Early and intensive therapy of intravascular coagulation in acute liver failure

Microcirculatory disturbance in acute liver injury is triggered by IFNγ-CD40 axis

BACKGROUND

Acute liver failure (ALF) is a life-threatening disorder that progresses from self-limiting acute liver injury (ALI). Microcirculatory disturbance characterized by sinusoidal hypercoagulation and subsequent massive hypoxic hepatocyte damage have been proposed to be the mechanism by which ALI deteriorates to ALF; however, the precise molecular pathway of the sinusoidal hypercoagulation remains unknown. Here, we analyzed ALI patients and mice models to uncover the pathogenesis of ALI with microcirculatory disturbance.

METHODS

We conducted a single-center retrospective study for ALI and blood samples and liver tissues were analyzed to evaluate the microcirculatory disturbance in ALI patients (n = 120). Single-cell RNA sequencing analysis (scRNA-seq) was applied to the liver from the concanavalin A (Con A)‑induced mouse model of ALI. Interferon-gamma (IFNγ) and tumor necrosis factor-alpha knockout mice, and primary human liver sinusoidal endothelial cells (LSECs) were used to assess the mechanism of microcirculatory disturbance.

RESULTS

The serum IFNγ concentrations were significantly higher in ALI patients with microcirculatory disturbance than in patients without microcirculatory disturbance, and the IFNγ was upregulated in the Con A mouse model which presented microcirculatory disturbance. Hepatic IFNγ expression was increased as early as 1 hour after Con A treatment prior to sinusoidal hypercoagulation and hypoxic liver damage. scRNA-seq revealed that IFNγ was upregulated in innate lymphoid cells and stimulated hepatic vascular endothelial cells at the early stage of liver injury. In IFNγ knockout mice treated with Con A, the sinusoidal hypercoagulation and liver damage were remarkably attenuated, concomitant with the complete inhibition of CD40 and tissue factor (TF) upregulation in vascular endothelial cells. By ligand-receptor analysis, CD40-CD40 ligand interaction was identified in vascular endothelial cells. In human LSECs, IFNγ upregulated CD40 expression and TF was further induced by increased CD40-CD40 ligand interaction. Consistent with these findings, hepatic CD40 expression was significantly elevated in human ALI patients with microcirculatory disturbance.

CONCLUSION

We identified the critical role of the IFNγ-CD40 axis as the molecular mechanism of microcirculatory disturbance in ALI. This finding may provide novel insights into the pathogenesis of ALI and potentially contribute to the emergence of new therapeutic strategies for ALI patients.

Platelet function during haemoperfusion in acute liver failure

The changes in platelet-related haemostatic parameters have been studied during haemoperfusion of eleven patients with acute liver failure. Five patients were treated by haemoperfusion with an albumin-coated resin column and six with a polymer-coated charcoal column. The platelet and white cell losses over four hours’ haemoperfusion were small in both groups. Significant increases in β-thromboglobulin (mean 341 ± SE 145 ng/ml) were seen after one hour in the patients treated by charcoal haemoperfusion. One patient in the charcoal group with the greatest rises in β-thromboglobulin (860 hg/ml) and screen filtration pressure (205 mmHg) developed severe hypotension and haemoperfusion was terminated after 1 hour. One patient in the resin group showed rapid consumption of heparin after 2 hours. Measurement of β-thromboglobulin is a sensitive assay of platelet activation during haemoperfusion. Albumin-coated resin haemoperfusion appears to be a more blood-compatible procedure with respect to platelets than charcoal haemoperfusion.

