Recombinant activated factor VII (rFVIIa) as a hemostatic agent in liver disease: a break from convention in need of controlled trials

Establishment of a risk assessment score for deep vein thrombosis after artificial liver support system treatment

BACKGROUND

The artificial liver support system (ALSS) is an effective treatment method for liver failure, but it requires deep venous intubation and long-term indwelling catheterization. However, the coagulation mechanism disorder of basic liver failure diseases, and deep venous thrombosis (DVT) often occur.

AIM

To evaluate the risk factors for DVT following use of an ALSS and establish a risk assessment score.

METHODS

This study was divided into three stages. In the first stage, the risk factors for DVT were screened and the patient data were collected, including ALSS treatment information; biochemical indices; coagulation and hematology indices; complications; procoagulant use therapy status; and a total of 24 indicators. In the second stage, a risk assessment score for DVT after ALSS treatment was developed. In the third stage, the DVT risk assessment score was validated.

RESULTS

A total of 232 patients with liver failure treated with ALSS were enrolled in the first stage, including 12 with lower limb DVT. Logistic regression analysis showed that age [odds ratio (OR), 1.734; P = 0.01], successful catheterization time (OR, 1.667; P = 0.005), activity status (strict bed rest) (OR, 3.049; P = 0.005), and D-dimer level (≥ 500 ng/mL) (OR, 5.532; P < 0.001) were independent risk factors for DVT. We then established a scoring system for risk factors. In the validation group, a total of 213 patients with liver failure were treated with ALSS, including 14 with lower limb DVT. When the cutoff value of risk assessment was 3, the specificity and sensitivity of the risk assessment score were 88.9% and 85.7%, respectively.

CONCLUSION

A simple risk assessment scoring system was established for DVT patients with liver failure treated with ALSS and was verified to have good sensitivity and specificity.

Effect of a Rapidly Degrading Presolidified 10 kDa Chitosan/Blood Implant and Subchondral Marrow Stimulation Surgical Approach on Cartilage Resurfacing in a Sheep Model

Objective This study tested the hypothesis that presolidified chitosan-blood implants are retained in subchondral bone channels perforated in critical-size sheep cartilage defects, and promote bone repair and hyaline-like cartilage resurfacing versus blood implant. Design Cartilage defects (10 × 10 mm) with 3 bone channels (1 drill, 2 Jamshidi biopsy, 2 mm diameter), and 6 small microfracture holes were created bilaterally in n = 11 sheep knee medial condyles. In one knee, 10 kDa chitosan-NaCl/blood implant (presolidified using recombinant factor VIIa or tissue factor), was inserted into each drill and Jamshidi hole. Contralateral knee defects received presolidified whole blood clot. Repair tissues were assessed histologically, biochemically, biomechanically, and by micro-computed tomography after 1 day ( n = 1) and 6 months ( n = 10). Results Day 1 defects showed a 60% loss of subchondral bone plate volume fraction along with extensive subchondral hematoma. Chitosan implant was resident at day 1, but had no effect on any subsequent repair parameter compared with blood implant controls. At 6 months, bone defects exhibited remodeling and hypomineralized bone repair and were partly resurfaced with tissues containing collagen type II and scant collagen type I, 2-fold lower glycosaminoglycan and fibril modulus, and 4.5-fold higher permeability compared with intact cartilage. Microdrill holes elicited higher histological ICRS-II overall assessment scores than Jamshidi holes (50% vs. 30%, P = 0.041). Jamshidi biopsy holes provoked sporadic osteonecrosis in n = 3 debrided condyles. Conclusions Ten kilodalton chitosan was insufficient to improve repair. Microdrilling is a feasible subchondral marrow stimulation surgical approach with the potential to elicit poroelastic tissues with at least half the compressive modulus as intact articular cartilage.

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.

Outcomes and complications of intracranial pressure monitoring in acute liver failure: a retrospective cohort study

OBJECTIVE

To determine if intracranial pressure monitor placement in patients with acute liver failure is associated with significant clinical outcomes.

