.5 x 10(6) KIU per hour until the end of surgery. The same protocol was used during the whole study period.

RESULTS

Preoperative data of the two groups did not differ except for the number of grafts performed, which was higher in group A. Prothrombin time and activated clotting time increased in both groups after surgery. The use of packed red blood cells or fresh frozen plasma was not significantly different between both groups. Postoperative blood loss was significantly reduced in the aprotinin group (540 mL +/- 320 vs. 770 mL +/- 390, p = 0.006). No increase in postoperative troponin values was found in group A.

CONCLUSIONS

Aprotinin significantly reduced postoperative blood loss without reducing the transfusion rate. Aprotinin was not associated with any increase in postoperative complications.

Comparison of the effects of aprotinin and tranexamic acid on blood loss and red blood cell transfusion requirements during the late stages of liver transplantation

BACKGROUND

During liver transplantation (LT), profound activation of the fibrinolytic system can contribute significantly to perioperative bleeding. Prophylactic administration of antifibrinolytic agents has been shown to reduce blood loss and the need for allogeneic transfusion in these conditions.

STUDY DESIGN AND METHODS

This prospective randomized trial included 51 cirrhotic patients undergoing LT. Patients were randomly assigned to receive either 280 mg of aprotinin (AP) followed by 70 mg per hour or 40 mg per kg tranexamic acid (TA) followed by 40 mg per kg per hour, administered from the end of the anhepatic phase until 2 hours after reperfusion of the graft, and the effects on blood loss and red blood cell (RBC) transfusion requirements were compared. Transfusion policy was standardized in all patients. In addition, the biological effects of the two drugs, as assessed by coagulation and fibrinolytic markers obtained during surgery, were evaluated in a subgroup of patients from each treatment group and compared with an historical control group that did not receive antifibrinolytic drugs.

RESULTS

There was no significant difference between the two groups in perioperative blood losses (AP, 6200 [4620-8735] mL; TA, 5945 [4495-8527] mL; median [range]) or in RBC transfusions requirements (AP, 9 [6.75-15.25] units; TA, 10 [6.5-13.5] units). Inhibition of fibrinolysis was observed with both drugs compared with the control group. Coagulation appeared to be activated more with AP, however, whereas fibrinolysis was inhibited more by TA.

CONCLUSION

Blood losses and RBC transfusion requirements were comparable regardless of the drug administered. TA may be as valuable as AP for controlling fibrinolysis in LT.

Effect of low central venous pressure and phlebotomy on blood product transfusion requirements during liver transplantations

Correction of coagulation defects with plasma transfusion did not decrease the need for intraoperative red blood cells (RBC) transfusions during liver transplantations. On the contrary, it led to a hypervolemic state that resulted in an increase of shed blood. As well, plasma transfusion has been associated with a decreased one-year survival rate. The aim of the present prospective survey was to evaluate whether anesthesiologists could reduce intraoperative RBC transfusions during liver transplantations by changing their anesthesia practice, more specifically by maintaining a low central venous pressure (CVP), through restriction of volume replacement, elimination of all plasma transfusion and by using intraoperative phlebotomy during the transplantation. One hundred consecutive liver transplantations were prospectively studied during a two-year period and were compared to a retrospective series (1998-2002). A low CVP was maintained in all patients prior the anhepatic phase. Coagulation disorders were not corrected preoperatively, intraoperatively, or post-operatively unless uncontrollable bleeding. Phlebotomy and Cell Saver (CS) were used following pre-established criteria. Independent variables were analyzed in a univariate and multivariate fashion. The mean number of intraoperative RBC units transfused was 0.4 +/- 0.8. No plasma, platelets, albumin, or cryoprecipitate were transfused. Seventy-nine percent of the patients received no blood products during their liver transplantation. The average final hemoglobin value was 85.9 +/- 17.8 g/L. In 57 patients (58.2%), intraoperative phlebotomy and CS were used either together or separately. The one-year year survival rate was 89.1%. Logistic regression showed that avoidance of plasma transfusion, starting hemoglobin value and phlebotomy were significantly linked to liver transplantation without RBC transfusion. In conclusion, the avoidance of plasma transfusion and maintenance of a low CVP prior to the anhepatic phase were associated with a decrease in RBC transfusions during liver transplantations. Previous reports indicating that it is neither useful nor necessary to correct coagulation defects with plasma transfusion prior to liver transplantation are further corroborated by this prospective survey. We believe that this work also supports the practice of lowering CVP with phlebotomy in order to reduce blood loss, during liver dissection, without any deleterious effect.