Fibrinogen-γ proteolysis and solubility dynamics during apoptotic mouse liver injury: heparin prevents and treats liver damage

Fas ligand (FasL)-mediated hepatocyte apoptosis occurs in the context of acute liver injury that can be accompanied by intravascular coagulation (IC). We tested the hypothesis that analysis of selected protein fractions from livers undergoing apoptosis will shed light on mechanisms that are involved in liver injury that might be amenable to intervention. Proteomic analysis of the major insoluble liver proteins after FasL exposure for 4-5 hours identified fibrinogen-γ (FIB-γ) dimers and FIB-γ-containing high molecular mass complexes among the major insoluble proteins visible via Coomassie blue staining. Presence of the FIB-γ-containing products was confirmed using FIB-γ-specific antibodies. The FIB-γ-containing products partition selectively and quantitatively into the liver parenchyma after inducing apoptosis. Similar formation of FIB-γ products occurs after acetaminophen administration. The observed intrahepatic IC raised the possibility that heparin therapy may ameliorate FasL-mediated liver injury. Notably, heparin administration in mice 4 hours before or up to 2 hours after FasL injection resulted in a dramatic reduction of liver injury-including liver hemorrhage, serum alanine aminotransferase, caspase activation, and liver apoptosis-compared with heparin-untreated mice. Heparin did not directly interfere with FasL-induced apoptosis in isolated hepatocytes, and heparin-treated mice survived the FasL-induced liver injury longer compared with heparin-untreated animals. There was a sharp, near-simultaneous rise in FasL-induced intrahepatic apoptosis and coagulation, with IC remaining stable while apoptosis continued to increase.

CONCLUSION

Formation of FIB-γ dimers and their high molecular mass products are readily detectable within the liver during mouse apoptotic liver injury. Heparin provides a potential therapeutic modality, because it not only prevents extensive FasL-related liver injury but also limits the extent of injury if given at early stages of injury exposure.

Early prediction of short-term development of hepatic encephalopathy in patients with acute liver disease unrelated to paracetamol. A prospective study in Japan

BACKGROUND/AIMS

The aim of our study was to provide a predictive model for early recognition of the risk of short-term development of hepatic encephalopathy (HE) in patients with symptomatic acute liver disease (ALD).

METHODS

From a retrospective analysis of 220 patients with ALD, prothrombin time (PT) equal to, or lower than, 80% of normal, was set as the registration criteria in the subsequent patient cohorts of the study. Then, a HE-prediction model was derived by a logistic regression analysis of data in 259 new patients, and prospectively validated in 124 other patients, both groups of patients were affected by ALD unrelated to paracetamol (non-P ALD).

RESULTS

The following HE-prediction model was established: lambda = [0.692 x ln(1 + total bilirubin(mg/dL))] - 0.065 x PT(%) + [1.388 x Age(years)] + [0.868 x Etiology] - 1.156, where Age is 1 in patients older than 50 years and Etiology is 1 when the cause of non-P ALD is flare-up of type B hepatitis, auto-immune hepatitis or unknown, and 0 otherwise. In the validation group, according to the model-based risk of subsequent development of HE, sensitivity and specificity of the model were 100% and 69.0%, respectively, in patients with an evaluated risk lower than 20%, and 62.5% and 93.1%, respectively, in those with an evaluated risk equal to, or greater than, 50%.

CONCLUSION

In Japanese patients with symptomatic non-P ALD, our model, which includes four of the five items used in the King's College Hospital criteria, represents an acceptable, effective model to allow early detection of the risk of short-term development of HE. Using this model in other populations requires further validation specific to each of them.

Intravenous N-acetylcysteine improves transplant-free survival in early stage non-acetaminophen acute liver failure

BACKGROUND & AIMS

N-acetylcysteine (NAC), an antidote for acetaminophen poisoning, might benefit patients with non-acetaminophen-related acute liver failure.

METHODS

In a prospective, double-blind trial, acute liver failure patients without clinical or historical evidence of acetaminophen overdose were stratified by site and coma grade and assigned randomly to groups that were given NAC or placebo (dextrose) infusion for 72 hours. The primary outcome was overall survival at 3 weeks. Secondary outcomes included transplant-free survival and rate of transplantation.