DESIGN

Retrospective multicenter cohort study.

SETTING

Academic liver transplant centers comprising the U.S. Acute Liver Failure Study Group.

PATIENTS

Adult critically ill patients with acute liver failure presenting with grade III/IV hepatic encephalopathy (n = 629) prospectively enrolled between March 2004 and August 2011.

INTERVENTION

Intracranial pressure monitored (n = 140) versus nonmonitored controls (n = 489).

MEASUREMENTS AND MAIN RESULTS

Intracranial pressure monitored patients were younger than controls (35 vs 43 yr, p < 0.001) and more likely to be on renal replacement therapy (52% vs 38%, p = 0.003). Of 87 intracranial pressure monitored patients with detailed information, 44 (51%) had evidence of intracranial hypertension (intracranial pressure > 25 mm Hg) and overall 21-day mortality was higher in patients with intracranial hypertension (43% vs 23%, p = 0.05). During the first 7 days, intracranial pressure monitored patients received more intracranial hypertension-directed therapies (mannitol, 56% vs 21%; hypertonic saline, 14% vs 7%; hypothermia, 24% vs 10%; p < 0.03 for each). Forty-one percent of intracranial pressure monitored patients received liver transplant (vs 18% controls; p < 0.001). Overall 21-day mortality was similar (intracranial pressure monitored 33% vs controls 38%, p = 0.24). Where data were available, hemorrhagic complications were rare in intracranial pressure monitored patients (4 of 56 [7%]; three died). When stratifying by acetaminophen status and adjusting for confounders, intracranial pressure monitor placement did not impact 21-day mortality in acetaminophen patients (p = 0.89). However, intracranial pressure monitor was associated with increased 21-day mortality in nonacetaminophen patients (odds ratio, ~ 3.04; p = 0.014).

CONCLUSIONS

In intracranial pressure monitored patients with acute liver failure, intracranial hypertension is commonly observed. The use of intracranial pressure monitor in acetaminophen acute liver failure did not confer a significant 21-day mortality benefit, whereas in nonacetaminophen acute liver failure, it may be associated with worse outcomes. Hemorrhagic complications from intracranial pressure monitor placement were uncommon and cannot account for mortality trends. Although our results cannot conclusively confirm or refute the utility of intracranial pressure monitoring in patients with acute liver failure, patient selection and ancillary assessments of cerebral blood flow likely have a significant role. Prospective studies would be required to conclusively account for confounding by illness severity and transplant.

Preliminary experience with use of recombinant activated factor VII to control postpartum hemorrhage in acute fatty liver of pregnancy and other pregnancy-related liver disorders

Control of postpartum hemorrhage is difficult in patients with coagulopathy due to acute liver failure. Recombinant activated factor VII (rFVIIa) can help in control of bleed; however, it has short duration of action (2-4 h). The study aimed to report the use of rFVIIa in this setting. We retrospectively analyzed all patients with acute liver failure secondary to pregnancy-related liver disorders who received rFVIIa for control of postpartum hemorrhage (six patients, all six met diagnostic criteria for acute fatty liver of pregnancy). One dose of rFVIIa achieved adequate control of bleeding in five patients, while one patient needed a second dose. rFVIIa administration corrected coagulopathy and significantly reduced requirement of packed red cells and other blood products. No patient had thrombotic complications. In conclusion, rFVIIa was a useful adjunct to standard management in postpartum hemorrhage secondary to acute liver failure of pregnancy-related liver disorders.

