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

Anticoagulation for the treatment of thrombotic complications in patients with cirrhosis

Cirrhotic patients can develop thrombotic complications, which in this group of patients occur with a greater frequency than in the general population. Portal vein thrombosis (PVT) is the most common thrombotic phenomenon, although deep venous thrombosis and pulmonary embolism can also occur. Risk factors for thrombosis include inherited and acquired deficiency of factors involved in anticoagulation mechanisms, venous stasis of the portal vein owing to architectural derangement of the liver and possibly local factors related to the endothelium. Clinical manifestations of PVT range from asymptomatic disease to a life-threatening complication, and although it is no longer considered an absolute contraindication for liver transplant, its presence may require challenging surgical techniques, which entail greater morbidity. Anticoagulation therapy is henceforth an important strategy to treat cirrhotic patients with PVT, although experience in this group of patients is limited. Vitamin K antagonists and low-molecular-weight heparin have been used successfully, achieving recanalization of the thrombosed vessel in patients with cirrhosis; however, the precise drug regimen management and monitoring has not be fully explored in this group of patients.

Evaluation of coagulation abnormalities in acute liver failure

BACKGROUND & AIMS

In acute liver failure (ALF), prothrombin time (PT) and its derivative prothrombin time ratio (PTR) are elevated, and are considered predictors of increased bleeding risk. We aimed at determining whether increased PT/PTR reflects the haemostatic potential and bleeding risk in ALF patients.

METHODS

Twenty consecutive ALF patients were recruited. Samples were analysed on admission for standard laboratory clotting tests (e.g. PT), thromboelastography (TEG), individual pro and anticoagulant factors and thrombin generation (TG) kinetics with and without Protac, a snake venom protein C activator, and microparticle assay. TG was also measured in 20 age and sex matched healthy volunteers.

RESULTS

PT was significantly raised (50.7s ± 7.2, p=0.0001) but did not correlate with TEG parameters. TEG tracings were consistent with a hypocoagulable state in 20%, normal in 45%, and hypercoagulable in 35% of the patients. There was a concomitant and proportional reduction in plasma levels of both procoagulants and natural anticoagulant proteins, in conjunction with a significant elevation in plasma levels of factors-VIII (FVIII) and Von Willebrand factor, and microparticles, culminating in an overall efficient, albeit reduced, thrombin generation capacity in comparison with healthy individuals. A heparin-like effect (HLE) was also noted in most patients. No significant clinical bleeding complications occurred and no blood transfusions were required.

CONCLUSIONS

In ALF, despite grossly deranged PT in all patients, estimation of bleeding risk suggests that the coagulation disturbance in ALF patients is complex and heterogeneous for which an individualised approach is required.

Regional citrate anticoagulation in patients with liver failure--time for a rethink?

Regional citrate anticoagulation (RCA) for continuous renal replacement therapy (CRRT) has become increasingly attractive in recent years due to its favourable low bleeding risk profile. Its use in liver failure, however, has been limited due to the risk of citrate accumulation and toxicity. In the previous issue of Critical Care, Schultheiss and colleagues look at CRRT using RCA in liver failure patients. They demonstrate that citrate accumulation can be predicted using the total calcium (Ca_tot) to ionised calcium (Ca_ion) ratio (Ca_tot/Ca_ion), and determine that despite the occurrence of significant citrate accumulation, the effects of citrate accumulation are not as severe as might have been expected. This study raises interesting prospects with regard to RCA use in liver failure, and we postulate that citrate may have a role as a prognostic marker of metabolic capacity much as in the way of lactate and methacetin. However, further studies are warranted, in particular examining its application in subgroups of liver failure (chronic, acute, hyperacute and subacute), before its use becomes commonplace.