RESULTS

A total of 173 patients received NAC (n = 81) or placebo (n = 92). Overall survival at 3 weeks was 70% for patients given NAC and 66% for patients given placebo (1-sided P = .283). Transplant-free survival was significantly better for NAC patients (40%) than for those given placebo (27%; 1-sided P = .043). The benefits of transplant-free survival were confined to the 114 patients with coma grades I-II who received NAC (52% compared with 30% for placebo; 1-sided P = .010); transplant-free survival for the 59 patients with coma grades III-IV was 9% in those given NAC and 22% in those given placebo (1-sided P = .912). The transplantation rate was lower in the NAC group but was not significantly different between groups (32% vs 45%; P = .093). Intravenous NAC generally was well tolerated; only nausea and vomiting occurred significantly more frequently in the NAC group (14% vs 4%; P = .031).

CONCLUSIONS

Intravenous NAC improves transplant-free survival in patients with early stage non-acetaminophen-related acute liver failure. Patients with advanced coma grades do not benefit from NAC and typically require emergency liver transplantation.

Acute liver failure: Summary of a workshop

Acute liver failure (ALF) is a rare but challenging clinical syndrome with multiple causes; a specific etiology cannot be identified in 15% of adult and 50% of pediatric cases. The course of ALF is variable and the mortality rate is high. Liver transplantation is the only therapy of proven benefit, but the rapidity of progression and the variable course of ALF limit its use. Currently in the United States, spontaneous survival occurs in approximately 45%, liver transplantation in 25%, and death without transplantation in 30% of adults with ALF. Higher rates of spontaneous recovery (56%) and transplantation (31%) with lower rates of death (13%) occur in children. The outcome of ALF varies by etiology, favorable prognoses being found with acetaminophen overdose, hepatitis A, and ischemia (approximately 60% spontaneous survival), and poor prognoses with drug-induced ALF, hepatitis B, and indeterminate cases (approximately 25% spontaneous survival). Excellent intensive care is critical in management of patients with ALF. Nonspecific therapies are of unproven benefit. Future possible therapeutic approaches include N-acetylcysteine, hypothermia, liver assist devices, and hepatocyte transplantation. Advances in stem cell research may allow provision of cells for bioartificial liver support. ALF presents many challenging opportunities in both clinical and basic research.

Recombinant activated factor VII for coagulopathy in fulminant hepatic failure compared with conventional therapy

Severe coagulopathy in fulminant hepatic failure (FHF) is difficult to correct by conventional means. Recombinant activated factor VII (rFVIIa) is an antihemophilic factor that has shown promise in treating coagulopathy in liver disease. Our aim is to review our experience with rFVIIa in treating the coagulopathy of FHF and compare these results with those of conventional therapy. Fifteen patients with FHF who met King's College criteria for orthotopic liver transplantation were studied. All were ascertained from our liver disease registry. Eight consecutive patients were administered fresh frozen plasma (FFP) alone, whereas seven consecutive patients were administered FFP and rFVIIa (40 microg/kg intravenous bolus). The two groups, with similar demographic characteristics, were compared in terms of measured parameters of coagulopathy (prothrombin time and international normalized ratio), amount of plasma infused, development of anasarca, ability to undergo intracranial pressure (ICP) transducer placement, bleeding complications, ability to undergo transplantation, and survival. All patients administered rFVIIa (after a single dose) versus none administered FFP alone had temporary (2- to 6-hour) correction of coagulopathy (P <.0002). All patients administered rFVIIa versus 38% administered FFP alone were able to have an ICP transducer placed (P =.03). The rFVIIa group had less anasarca (P =.04). An equal number of patients underwent transplantation from each group, but overall survival was slightly better in the rFVIIa group (P =.04). Five of seven patients in the rFVIIa group were administered one or more subsequent doses of rFVIIa after placement of the ICP monitor (two patients, for additional procedures; three patients, prophylactically in the first 24 hours after ICP transducer placement) at the discretion of the attending physicians. We conclude that rFVIIa is effective in transiently correcting laboratory parameters of coagulopathy in patients with FHF. It facilitates the performance of invasive procedures and is associated with less frequent anasarca compared with conventional therapy. Our preliminary experience supports the need for further studies to define the optimal dosing, safety, and efficacy of rFVIIa in patients with FHF.

