Randomized controlled trial of desmopressin plus terlipressin vs. terlipressin alone for the treatment of acute variceal hemorrhage in cirrhotic patients: a multicenter, double-blind study. New Italian Endoscopic Club

The evolving knowledge on primary hemostasis in patients with cirrhosis: A comprehensive review

Patients with cirrhosis develop complex alterations in primary hemostasis that include both hypocoagulable and hypercoagulable features. This includes thrombocytopenia, multiple alterations of platelet function, and increased plasma levels of von Willebrand factor. Contrary to the historical view that platelet dysfunction in cirrhosis might be responsible for an increased bleeding tendency, the current theory posits a rebalanced hemostasis in patients with cirrhosis. Severe thrombocytopenia is not indicative of the bleeding risk in patients undergoing invasive procedures and does not dictate per se the need for pre-procedural prophylaxis. A more comprehensive and individualized risk assessment should combine hemostatic impairment, the severity of decompensation and systemic inflammation, and the presence of additional factors that may impair platelet function, such as acute kidney injury and bacterial infections. Although there are multiple, complex alterations of platelet function in cirrhosis, their net effect is not yet fully understood. More investigations evaluating the association between alterations of platelet function and bleeding/thrombosis may improve risk stratification in patients with decompensated cirrhosis. Besides hemostasis, the assessment of von Willebrand factor Ag and ADP-induced, whole-blood platelet aggregation normalized by platelet count (VITRO score and PLT ratio) are promising biomarkers to predict the risk of hepatic decompensation and survival in both compensated and decompensated patients. Further investigations into the in vivo interplay between platelets, circulating blood elements, and endothelial cells may help advance our understanding of cirrhotic coagulopathy. Here, we review the complex changes in platelets and primary hemostasis in cirrhosis and their potential clinical implications.

Desmopressin as a hemostatic and blood sparing agent in bleeding disorders

Intranasal, subcutaneous, or intravenous desmopressin can be utilized to release von Willebrand Factor and Factor VIII into circulation, enhance platelet adhesion and shorten bleeding time. Due to these properties, desmopressin can be effective in controlling bleeding in mild hemophilia A, certain subtypes of von Willebrand disease and in acute bleeding from uremia, end stage renal disease, and liver disease. Its use, however, can be complicated by hyponatremia and rarely arterial thrombotic events. While desmopressin has also been used as a prophylactic blood sparing agent in orthopedic, renal, and hepatic procedures, clinical studies have shown limited benefit in these settings. The purpose of this article is to review the evidence for desmopressin in primary hematologic disorders, discuss its mechanism of action and evaluate its utility as a hemostatic and blood sparing product in various bleeding conditions.

Recent Advances in the Management of Acute Variceal Hemorrhage

Gastrointestinal bleeding is one of the most relevant causes of death in patients with cirrhosis and clinically significant portal hypertension, with gastroesophageal varices being the most frequent source of hemorrhage. Despite survival has improved thanks to the standardization on medical treatment aiming to decrease portal hypertension and prevent infections, mortality remains significant. In this review, our goal is to discuss the most recent advances in the management of esophageal variceal hemorrhage in cirrhosis with specific attention to the treatment algorithms involving the use of indirect measurement of portal pressure (HVPG) and transjugular intrahepatic portosystemic shunt (TIPS), which aim to further reduce mortality in high-risk patients after acute variceal hemorrhage and in the setting of secondary prophylaxis.

Treatment for bleeding oesophageal varices in people with decompensated liver cirrhosis: a network meta-analysis

BACKGROUND

Approximately 40% to 95% of people with liver cirrhosis have oesophageal varices. About 15% to 20% of oesophageal varices bleed within about one to three years after diagnosis. Several different treatments are available, including, among others, endoscopic sclerotherapy, variceal band ligation, somatostatin analogues, vasopressin analogues, and balloon tamponade. However, there is uncertainty surrounding the individual and relative benefits and harms of these treatments.

OBJECTIVES

To compare the benefits and harms of different initial treatments for variceal bleeding from oesophageal varices in adults with decompensated liver cirrhosis, through a network meta-analysis; and to generate rankings of the different treatments for acute bleeding oesophageal varices, according to their benefits and harms.

SEARCH METHODS

We searched CENTRAL, MEDLINE, Embase, Science Citation Index Expanded, World Health Organization International Clinical Trials Registry Platform, and trials registers until 17 December 2019, to identify randomised clinical trials (RCTs) in people with cirrhosis and acute bleeding from oesophageal varices.

SELECTION CRITERIA

We included only RCTs (irrespective of language, blinding, or status) in adults with cirrhosis and acutely bleeding oesophageal varices. We excluded RCTs in which participants had bleeding only from gastric varices, those who failed previous treatment (refractory bleeding), those in whom initial haemostasis was achieved before inclusion into the trial, and those who had previously undergone liver transplantation.