Surgery in a patient with liver disease

Surgery is often needed in patients with concurrent liver disease. The multiple physiological roles of the liver places these patients at an increased risk of morbidity and mortality. Diseases necessitating surgery like gallstones and hernia are more common in patients with cirrhosis. Assessment of severity of liver dysfunction before surgery is important and the risk benefit of the procedure needs to be carefully assessed. The disease severity may vary from mild transaminase rise to decompensated cirrhosis. Surgery should be avoided if possible in the emergency setting, in the setting of acute and alcoholic hepatitis, in a patient of cirrhosis who is child class C or has a MELD score more than 15 or any patient with significant extrahepatic organ dysfunction. In this subset of patients, all possible means to manage these patients conservatively should be attempted. Modified Child-Pugh scores and model for end-stage liver disease (MELD) scores can predict mortality after surgery fairly reliably including nonhepatic abdominal surgery. Pre-operative optimization would include control of ascites, correction of electrolyte imbalance, improving renal dysfunction, cardiorespiratory assessment, and correction of coagulation. Tests of global hemostasis like thromboelastography and thrombin generation time may be more predictive of the risk of bleeding compared with the conventional tests of coagulation in patients with cirrhosis. Correction of international normalized ratio with fresh frozen plasma does not necessarily mean reduction of bleeding risk and may increase the risk of volume overload and lung injury. International normalized ratio liver may better reflect the coagulation status. Recombinant factor VIIa in patients with cirrhosis needing surgery needs further study. Intra-operatively, safe anesthetic agents like isoflurane and propofol with avoidance of hypotension are advised. In general, nonsteroidal anti-inflammatory drug (NSAIDs) and benzodiazepines should not be used. Intra-abdominal surgery in a patient with cirrhosis becomes more challenging in the presence of ascites, portal hypertension, and hepatomegaly. Uncontrolled hemorrhage due to coagulopathy and portal hypertension, sepsis, renal dysfunction, and worsening of liver failure contribute to the morbidity and mortality in these patients. Steps to reduce ascitic leaks and infections need to be taken. Any patient with cirrhosis undergoing major surgery should be referred to a specialist center with experience in managing liver disease.

Eltrombopag before procedures in patients with cirrhosis and thrombocytopenia

BACKGROUND

Eltrombopag is an oral thrombopoietin-receptor agonist. This study evaluated the efficacy of eltrombopag for increasing platelet counts and reducing the need for platelet transfusions in patients with thrombocytopenia and chronic liver disease who are undergoing an elective invasive procedure.

METHODS

We randomly assigned 292 patients with chronic liver disease of diverse causes and platelet counts of less than 50,000 per cubic millimeter to receive eltrombopag, at a dose of 75 mg daily, or placebo for 14 days before a planned elective invasive procedure that was performed within 5 days after the last dose. The primary end point was the avoidance of a platelet transfusion before, during, and up to 7 days after the procedure. A key secondary end point was the occurrence of bleeding (World Health Organization [WHO] grade 2 or higher) during this period.

RESULTS

A platelet transfusion was avoided in 104 of 145 patients who received eltrombopag (72%) and in 28 of 147 who received placebo (19%) (P<0.001). No significant difference between the eltrombopag and placebo groups was observed in bleeding episodes of WHO grade 2 or higher, which were reported in 17% and 23% of patients, respectively. Thrombotic events of the portal venous system were observed in 6 patients who received eltrombopag, as compared with 1 who received placebo, resulting in the early termination of the study. The incidence and severity of other adverse events were similar in the eltrombopag and placebo groups.

CONCLUSIONS

Eltrombopag reduced the need for platelet transfusions in patients with chronic liver disease who were undergoing elective invasive procedures, but it was associated with an increased incidence of portal-vein thrombosis, as compared with placebo. (Funded by GlaxoSmithKline; ELEVATE ClinicalTrials.gov number, NCT00678587.).