Indications and criteria for liver transplantation for fulminant hepatic failure

Liver transplantation is the only effective treatment for potentially fatal cases of fulminant hepatic failure. However, it is very difficult to predict which cases will be fatal. The mortality may depend on alternative medical therapies. According to a nationwide survey of patients with fulminant hepatic failure presenting with encephalopathy of a coma grade greater than II within 8 weeks from the first symptoms of illness with a prothrombin time less than 40% of normal value, there were 93 patients in 311 hospitals between January and December 1998 in Japan. During this period, there were 11 patients with late-onset hepatic failure. The etiology was HAV infection in 4%, HBV infection in 44%, and nonA-nonB in 41%. Specific therapies were intensively used in all patients. The mean survival rate was 41%, with differences depending on the etiology. Six patients underwent liver transplantation, and 5 survived. In animal experiments, sinusoidal fibrin deposition caused massive liver necrosis. Activation of Kupffer cells and hepatic macrophages was a major contributing factor of this development. There were different mechanisms of such fibrin deposition. Tumor necrosis factor-alpha and superoxide anions released from hepatic macrophages after endotoxin administration destroyed endothelial cells, and then coagulopathy occurred in the sinusoids in rats given Propionibacteriom acnes, while a tissue factor from Kupffer cells played that role in rats undergoing partial hepatectomy. The prognosis of fulminant hepatic failure may depend on the etiology. The indication for liver transplantation for this disease must be carefully decided by analyzing the etiology, pathological conditions, and response to therapies in each case.

Molecular and functional analysis of the human prothrombinase gene (HFGL2) and its role in viral hepatitis

In the present studies, we report the cloning and structural characterization of the HFGL2 gene and its functional role in human fulminant hepatitis. The HFGL2 gene is approximately 7 kb in length with 2 exons. The putative promoter contains cis element consensus sequences that strongly suggest the inducibility of its expression. From the nucleotide sequence of the human gene, a 439-amino acid long protein is predicted. The overall identity between the murine fgl2 and hfgl2 coded proteins is over 70%. About 225 amino acids at the carboxyl end of these molecules are almost 90% identical, and correspond to a well-conserved fibrinogen-related domain. Both HFGL2 and FGL2 encode a type II transmembrane protein with a predicted catalytic domain toward the amino terminus of the protein. Transient transfection of Chinese hamster ovary (CHO) cells with a full-length cDNA of HFGL2 coding region resulted in high levels of prothrombinase activity. Livers from 8 patients transplanted for fulminant viral hepatitis were examined for extent of necrosis, inflammation, fibrin deposition, and HFGL2 induction. In situ hybridization showed positive staining of macrophages in areas of active hepatocellular necrosis. Fibrin stained positively in these areas and was confirmed by electron microscopy. These studies define a unique prothrombinase gene (HFGL2) and implicate its importance in the pathogenesis of fulminant viral hepatitis.

Expression of the thrombin receptor in human liver: up-regulation during acute and chronic injury

Thrombin is generated during tissue damage in several organs, including the liver, and participates in the process of tissue repair through proteolytic activation of a specific thrombin receptor (TR). The aim of this study was to investigate TR expression in human liver by immunohistochemistry and in situ hybridization. In normal liver, immunostaining for TR was present in the endothelial lining of the hepatic sinusoids. During chronic hepatitis, several cells expressing the TR were detected in the inflammatory infiltrate of portal tracts. In cirrhosis with chronic active hepatitis, expression of the TR was also present in mesenchymal cells of fibrous septa. TR expression was markedly up-regulated during fulminant hepatitis, with the highest expression in mesenchymal cells in areas of regeneration. Up-regulation of TR expression was associated with increased levels of TR messenger RNA (mRNA), as assessed by in situ hybridization and RNAse protection assay of liver RNA. Immunostaining of serial sections using specific cellular markers showed that different nonparenchymal cells contribute to TR expression during liver injury. TR expression was also shown in cultured human hepatic stellate cells, with increasing signal comparing activated versus quiescent cells. Because thrombin is rapidly generated after tissue damage, regulated TR expression may be involved in tissue remodeling and/or scarring during liver damage.