Gene expression profiling in rat liver treated with various hepatotoxic-compounds inducing coagulopathy

A large-scale transcriptome database of rat liver (TG-GATEs) has been established by the Toxicogenomics Project in Japan. In the present study, we focused on 8 hepatotoxic compounds within TG-GATEs, i.e., clofibrate, omeprazole, ethionine, thioacetamide, benzbromarone, propylthiouracil, Wy-14,643 and amiodarone, which induced coagulation abnormalities. Aspirin was selected as a reference compound that directly causes coagulation abnormality, but not through liver toxicity. In blood chemical examinations, for all the coagulopathic compounds there was little elevation of aspartate aminotransferase (AST) and/or alanine aminotransferase (ALT), suggesting no severe cell death by treatment with the compounds. We extracted 344 probe sets from the data for these 8 typical drugs, which induced this phenotype at any time from 3 to 28 days of repeated administration. Principal component analysis using these probe sets clearly separated dose- and time-dependent clusters of the treated groups from their controls, except aspirin and propylthiouracil, both of which were considered to cause coagulopathy not due to their hepatotoxicity but due to their direct effects on the blood coagulation system. Reviewing the extracted genes, changes in lipid metabolism were found to be dominant. Genes related to blood coagulation were generally down-regulated by these drugs except that vitamin K epoxide reductase complex subunit 1 (Vkorc1) like 1, a paralogous gene of Vkorc1, was up-regulated. As expected, expression changes of these genes were least prominent in aspirin or propylthiouracil-treated liver. We concluded that these probe sets could be a good starting point in developing mechanism-based biomarkers for diagnosis or prognosis of hepatotoxicity-related coagulation abnormalities in the early stage of drug development.

Management of Life-Threatening Hemorrhages and Unsafe Interventions in Nonhemophiliac Children by Recombinant Factor VIIa

The literature on the use of recombinant factor VIIa (rFVIIa), which was initially used in hemophiliac patients with inhibitors, for hemorrhages that cannot be managed with conventional methods or operations that cannot be performed safely is increasingly growing. This study presents a group of nonhemophiliac patients with hemorrhagic problems or hemorrhage risk for some interventions that were successfully resolved with the use of rFVIIa. The patient group was composed of 20 patients with different disorders resulting in similar results as hemorrhage or hemorrhage risk. Most of the patients were diagnosed with liver disorders primary or secondary to other diseases. The remaining cases were patients with leukemia, sepsis, intracranial hemorrhage, and burn. Some of the patients had multiple problems like a patient with liver disorder and intracranial hemorrhage or a leukemia patient with sepsis and disseminated intravascular coagulation. rFVIIa had been administered to the patients at dosages between 70 and 150 μg/kg up to 6 doses with 2-hour to 3-hour intervals. All the patients had benefited from the use of rFVIIa even though some of them died because of primary disease. This study shows that rFVIIa can be safely used in high-risk patients with a history of recurrent hemorrhage, for whom no improvement can be achieved in the hemostasis tests.

Acute liver failure including acetaminophen overdose

Acute liver failure (ALF) is a dramatic, highly unpredictable clinical syndrome defined by the sudden onset of coagulopathy and encephalopathy. Acetaminophen overdose, the leading cause of ALF in the United States, has a 66% chance of recovery with early N-acetylcysteine treatment and supportive care. Cerebral edema and infectious complications are difficult to detect and treat in these patients and may cause irreversible brain damage and multiorgan failure. One-year survival after emergency liver transplantation is 70%, but 20% of listed patients die, highlighting the importance of early referral of patients who have ALF with a poor prognosis to a transplant center.

Intensive care of patients with acute liver failure: recommendations of the U.S. Acute Liver Failure Study Group

OBJECTIVE

To provide a uniform platform from which to study acute liver failure, the U.S. Acute Liver Failure Study Group has sought to standardize the management of patients with acute liver failure within participating centers.

METHODS

In areas where consensus could not be reached because of divergent practices and a paucity of studies in acute liver failure patients, additional information was gleaned from the intensive care literature and literature on the management of intracranial hypertension in non-acute liver failure patients. Experts in diverse fields were included in the development of a standard study-wide management protocol.