DATA COLLECTION AND ANALYSIS

We performed a network meta-analysis with OpenBUGS software, using Bayesian methods, and calculated the differences in treatments using odds ratios (OR) and rate ratios with 95% credible intervals (CrI) based on an available-case analysis, according to National Institute of Health and Care Excellence Decision Support Unit guidance. We performed also the direct comparisons from RCTs using the same codes and the same technical details.

MAIN RESULTS

We included a total of 52 RCTs (4580 participants) in the review. Forty-eight trials (4042 participants) were included in one or more comparisons in the review. The trials that provided the information included people with cirrhosis due to varied aetiologies and those with and without a previous history of bleeding. We included outcomes assessed up to six weeks. All trials were at high risk of bias. A total of 19 interventions were compared in the trials (sclerotherapy, somatostatin analogues, vasopressin analogues, sclerotherapy plus somatostatin analogues, variceal band ligation, balloon tamponade, somatostatin analogues plus variceal band ligation, nitrates plus vasopressin analogues, no active intervention, sclerotherapy plus variceal band ligation, balloon tamponade plus sclerotherapy, balloon tamponade plus somatostatin analogues, balloon tamponade plus vasopressin analogues, variceal band ligation plus vasopressin analogues, balloon tamponade plus nitrates plus vasopressin analogues, balloon tamponade plus variceal band ligation, portocaval shunt, sclerotherapy plus transjugular intrahepatic portosystemic shunt (TIPS), and sclerotherapy plus vasopressin analogues). We have reported the effect estimates for the primary and secondary outcomes when there was evidence of differences between the interventions against the reference treatment of sclerotherapy, but reported the other results of the primary and secondary outcomes versus the reference treatment of sclerotherapy without the effect estimates when there was no evidence of differences in order to provide a concise summary of the results. Overall, 15.8% of the trial participants who received the reference treatment of sclerotherapy (chosen because this was the commonest treatment compared in the trials) died during the follow-up periods, which ranged from three days to six weeks. Based on moderate-certainty evidence, somatostatin analogues alone had higher mortality than sclerotherapy (OR 1.57, 95% CrI 1.04 to 2.41; network estimate; direct comparison: 4 trials; 353 participants) and vasopressin analogues alone had higher mortality than sclerotherapy (OR 1.70, 95% CrI 1.13 to 2.62; network estimate; direct comparison: 2 trials; 438 participants). None of the trials reported health-related quality of life. Based on low-certainty evidence, a higher proportion of people receiving balloon tamponade plus sclerotherapy had more serious adverse events than those receiving only sclerotherapy (OR 4.23, 95% CrI 1.22 to 17.80; direct estimate; 1 RCT; 60 participants). Based on moderate-certainty evidence, people receiving vasopressin analogues alone and those receiving variceal band ligation had fewer adverse events than those receiving only sclerotherapy (rate ratio 0.59, 95% CrI 0.35 to 0.96; network estimate; direct comparison: 1 RCT; 219 participants; and rate ratio 0.40, 95% CrI 0.21 to 0.74; network estimate; direct comparison: 1 RCT; 77 participants; respectively). Based on low-certainty evidence, the proportion of people who developed symptomatic rebleed was smaller in people who received sclerotherapy plus somatostatin analogues than those receiving only sclerotherapy (OR 0.21, 95% CrI 0.03 to 0.94; direct estimate; 1 RCT; 105 participants). The evidence suggests considerable uncertainty about the effect of the interventions in the remaining comparisons where sclerotherapy was the control intervention.

AUTHORS' CONCLUSIONS

Based on moderate-certainty evidence, somatostatin analogues alone and vasopressin analogues alone (with supportive therapy) probably result in increased mortality, compared to endoscopic sclerotherapy. Based on moderate-certainty evidence, vasopressin analogues alone and band ligation alone probably result in fewer adverse events compared to endoscopic sclerotherapy. Based on low-certainty evidence, balloon tamponade plus sclerotherapy may result in large increases in serious adverse events compared to sclerotherapy. Based on low-certainty evidence, sclerotherapy plus somatostatin analogues may result in large decreases in symptomatic rebleed compared to sclerotherapy. In the remaining comparisons, the evidence indicates considerable uncertainty about the effects of the interventions, compared to sclerotherapy.

Management of acute variceal hemorrhage

Gastrointestinal bleeding is one of the major causes of death in patients with cirrhosis, and gastroesophageal varices represent the main source of hemorrhage. Even though in the last decades survival has been improved because of the widespread adoption of effective treatments and optimization of general medical care, mortality is still significantly high, and decompensated patients pose a complex challenge requiring a multidisciplinary approach that is crucial to improve survival. The aims of this commentary are to review the most recent advances in the management of esophageal variceal bleeding and to highlight useful information to aid hepatologists in clinical practice.