Management of critically-ill cirrhotic patients

Cirrhotic patients are prone to develop life-threatening complications that require emergency care and ICU admission. They can present specific decompensations related to cirrhosis such as variceal bleeding and hepatorenal syndrome (HRS) or other critical events also observed in the general population such as severe sepsis or septic shock. Clinical management of all these entities requires a specific approach in cirrhosis. Cirrhotic patients have a hyperdynamic circulation with high cardiac output and low systemic vascular resistance in the absence of infection. Circulatory dysfunction increases the susceptibility of critically-ill cirrhotic patients to develop multiple organ failure and attenuates vascular reactivity to vasopressor drugs. HRS, a severe functional renal failure occurring in patients with advanced cirrhosis and ascites, is also secondary to this circulatory dysfunction that leads to an extreme renal vasoconstriction. Moreover, hypotensive cirrhotic patients require a carefully balanced replacement of volemia, since overtransfusion increases portal hypertension and the risk of variceal bleeding and undertransfusion causes tissue hypoperfusion which increases the risk of multiple organ failure. Cirrhotic patients are also at a high risk for development of other bleeding complications and are more susceptible to nosocomial infections. This extreme complexity of critically-ill cirrhotic patients requires a specific medical approach that should be known by general intensivists since it has a negative impact on patient prognosis. This review will focus on the diagnostic approach and treatment strategies currently recommended in the critical care management of patients with cirrhosis.

Coagulation in hepatobiliary disease

OBJECTIVE

To review the pathogenesis and clinical consequences of coagulation abnormalities accompanying hepatobiliary disorders and to highlight the need for further studies to characterize these derangements and their treatment options in small animal patients.

DATA SOURCES

Veterinary and human medical literature: original research articles, scientific reviews, consensus statements, and recent texts.

SUMMARY

The liver plays an important role in the production and clearance of many components of coagulation. A wide range of hemostatic derangements can occur in patients with hepatobiliary disease including alterations in platelet number and function, coagulation factor levels, anticoagulants, vascular endothelial function, and fibrinolysis. As these hemostatic alterations include both pro- and anticoagulation pathways, the net result is often a rebalanced hemostatic system that can be easily disrupted by concurrent conditions resulting in either clinical bleeding or thrombosis. Conventional coagulation tests are inadequate at identifying the spectrum of coagulation alterations occurring in patients with hepatobiliary disease, but their evaluation is necessary to assess bleeding risk and provide prognostic information. A paucity of information exists regarding the treatment of the coagulation derangements in small animals with hepatobiliary disease. Extrapolation from human studies provides some information about potential treatment options, but further studies are warranted in this area to elucidate the best management for coagulation abnormalities in dogs and cats with hepatobiliary disease.

CONCLUSION

Hepatobiliary disease can have profound effects on coagulation function leading to hypercoagulable or hypocoagulable states. Overall coagulation status with hepatobiliary disease depends on both the type and severity of disease and the presence of associated complications.

[Anesthesia in the patient with impaired liver function]

We review information on impaired liver function, focusing on concepts relevant to anesthesia and postoperative recovery. The effects of impaired function are analyzed by systems of the body, with attention to the complications the patient with liver cirrhosis may develop according to type of surgery. Approaches to correcting coagulation disorders in the cirrhotic patient are particularly controversial because an increase in volume may be a factor in bleeding owing to increased portal venous pressure and imbalances in the factors that favor or inhibit coagulation. Perioperative morbidity and mortality correlate closely to Child-Pugh class and the score derived from the model for end-stage liver disease (MELD). Patients in Child class A are at moderate risk and surgery is therefore not contraindicated. Patients in Child class C or with a MELD score over 20, on the other hand, are at high risk and should not undergo elective surgical procedures. Abdominal surgery is generally considered to put patients with impaired liver function at high risk because it causes changes in hepatic blood flow and increases intraoperative bleeding because of high portal venous pressures.

[Acute liver failure. How much diagnostic work-up and therapy does my patient need?]