Loss of resistance to murine hepatitis virus strain 3 infection after treatment with corticosteroids is associated with induction of macrophage procoagulant activity

Activation of the immune coagulation system has been implicated in the pathogenesis of liver injury following infection of inbred mice with murine hepatitis virus strain 3 (MHV-3). Following MHV-3 infection, macrophages isolated from MHV-3-susceptible and -semisusceptible inbred strains of mice express increased procoagulant activity (PCA), whereas macrophages from resistant strains express no increase in PCA over basal levels. The PCA induced by MHV-3 is a prothrombinase, encoded by the gene Fgl-2, which encodes a fibrinogen-like protein (musfiblp). In this study, MHV-3-resistant A/J mice treated with methylprednisolone prior to infection with MHV-3 developed elevated levels of alanine aminotransferase in serum and died within 10 days of infection, with histological findings of fulminant hepatitis. In vitro, macrophages isolated from A/J mice and pretreated with methylprednisolone produced a marked increase in functional PCA following infection with MHV-3. The PCA was shown to be a prothrombinase by its ability to cleave 125I-prothrombin. Northern blot analysis of RNA transcripts from these macrophages demonstrated increased transcription of the Fgl-2 gene relative to that in macrophages which had not been pretreated with methylprednisolone prior to MHV-3 infection. Methylprednisolone pretreatment of MHV-3-infected macrophages stabilized the Fgl-2 mRNA. Thus, loss of resistance to MHV-3 secondary to methylprednisolone therapy is associated with increased transcription and stability of Fgl-2 mRNA resulting in expression of the Fgl-2 gene product, musfiblp. These results provide further insight into mechanisms of PCA regulation in response to MHV-3 infection in inbred strains of mice.

Thrombin stimulates proliferation of liver fat-storing cells and expression of monocyte chemotactic protein-1: potential role in liver injury

Liver fat-storing cells (FSC) proliferate and secrete extracellular matrix in experimental models of liver injury. In this study, we determined if thrombin, a serine protease produced during acute and chronic tissue injury, modulates the functions of FSC. Thrombin stimulated DNA synthesis and proliferation of FSC, as assessed by [3H]-thymidine incorporation assay and measurement of cell number, respectively. Thrombin also increased the secretion of monocyte chemotactic protein-1 (MCP-1) in a time- and dose-dependent fashion. The effect of thrombin on both DNA synthesis and MCP-1 secretion was neutralized by pretreatment of thrombin with hirudin. The increased MCP-1 secretion was associated with increased steady-state levels of MCP-1 messenger RNA. Pretreatment of FSC with 5 mumol/retinol for 48 hours inhibited the mitogenic effects of thrombin but not the induction of MCP-1 secretion. FSC express specific transcripts encoding for the human thrombin receptor, as shown by Northern blot analysis of poly(A)+ RNA. Proteolytic activation of the thrombin receptor results in the formation of a new N-terminus that functions as a tethered ligand. We studied the effects of a thrombin receptor activating peptide (TRAP) corresponding to the newly formed N-terminus on FSC. TRAP mimicked the effects of thrombin on [3H]-thymidine incorporation, MCP-1 secretion, and MCP-1 gene expression. This study suggest that thrombin may be involved in modulating FSC proliferation and monocyte chemotaxis during human liver disease, through proteolytic activation of its receptor.