Coagulopathy Before and After Liver Transplantation: From the Hepatic to the Systemic Circulatory Systems

The hemostatic environment in patients with cirrhosis is a delicate balance between prohemostatic and antihemostatic factors. There is a lack of effective laboratory measures of the hemostatic system in patients with cirrhosis. Many are predisposed to pulmonary embolus, deep vein thrombosis, and portal vein thrombosis in the pretransplantation setting. This pretransplantation hypercoagulable milieu seems to extend for at least several months post-transplantation. Patients with nonalcoholic fatty liver disease, inherited thrombophilia, portal hypertension in the absence of cirrhosis, and hepatocellular carcinoma often require individualized approach to anticoagulation. Early reports suggest a potential role for low-molecular-weight heparins and direct-acting anticoagulants.

Hemostatic balance in patients with liver cirrhosis: Report of a consensus conference

Patients with cirrhosis present with hemostatic alterations secondary to reduced availability of pro-coagulant and anti-coagulant factors. The net effect of these changes is a rebalanced hemostatic system. The Italian Association of the Study of the Liver (AISF) and the Italian Society of Internal Medicine (SIMI) promoted a consensus conference on the hemostatic balance in patients with cirrhosis. The consensus process started with the review of the literature by a scientific board of experts and ended with a formal consensus meeting in Rome in December 2014. The statements were graded according to quality of evidence and strength of recommendations, and approved by an independent jury. The statements presented here highlight strengths and weaknesses of current laboratory tests to assess bleeding and thrombotic risk in cirrhotic patients, the pathophysiology of hemostatic perturbations in this condition, and outline the optimal management of bleeding and thrombosis in patients with liver cirrhosis.

Hemostasis abnormalities in cirrhosis

PURPOSE OF REVIEW

The long-lasting paradigm of cirrhosis as the epitome of the acquired hemorrhagic coagulopathies has been challenged by evidence from the literature. This article reviews the mechanisms responsible for regulation of hemostasis in the light of the evidence provided within the last few years.

RECENT FINDINGS

Numerous studies have evaluated the mechanisms responsible for regulation of primary hemostasis, coagulation and fibrinolysis which were thought to be severely impaired in cirrhosis and were considered responsible for the abnormalities of the prothrombin time and the bleeding events observed in these patients. These evaluations have been performed by newer laboratory tests under experimental conditions that mimic closely the condition operating in vivo.

SUMMARY

Cirrhosis presents with thrombocytopenia and decreased levels of both pro- and anticoagulants. Notable exceptions are factor VIII and von Willebrand factor (VWF) which are increased. Thrombocytopenia (unless very severe) is no longer considered a bleeding risk as platelets from cirrhosis display normal adhesiveness in a flowing system that is mainly supported by the increased levels of VWF. Patients with cirrhosis generate normal amounts of thrombin that is mainly supported by the concomitant deficiency of pro- and anticoagulants that restores the balance between these two opposing drivers.

Bleeding complications in critically ill patients with liver cirrhosis

BACKGROUND/AIMS

Patients with liver cirrhosis (LC) are at risk for critical events leading to Intensive Care Unit (ICU) admission. Coagulopathy in cirrhotic patients is complex and can lead to bleeding as well as thrombosis. The aim of this study was to investigate bleeding complications in critically ill patients with LC admitted to a medical ICU (MICU).

METHODS

All adult patients admitted to our MICU with a diagnosis of LC from January 2006 to December 2012 were retrospectively assessed. Patients with major bleeding at the time of MICU admission were excluded from the analysis.

RESULTS

A total of 205 patients were included in the analysis. The median patient age was 62 years, and 69.3% of the patients were male. The most common reason for MICU admission was acute respiratory failure (45.4%), followed by sepsis (27.3%). Major bleeding occurred in 25 patients (12.2%). The gastrointestinal tract was the most common site of bleeding (64%), followed by the respiratory tract (20%). In a multivariate analysis, a low platelet count at MICU admission (odds ratio [OR], 0.98; 95% confidence interval [CI], 0.97 to 0.99) and sepsis (OR, 8.35; 95% CI, 1.04 to 67.05) were independent risk factors for major bleeding. The ICU fatality rate was significantly greater among patients with major bleeding (84.0% vs. 58.9%, respectively; p = 0.015).

CONCLUSIONS

Major bleeding occurred in 12.2% of critically ill cirrhotic patients admitted to the MICU. A low platelet count at MICU admission and sepsis were associated with an increased risk of major bleeding during the MICU stay. Further study is needed to better understand hemostasis in critically ill patients with LC.

Infusion of DDAVP does not improve primary hemostasis in patients with cirrhosis

BACKGROUND & AIMS

Cirrhosis frequently affects multiple components of hemostasis. Reversal of the coagulopathy of these patients is frequently required in case of bleeding episodes, or as prophylaxis before invasive procedures. Although 1-deamino-8-D-arginine vasopressin (DDAVP) is widely used as a pro-hemostatic agent in patients with cirrhosis, it is unclear whether DDAVP truly enhances hemostasis in these patients. Here we investigated the hemostatic effects of a single bolus of DDAVP in patients with cirrhosis.

