Hepatic encephalopathy: Novel insights into classification, pathophysiology and therapy

Hepatic encephalopathy (HE) is a frequent and serious complication of both chronic liver disease and acute liver failure. HE manifests as a wide spectrum of neuropsychiatric abnormalities, from subclinical changes (mild cognitive impairment) to marked disorientation, confusion and coma. The clinical and economic burden of HE is considerable, and it contributes greatly to impaired quality of life, morbidity and mortality. This review will critically discuss the latest classification of HE, as well as the pathogenesis and pathophysiological pathways underlying the neurological decline in patients with end-stage liver disease. In addition, management strategies, diagnostic approaches, currently available therapeutic options and novel treatment strategies are discussed.

Hepatic encephalopathy for the hospitalist

The care of patients with advanced liver disease is often complicated by episodes of acute decline in alertness and cognition, termed hepatic encephalopathy (HE). Hospitalists must be familiar with HE, as it is a common reason for hospitalization in this population and is associated with significantly increased mortality. This narrative review addresses common issues related to diagnosis and classification, precipitants, inpatient management, and transitions of care for patients with HE. The initial presentation can be variable, and HE remains a clinical diagnosis. The spectrum of HE manifestations spans from mild, subclinical cognitive deficits to overt coma. The West Haven scoring system is the most widely used classification system for HE. Various metabolic insults may precipitate HE, and providers must specifically seek to rule out infection and bleeding in cirrhotic patients presenting with altered cognition. This is consistent with the 4-pronged approach of the American Association for the Study of Liver Disease practice guidelines. Patients with HE are typically treated primarily with nonabsorbable disaccharide laxatives, often with adjunctive rifaximin. The evidence for these agents is discussed, and available support for other treatment options is presented. Management issues relevant to general hospitalists include those related to acute pain management, decisional capacity, and HE following transjugular intrahepatic portosystemic shunt placement. These issues are examined individually. Successfully transitioning patients recovering from HE to outpatient care requires open communication with multiple role players including patients, caregivers, and outpatient providers. Journal of Hospital Medicine 2016;11:591-594. © 2016 Society of Hospital Medicine.

From Child-Pugh to Model for End-Stage Liver Disease: Deciding Who Needs a Liver Transplant

This article reviews the historical evolution of the liver transplant organ allocation policy and the indications/contraindications for liver transplant, and provides an overview of the liver transplant evaluation process. The article is intended to help internists determine whether and when referral to a liver transplant center is indicated, and to help internists to counsel patients whose initial evaluation at a transplant center is pending.

[Hepatic encephalopathy – the acute management]

Hepatic encephalopathy causes significant impairment and morbidity. Hepatic encephalopathy is just one of many causes for altered mental status in patients with cirrhosis of the liver. The initial management at admission to hospital includes a search for differential diagnoses and precipitating factors. A structured description of the type, cause, time course and clinical severity is essential for achieving medically safe communication and care of the HE patient. Lactulose and correction of any precipitating factors is the basis for initial therapy. A post-discharge management which includes frequent monitoring, preventive measures as well as education of patient and caregivers may ameliorate the often very high readmission rate.

Ammonia and Its Role in the Pathogenesis of Hepatic Encephalopathy

Hepatic encephalopathy (HE) is a commonly encountered sequela of chronic liver disease and cirrhosis with significant associated morbidity and mortality. Although ammonia is implicated in the pathogenesis of HE, the exact underlying mechanisms still remain poorly understood. Its role in the urea cycle, astrocyte swelling, and glutamine and gamma-amino-n-butyric acid systems suggests that the pathogenesis is multifaceted. Greater understanding in its underlying mechanism may offer more targeted therapeutic options in the future, and thus further research is necessary to fully understand the pathogenesis of HE.

Viability assessment of magnetic resonance spectroscopy for the detection of minimal hepatic encephalopathy severity

OBJECTIVE

To evaluate regional cerebral metabolic changes in minimal hepatic encephalopathy (MHE) patients using magnetic resonance spectroscopy (MRS) in 3T scanner.

MATERIALS AND METHODS

This study comprised 30 cirrhotic patients with MHE, 29 cirrhotic patients without MHE and 30 healthy volunteers. Single-voxel proton MRS data in the anterior cingulate cortex (ACC) and basal ganglia were acquired using a 3-T scanner. The concentrations of N-acetylaspartate (NAA), mI (myo-inositol), glutamate (Glu), glutamine (Gln) and creatine (Cr) were obtained by LC-model software. Statistical analysis was performed to evaluate the differences between the three groups.

RESULTS

There was a significant increase in Glu for the cirrhotic patients, particularly the MHE patients. There was an elevation of Gln in the cirrhotic patients, but not in all cirrhotic patients or controls. There was a significant decrease in mI for the cirrhotic patients, but no significant difference between the two cirrhosis groups. There was no significant difference in NAA between the three groups.

CONCLUSIONS

MRS using a 3-T MR scanner could detect cerebral metabolic changes in cirrhotic patients with MHE. Glu levels were elevated in cirrhotic patients with MHE; Glu levels could be used as a sensitive indicator to evaluate the severity of MHE in patients with cirrhosis.

[Hepatic encephalopathy: recent developments]

Hepatic encephalopathy is a neurological syndrome occurring in patients with liver failure or in those with a large porto-systemic shunt. In cirrhotic patients, the current classification comprises covert and overt encephalopathy. Diagnosis of covert encephalopathy requires sensitive tests. Lactulose and rifaximin are the two leading therapeutic options. Rifaximin is efficacious for maintaining remission from hepatic encephalopathy. Liver transplantation should be discussed in cirrhotic patients with encephalopathy.