MEASUREMENTS AND MAIN RESULTS

Intracranial pressure monitoring is recommended in patients with advanced hepatic encephalopathy who are awaiting orthotopic liver transplantation. At an intracranial pressure of > or =25 mm Hg, osmotic therapy should be instituted with intravenous mannitol boluses. Patients with acute liver failure should be maintained in a mildly hyperosmotic state to minimize cerebral edema. Accordingly, serum sodium should be maintained at least within high normal limits, but hypertonic saline administered to 145-155 mmol/L may be considered in patients with intracranial hypertension refractory to mannitol. Data are insufficient to recommend further therapy in patients who fail osmotherapy, although the induction of moderate hypothermia appears to be promising as a bridge to orthotopic liver transplantation. Empirical broad-spectrum antibiotics should be administered to any patient with acute liver failure who develops signs of the systemic inflammatory response syndrome, or unexplained progression to higher grades of encephalopathy. Other recommendations encompassing specific hematologic, renal, pulmonary, and endocrine complications of acute liver failure patients are provided, including their management during and after orthotopic liver transplantation.

CONCLUSIONS

The present consensus details the intensive care management of patients with acute liver failure. Such guidelines may be useful not only for the management of individual patients with acute liver failure, but also to improve the uniformity of practices across academic centers for the purpose of collaborative studies.

Potential role of recombinant activated factor VII for the treatment of severe bleeding associated with disseminated intravascular coagulation: a systematic review

Recombinant activated factor VII (rFVIIa) is a novel hemostatic agent, originally developed for the treatment of hemorrhage in hemophiliacs with inhibitors, which has been successfully used recently in an increasing number of nonhemophilic bleeding conditions. In the present systematic review we report the existing literature data on the use of this hemostatic agent in severe bleeding, unresponsive to standard treatment, associated with disseminated intravascular coagulation. A total of 99 disseminated intravascular coagulation-associated bleeding episodes treated with rFVIIa were collected from 27 published articles: in the majority of the cases, the underlying disorder complicated by disseminated intravascular coagulation was a postpartum hemorrhage, while in the remaining cases it was a cancer, trauma, sepsis or liver failure. Although limited, the data available suggest that rFVIIa could have a potential role in this clinical setting. Large randomized trials are needed, however, to confirm the preliminary results and to assess the safety and dosing regimens of this agent in refractory bleeding associated with disseminated intravascular coagulation.

Prophylactic and therapeutic use of recombinant activated factor VII in patients with cirrhosis and coagulation impairment

Patients with cirrhosis and impaired coagulation often pose major therapeutic problems during bleeding episodes or invasive procedures. Recombinant activated factor VII (rFVIIa), which has been licensed for the treatment of haemophilia patients with factor VIII or IX inhibitors, has been occasionally used in cirrhotic patients. We present five patients with cirrhosis and coagulopathy who received 1-4 recombinant activated factor VII infusions either prophylactically in order to safely undergo an invasive procedure or therapeutically in order to control a severe bleeding episode which did not respond to standard supportive care. In particular, recombinant activated factor VII infusions were given in two patients before a percutaneous liver biopsy, in one patient before teeth extraction and in two patients with haemoperitoneum after an invasive procedure. Infusions of recombinant activated factor VII achieved rapid correction of prothrombin time in all cases allowing the safe performance of invasive procedures or resulting in efficient control of the bleeding episode. In conclusion, recombinant activated factor VII seems to be a rather promising agent for the prevention or treatment of complications of haemostasis impairment in cirrhotic patients. However, its exact role in this setting needs to be evaluated within well-designed, controlled clinical trials.