Acute liver failure is a multisystem disease with predominantly sudden and severe hepatic injury and hepatic encephalopathy caused by apoptotic or necrotic hepatocyte damage. The clinical challenge in patients with acute liver failure is to promptly identify those with poor prognosis and refer them for emergency liver transplantation. This review article highlights the main aspects of decision making in the setting of acute liver failure, summarizes new aspects of its critical care management and gives an overview of sclerosing cholangitis in the critically ill patient, an under-recognized disease entity that can progress to acute liver failure.

Should cirrhosis change our attitude towards treating non-hepatic cancer?

Cirrhosis is a major cause of morbidity and mortality and is the end stage of any chronic liver disease. Cancer, a leading cause of death worldwide, is a growing global health issue. There are limited data in the literature on the incidence, prevalence and management of non-hepatic cancers (NHC) in cirrhotic patients. The aim of this brief review was to underline the main concerns, pitfalls and warnings regarding practice for these patients. Survival of patients with compensated cirrhosis is significantly longer than that of decompensated cirrhosis and patients with NHC and in Child-Pugh class C should not be candidates for cytotoxic chemotherapy. It is important before starting cytotoxic chemotherapy to assess the aetiology and stage of liver disease and to screen these patients for portal hypertension and fluid retention. During cytotoxic chemotherapy, the effectiveness of cancer treatment, as well the appearance of early signs of hepatic decompensation, must be thoroughly monitored. Future phase 3 trial designs in oncology should include a share of patients with compensated cirrhosis to obtain specific information in this setting. Identification of tests able to measure the global degree of hepatic impairment caused by cirrhosis could help in the management of this particular clinical situation.

Management of coagulopathy in patients with decompensated liver cirrhosis

Patients with decompensated liver cirrhosis have significantly impaired synthetic function. Many proteins involved in the coagulation process are synthesized in the liver. Routinely performed tests of the coagulation are abnormal in patients with decompensated liver cirrhosis. This has led to the widespread belief that decompensated liver cirrhosis is prototype of acquired hemorrhagic coagulopathy. If prothrombin time is prolonged more than 3 seconds over control, invasive procedures like liver biopsy, splenoportogram, percutaneous cholangiography, or surgery were associated with increased risk of bleeding, and coagulopathy should be corrected with infusion of fresh frozen plasma. These practices were without any scientific evidence and were associated with significant hazards of fresh frozen plasma transfusion. Now, it is realized that coagulation is a complex process involving the interaction of procoagulation and anticoagulation factors and the fibrinolytic system. As there is reduction in both anti and procoagulant factors, global tests of coagulation are normal in patients with acute and chronic liver disease indicating that coagulopathy in liver disease is more of a myth than a reality. In the last few years, surgical techniques have substantially improved, and complex procedures like liver transplantation can be done without the use of blood or blood products. Patients with liver cirrhosis may also be at increased risk of thrombosis. In this paper, we will discuss coagulopathy, increased risk of thrombosis, and their management in decompensated liver cirrhosis.

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.

Recipient and donor thrombophilia and the risk of portal venous thrombosis and hepatic artery thrombosis in liver recipients

Background

Vascular complications, such as HAT, are an important cause of graft loss and recipient mortality. We aimed to characterize post-transplant thrombotic events in a cohort of liver transplant recipients, and identify independent risk factors for these complications.

Methods

We conducted a thrombophilic study of 293 orthotopic liver transplants performed in the Digestive Surgery Department of the 12 de Octubre Hospital (Madrid, Spain) between January 2001 and December 2006.

Results

The most frequent post-transplant thrombotic events were HAT (9%) and PVT (1.7%). The one variable associated with post-transplant thrombotic event was a high fibrinogen level in the global cohort of liver transplantation. But toxicity as event post-OLT has been associated with post-transplant thrombotic event in the retrospective group and high fibrinogen level and low protein C levels were associated post-transplant thrombotic event in the prospective group. Liver disease relapse (HR 6.609, p < 0.001), high levels of FVIII (HR 1.008, p = 0.019)) and low levels of antithrombin (HR 0.946, p < 0.001) were associated with poor overall survival (OS).