Concise review of current concepts on nomenclature and pathophysiology of hepatic encephalopathy

Hepatic encephalopathy is a neuropsychiatric complication of liver cirrhosis the symptoms of which may vary from imperceptible to severe, invaliding, and even lethal. Minimal hepatic encephalopathy is also important because of its tendency to impair patients' cognitive functions and quality of life. The polyetiological pathogenesis of hepatic encephalopathy is intensively studied. A general consensus exists that not only excess of ammonia but also inflammatory, oxidative, and other processes are significant in the development of hepatic encephalopathy.

Acetyl-L-carnitine in hepatic encephalopathy

Hepatic encephalopathy is a common complication of hepatic cirrhosis. The clinical diagnosis is based on two concurrent types of symptoms: impaired mental status and impaired neuromotor function. Impaired mental status is characterized by deterioration in mental status with psychomotor dysfunction, impaired memory, and increased reaction time, sensory abnormalities, poor concentration, disorientation and coma. Impaired neuromotor function include hyperreflexia, rigidity, myoclonus and asterixis. The pathogenesis of hepatic encephalopathy has not been clearly defined. The general consensus is that elevated levels of ammonia and an inflammatory response work in synergy to cause astrocyte to swell and fluid to accumulate in the brain which is thought to explain the symptoms of hepatic encephalopathy. Acetyl-L-carnitine, the short-chain ester of carnitine is endogenously produced within mitochondria and peroxisomes and is involved in the transport of acetyl-moieties across the membranes of these organelles. Acetyl-L-carnitine administration has shown the recovery of neuropsychological activities related to attention/concentration, visual scanning and tracking, psychomotor speed and mental flexibility, language short-term memory, attention, and computing ability. In fact, Acetyl-L-carnitine induces ureagenesis leading to decreased blood and brain ammonia levels. Acetyl-L-carnitine treatment decreases the severity of mental and physical fatigue, depression cognitive impairment and improves health-related quality of life. The aim of this review was to provide an explanation on the possible toxic effects of ammonia in HE and evaluate the potential clinical benefits of ALC.

New perspectives in hepatic encephalopathy

The terminology of hepatic encephalopathy (HE) remained poorly defined for decades. One major problem was the lack of definition of what constituted acute versus chronic HE. Chronic HE caused more confusion because it was proposed to signify any bout of HE in patients with chronic liver disease, whereas others thought it denoted a protracted period of loss of consciousness. Numerous other versions were rampant. This mass confusion was solved by the report of the Hepatic Encephalopathy Consensus Group at the World Congress of Gastroenterology in 1998. This new multi-axial definition led to standardization of diagnosis and explosion in the field of research in HE.

Blood manganese levels in patients with hepatic encephalopathy

PROJECT

Hepatic encephalopathy is an increasingly common disease. Identification of prognosis risk factors in patients with liver damage may lead to preventive actions, towards decreasing its mortality. Manganese (Mn) levels are increased in basal ganglia of patients with hepatic encephalopathy as well as in cases of cirrhotic and liver failure patients. The present is a clinical, prospective, prolective and observational study developed at the Internal Medicine Service from "Dr. Darío Fernández Fierro" General Hospital, ISSSTE, Mexico City. The objective of this work was to report whole blood Mn levels and mortality in encephalopathic patients.

PROCEDURE

Consecutive patients over 18 years of age, diagnosed with hepatic encephalopathy were recruited at the emergency room service. An informed consent, signed by their families was collected. Patients' clinical characteristics, biochemical tests of renal function, hemoglobin, glucose, bilirubins and albumin levels were obtained along with a blood sample to analyze Mn. Patients evolution was followed up for 6 months.

RESULTS

Blood Mn in patients [median, (range)] [20.5, (10.5-39.5) μg/L] were higher than blood levels from a group of healthy volunteers [7.5, (6.1-12.8) μg/L] (P<0.001). Among 9 patients studied four died, 2 women and 2 men, those patients showed higher (P=0.032) Mn levels [28, (17-39.5) μg/L] than those alive [13.5, (10.5-32) μg/L] after the follow up period.

CONCLUSIONS

In this pilot study, Mn blood levels were higher in hepatic encephalopathy that died as consequence of the disease that those that survived in a 6 month follow up period. Blood Mn could be a potential prognosis factor for death in patients with hepatic encephalopathy.

Acute liver failure

Acute liver failure (ALF) is an uncommon condition involving the rapid deterioration of liver functions and coagulation in previously well patients. The loss of liver function produces a cascade of systemic effects that rapidly overwhelm patients unless acted on. The key to managing patients with ALF revolves around having the resources and expertise to manage patients with rapidly evolving multiple system failure.

Independent prognostic factors in patients with liver cirrhosis

BACKGROUND/AIMS

Evaluation of the urgency of the liver transplantation in individual patients may help to prioritize patients at risk of death. Consequently we undertook the search for independent prognostic factors in patients with liver cirrhosis.

METHODOLOGY

The study group was composed of 219 patients with liver cirrhosis, treated in our Department, from 1996 to 2005. Patients' files were examined for details of physical findings, results of laboratory examinations, and patients' survival. Prognostic significance of 15 variables was analyzed. All prognostic factors which turned out to be statistically significant in univariate analysis were included in the Cox proportional hazard model.