Importance of measuring plasma thrombin-antithrombin III complex levels when using antithrombin III concentrate therapy in fulminant hepatic failure

We investigated changes in the concentrations of thrombin-antithrombin III complex (TAT) and plasmin-alpha 2 plasmin inhibitor complex (PIC) after the intravenous administration of 4000 units of antithrombin III (AT III) concentrate to patients with fulminant hepatic failure (FHF), subacute hepatitis (SH), or liver cirrhosis (LC). FHF patients showed shortening of the initial half-life of exogenous AT III. In addition, a marked rise in plasma TAT was noted 3 to 6 h after the intravenous administration of AT III, even in patients who had a normal plasma TAT level before AT III therapy. In contrast, SH and LC patients showed no marked changes of plasma TAT levels after AT III administration. No marked changes were observed in the PIC concentration in any of the patients. These findings suggest that thrombin formation is increased in FHF and that simple measurement of the plasma TAT concentration is not an adequate method for assessing thrombin formation in FHF patients who have suspected disseminated intravascular coagulation associated with an apparent decrease in AT III synthesis. Instead, it seems necessary to measure the plasma TAT concentration in FHF patients after replacement therapy with AT III concentrate has been performed, to evaluate their hypercoagulability more accurately.

Hepatic sinusoidal cell destruction in the development of intravascular coagulation in acute liver failure of rats

Rats received a dose of dimethylnitrosamine (DMN) or carbon tetrachloride (CCl4). In the liver of rats given DMN, apoptosis of fat-storing cells occurred at 7.5 h, and sinusoidal endothelial cell degeneration followed, with parenchymal cell necrosis after 9 h. Fibrin thrombi appeared in the sinusoids as well as in these necrotic areas after 12 h. In contrast, in the liver of rats given CCl4, parenchymal cell degeneration was seen after 6 h and necrosis with fibrin thrombi developed after 9 h. Fat-storing cells and endothelial cells were almost intact, and fibrin thrombi were not present in the sinusoids. SGPT values increased with decreased plasma levels of fibrinogen and antithrombin III and prolonged prothrombin time after 3 and 6 h, in the CCl4 and DMN models, respectively. An extensive reduction in plasma factor VIIIC levels and peripheral platelets was seen after 18 and 24 h, respectively, only in the DMN model. These results suggest that endothelial cells destruction can cause fibrin formation in the hepatic sinusoids in acute liver injury. Fat-storing cell injury may contribute to the destruction.

Plasma alpha 2-plasmin inhibitor-plasmin complex and FDP-D-Dimer in fulminant hepatic failure

Plasma levels of alpha 2-plasmin inhibitor-plasmin complex (PI-Pm) and FDP-D-Dimer (FDP-D), one of cross-linked fibrin degradation products, were determined at 42 points in time in 8 patients with fulminant hepatic failure. PI-Pm was abnormally increased at all 25 points when intractable bleeding was present, whereas FDP-D was increased only at 5 of these points. Of 17 points unassociated with such bleeding, both PI-Pm and FDP-D were increased at 3 points; increased PI-Pm alone was found at 1 point measured next day after the bleeding ceased; and increased FDP-D alone were at 5 points when ascites, one of common complications of fulminant hepatic failure, developed. When PI-Pm was increased, plasma levels of fibrin/fibrinogen degradation products (FDP) changed together with FDP-D.

Antithrombin III concentrate in the treatment of fulminant hepatic failure

Twenty-six patients with fulminant hepatic failure were treated with daily infusions of antithrombin III concentrate until recovery of consciousness or death. Seven patients were alive (group A), 7 survived 17 to 47 days after treatment (group B), and 12 died within 9 days (group C). Decreased plasma antithrombin III levels increased on the day after treatment, irrespective of the pretreatment levels in all patients. Continuous or temporary normalization was seen in all patients in groups A and B, but in only 5 in group C patients whose bleeding was extensive (p less than 0.05). An abrupt drop in peripheral platelet counts occurred when plasma antithrombin III levels were below normal. General bleeding accompanied this drop. These results suggest that maintained normal plasma antithrombin III levels are beneficial for prolonged survival time in fulminant hepatic failure, probably through controlling intravascular coagulation, and that antithrombin III infusion may be useful for such treatment.