Successful use of recombinant factor VIIa (NovoSeven) in children with compartment syndrome: two case reports

Compartment syndrome (CS) is an uncommon bleeding manifestation in patients with liver failure and end-stage renal disease (ESRD). Although prompt intervention is paramount in preventing the tissue necrosis and the permanent functional deficits that may be associated with untreated CS, the indications for initiating therapies for children with CS are not standardized. In this report, we present 2 children, one with ESRD and the other with liver failure, who have CS related to life-threatening bleeding complications and were treated with recombinant factor VIIa (rFVIIa). In conclusion, treatment decisions for patients with CS should be made on a case-by-case basis. The use of rFVIIa is an effective and safe treatment in children with liver failure and ESRD. Surgical treatment should be preferred in patients with CS. However, in patients who have a coagulation defect, the first priority is to correct the clotting deficiency. The use of rFVIIa is a treatment option in children with CS due to a coagulation defect.

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.

Successful treatment of intractable hemothorax with recombinant factor VIIa in a nonhemophilic patient

Recombinant factor VIIa (rFVIIa) was developed for the treatment of bleeding in hemophilic patients with inhibitors. It has also been used to stop bleeding in nonhemophilic patients who fail to respond to conventional treatment. We report a case of catastrophic hemothorax in which bleeding was stopped by administration of rFVIIa. A 68-year-old woman with chronic hepatitis C-related liver cirrhosis was admitted due to pneumonia and parapneumonic effusion. The patient developed hemothorax and hypovolemic shock after thoracentesis. Conventional therapies including tube thoracostomy and transarterial embolization failed to stop the life-threatening bleeding. The bleeding stopped after administration of rFVIIa 100 microg/kg/BW at 2-hour intervals for a total of two doses on the 3rd day of hospitalization. Despite intensive care, however, the patient died due to nosocomial infection and multiple organ failure on the 12th day of hospitalization. Hemothorax in a nonhemophilic patient can be successfully treated with rFVIIa.

Pharmacologic therapy of portal hypertension

Portal hypertension is a progressively debilitating complication of cirrhosis and a principal cause of mortality in patients who have hepatic decompensation. During the last few decades, significant clinical advances in the prevention of initial variceal hemorrhage, the management of acute variceal hemorrhage, and the prevention of recurrent variceal hemorrhage have reduced the morbidity and mortality of this lethal complication of cirrhosis. This article discusses the pharmacologic treatment of portal hypertension, including preprimary prophylaxis, prevention of a first variceal hemorrhage, treatment of acute variceal hemorrhage, and secondary prophylaxis of a variceal hemorrhage.

Recombinant factor VIIa in patients with coagulopathy secondary to anticoagulant therapy, cirrhosis, or severe traumatic injury: review of safety profile

BACKGROUND

In recent years, the hemostatic agent recombinant factor VIIa (rFVIIa) has emerged as a potentially new therapeutic agent for management of coagulopathy in patients with cirrhosis or following severe traumatic injury, a complex problem for clinicians in which standard treatment strategies are not always effective. As with other hemostatic agents, a primary safety concern of rFVIIa therapy is the theoretical possibility that systemic administration could confer an increased risk of thrombotic complications. So far, clinical experience indicates rFVIIa to be a safe treatment for currently approved indications within hemophilia. Little information is available, however, for patient populations outside this clinical setting.

STUDY DESIGN AND METHODS

This article reviews critical safety data obtained from 13 Novo Nordisk-sponsored clinical trials of rFVIIa in patients with coagulopathy secondary to anticoagulant therapy, cirrhosis, or severe traumatic injury.

RESULTS

Thrombotic adverse events were reported for 5.3 percent (23/430) of placebo-treated patients and 6.0 percent (45/748) of patients on active treatment. No significant difference was found between placebo-treated and rFVIIa-treated patients with respect to the incidence of thrombotic AEs, either on an individual trial basis or for these trial populations combined (p=0.57).

CONCLUSION

An important determinant for the safety profile reported here is likely to be the specific mechanism of action of rFVIIa, shown in experimental studies to be localized to the site of vascular injury where tissue factor is exposed.

Benefits of recombinant activated factor VII in complicated liver transplantation

INTRODUCTION

Recombinant activated factor VII (rFVIIa, NovoSeven, NovoNordiskA/S, Bagsvaerd, Denmark) has shown benefits in hemophilic patients and recently in transplant recipients. This study presents our experiences with rFVIIa in complicated liver transplant recipients.