RESULTS

Child-Turcotte-Pugh (CTP) score B (p<0.001; hazard ratio (HR): 13.33), CTP score C (p<0.001; HR=7.45), presence of hepato-renal syndrome (p<0.001; HR=3.54), history of esophageal bleeding (p=0.048; HR=1.63) and presence of peripheral edema (p=0.034; HR=1.61) were found to be independently associated with survival. Model of End-stage Liver Disease score, etiology of cirrhosis, sex, ascites, bacterial spontaneous peritonitis, encephalopathy, serum creatinine concentration, INR and serum bilirubin concentration were shown to be significantly associated with patients' prognosis, however not independently.

CONCLUSIONS

Analysis of presence of common clinical symptoms is crucial for evaluation of patients' prognosis.

Prognostic factors in paediatric acute liver failure

OBJECTIVES

To study the aetiology, outcome and prognostic indicators in children with acute liver failure (ALF).

STUDY DESIGN

Retrospective chart review of 210 patients (107 males/103 females; median age: 5.33 years, range: 1-17.4). Patients were followed until discharge (group 1), death (group 2) or liver transplantation (LT; group 3). Data from group 1 were compared to data from the other two groups and King's College criteria were also assessed.

RESULTS

Final diagnoses were: 128 (61%) hepatitis A, 68 (32%) indeterminate and 14 (7%) others. The characteristics of patients who survived (n = 59), died (n = 61) and underwent LT (n = 90) were analysed. In multivariate analysis, prothrombin time and encephalopathy III/IV were the most significant parameters suggesting a high likelihood of death. When King's College criteria were applied on admission in patients with and without transplantation, the positive predictive values were 96% and 95%, and the negative predictive values were 82% and 82%, respectively.

CONCLUSIONS

Hepatitis A is the main cause of ALF in children in Argentina. Advanced encephalopathy and prolonged prothrombin time were significantly associated with death or need for LT. King's College criteria for predicting the outcome of ALF are applicable in children, including those with ALF due to hepatitis A infection.

Role of the nurse in managing patients with hepatic cerebral oedema

Acute liver failure occurs abruptly often without pre-existing liver disease being present. Management comprises support of the patient and treatment of symptoms until recovery or transplantation can occur. Cerebral oedema is one of the recognized complications of acute liver failure with a mortality rate of 30-50% when it occurs. Effective supportive nursing management includes use of sedative agents, positioning and thermoregulation if the patient is to recover or be optimized for transplantation.

Plasma met-enkephalin, beta-endorphin and leu-enkephalin levels in human hepatic encephalopathy

To address the role of the opioid system in the pathogenesis of hepatic encephalopathy (HE) we measured plasma met-enkephalin, beta-endorphin and leu-enkephalin in patients with different grades of HE compared to control subjects and patients with cirrhosis. Plasma met-enkephalin levels were significantly higher in patients with cirrhosis and all grades of HE than controls. Plasma beta-endorphin levels were similar in the 3 groups. Plasma leu-enkephalin levels were significantly higher in HE grades II, III and IV than in controls, patients with cirrhosis and HE grade I patients. Our results support data on the involvement of met-enkephalin and leu-enkephalin in the pathogenesis of HE and provide a rationale for the use of opioid receptor antagonists in the treatment of HE.

MELD score as a prognostic model for listing acute liver failure patients for liver transplantation

OBJECTIVES

The King's College Hospital (KCH) criteria are widely used for listing patients with acute liver failure (ALF) for liver transplantation (LT). Recent reports have suggested that the Model for End-Stage Liver Disease (MELD) score may be useful in assessing prognosis in ALF (nonparacetamol). This study compares prognostic accuracy of the two systems in patients with paracetamol (POD)-induced ALF treated in this unit.

METHODS

Seventy-two patients (average age 38 years; F:M ratio 2:1) admitted from 1994 to 2005 with POD-related ALF were studied. Clinical and biochemical parameters were recorded. The effect of applying a MELD score of greater than 30 as listing criteria for LT was calculated and compared with the KCH criteria. Outcomes were defined as LT, death, or full recovery.

RESULTS

Thirty-one patients (43%) recovered with medical therapy, 29 (40%) patients died, and 12 (17%) underwent LT. Sixty five percent of patients had a MELD > 30 and therefore could potentially be listed on admission; however, using KCH criteria only 24% patients were listed immediately. Sensitivity and negative predictive value of MELD was higher then KCH; however, we found KCH to have much higher specificity and positive predictive value.

CONCLUSION

MELD has higher sensitivity and negative predictive value for POD-induced ALF than the KCH criteria. However, the high false-positive rate associated with MELD limits its clinical utility. The high negative predictive value of MELD score may allow it to be used in conjunction with KCH criteria to avoid unneeded LT in patients who will likely recover spontaneously.

The EEG assessment of low-grade hepatic encephalopathy: Comparison of an artificial neural network-expert system (ANNES) based evaluation with visual EEG readings and EEG spectral analysis

OBJECTIVE

The EEG provides an objective staging of hepatic encephalopathy (HE), but its interpretation may be biased by inter-observer variability. This study aims at comparing an entirely automatic EEG classification of HE based on an artificial neural network-expert system procedure (ANNES) with visual and spectral analysis based EEG classifications.