METHODS

Ten patients with cirrhosis (child B or C) and ten patients with mild haemophilia A received an intravenous single bolus of 0.3 microgram/kg DDAVP. Plasma was collected prior to and at 1, 3, 6, and 24 h after DDAVP administration. Levels of Von Willebrand factor (VWF), VWF propeptide, factor VIII (FVIII), and ADAMTS13 were measured in all plasma samples, whereas VWF multimers and functional VWF-dependent platelet adhesion were determined in the samples pre- and 1 h after DDAVP administration.

RESULTS

Following DDAVP administration, VWF, FVIII, and VWF propeptide levels increased in patients with haemophilia, while patients with cirrhosis only showed an increase in VWF propeptide and FVIII levels. High molecular weight VWF multimers and VWF-dependent platelet adhesion increased in patients with haemophilia one hour after DDAVP administration, but did not change in the patients with cirrhosis. Levels of ADAMTS13 were unaffected in both patient groups after DDAVP.

CONCLUSION

The lack of relevant effects of DDAVP on laboratory indices of primary hemostasis in patients with cirrhosis is in line with previous clinical study results in these patients.

Managing complications in cirrhotic patients

Liver cirrhosis is a serious and potentially life-threatening condition. This life-threatening condition usually arises from complications of cirrhosis. While variceal bleeding is the most acute and probably best studied, several other complications of liver cirrhosis are more insidious in their onset but nevertheless more important for the long-term management and outcome of these patients. This review summarizes the topics discussed during the UEG-EASL Hepatology postgraduate course of the United European Gastroenterology Week 2013 and discusses emergency surgical conditions in cirrhotic patients, the management of hepatic encephalopathy, ascites and hepatorenal syndrome, coagulation disorders, and liver cancer.

The coagulation system in patients with end-stage liver disease

In patients with cirrhosis, routine laboratory tests for primary hemostasis and coagulation usually show anomalies that are associated with excess bleeding in other settings, in particular low platelet counts and prolonged prothrombin time. However, under conditions similar to those in vivo, primary hemostasis and thrombin production do not appear to be decreased in patients with cirrhosis, particularly when the platelet count is above 75,000/μl. Furthermore, there is laboratory and epidemiological evidence of a mild procoagulant and prothrombotic state in patients with cirrhosis. Bleeding is mainly because of portal hypertension rather than defective hemostasis. There is some evidence that anticoagulation therapy is not associated with an excess of severe bleeding and that it could improve the outcome in patients without portal vein thrombosis. At present, there is no clear evidence that portal vein thrombosis is responsible for the progression of liver disease and that anticoagulation therapy would improve the outcome of patients with portal vein thrombosis.

Procoagulant therapeutics in liver disease: a critique and clinical rationale

The complex nature of haemostasis in patients with liver disease can result in bleeding and/or thrombosis. These opposing outcomes, which have multiple contributing factors, can pose diagnostic and therapeutic dilemmas for physicians. With the high rate of haemorrhagic complications in patients with cirrhosis, we examine the various procoagulants available for use in this population. In this Review, we describe the clinical and current rationale for using each of the currently available procoagulants-vitamin K, fresh frozen plasma (FFP), cryoprecipitate, platelets, recombinant factor VIIa (rFVIIa), antifibrinolytics, prothrombin concentrate complexes (PCC), desmopressin and red blood cells. By examining the evidence and use of these agents in liver disease, we provide a framework for targeted, goal-directed therapy with procoagulants.

Update of endoscopy in liver disease: More than just treating varices

The management of complications in liver disease is often complex and challenging. Endoscopy has undergone a period of rapid expansion with numerous novel and specialized endoscopic modalities that are of increasing value in the investigation and management of the patient with liver disease. In this review, relevant literature search and expert opinions have been used to provide a brief overview and update of the current endoscopic management of patients with liver disease and portal hypertension. The main areas covered are safety of endoscopy in patients with liver disease, the use of standard endoscopy for the treatment of varices and the role of new endoscopic modalities such as endoscopic ultrasound, esophageal capsule, argon plasma coagulation, spyglass and endomicroscopy in the investigation and treatment of liver-related gastrointestinal and biliary pathology. It is clear that the role of the endoscopy in liver disease is well beyond that of just treating varices. As the technology in endoscopy expands, so does the role of the endoscopist in liver disease.

Patients with liver cirrhosis suffer from primary haemostatic defects? Fact or fiction?