In conclusion, high fibrinogen and decreased protein C levels were associated with allograft thrombosis. Further studies are required in order to assess the clinical relevance of these parameters in prospective studies and to study the effect of anticoagulation prophylaxis in this group of risk.

Clinical Usefulness of Recombinant Activated Factor VII in Patients with Liver Failure Undergoing Invasive Procedures

Objective:

To evaluate the use of recombinant activated factor VII (rFVIIa) in patients with liver failure undergoing invasive procedures.

Methods:

An OVID/MEDUNE and PubMed search (1997-June 2011) was performed to identify literature on the use of rFVIIa to reduce bleeding risk in patients with liver failure undergoing invasive procedures.

Study Selection and Data Extraction:

English-language data evaluating the efficacy of rFVIIa to reverse coagulopathies prior to invasive procedures in patients with liver disease were included.

Data Synthesis:

Following administration of rFVIIa, prothrombin time (PT) and international normalized ratio (INR) response is within 30 minutes. Doses ranging from 20 to 120 μg/kg have been studied, with a reduction in PT seen in a dose-dependent manner. One study in patients with no bleeding administered 5, 20, and 80 μg/kg sequentially during a 24-day period. All doses provided reversal of prolonged PT within 10 minutes, and the duration was dose-dependent. In a study of 15 patients with fulminant liver failure, requiring intracranial pressure monitor placement, a rFVIIa dose of 40 μg/kg was compared to fresh frozen plasma. In patients who received rFVIIa, the PT and INR normalized, compared to none of the patients in the fresh frozen plasma group.

Conclusions:

Retrospective and prospective data demonstrate that rFVIIa effectively reverses elevated PT and INR, reducing the risk of bleeding and safely facilitating invasive procedures. Based on available data, a dose of 20-40 μg/kg 30 minutes prior to an invasive procedure should be considered in patients with acute or chronic liver failure at risk for bleeding complications. A major limitation of rFVIIa use is the high cost of therapy. A prospective, randomized trial could help determine the appropriate dose of rFVIIa, timing of dose in relationship to procedure, and usefulness of subsequent doses.

The role of hypercoagulability in liver fibrogenesis

The development of hepatic fibrosis on a background of chronic liver injury represents a complex disease trait modulated through the interaction of host genetic factors and environmental influences. Early observations that hepatic inflammation and cirrhosis are associated with the presence of microthrombi within the hepatic vasculature and fibrin/fibrinogen deposition were followed by epidemiological studies showing that carriage of the Factor V Leiden (FvL) mutation, protein C deficiency and increased expression of factor VIII are associated with accelerated progression to cirrhosis in a chronic hepatitis C infection. Additional data suggest that these factors may influence fibrogenesis in many forms of chronic liver disease and extra-hepatic fibrotic processes. Drawing evidence both from liver research and studies of fibrogenesis in other organ systems, two hypotheses may explain how activity of the coagulation cascade influences the rate of hepatic fibrogenesis: tissue ischaemia and parenchymal extinction and direct thrombin mediated stellate cell activation via PAR-1 cleavage. Drawing on preclinical and clinical studies we discuss the evidence for a role for coagulation cascade activity in hepatic fibrogenesis and explore the proposed pathogenic mechanisms that lead to stellate cell activation. The corollary of an association between hypercoagulation and increased fibrosis is that interference with the coagulation cascade may reduce hepatic fibrosis. We conclude this article by examining the implications for future therapeutic intervention.