METHODS

Two hundred and thirty-eight consecutive cirrhotic patients underwent closed-eye EEG. They were followed up for up to one-year to detect bouts of overt HE and death. The EEG was classified by ANNES, qualitative visual reading, main basic rhythm frequency and spectral analysis. The classifications were assessed on the basis of: (i) match with liver function, (ii) prognostic value and (iii) repeatability.

RESULTS

All classifications were found to be related to the severity of liver failure, with cognitive findings and a history of previous bouts of HE. All of them had prognostic value on the occurrence of overt HE and on survival. The ANNES based classification was more repeatable than the qualitative visual one, and had the advantage of detecting low power EEG, but its efficiency in analyzing low-grade alterations was questionable.

CONCLUSIONS

An entirely automatic - ANNES based - EEG classification of HE can improve the repeatability of EEG assessment, but further improvement of the device is required to classify mild alterations.

SIGNIFICANCE

The ANNES based EEG grading of HE needs further improvements to be recommended in clinical practice, but it is already sufficient for detecting normal and clearly altered EEG tracings.

The pathophysiology of hepatic encephalopathy

Hepatic encephalopathy (HE) is a complicated disorder, the pathophysiology of which remains to be fully understood. This article reviews the current main theories including the potential involvement of ammonia, gamma-aminobutyric acid (GABA)/benzodiazipines and false neurotransmitters. Each theory is critically examined with the evidence for each reviewed carefully, and the potential relationship of ammonia to the remaining two theories explored. Known preciptating factors of HE are also considered as evidence. The conclusions drawn from the evidence provided indicate the large role played by ammonia and suggest that this may be the key to understanding HE as science progresses.

Prognostic implications of hyperlactatemia, multiple organ failure, and systemic inflammatory response syndrome in patients with acetaminophen-induced acute liver failure

OBJECTIVE

Hyperlactatemia has been suggested as a prognostic marker in acetaminophen-induced fulminant hepatic failure, and a modification of the King's College Hospital criteria to incorporate arterial lactate measurements has recently been proposed. The aims of the present study were to further evaluate arterial lactate as a prognostic marker in acetaminophen-induced fulminant hepatic failure and to analyze its relationship to known causes of hyperlactatemia such as multiple organ failure and inflammation.

DESIGN

Data were collected early after admission and again at the time of onset of grade 3-4 hepatic encephalopathy from acetaminophen-induced fulminant hepatic failure. Multiple organ failure and inflammatory response were assessed by the sequential organ failure assessment (SOFA) score and manifestation of the severe inflammatory response syndrome (SIRS), respectively.

SETTING

A specialized liver intensive care unit at a tertiary liver center.

PATIENTS

One hundred and one consecutive patients with acetaminophen-induced fulminant hepatic failure and grade 3-4 hepatic encephalopathy.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Arterial lactate was higher in nonsurvivors than in survivors both early after admission (9.8 +/- 6.5 mmol/L vs. 5.2 +/- 4.2 mmol/L, p = .00004) and at the time of onset of hepatic encephalopathy (6.9 +/- 5.6 mmol/L vs. 3.2 +/- 2.0 mmol/L, p < .00001). At both time points, arterial lactate significantly correlated with SOFA score and the number of SIRS components fulfilled. Applying the lactate modification of the King's College Hospital criteria increased their sensitivity but reduced their specificity to <50%.

CONCLUSIONS

The study confirmed arterial lactate as a prognostic marker in acetaminophen-induced fulminant hepatic failure. Arterial lactate correlated with SOFA score and with the number of SIRS components fulfilled. The lactate modification of the King's College Hospital criteria showed no obvious advantages over the existing selection criteria.

Increased oro-cecal transit time in grade I or II hepatic encephalopathy

The pathogenic mechanisms of hepatic encephalopathy remain to be elucidated. It has been suggested that a digestive motor disorder could promote the absorption of toxins produced within the lumen and thus enhance hepatic encephalopathy.

AIM

To evaluate oro-cecal transit time in cirrhotic patients with and without hepatic encephalopathy.

METHODS

Hospitalized patients with alcoholic cirrhosis without encephalopathy and with spontaneous grade I and II encephalopathy were included. Severity of hepatic encephalopathy was assessed clinically and the Child-Pugh score was used to describe cirrhosis severity. Nine healthy volunteers constituted a control group. Oro-cecal transit time was measured with the sulfasalazine test.

RESULTS

Twenty-eight patients (mean age 62.5 +/- 8.5 years) were included. Ten had hepatic encephalopathy of unknown cause and 18 were free of hepatic encephalopathy. Oro-cecal transit time was significantly longer in patients with hepatic encephalopathy (641 +/- 350 min) compared to patients without hepatic encephalopathy (298 +/- 96; P<0.05) and to controls (354 +/- 90; P<0.05). Oro-cecal transit time was comparable for each Child-Pugh score and was not different between the two grades of hepatic encephalopathy.

CONCLUSION

Oro-cecal transit time is longer in alcoholic cirrhosis patients with hepatic encephalopathy. This digestive motor disorder provides a partial explanation of hepatic encephalopathy of unknown etiology.

Improvement of prognostic power of the Child-Pugh classification of liver cirrhosis by hyaluronan

BACKGROUND/AIMS

Modifications of the Child-Pugh classification of liver cirrhosis by incorporation of hyaluronan were tested to improve the prognostic power for long term evaluation of liver cirrhosis in 126 patients observed over a period of 10 years.