Patients with cirrhosis can have abnormalities in laboratory tests reflecting changes in primary haemostasis, including bleeding time, platelet function tests, markers of platelet activation, and platelet count. Such changes have been considered particularly relevant in the bleeding complications that occur in cirrhosis. However, several studies have shown that routine diagnostic tests, such as platelet count, bleeding time, PFA-100, thromboelastography are not clinically useful to stratify bleeding risk in patients with cirrhosis. Moreover, treatments used to increase platelet count or to modulate platelet function could potentially do harm. Consequently the optimal management of bleeding complications is still a matter of discussion. Moreover, in the last two decades there has been an increased recognition that not only bleeding but also thrombosis complicates the clinical course of cirrhosis. Thus, we performed a literature search looking at publications studying both qualitative and quantitative aspects of platelet function to verify which primary haemostasis defects occur in cirrhosis. In addition, we evaluated the contribution of qualitative and quantitative aspects of platelet function to the clinical outcome in cirrhosis and their therapeutic management according to the data available in the literature. From the detailed analysis of the literature, it appears clear that primary haemostasis may not be defective in cirrhosis, and a low platelet count should not necessarily be considered as an automatic index of an increased risk of bleeding. Conversely, caution should be observed in patients with severe thrombocytopenia where its correction is advised if bleeding occurs and before invasive diagnostic and therapeutic procedures.

Hemostasis and thrombosis in patients with liver disease: the ups and downs

Patients with chronic or acute liver failure frequently show profound abnormalities in their hemostatic system. Whereas routine laboratory tests of hemostasis suggest these hemostatic alterations result in a bleeding diathesis, accumulating evidence from both clinical and laboratory studies suggest that the situation is more complex. The average patient with liver failure may be in hemostatic balance despite prolonged routine coagulation tests, since both pro- and antihemostatic factors are affected, the latter of which are not well reflected in routine coagulation testing. However, this balance may easily tip towards a hypo- or hypercoagulable situation. Indeed, patients with liver disease may encounter both hemostasis-related bleeding episodes as well as thrombotic events. During the 3rd International Symposium on Coagulopathy and Liver disease, held in Groningen, The Netherlands (18-19 September 2009), a multidisciplinary panel of experts critically reviewed the current data concerning pathophysiology and clinical consequences of hemostatic disorders in patients with liver disease. Highlights of this symposium are summarized in this review.

Acute esophageal variceal bleeding: Current strategies and new perspectives

Management of acute variceal bleeding has greatly improved over recent years. Available data indicates that general management of the bleeding cirrhotic patient by an experienced multidisciplinary team plays a major role in the final outcome of this complication. It is currently recommended to combine pharmacological and endoscopic therapies for the initial treatment of the acute bleeding. Vasoactive drugs (preferable somatostatin or terlipressin) should be started as soon as a variceal bleeding is suspected (ideally during transfer to hospital) and maintained afterwards for 2-5 d. After stabilizing the patient with cautious fluid and blood support, an emergency diagnostic endoscopy should be done and, as soon as a skilled endoscopist is available, an endoscopic variceal treatment (ligation as first choice, sclerotherapy if endoscopic variceal ligation not feasible) should be performed. Antibiotic prophylaxis must be regarded as an integral part of the treatment of acute variceal bleeding and should be started at admission and maintained for at least 7 d. In case of failure to control the acute bleeding, rescue therapies should be immediately started. Shunt therapies (especially transjugular intrahepatic portosystemic shunt) are very effective at controlling treatment failures after an acute variceal bleeding. Therapeutic developments and increasing knowledge in the prognosis of this complication may allow optimization of the management strategy by adapting the different treatments to the expected risk of complications for each patient in the near future. Theoretically, this approach would allow the initiation of early aggressive treatments in high-risk patients and spare low-risk individuals unnecessary procedures. Current research efforts will hopefully clarify this hypothesis and help to further improve the outcomes of the severe complication of cirrhosis.

The coagulopathy of chronic liver disease: is there a causal relationship with bleeding? Yes

Variceal hemorrhage is a major cause of death in patients with cirrhosis. Much still could be performed in clinical practice to reduce the risk for bleeding in cirrhotic patients and accurate predictive rules should be provided for early recognition of high-risk patients. Liver cirrhosis patients present a complex hemostatic dysfunction with prolongation of bleeding time, chronic coagulation activation, and secondary hyperfibrinolysis. Therefore, liver failure determines an acquired coagulopathy that has been considered to be one potential underlying mechanism of bleeding. Endotoxemia may play a pivotal role in activating clotting system in portal and systemic circulation and it could represent a common mechanism accounting for portal vein thrombosis, systemic hyperfibrinolysis and eventually gastrointestinal bleeding. Nevertheless, clinical trials should also be planned to investigate the causal relationship between acquired coagulopathy and bleeding in patients with chronic liver disease.

Abnormalities of hemostasis and bleeding in chronic liver disease: the paradigm is challenged

Chronic liver disease is characterized by a global hemostatic defect including platelet-vessel wall interaction (primary hemostasis), coagulation and fibrinolysis that may cause abnormalities of the relevant laboratory tests. The causal relationship between abnormal tests and bleeding has been widely accepted, despite the fact that abnormal tests are poorly associated with the timing and incidence of actual bleeding. In this article, we review recent evidence from the literature that disputes the above paradigm, and opens new venues for laboratory/clinical research and patient management in this field.