Acute liver failure: current practice and recent advances

ALF is an important cause of liver-related morbidity and mortality. Advances in the management of ICH and SIRS, and cardiorespiratory, metabolic, and renal support have improved the outlook of such patients. Early transfer to a liver transplant center is essential. Routine use of NAC is recommended for patients with early hepatic encephalopathy, irrespective of the etiology. The role of hypothermia remains to be determined. Liver transplantation plays a critical role, particularly for those with advanced encephalopathy. Several detoxification and BAL support systems have been developed to serve as a bridge to transplantation or to spontaneous recovery. However, such systems lack sufficient reliability and efficacy to be applied routinely in clinical practice. Hepatocyte and stem cell transplantation may provide valuable adjunctive therapy in the future.

Fibrinogen deficiency increases liver injury and early growth response-1 (Egr-1) expression in a model of chronic xenobiotic-induced cholestasis

Chronic cholestatic liver injury induced by cholestasis in rodents is associated with hepatic fibrin deposition, and we found evidence of fibrin deposition in livers of patients with cholestasis. Key components of the fibrinolytic pathway modulate cholestatic liver injury by regulating activation of hepatocyte growth factor. However, the exact role of hepatic fibrin deposition in chronic cholestasis is not known. We tested the hypothesis that fibrinogen (Fbg) deficiency worsens liver injury induced by cholestasis. Fbg-deficient mice (Fbgα(-/-) mice) and heterozygous control mice (Fbgα(+/-) mice) were fed either the control diet or a diet containing 0.025% α-naphthylisothiocyanate (ANIT), which selectively injures bile duct epithelial cells in the liver, for 2 weeks. Hepatic fibrin and collagen deposits were evident in livers of heterozygous control mice fed the ANIT diet. Complete Fbg deficiency was associated with elevated serum bile acids, periportal necrosis, and increased serum alanine aminotransferase activity in mice fed the ANIT diet. Fbg deficiency was associated with enhanced hepatic expression of the transcription factor early growth response-1 (Egr-1) and enhanced induction of genes encoding the Egr-1-regulated proinflammatory chemokines monocyte chemotactic protein-1, KC growth-regulated protein, and macrophage inflammatory protein-2. Interestingly, peribiliary collagen deposition was not evident near necrotic areas in Fbg-deficient mice. The results suggest that in this model of chronic cholestasis, fibrin constrains the release of bile constituents from injured intrahepatic bile ducts, thereby limiting the progression of hepatic inflammation and hepatocellular injury.

Advances in alcoholic liver disease

Alcoholic liver disease (ALD) remains a leading cause of death from liver disease in the United States. In studies from the Veterans Administration, patients with cirrhosis and superimposed alcoholic hepatitis had greater than 60% mortality over a 4-year period, with most of those deaths occurring in the first month. Thus, the prognosis for this disease is more ominous than for many common types of cancer (eg, breast, prostate, and colon). Moreover, ALD imposes a significant economic burden from lost wages, health care costs, and lost productivity. Unfortunately, there is still no Food and Drug Administration-approved or widely accepted drug therapy for any stage of ALD. Thus, a pressing need exists for a more detailed understanding of mechanisms of liver injury. This article reviews recent advances in mechanisms and therapy related to five major areas of direct relevance to ALD: oxidative stress; gut-liver axis and cytokine signaling; malnutrition; fibrin/clotting; and stellate cell activation/fibrosis. We also review why therapies related to these mechanisms have performed well in experimental animals and in vitro systems, but have not necessarily translated into effective therapy for humans with ALD.

Risk factors for bleeding and transfusion during orthotopic liver transplantation

OBJECTIVE

While orthotopic liver transplantation (OLT) can be associated with haemorrhage, the risk factors for bleeding and transfusion remain difficult to predict. Perioperative transfusion has potentially deleterious side effects and impairs graft and patient survival. Preoperative identification of patients at high risk of bleeding is of clinical interest to manage perioperative transfusion and blood product storage.

STUDY DESIGN

Retrospective study.