METHODS

Serum concentrations of HA were determined at study entry. Statistical analysis included Kaplan-Meier life tables and stepwise multivariant Cox-regression analysis for each parameter of Child-Pugh classification and hyaluronan. Prognostic models were developed by exchanging prothrombin time, albumin and encephalopathy by HA in different combinations.

RESULTS

Based on a good single correlation between hyaluronan (0.62) and clinical course (P<0.01) we conclude that models with hyaluronan instead of albumin or encephalopathy and with or without shifted threshold values of bilirubin and albumin are superior for the prediction of the long term prognosis. In Cox-regression analysis, apart from hyaluronan and bilirubin, no other parameters contributed to an improvement.

CONCLUSIONS

We conclude that a modification of the Child-Pugh classification of liver cirrhosis by inclusion of HA significantly improves the predictive power of CP, especially in alcoholic etiology. A prospective validation of the newly defined scores needs to be done in the future.

MR and 1H MR spectroscopy of the brain in patients with liver cirrhosis and early stages of hepatic encephalopathy

BACKGROUND/AIMS

Hepatic encephalopathy is a serious problem in patients with liver cirrhosis and precise pathophysiological mechanisms responsible for encephalopathy are not fully understood. Magnetic resonance imaging and magnetic resonance spectroscopy can be used to detect specific morphological and metabolic abnormalities in the brain even in patients with early stages of hepatic encephalopathy.

METHODOLOGY

Twenty patients with liver cirrhosis and 14 patients with grade I-II hepatic encephalopathy were studied with magnetic resonance and proton magnetic resonance spectroscopy. Localized magnetic resonance spectra were acquired in the parietal gray/white matter regions and basal ganglia. Control group consisted of 20 healthy volunteers.

RESULTS

Frequency and degree of brain atrophy and bilateral signal hyperintensities in globus pallidus were similar in groups with liver cirrhosis and with encephalopathy. Decreased myoinositol, choline and increased glutamine levels were noted in both groups whereas N-acetylaspartate levels were unchanged. The statistically significant differences between cirrhotic and encephalopathic groups were observed only in myoinositol/creatine ratio in basal ganglia. There were no significant differences in metabolic concentrations between parietal and basal ganglia regions.

CONCLUSIONS

Metabolic brain alterations occur earlier than clinical evidence of hepatic encephalopathy but there is no correlation between presence of symptoms encephalopathy and magnetic resonance and magnetic resonance spectroscopy findings.

Correlation between ammonia levels and the severity of hepatic encephalopathy

PURPOSE

Because the correlation between ammonia levels and the severity of hepatic encephalopathy remains controversial, we prospectively evaluated the correlation in 121 consecutive patients with cirrhosis.

METHODS

The diagnosis of hepatic encephalopathy was based on clinical criteria, and the severity of hepatic encephalopathy was based on the West Haven Criteria for grading of mental status. Arterial and venous blood samples were obtained from each patient. Four types of ammonia measurements were analyzed: arterial and venous total ammonia, and arterial and venous partial pressure of ammonia. Spearman rank correlations (r(s)) were calculated.

RESULTS

Of the 121 patients, 30 (25%) had grade 0 encephalopathy (no signs or symptoms), 27 (22%) had grade 1, 23 (19%) had grade 2, 28 (23%) had grade 3, and 13 (11%) had grade 4 (the most severe signs and symptoms). Each of the four measures of ammonia increased with the severity of hepatic encephalopathy: arterial total ammonia (r(s) = 0.61, P < or = 0.001), venous total ammonia (r(s) = 0.56, P < or = 0.001), arterial partial pressure of ammonia (r(s) = 0.55, P < or = 0.001), and venous partial pressure of ammonia (r(s) = 0.52, P < or = 0.001).

CONCLUSION

Ammonia levels correlate with the severity of hepatic encephalopathy. Venous sampling is adequate for ammonia measurement. There appears to be no additional advantage of measuring the partial pressure of ammonia compared with total ammonia levels.

Hepatic encephalopathy: nomenclature, pathogenesis and treatment

Hepatic encephalopathy (HE) is a neuropsychiatric syndrome in patients with liver failure and/or a portal-systemic bypass. Since 2002 a new nomenclature of HE exists, that classifies HE in encephalopathy type A (associated with acute liver failure), type B (associated with portal-systemic bypass), and type C (associated with liver cirrhosis). HE type A is characterized by a rapid development to coma, cerebral edema, and a poor short-term prognosis. Therefore, these patients should be referred to a liver transplantation center. Standard treatment of HE consists of non absorbable disaccharides, non absorbable antibiotics, and a diet with an appropriate amount of proteins. In addition, the possibility of performing a liver transplantation should be evaluated. In patients with intractable HE other alternative treatments adjunct to standard treatment, like zinc, sodium benzoate, ornithine aspartate, branched chain amino acids, flumazenil, and bromocriptine should be considered.

[Hepatic encephalopathy]

Hepatic encephalopathy (HE) is a neuropsychiatric syndrome which develops during chronic or acute liver disease. It is functional in nature and potentially reversible and symptoms range from subtle personality changes to deep coma. Diagnosis of manifest HE is made on a clinical basis, whereas psychometric tests are required to diagnose subclinical HE (SHE). Paper-pencil tests are frequently used for diagnosing SHE, but they may be inferior to measurements of critical flicker frequency, which pick minimal and low grade manifest HE as a continuum. Pathogenetically, HE is seen as clinical manifestation of low grade chronic cerebral edema, which is accompanied by alterations in glioneuronal communication. Different factors such as ammonia, inflammatory cytokines, benzodiazepines and electrolyte imbalances may precipitate or aggravate glia edema, thereby explaining precipitation of HE episodes by a variety of unrelated factors. Recognition and rigorous treatment of these precipitating factors is the most important measure in HE therapy, which may be augmented by dietary and medical approaches.