The platelet and platelet function testing in liver disease

Patients who have liver disease commonly present with alterations in platelet number and function. Recent data have questioned the contribution of these changes to bleeding complications in these patients. Modern tests of platelet function revealed compensatory mechanisms for the decreased platelet number and function, the most prominent compensatory mechanism being substantially elevated levels of the adhesive protein von Willebrand's factor. Consequently, standard diagnostic tests of platelet functions seem to be of little use to predict bleeding complication in patients who have liver disease. This article outlines the role of platelet abnormalities and possibilities for platelet function testing in patients who have liver disease.

Acute variceal bleeding: pharmacological treatment and primary/secondary prophylaxis

Variceal bleeding is one of the most severe complications of portal hypertension related to liver cirrhosis. Primary prophylaxis is considered mandatory in patients with cirrhosis and high-risk oesophageal varices, and once varices have bled, every effort should be made to arrest the haemorrhage and prevent further bleeding episodes. In acute variceal bleeding, vasoactive drugs that lower portal pressure should be started even before endoscopy, and should be maintained for up to 5 days. The choice of vasoactive drug should be made according to local resources. Terlipressin, somatostatin and octreotide can be used; vasopressin plus transdermal nitroglycerin may be used if no other drug is available. In variceal bleeding, antibiotic therapy is also mandatory. In primary and secondary prophylaxis, beta-blockers are the mainstay of therapy. In secondary prophylaxis (but not in primary prophylaxis) these drugs can be combined with organic nitrates.

The use of desmopressin as a hemostatic agent: a concise review

Desmopressin, a synthetic derivative of the antidiuretic hormone vasopressin, is the treatment of choice for most patients with von Willebrand disease and mild hemophilia A. Moreover, the compound has been shown to be useful in a variety of inherited and acquired hemorrhagic conditions, including some congenital platelet function defects, chronic liver disease, uremia, and hemostatic defects induced by the therapeutic use of antithrombotic drugs such as aspirin and ticlopidine. Finally, desmopressin has been used as a blood saving agent in patients undergoing operations characterized by large blood loss and transfusion requirements, but studies suggest that this is not as effective as other methods. This review briefly summarizes the current clinical indications on the use of desmopressin as a hemostatic agent.

New insights into the coagulopathy of liver disease and liver transplantation

The liver is an essential player in the pathway of coagulation in both primary and secondary haemostasis. Only von Willebrand factor is not synthetised by the liver, thus liver failure is associated with impairment of coagulation. However, recently it has been shown that the delicate balance between pro and antithrombotic factors synthetised by the liver might be reset to a lower level in patients with chronic liver disease. Therefore, these patients might not be really anticoagulated in stable condition and bleeding may be caused only when additional factors, such as infections, supervene. Portal hypertension plays an important role in coagulopathy in liver disease, reducing the number of circulating platelets, but platelet function and secretion of thrombopoietin have been also shown to be impaired in patients with liver disease. Vitamin K deficiency may coexist, so that abnormal clotting factors are produced due to lack of gamma carboxylation. Moreover during liver failure, there is a reduced capacity to clear activated haemostatic proteins and protein inhibitor complexes from the circulation. Usually therapy for coagulation disorders in liver disease is needed only during bleeding or before invasive procedures. When end stage liver disease occurs, liver transplantation is the only treatment available, which can restore normal haemostasis, and correct genetic clotting defects, such as haemophilia or factor V Leiden mutation. During liver transplantation haemorrage may occur due to the pre-existing hypocoagulable state, the collateral circulation caused by portal hypertension and increased fibrinolysis which occurs during this surgery.

Coagulation disorders and hemostasis in liver disease: pathophysiology and critical assessment of current management

Normal coagulation has classically been conceptualized as a Y-shaped pathway, with distinct "intrinsic" and "extrinsic" components initiated by factor XII or factor VIIa/tissue factor, respectively, and converging in a "common" pathway at the level of the FXa/FVa (prothrombinase) complex. Until recently, the lack of an established alternative concept of hemostasis has meant that most physicians view the "cascade" as a model of physiology. This view has been reinforced by the fact that screening coagulation tests (APTT, prothrombin time--INR) are often used as though they are generally predictive of clinical bleeding. The shortcomings of this older model of normal coagulation are nowhere more apparent than in its clinical application to the complex coagulation disorders of acute and chronic liver disease. In this condition, the clotting cascade is heavily influenced by numerous currents and counter-currents resulting in a mixture of pro- and anticoagulant forces that are themselves further subject to change with altered physiological stress such as super-imposed infection or renal failure. This report represents a summary of a recent multidisciplinary symposium held in Charlottesville, VA. We present an overview of the coagulation system in liver disease with emphasis on the limitations of the current clinical paradigm and the need for a critical re-evaluation of the current tenets governing clinical practice. With the realization that there is often limited or conflicting data, we have attempted to represent diverse opinion and experience from the perspectives of both hepatology and hematology beginning with a brief update on the physiology of normal coagulation.