Four cases of cardiopulmonary thromboembolism during liver transplantation without the use of antifibrinolytic drugs

Orthotopic liver transplantation (OLT) is one of the most demanding surgical procedures performed. Intraoperative bleeding can be substantial and related to both surgical and nonsurgical causes. A less common but previously reported phenomenon is intraoperative cardiopulmonary thromboembolism precipitating major patient morbidity and mortality. In this paper, we present four cases of intraoperative thromboembolism during OLT. These cases were performed without the concomitant use of antifibrinolytic drugs. We performed a review and analysis of previously reported cases of intraoperative thromboembolism during OLT. Possible causes of thromboembolism, clinical management, use of thromboelastography, and the role of antifibrinolytic drugs are discussed.

Survival rate changes with transfusion of blood products during liver transplantation

PURPOSE

To determine whether red blood cell (RBC) or plasma transfusion is associated with the one-year survival rate variation previously detected in liver transplantation.

METHODS

A retrospective study of 206 consecutive liver transplantations was undertaken. Intraoperative transfusions of blood products were identified. Twenty-seven variables were studied using univariate and multivariate analyses to identify factors that were associated significantly with survival rate. For analysis of one-year survival, the cases were studied according to the transfused blood products. Patients were stratified according to the degree of RBC and plasma transfusion into four groups: more than four units of RBC, one to four units of RBC, plasma transfusion only, and no plasma or RBC transfusions.

RESULTS

Patients received an average of 2.8 +/- 3.5 units of RBC and 4.1 +/- 4.1 units of plasma. Thirty-two percent of the patients did not receive any RBC transfusion and 19.4% did not receive any blood products. The one-year survival rate was 81.9% for all patients and 97.4% for patients without any transfusions. Of the 27 variables evaluated, only RBC and plasma transfusions were associated with significant decrease in the one-year survival rate, which was seen in the group who received only plasma (76.9%, P = 0.014) and the group who received more than four units of RBC (62.5%, P < 0.0001).

CONCLUSION

Although we cannot demonstrate causality, our analysis shows that our one-year survival rate following liver transplantation decreased significantly with the intraoperative transfusion of any amount of plasma or more than four units of RBC.

Single pretransplant bolus of recombinant activated factor VII ameliorates influence of risk factors for blood loss during orthotopic liver transplantation

Large blood loss and transfusions during liver transplantation (LTx) may lead to serious complications and have a negative impact on post-transplant mortality and morbidity. In the retrospective study we compared two groups of recipients of primary cadaveric liver transplantation: group I (study group), consisted of 28 patients with preoperative risk of high intraoperative blood loss, including severe uncorrected coagulopathy. This group was given a bolus of recombinant activated factor VII (rFVIIa) just before LTx. Group II (control group) included 61 patients without a particular risk for increased intraoperative blood loss. These patients were not given rFVIIa. We analyzed both groups for: coagulation parameters before, during and after surgery (INR, APTT, factor VII activity), blood and FFP transfusions, operative time, postoperative complications (vascular thrombosis, reoperation for bleeding), postoperative ICU stay, post-transplant hospitalization time and mortality. Patients from the study group (I) had significantly worse coagulation parameters than patients in the control group (II) at the start of the surgical procedure; however, after administration of a bolus of rFVIIa there was immediate correction of coagulation in all recipients. No significant differences in intraoperative blood transfusions were observed between study and control groups (1980 +/- 311.4 mL vs. 1527 +/- 154.2 mL, respectively), operating time (8.7 h vs. 8.9 h) or ICU and hospital stay (7.03 days vs. 6.15 days and 40.89 days vs. 41.1 days). Re-exploration because of bleeding was performed in three patients from group I (10.7%) and in seven patients (11.5%) from group II. No single case of vascular thrombosis was observed in the study group, while in the control group there were three hepatic artery thromboses, two portal vein thromboses and one hepatic vein thrombosis. We conclude that rFVIIa given preoperatively to liver transplant recipients with several risk factors for high intraoperative bleeding adjusts these patients to a normal risk group, without an increased risk for thrombotic complications.