Report of a case with fulminant hepatitis A associated with acute renal failure

A 34-year-old male presented with fulminant hepatitis A associated with acute renal failure. The patient was admitted four days after flu-like symptoms developed. Physical examination was unremarkable except for icteric sclerae. Laboratory studies showed SGOT 10719 U/l, SGPT 5780 U/l, prothrombin time 22%, BUN 25.5 mg/dl, and creatinine 2 mg/dl. Serum complements were within normal ranges, and circulating immune complexes were not detected. Anti-HAV IgM was positive. He developed hepatic coma on the fourth hospital day, and his renal function deteriorated progressively. He was treated with hemodialysis, but there was no improvement in consciousness. Although acute liver failure improved, he died on the 74th hospital day of subendocardial infarction. Autopsy examination showed acute renal tubular necrosis. The liver was enlarged and was in the residual stage of acute hepatitis without submassive necrosis. The development of fulminant hepatitis in hepatitis A has been rare, but in recent years acute renal failure in hepatitis A has been reported. Although the mechanisms responsible for renal failure in liver diseases are uncertain but could be multifactorial, immune complex-mediated nephritis and/or endotoxemia have been considered.

Treatment of severe coagulation disturbances as a condition of improved prognosis in fulminant liver failure

A favourable outcome of fulminant liver failure by replacement treatment with antithrombin III, prothrombin concentrate, fresh frozen plasma, and plasminogen is reported. Haemostatic balance was maintained and no severe bleeding complications occurred during the 15 days of disturbed liver function.

Characterization of the biological activity of antithrombin III in patients with hepatic cirrhosis

A discrepancy was found in hepatic cirrhosis patients between two forms of biological activities, i.e. progressive antithrombin activity (prog AT) and heparin cofactor activity (heparin AT). A reduced level of heparin AT was obtained in comparison with that of prog AT, despite the fact that both activities correlated well in normal controls. The binding ability of AT III to heparin was observed by crossed immunoelectrophoresis, and showed a reduced second peak of AT III with a faster AT III with a qualitative defect in its binding ability to heparin due to impaired protein synthesis.

Fulminant hepatic failure: a rare but often lethal coma syndrome

Fulminant hepatic failure is an extremely rare coma syndrome resulting from massive necrosis of liver cells. A wide variety of etiologic agents have been identified, including viruses, drugs, and other toxic agents. Treatment focuses on reducing the ammonia load presented to the liver and on preventing or controlling complications, including sepsis, bleeding, cerebral edema, renal failure, and respiratory failure. With further research and identification of the specific toxins or metabolic derangements underlying the pathophysiology of this syndrome, more effective therapeutic measures may be devised.

Idiopathic fatty liver of pregnancy with maternal and fetal survival

A case of idiopathic fatty liver of pregnancy with survival of mother and child is reported. The management of this condition is essentially supportive; coagulation disturbances may require special attention. Maternal survival should be the major consideration and is favourably influenced by early delivery. Fetal monitoring aids obstetric management and may indirectly improve fetal survival. Evidence from the literature suggests that the condition does not usually recur in subsequent pregnancies.

Pitfalls in peripheral vascular surgery: Disseminated intravascular coagulation

Disseminated intravascular coagulation is infrequently encountered in the practice of peripheral vascular surgery. Nonetheless, it has devastating and often fatal effects. In our series of eight cases, the mortality rate was 62.5 per cent. A better understanding of the basic disease process as prompted by this review, earlier diagnosis, and rational treatment should lead to higher survival rates and lowered morbidity.