PATIENTS AND METHODS

All OLT conducted between 2004 and 2008 in the University Hospital of Bordeaux were studied. Risk factors for bleeding greater than one blood volume and for massive red blood cell (RBC) transfusion were determined using univariate and multivariate analysis. Thresholds were determined with ROC curve analysis.

RESULTS

One hundred and forty-eight transplantations were studied. Preoperative haemoglobin and Child class A were independent protective risk factors for bleeding greater than one blood volume (OR 0.81 [0.67-0.98] and 0.27 [0.10-0.72], respectively). Preoperative Hb was a protective risk factor (OR 0.71 [0.58-0.88]) whereas history of oesophageal varicose bleeding was a risk factor (OR 4.67 [1.45-15.05]) for transfusion of more than eight RBC.

CONCLUSION

Risk factors for bleeding and transfusion during OLT identified in this study were of little clinical usefulness so blood products should always be available during the procedure.

Management of coagulopathy in patients with decompensated liver cirrhosis

Patients with decompensated liver cirrhosis have significantly impaired synthetic function. Many proteins involved in the coagulation process are synthesized in the liver. Routinely performed tests of the coagulation are abnormal in patients with decompensated liver cirrhosis. This has led to the widespread belief that decompensated liver cirrhosis is prototype of acquired hemorrhagic coagulopathy. If prothrombin time is prolonged more than 3 seconds over control, invasive procedures like liver biopsy, splenoportogram, percutaneous cholangiography, or surgery were associated with increased risk of bleeding, and coagulopathy should be corrected with infusion of fresh frozen plasma. These practices were without any scientific evidence and were associated with significant hazards of fresh frozen plasma transfusion. Now, it is realized that coagulation is a complex process involving the interaction of procoagulation and anticoagulation factors and the fibrinolytic system. As there is reduction in both anti and procoagulant factors, global tests of coagulation are normal in patients with acute and chronic liver disease indicating that coagulopathy in liver disease is more of a myth than a reality. In the last few years, surgical techniques have substantially improved, and complex procedures like liver transplantation can be done without the use of blood or blood products. Patients with liver cirrhosis may also be at increased risk of thrombosis. In this paper, we will discuss coagulopathy, increased risk of thrombosis, and their management in decompensated liver cirrhosis.

Bleeding and clotting disorders in pediatric liver disease

The coagulopathy of liver disease in pediatric patients presents an unusual set of challenges. Little pediatric data have been published, so this review is based largely on adult studies. There is a precarious balance between deficiencies of clotting factors and anticoagulation factors in liver disease that result in abnormal prothrombin time (PT) and activated partial thromboplastin time (aPTT) tests that would suggest a bleeding tendency, yet the patients can form a clot and are at risk of thromboembolic disease. Attention has centered on thromboelastography and thrombin-generation assays to clarify the patient's ability to control bleeding, but these tests are not routinely available to many treating physicians.

Rebalanced hemostasis in patients with liver disease: evidence and clinical consequences

Patients with liver disease frequently acquire a complex disorder of hemostasis secondary to their disease. Routine laboratory tests such as the prothrombin time and the platelet count are frequently abnormal and point to a hypocoagulable state. With more sophisticated laboratory tests it has been shown that patients with liver disease may be in hemostatic balance as a result of concomitant changes in both pro- and antihemostatic pathways. Clinically, this rebalanced hemostatic system is reflected by the large proportion of patients with liver disease who can undergo major surgery without any requirement for blood product transfusion. However, the hemostatic balance in the patient with liver disease is relatively unstable as evidenced by the occurrence of both bleeding and thrombotic complications in a significant proportion of patients. Although it is still common practice to prophylactically correct hemostatic abnormalities in patients with liver disease before invasive procedures by administration of blood products guided by the prothrombin time and platelet count, we believe that this policy is not evidence-based. In this article, we will provide arguments against the traditional concept that patients with liver failure have a hemostasis-related bleeding tendency. Consequences of these new insights for hemostatic management will be discussed.