A review of aprotinin in orthotopic liver transplantation: can its harmful effects offset its beneficial effects?

Blood transfusion can adversely affect patient outcome and graft survival in orthotopic liver transplantation (OLT). With this respect, prophylactic aprotinin administration decreases blood loss, transfusion requirements, and the hemodynamic changes associated with graft reperfusion in patients undergoing OLT. However, data indicate limiting the use of aprotinin in OLT: (a) clinical, biological, echocardiographic, and postmortem findings recorded in patients with chronic liver disease or undergoing OLT suggest that a continuous prothrombotic state exists in these patients. Whether the inhibition of fibrinolysis associated with aprotinin therapy will expose some patients to untoward thrombosis is questionable; (b) aprotinin does not appear to alter postoperative outcome in patients undergoing OLT; (c) aprotinin decreases blood transfusion requirements only when surgery is associated with significant blood loss. However, at the present time, median transfusion requirements of 2 to 5 red blood cell units are required in OLT.

Hypercoagulability Is Most Prevalent Early after Injury and in Female Patients

BACKGROUND

Hypercoagulability after injury is a major source of morbidity and mortality. Recent studies indicate that there is a gender-specific risk in trauma patients. This study was performed to determine the course of coagulation after injury and to determine whether there is a gender difference. We hypothesized that hypercoagulability would occur early after injury and that there would be no difference between men and women.

METHODS

This was a prospective cohort study. Inclusion criteria were admission to the intensive care unit, Injury Severity Score > 4, and the ability to obtain consent from the patient or a relative. A Thrombelastograph (TEG) analysis was performed and routine coagulation parameters and thrombin-antithrombin complexes were measured within 24 hours of injury and then daily for 4 days.

RESULTS

Sixty-five patients met criteria for entry into the study. Their mean age was 42 +/- 17 years and their mean Injury Severity Score was 23 +/- 12. Forty patients (62%) were men. The prevalence of a hypercoagulable state by TEG was 62% on day 1 and 26% on day 4 (p < 0.01). Women were significantly more hypercoagulable on day 1 than men as measured by the time to onset of clotting (women, 2.9 +/- 0.7 minutes; men, 3.9 +/- 1.5 minutes; p < 0.01; normal, 3.7-8.3 minutes). Mean platelet counts, international normalized ratios, and partial thromboplastin times were within normal limits throughout the study. Thrombin activation as measured by thrombin-antithrombin complexes decreased from 34 +/- 15 microg/L on day 1 to 18 +/- 8 microg/L (p < 0.01) on day 4, consistent with the prevalence of hypercoagulability by TEG.

CONCLUSION

Hypercoagulability after injury is most prevalent during the first 24 hours. Women are more hypercoagulable than men early after injury. The TEG is more sensitive than routine coagulation assays for the detection of a hypercoagulable state.

Anesthesia for liver transplant surgery

Liver transplantation offers patients with liver disease an optimal chance for long-term survival. Current indications, preoperative assessment, patient selection, intraoperative anesthetic management and outcomes are described. The management of special situations, including retransplantation, pediatric transplantation, and fulminant hepatic failure are also reviewed. The success of liver transplantation has led to increased demand. This demand, coupled with a nonexpanding supply of deceased donor organs, has resulted in a shortage of grafts and prolonged waiting times. Novel solutions using segmental liver grafts from living donors, and the challenges associated with this approach, are discussed.