Blood coagulations studies in pregnant patients with infective hepatitis

Coagulation studies were made on 22 pregnant women with acute infective hepatitis and on 15 normal control pregnant women in third trimester. Fourteen hapatitis patients had clinical evidence of liver failure and all of them had a haemorrhagic diathesis; none of the patients without liver failure showed clinical evidence of haemostatic defects. Coagulopathy was present in most patients, its severity being greater in those with hepatic failure. Significant alterations were observed in bleeding time, whole blood clotting time, prothrombin time, thrombin time, plasma fibrinogen and serum levels of fibrinogen degradation products. The last three disturbances were most frequent in patients with liver failure. Increased fibrinolysis and disseminated intravascular coagulation also appeared to play a contributory role, particularly in patients with hepatic failure.

Acute liver failure. Experience in a special unit

Acute liver failure involves disturbances of all major organ systems. The pathophysiology of these disturbances are reviewed and details of management for each system is discussed in clinical work in a special Liver Failure Unit is used to derive principles of treatment, and the use of extracorporeal charcoal haemoperfusion is outlined.

Fulminant hepatic failure secondary to congestive heart failure

An elderly female with an acute episode of congestive heart failure, unaccompanied by any periods of hypotension, developed fulminant hepatic failure with an accompanying coagulopathy. Attempts to establish an etiology for her acute hepatic insufficiency, other than cardiac failure, proved negative. Fulminant hepatic failure as a consequence of congestive heart failure, without prolonged periods of hypotension preceding alteration in hepatic function, has not heretofore been described. Liver function is adversely effected in congestive heart failure. Hepatic ammonia clearance is impaired in cardiac failure and may be diminished to the point of resulting in hepatic encephalopathy. Coagulopathy is a frequent concomitant of fulminant hepatic failure. Establishing a clear etiology for a coagulopathy in the face of concomitant liver disease is difficult, thus making any therapeutic intervention fraught with peril.

Jaundice in pregnancy--1976

An integrative survey is given of three disease processes, in which recent progress of a fundamental nature has been made, primarily affecting the liver, either coincident with or caused by the gravid state. The three conditions considered include (1) recurrent cholestasis of pregnancy (RCP), (2) viral hepatitis coincident with pregnancy, and (3) acute fatty liver of pregnancy (AFLP). In addition to an assessment of our present knowledge with respect to RCP and AFLP, new genetic hypotheses are proposed. In the latter, the proposal of an ornithine transcarbamylase deficiency, similar to that seen in Reye's syndrome, has potential therapeutic implications that are explored. In light of the currently available information on the interaction between maternal viral hepatitis and the variant forms of vertical maternal-fetal transmission, tentative recommendations regarding management of the newborn are suggested.

A model which can be used to improve the treatment of acute hepatic failure

A model using the pig from wich the liver has been removed for isolated perfusion, as a subject showing some of the features of acute hepatic failure for later treatment by cross-circulation with its own perfused liver, is desceribed. Effects of such a procedure on such a procedure on the glucose and halothane metabolism and intravascular coagulation and bleeding are detailed.

Haemorrhage as a complication of extracorporeal pig liver perfusion: studies on mechanism and prevention

The use of extracorporeal pig liver perfusion for temporary liver support has been followed not infrequently by major bleeding with a fall in coagulation factors and platelets, rather than a rise as hoped. In 18 experimental perfusions in which (125)I-labelled fibrinogen was used as a marker there was in every instance a significant loss of the fibrinogen into the fluid supporting the liver in the perfusion chamber. Further, in 11 of the perfusions there was an additional loss into liver substance, this being associated with a very rapid fall in (125)I fibrinogen and platelets content of the perfusion fluid. Damage to the sinusoids from ischaemic damage incurred during removal of the liver could explain both the direct loss of fibrinogen and, as a result of intravascular coagulation, the associated loss within the perfused liver. No correlation could be found with biochemical function, but it proved possible to assess haematological safety before connexion of the patient to the perfusion by a shortened (125)I fibrinogen test. This was done in three patients treated by five perfusions and in none was the thrombocytopenia or coagulation disturbance adversely affected.