Hepatic encephalopathy--definition, nomenclature, diagnosis, and quantification: final report of the working party at the 11th World Congresses of Gastroenterology, Vienna, 1998

Research on hepatic encephalopathy is hampered by the imprecise definition of this disabling complication of liver disease. Under this light, the Organisation Mondiale de Gastroentérologie commissioned a Working Party to reach a consensus in this area and to present it at the 11th World Congress of Gastroenterology in Vienna (1998). The Working Party continued its work thereafter and now present their final report. In summary, the Working Party has suggested a modification of current nomenclature for clinical diagnosis of hepatic encephalopathy; proposed guidelines for the performance of future clinical trials in hepatic encephalopathy; and felt the need for a large study to redefine neuropsychiatric abnormalities in liver disease, which would allow the diagnosis of minimal (subclinical) encephalopathy to be made on firm statistical grounds. In the interim, it proposes the use of a psychometric hepatic encephalopathy score, based on the result of 5 neuropsychologic tests. Finally, the need for a careful evaluation of the newer neuroimaging modalities for the diagnosis of hepatic encephalopathy was stressed.

[A discussion on diagnosis and typing of viral hepatitis]

OBJECTIVE

To bring forward a suggestion about clinical diagnostic standard and clinical typing for chronic and severe hepatitis.

METHODS

To make a comprehensive study on clinical features and pathology of 895 cases of severe and chronic hepatitis, liver cirrhosis after hepatitis based on the viral prevention and control plan laid down in 1995.

RESULTS

The chronic hepatitis can still be divided into mild, moderate and severe types clinically, but the PTA should be changed for normol-71, 70-61, 60-51, the A/G value for normal, 1.5-1.3, 1.2-1.0 respectively. ALT, BIL, alpha-globulin are kept unchanged. The albumin value can be cut out from the reference indexes of clinical typing for chronic hepatitis. Acute severe hepatitis can be divided into early stage (taking edema as the main type) and late stage (taking necrosis as the main type); subacute severe hepatitis can be divided into ascite type, coma type and mixed type; if those lacking of coma and ascite with PTA about 60%. 50% can be treated as earlier stage. Subacute and chronic severe hepatitis still can be divided into early, middle and late stages. The disease course of subacute severe hepatitis may prolong to six months. Chronic severe hepatitis can be divided into type B (typical chronic hepatitis type) type C (liver cirrhosis type) and type c (acute liver failure type developed from chronic hepatitis and viral carriers).

CONCLUSIONS

The original procedure of 1995 are feasible on the whole.

Cerebral vascular resistance assessed by transcranial color Doppler ultrasonography in patients with chronic liver diseases

BACKGROUND AND AIM

Cerebral hemodynamic derangement is well known in patients with liver cirrhosis. The advent of transcranial Doppler enables a non-invasive observation of cerebral hemodynamics. To evaluate the clinical usefulness we examined cross-sectionally and longitudinally cerebral hemodynamic parameters in patients with cirrhosis.

METHODS

The subjects of the cross-sectional study were 117 patients with cirrhosis, 15 patients with chronic hepatitis and 25 healthy controls. The longitudinal study included 26 cirrhotic patients without encephalopathy, and 27 cirrhotic patients with encephalopathy. The pulsatility and resistive indices of the right middle cerebral artery were used as parameters of cerebral hemodynamics.

RESULTS

Cerebral pulsatility and resistive indices were significantly higher in patients with cirrhosis (1.05 +/- 0.23, P < 0.0001 and 0.63 +/- 0.07, P < 0.0001, respectively) than in the controls (0.75 +/- 0.11 and 0.55 +/- 0.05, respectively) and patients with chronic hepatitis (0.81 +/- 0.11 and 0.52 +/- 0.05, respectively). Cerebral pulsatility and resistive indices were significantly related with the severity of liver cirrhosis. Patients with encephalopathy had higher cerebral pulsatility and resistive indices than patients without encephalopathy. In the longitudinal studies, cerebral pulsatility and resistive indices were changed in parallel with the severity of cirrhosis and encephalopathy. Cerebral pulsatility and resistive indices were significantly correlated with the blood ammonia level and serum levels of bilirubin and albumin.

CONCLUSION

These cross-sectional and longitudinal studies showed that cerebral vascular resistance indices measured by using transcranial Doppler were increased in association with the severity of cirrhosis and encephalopathy. Cerebral pulsatility and resistive indices are real-time and useful parameters to assess and monitor cirrhotic patients.