Antifibrinolytics in orthotopic liver transplantation: current status and controversies

This article reviews the current status and controversies of the 3 commonly used antifibrinolytics-epsilon-aminocaproic acid, tranexamic acid and aprotinin-during liver transplantation. There is no general consensus on how, when or which antifibrinolytics should be used in liver transplantation. Although these drugs appear to reduce blood loss and decrease transfusion requirements during liver transplantation, their use is not supported uniformly in clinical trials. Aprotinin has been studied more extensively in clinical trials and appear to offer more advantages compared to two other antifibrinolytics. Because of the diverse population of liver transplant recipients and the potential adverse effects of antifibrinolytics, especially life-threatening thromboembolism, careful patient selection and close monitoring is prudent. Further studies addressing the risks and benefits of antifibrinolytics in the setting of liver transplantation are warranted.

Intraoperative blood transfusion requirement is the main determinant of early surgical re-intervention after orthotopic liver transplantation

Liver transplantation is the treatment of choice in selected patients with end-stage liver disease. Postoperative complications often require surgical re-intervention. This study is a retrospective single-centre study to assess the incidence and type of surgical re-intervention during the in-hospital period after liver transplantation and to identify predictors of this re-intervention. From 1994 to 2002, 231 consecutive adult liver transplantations were performed. Re-intervention was classified as biliary, vascular, bleeding, septicaemia, re-transplantation or as miscellaneous. One hundred and thirty-nine surgical re-interventions were performed in 79 of 231 patients (34%). Septicaemia (44%) and bleeding (27%) were the most frequent indications for re-intervention, followed by biliary (10%) re-intervention. Vascular re-intervention, re-transplantation, and re-intervention for miscellaneous reasons, were performed in 7% each. Of all analysed variables (gender, age, diagnosis, acute liver failure, Child-Pugh classification, Karnofsky score, previous abdominal surgery, creatinine clearance, prothrombin time, anti-thrombin, platelet count, surgical technique, cold ischaemia time, warm ischaemia time, functional anhepatic time, anatomic anhepatic time, revascularisation time, year of transplantation, aprotinin administration, transfused platelet concentrate, and red blood cell transfusion requirements), only the number of transfused red blood cell concentrates (RBCs) was identified as a predictor of surgical re-intervention. Median RBC transfusion requirement during liver transplantation was 2.9 l (range 0-18.8 l) in the re-intervention group compared with 1.5 l (range 0-13.4 l) in the non-re-intervention group (P<0.001). This study revealed intraoperative blood loss as the main determinant of early surgical re-intervention after liver transplantation and emphasises the need for further attempts to control blood loss during liver transplantation.

Intraoperative blood transfusion requirement is the main determinant of early surgical re-intervention after orthotopic liver transplantation

Liver transplantation is the treatment of choice in selected patients with end-stage liver disease. Postoperative complications often require surgical re-intervention. This study is a retrospective single-centre study to assess the incidence and type of surgical re-intervention during the in-hospital period after liver transplantation and to identify predictors of this re-intervention. From 1994 to 2002, 231 consecutive adult liver transplantations were performed. Re-intervention was classified as biliary, vascular, bleeding, septicaemia, re-transplantation or as miscellaneous. One hundred and thirty-nine surgical re-interventions were performed in 79 of 231 patients (34%). Septicaemia (44%) and bleeding (27%) were the most frequent indications for re-intervention, followed by biliary (10%) re-intervention. Vascular re-intervention, re-transplantation, and re-intervention for miscellaneous reasons, were performed in 7% each. Of all analysed variables (gender, age, diagnosis, acute liver failure, Child-Pugh classification, Karnofsky score, previous abdominal surgery, creatinine clearance, prothrombin time, anti-thrombin, platelet count, surgical technique, cold ischaemia time, warm ischaemia time, functional anhepatic time, anatomic anhepatic time, revascularisation time, year of transplantation, aprotinin administration, transfused platelet concentrate, and red blood cell transfusion requirements), only the number of transfused red blood cell concentrates (RBCs) was identified as a predictor of surgical re-intervention. Median RBC transfusion requirement during liver transplantation was 2.9 l (range 0-18.8 l) in the re-intervention group compared with 1.5 l (range 0-13.4 l) in the non-re-intervention group (P<0.001). This study revealed intraoperative blood loss as the main determinant of early surgical re-intervention after liver transplantation and emphasises the need for further attempts to control blood loss during liver transplantation.

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.