Hemostatic defects in end stage liver disease

End stage liver disease results in a complex and variably severe failure of hemostasis that predisposes to abnormal bleeding. The diverse spectrum of hemostatic defects includes impaired synthesis of clotting factors, excessive fibrinolysis, disseminated intravascular coagulation, thrombocytopenia, and platelet dysfunction. Hemostasis screening tests are used to assess disease severity and monitor the response to therapy. Correction of hemostatic defects is required in patients who are actively bleeding or require invasive procedures. Fresh frozen plasma, cryoprecipitate, and platelet transfusion remain the mainstays of therapy until larger trials confirm the safety and efficacy of recombinant factor VIIa in this population.

Recombinant FVIIa in children with liver disease

INTRODUCTION

The aim of this study was to investigate the clinical and biochemical effects of recombinant activated factor VII (rFVIIa) in the treatment of bleeding in children with liver disease.

PATIENTS AND METHODS

12 patients (0.3-15.9 years) with chronic liver disease were included. The indication for treatment was life threatening bleeding and failing conventional therapy (group A, 7 patients) or as prophylaxis before invasive procedures (group B, 6 patients). One patient received treatment on both indications. rFVIIa was administered as intravenous bolus doses of 34-163 microg/kg (median 66 mug/kg) alone or in combination with packed red cells and/or octreotide and/or fresh frozen plasma. The follow-up included repeated INR and haemoglobin measurements as well as clinical evaluation.

RESULTS

In group A rFVIIa was given on 22 occasions and bleeding decreased, was unchanged, increased or could not be evaluated on 10, 7, 2 and 3 occasions respectively. On 14 occasions rFVIIa and octreotide were administered simultaneously, in 8 of those bleeding decreased. In group B no bleeding complication was seen, interpreted as a positive effect. One thrombotic event was suspected but could not be verified by computerized tomography.

CONCLUSIONS

rFVIIa may be beneficial in the short-term management of life threatening bleeding in some children with liver disease. This effect may be further enhanced with the additional use of octreotide. Furthermore, rFVIIa is useful for prophylaxis at invasive procedures, even without additional treatment with fresh frozen plasma. The possible risk of portal vein thrombosis needs to be considered.

Systematic review: terlipressin in acute oesophageal variceal haemorrhage

BACKGROUND

Controversy exists surrounding pharmacological therapy in acute variceal bleeding.

AIM

To determine the efficacy and safety of terlipressin.

METHODS

Randomized trials were identified and duplicate, independent, review identified 20 randomized trials involving 1609 patients that compared terlipressin with placebo, balloon tamponade, endoscopic treatment, octreotide, somatostatin or vasopressin for treatment of acute oesophageal variceal haemorrhage.

RESULTS

Meta-analysis showed that compared to placebo, terlipressin reduced mortality (relative risk 0.66, 95% CI 0.49-0.88), failure of haemostasis (relative risk 0.63, 95% CI 0.45-0.89) and the number of emergency procedures per patient required for uncontrolled bleeding or rebleeding (relative risk 0.72, 95% CI 0.55-0.93). When used as an adjuvant to endoscopic sclerotherapy, terlipressin reduced failure of haemostasis (relative risk 0.75, 95% CI 0.58-0.96), and had an effect on reducing mortality that approached statistical significance (relative risk 0.74, 95% CI 0.53-1.04). No significant difference was demonstrated between terlipressin and endoscopic sclerotherapy, balloon tamponade, somatostatin or vasopressin. Haemostasis was achieved more frequently with octreotide compared to terlipressin (relative risk 1.62, 95% CI 1.05-2.50), but this result was based on unblinded studies. Adverse events were similar between terlipressin and the other comparison groups except for vasopressin, which caused more withdrawals due to adverse events.

CONCLUSIONS

Terlipressin is a safe and effective treatment for acute oesophageal variceal bleeding, with or without adjuvant endoscopic sclerotherapy. Terlipressin appears to reduce mortality in acute oesophageal variceal bleeding compared to placebo, and is the only pharmacological agent shown to do so. Future studies will be required to detect potential mortality differences between terlipressin and other therapeutic approaches.

Terlipressin for acute esophageal variceal hemorrhage

BACKGROUND

Terlipressin (triglycyl lysine vasopressin) is a synthetic analogue of vasopressin, which has been used in the treatment of acute variceal hemorrhage. In contrast to vasopressin, terlipressin can be administered as intermittent injections instead of continuous intravenous infusion and it has a safer adverse reactions profile. However, its effectiveness remains uncertain.

OBJECTIVES

To determine if treatment with terlipressin improves outcome in acute esophageal variceal hemorrhage and is safe.