METHODS

From May 2001 to August 2004, rFVIIa was administered to 7 patients undergoing liver transplantation. All treatments were made on emergency bases, except for 1 case with hemophilia A, who received prophylactic treatment. The drug was delivered when severe bleeding with coagulopathy persisted despite the usual treatment with blood products. The drug doses were 60-90 mug/kg; the results were evaluated clinically and analytically.

RESULTS

Seven patients undergoing liver transplantation were treated with FVIIa. Mean prothrombin times before and after treatment were 17.5 and 10.9 seconds, respectively, with a mean reduction of 7.2 seconds (P = .03). Mean thromboplastin times before and after treatment were 38.1 and 29.4 seconds, respectively, with a mean reduction of 8.7 seconds (P = .034). The average dose was 83.6 mug/kg, leading to decreased consumption of blood products (P < .01). In all cases, rFVIIa allowed sufficient hemostasis to carry on definitive treatment. There was no mortality in this series.

CONCLUSIONS

These results provide new evidence on the potential benefits of rFVIIa in liver transplantation, especially for rescue therapy in cases of severe bleeding.

Keeping cool in acute liver failure: rationale for the use of mild hypothermia

Encephalopathy, brain edema and intracranial hypertension are neurological complications responsible for substantial morbidity/mortality in patients with acute liver failure (ALF), where, aside from liver transplantation, there is currently a paucity of effective therapies. Mirroring its cerebro-protective effects in other clinical conditions, the induction of mild hypothermia may provide a potential therapeutic approach to the management of ALF. A solid mechanistic rationale for the use of mild hypothermia is provided by clinical and experimental studies showing its beneficial effects in relation to many of the key factors that determine the development of brain edema and intracranial hypertension in ALF, namely the delivery of ammonia to the brain, the disturbances of brain organic osmolytes and brain extracellular amino acids, cerebro-vascular haemodynamics, brain glucose metabolism, inflammation, subclinical seizure activity and alterations of gene expression. Initial uncontrolled clinical studies of mild hypothermia in patients with ALF suggest that it is an effective, feasible and safe approach. Randomized controlled clinical trials are now needed to adequately assess its efficacy, safety, clinical impact on global outcomes and to provide the guidelines for its use in ALF.

Recombinant activated factor VII and the anaesthetist

Recombinant activated factor VII is a safe and effective for the treatment and prevention of haemorrhage in haemophiliacs with circulating inhibitors to replacement factors, and patients with Glanzmann's thrombasthenia refractory to platelet transfusion. By restoring thrombin generation on the surface of tissue factor bearing cells, such as activated platelets and monocytes, recombinant activated factor VII has the potential to effect haemostasis in the setting of many coagulopathic states encountered by the anaesthetist in the operating theatre or the intensive care unit. Case reports of successful rescue therapy make up the majority of the literature covering other, numerous, off-label uses of recombinant activated factor VII, although some randomised, controlled studies, mostly underpowered to address safety concerns, have been performed. However, off-label use is becoming increasingly popular judging by the number of published case reports. Additional randomised, controlled trials to determine the safe and appropriate use of this potentially valuable therapy in broader patient groups are eagerly awaited.

Complications and use of intracranial pressure monitoring in patients with acute liver failure and severe encephalopathy