Leukocyte arylsulfatase A activity in patients with alcohol-related cirrhosis

Arylsulfatase (ASA) enzyme deficiency is associated with metachromatic leukodystrophy (MLD), which is a hereditary myelin metabolic disease. It has been proposed that in alcoholic subjects with abnormal ASA, the accumulation of sulfatides may lead to demyelinization and generalized cerebral atrophy. ASA may be diminished in subjects with alcoholic cirrhosis having encephalopathic manifestations. This idea has not been previously proposed. Leukocyte arylsulfatase A (ASA) activity was measured in 30 healthy male volunteers and 28 patients with alcohol-related cirrhosis. The patients were divided into two groups: patients with alcohol-related cirrhosis with hepatic encephalopathy history and patients with alcoholic cirrhosis without history of hepatic encephalopathy. Alcoholic cirrhotic patients with history of encephalopathy showed 58.21% (40.95 nmol/mg protein/h) less enzymatic activity than a control group (98.00 nmol/mg protein/h), whereas the group without history of encephalopathy showed an ASA value which was 38.2% (60.55 nmol/mg protein/h) less than the control group. The results suggest that the low ASA activity is a factor associated to the appearance of encephalopathy in patients with alcohol-related cirrhosis.

Portal-systemic encephalopathy in non-cirrhotic patients: classification of clinical types, diagnosis and treatment

Hepatic encephalopathy is suspected in non-cirrhotic cases of encephalopathy because the symptoms are accompanied by hyperammonaemia. However, the cause of the large portal-systemic shunt formation observed in these cases is not clear, as cirrhosis and portal hypertension are absent. The frequency of such cases reported in the literature is increasing with progress and spread of abdominal imaging diagnostic techniques. Some cases have been misdiagnosed as psychiatric diseases (dementia, depression and others) and consequently patients have been hospitalized in psychiatric institutions or geriatric facilities. Some paediatric cases have also been misdiagnosed. Therefore, the importance of accurate diagnosis of this disease should be strongly emphasized. Some paediatric cases have also been misdiagnosed. When psychoneurological symptoms are suggestive of hepatic encephalopathy but objective and subjective symptoms or abnormal values of liver function tests are not sufficiently indicative of liver cirrhosis, portal-systemic encephalopathy should be suspected. Abnormal angiograms of the portal vein, superior mesenteric vein or splenic vein are conclusive evidence of portal-systemic encephalopathy. Transrectal portal scintigraphy also provides information useful for detection of shunts and a quantitative estimation of shunt index. We classified the disease into five types based on whether the shunt is formed inside or outside the liver. Type I (intrahepatic type) designates cases in which shunts are located between the portal and systemic veins. Type II designates a type of intra/extrahepatic shunt that originates from the umbilical part of the portal vein and serpentines in the liver, then leaves the liver. Type III (extrahepatic type) occurs most frequently. Type IV (extrahepatic) is accompanied by shunts similar to those in type III, but hepatic pathology presents as idiopathic portal hypertension. Type V (extrahepatic) represents the congenital absence of the portal vein, where the superior mesenteric vein joins the intrahepatic inferior vena cava or the left renal vein. The prevalence of each type in our country was examined by a nationwide investigation. In addition to the conventional diet or drug treatments, obliteration by less invasive interventional radiology using a metallic coil and ethanol has recently been used more frequently than surgical occlusion of shunts. Shunt-preserving disconnection of portal and systemic circulation and partial splenic artery embolization are also performed. International investigation of the disease status and establishment of diagnostic and therapeutic methods for the disease are awaited and investigation of long-term prognosis after therapy is also necessary.

Push-pull sorbent-based pheresis and hemodiabsorption in the treatment of hepatic failure: preliminary results of a clinical trial with the BioLogic-DTPF System

The BioLogic-DTPF System combines hemodiabsorption (the BioLogic-DT System with dialysis against powdered sorbent) with push-pull sorbent-based pheresis (the BioLogic-PF System with powdered sorbent surrounding plasma filters). At blood flow rates of 200 ml/min, the system clears creatinine and aromatic amino acids at 120-160 ml/min, unconjugated bilirubin at 20-40 ml/min, and cytokines at 15-25 ml/min. This article outlines a study of the DTPF System in treatment of patients with hepatic failure with Grade 3 or 4 encephalopathy and respiratory and kidney insufficiency. Treatment appeared to be safe, and there are no significant hematologic changes. Physiologic changes include improved blood pressure and encephalopathy and stable urine output. Chemical changes include decrease in plasma levels of bilirubin, aromatic amino acids, ammonium, creatinine, and interleukin-3 (IL-1beta). The BioLogic-DT System is now marketed for treatment of acute hepatic failure with encephalopathy. The BioLogic-DTPF System adds the capability of removing bilirubin and other strongly protein-bound toxins from treated patients and may be of clinical benefit in management of patients with the most severe hepatic failure and encephalopathy.

Acute hepatic failure in India: a perspective from the East

Acute hepatic failure (AHF) in India almost always presents with encephalopathy within 4 weeks of the onset of acute hepatitis. Further subclassification of AHF into hyperacute, acute and subacute forms may not be necessary in this geographical area, where the rapidity of onset of encephalopathy does not seem to influence survival. Viral hepatitis is the cause in approximately 95-100% of patients, who therefore constitute a more homogeneous population than AHF patients in the West. In India, hepatitis E (HEV) and hepatitis B (HBV) viruses are the most important causes of AHF; approximately 60% of cases are caused by to these viruses. Hepatitis B virus core mutants are very important agents in cases where hepatitis B results in AHF in this country. Half of the patients with AHF admitted to our centre are female, one-quarter of whom are pregnant. Therefore, pregnant females who contract viral hepatitis constitute a high-risk group for the development of AHF. However, the outcome of AHF in this group is similar to that in non-pregnant women and men. No association with any particular virus has been identified among sporadic cases of AHF. In our centre, approximately one-third of AHF patients survive with aggressive conservative therapy, whereas two-thirds of deaths occur within 72 h of hospitalization. Cerebral oedema and sepsis are the major fatal complications. Both fungal and gram-negative bacteria are major causes of sepsis. Among patients with AHF, despite the presence of sepsis, its overt clinical features (i.e. fever, leucocytosis) may be absent and objective documentation of the presence of sepsis in such patients is achieved by repeated culture of various body fluids. It should be possible to develop simple, clinical prognostic markers for AHF in this geographical region, in order to identify patients suitable for liver transplantation.