SEARCH STRATEGY

Randomized clinical trials were identified by searching the following databases: MEDLINE, EMBASE, the Cochrane Controlled Trials Register, the Cochrane Hepato-Biliary Group Controlled Trials Register, Biosis, and Current Contents. The bibliographies of identified publications were checked. Experts in the field and the manufacturers of terlipressin were contacted.

SELECTION CRITERIA

All randomized clinical trials which compared terlipressin with: (a) placebo or no treatment, (b) balloon tamponade, (c) endoscopic treatment, (d) octreotide, (e) somatostatin and (f) vasopressin, in the setting of acute variceal hemorrhage.

DATA COLLECTION AND ANALYSIS

Eligibility, trial quality assessment and data extraction were done independently by two reviewers. The primary outcome measure was mortality. Secondary outcomes were failure of initial hemostasis, rebleeding, procedures required for uncontrolled bleeding or rebleeding, transfusion requirements and length of hospitalization.

MAIN RESULTS

Twenty studies were identified for all the comparison groups, involving 1609 patients. There were seven studies (with 443 patients) comparing terlipressin to placebo, five of which were considered to be high quality studies based on the Jadad scale. The meta-analysis indicates that terlipressin was associated with a statistically significant reduction in all cause mortality compared to placebo (relative risk 0.66, 95% confidence interval 0.49 to 0.88). Three studies (with 302 patients) were identified comparing terlipressin to somatostatin, two of which were high quality studies; only one high quality study (219 patients) comparing terlipressin to endoscopic treatment was identified. Within the limited power provided by these small numbers of patients, no statistically significant difference was demonstrated between terlipressin and either somatostatin or endoscopic treatment in any of the outcomes. For the remaining comparison groups (terlipressin versus balloon tamponade, terlipressin versus octreotide and terlipressin versus vasopressin) only small, low quality studies were identified and no difference was demonstrated in any of the major outcomes. There was no difference between the terlipressin group and any of the comparison groups in the number of adverse events that caused death or withdrawal of medication.

REVIEWER'S CONCLUSIONS

On the basis of a 34% relative risk reduction in mortality, terlipressin should be considered to be effective in the treatment of acute variceal hemorrhage. Further, since no other vasoactive agent has been shown to reduce mortality in single studies or meta-analyses, terlipressin might be the vasoactive agent of choice in acute variceal bleeding.

Splenomegaly, hypersplenism and coagulation abnormalities in liver disease

Splenomegaly is a frequent finding in patients with liver disease. It is usually asymptomatic but may cause hypersplenism. Thrombocytopenia is the most frequent manifestation of hypersplenism and may contribute to portal hypertension related bleeding. A number of therapies are available for treating thrombocytopenia due to hypersplenism including splenectomy, partial splenectomy, partial splenic embolization, TIPS etc. None is entirely satisfactory. Hypersplenism usually improves following liver transplantation. Therapy with cytokines such as thrombopoietin may offer hope for the future. Patients with liver disease also have abnormalities in coagulation. This is not surprising as all coagulation proteins (except for von willebrand factor vWF) and most inhibitors of coagulation are synthesized in the liver. Genetic or acquired abnormalities of coagulation may predispose to thrombosis of the hepatic or portal veins with significant clinical sequelae. An understanding of the mechanisms involved in coagulation and thrombosis is valuable in choosing from the increasing treatment options available. These include clotting factors, haemeostatic drugs and newer therapies such as recombinant factor VIIa. Splenic artery aneurysms are the most common visceral artery aneurysms in man. Rupture is frequently catastrophic. These aneurysms are being increasingly recognized in liver transplant patients and require treatment before or during transplant surgery.

Early administration of terlipressin plus glyceryl trinitrate to control active upper gastrointestinal bleeding in cirrhotic patients

Upper gastrointestinal bleeding (GIB) is a major complication in cirrhotic patients. Endoscopy and oesophageal sclerosis are reference treatments and must be done as soon as possible. However, such treatment is not possible unless the patient is admitted to hospital. In a prospective, randomised, double-blind trial, we compared the efficacy of terlipressin combined with glyceryl trinitrate (TER-GTN), administered as early as possible to 76 patients with cirrhosis who had active GIB (84 bleeding episodes). Infusion was done at the patient's home by the physician on the emergency team (a mobile intensive care unit) if the patient had GIB and a history and clinical signs of cirrhosis. Patients received either an intravenous injection (1 to 2 mg) of TER-GTN or a double-placebo injection, and then another injection at 4 and 8 h. Control of bleeding, rebleeding, and mortality rate at days 15 and 42 were evaluated. In most patients, endoscopy confirmed the rupture of oesophageal varices (75.7%). Bleeding control was significantly better in the TER-GTN group (n = 41) than in the double-placebo group (n = 43) (p = 0.034). Mortality due to bleeding episodes was significantly lower in the TER-GTN group than in the double-placebo group at day 15 (p = 0.035) and at day 42 (p = 0.06). There were no serious side-effects. Early administration of TER-GTN lowers the deleterious consequences of prolonged hypovolaemia on the hepatic function of these patients.