Monitoring of intracranial pressure (ICP) in acute liver failure (ALF) is controversial as a result of the reported complication risk (approximately 20%) and limited therapeutic options for intracranial hypertension. Using prospectively collected information from 332 patients with ALF and severe encephalopathy, we evaluated a recent experience with ICP monitoring in the 24 centers constituting the U.S. ALF Study Group. Special attention was given to the rate of complications, changes in management, and outcome after liver transplantation (LT). ICP monitoring was used in 92 patients (28% of the cohort), but the frequency of monitoring differed between centers (P < 0.001). ICP monitoring was strongly associated with the indication of LT (P < 0.001). A survey performed in a subset of 58 patients with ICP monitoring revealed intracranial hemorrhage in 10.3% of the cohort, half of the complications being incidental radiological findings. However, intracranial bleeding could have contributed to the demise of 2 patients. In subjects listed for LT, ICP monitoring was associated with a higher proportion of subjects receiving vasopressors and ICP-related medications. The 30-day survival post-LT was similar in both monitored and nonmonitored groups (85% vs. 85%). In conclusion, the risk of intracranial hemorrhage following ICP monitoring may have decreased in the last decade, but major complications are still present. In the absence of ICP monitoring, however, patients listed for LT appear to be treated less aggressively for intracranial hypertension. In view of the high 30-day survival rate after LT, future studies of the impact of intracranial hypertension should also focus on long-term neurological recovery from ALF.

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.

Emerging Off-Label Uses for Recombinant Activated Factor VII: Grading the Evidence

Recombinant activated factor VII (rFVIIa) is currently licensed in the United States for treatment of bleeding episodes in patients with deficiencies of factor VIII (FVIII) or IX (FIX) who are refractory to factor replacement because of circulating inhibitors. A 1999 report of its successful use to stop what was deemed to be lethal hemorrhage after an abdominal gunshot wound in a young soldier without pre-existing coagulopathy has prompted exploration of other uses for rFVIIa. The virtual explosion of proposed uses of rFVIIa raises issues not only regarding our understanding of the coagulation system, but also regarding its efficacy, cost-effectiveness, and safety.

Liver failure

PURPOSE OF REVIEW

Liver failure is a rare but life-threatening condition affecting a multitude of other organ systems, most notably the brain and kidneys, following severe hepatocellular injury. Liver failure may develop in the absence ('acute') or presence ('acute-on-chronic') of liver disease with substantial differences in pathophysiology and therapeutic options. Within the last 12 months substantial progress has been made in identifying patients who will potentially benefit from extracorporeal support of their failing liver.

RECENT FINDINGS

In addition to traditional 'static' laboratory tests to assess liver function, the significance of 'dynamic' tests, such as indocyanine green clearance, has been better defined, and these tests are becoming more easily available. Transplantation remains the treatment of choice for fulminant, acute and subacute liver failure with predicted unfavorable outcome according to King's College or Clichy criteria, most notably in the absence of pre-existing liver disease, and should be performed before extrahepatic complications emerge. Encouraging results have been obtained with the use of support systems in patients with acute and acute-on-chronic liver failure in relatively small patient collectives, making well-conducted randomized trials a necessity to define their role in this high-risk population. Current (pre)clinical data suggest that programmed cell death is an important mechanism for the pathogenesis of acute and acute-on-chronic liver failure and, thus, antiapoptotic strategies are promising pharmacologically.

SUMMARY

Although mortality remains high, substantial progress has been made in 2004 regarding the understanding of pathophysiology, and the monitoring and support of the patient presenting with a failing liver.

The use of recombinant factor VIIa in the treatment of bleeding disorders

Recombinant factor VIIa was initially developed for the treatment of hemorrhagic episodes in hemophilic patients with inhibitors to factors VIII and IX. After its introduction, it has also been used "off-label" to enhance hemostasis in nonhemophilic patients who experience bleeding episodes not responsive to conventional therapy. Evidence so far indicates that the use of factor VIIa in hemophilic patients with inhibitors is both safe and effective. Anecdotal reports also suggest that the product is safe and effective in controlling bleeding in nonhemophilic patients. However, its use in these conditions has not been approved by the FDA, and conclusive evidence of its effectiveness from controlled clinical trials is not yet available. Several questions pertaining to the use of factor VIIa require further investigation, including the mechanism of action; the optimal dose; definitive indications; ultimate safety; and laboratory tests for monitoring therapy.