Discrimination of two different clinical entities, acute-type and subacute-type, human fulminant hepatitis by peripheral blood lymphocyte subsets

Human fulminant hepatitis tends to be classified into two groups: acute type (A-FH) and subacute type (S-FH). In order to define these two clinical entities more precisely, we examined and compared peripheral blood lymphocyte subsets in A-FH and S-FH patients. We found that S-FH patients had a higher prevalence of CD19+ B cells (31.1 +/- 7.6% in S-FH vs 12.7 +/- 3.7% in A-FH) and also a lower prevalence of CD3+T cells (50.2 +/- 8.7% in S-FH vs 65.6 +/- 10.5% in A-FH). Furthermore, by examining the absolute cell numbers of these subsets, we determined that their imbalance in S-FH was mainly due to a decrease in CD3+ T cells. Among several T cell subsets, the CD8+CD11b-T cell subset was elevated in A-FH and decreased in S-FH (6.1 +/- 2.1% in S-FH, 24.4 +/- 5.8% in A-FH, and 14.8 +/- 7.8% in control). Serial studies of two S-FH patients revealed that the imbalance of these lymphocyte subsets returned to their proper ratio together with the improvement of their liver injury. These results indicate that there might be a different immunological background between A-FH and S-FH.

Etiology and outcome for 295 patients with acute liver failure in the United States

Little information is available on acute liver failure (ALF) in the United States. We gathered demographic data retrospectively for a 2-year period from July 1994 to June 1996 on all cases of ALF from 13 hospitals (12 liver transplant centers). Data on the patients included age, hepatic coma grade on admission, presumed cause, transplantation, and outcome. Among 295 patients, 74 (25%) survived spontaneously, 121 (41%) underwent transplantation, and 99 (34%) died without undergoing transplantation. Ninety-two of 121 patients (76%) survived 1 year after transplantation. Acetaminophen overdose was the most frequent cause (60 patients; 20%), followed by cryptogenic/non A non B non C (NANBNC; 15%), idiosyncratic drug reactions (12%), hepatitis B (10%), and hepatitis A (7%). Spontaneous survival rates were highest for patients with acetaminophen overdose (57%) and hepatitis A (40%) and lowest for those with Wilson's disease (no survivors of 18 patients). The transplantation rate was highest for Wilson's disease (17 of 18 patients; 94%) and lowest for autoimmune hepatitis (29%) and acetaminophen overdose (12%). Age did not differ between survivors and nonsurvivors, perhaps reflecting a selection bias for patients transferred to liver transplant centers. Coma grade on admission was not a significant determinant of outcome, but showed a trend toward affecting both survival and transplantation rate. These findings on retrospectively studied patients from the United States differ from those previously gathered in the United Kingdom and France, highlighting the need for further study of trends in each country.

Flumazenil for hepatic encephalopathy grade III and IVa in patients with cirrhosis: an Italian multicenter double-blind, placebo-controlled, cross-over study

The rationale for use of benzodiazepine receptor antagonists is based on the so-called benzodiazepine pathogenetic hypothesis of hepatic encephalopathy (HE). To assess the efficacy of flumazenil, a specific benzodiazepine receptor antagonist, in a large and selected population of cirrhotic patients with severe HE, we conducted a double-blind, placebo-controlled, cross-over trial on 527 cirrhotic patients with HE grade III and IVa admitted to Intensive Care Units over a 5-year period; among them, 265 (132 of grade III and 133 of grade IVa) received flumazenil, whereas 262 (130 of grade III and 132 of grade IVa) received placebo. Treatment was begun within 15 minutes of randomization; the response to treatment was assessed by neurological score and by continuous electroencephalographic (EEG) recordings. Improvement of the neurological score was documented in 17.5% of grade III patients treated with flumazenil and in 14.7% of grade IVa patients, compared, respectively, with 3.8% and 2.7% of the patients of both groups treated with placebo. Improvements in EEG tracings were observed in 27.8% of grade III patients and in 21.5% of grade IVa patients, compared, respectively, with 5% and 3.3% of the patients of both groups treated with placebo. Benzodiazepines were detected in the serum of 10 patients (4 in grade III group and 6 in grade IVa group). Flumazenil is beneficial only in a selected subset of cirrhotic patients with severe HE; the applicability of this treatment to unselected patients with severe HE still remains to be determined.

Alpha-fetoprotein serum concentration in different stages of liver cirrhosis

Serum alpha-fetoprotein (AFP) concentration was measured in 41 patients with different stages of liver cirrhosis demonstrated through scored Child-Pugh classification. Mean value was elevated up to 65.9 21.9 U/l, butstatistically significant difference in comparison with control group was observed only in patients classified as Child-Pugh C. AFP concentration revealed significant positive correlation with score values. Dynamics of AFP during one-year follow up demonstrated three-fold and statistically significant increase of its concentration, that was accompanied by elevation of mean score values.

Hepatic encephalopathy and role of antibenzodiazepines

The majority of pharmacological agents are designed to accomplish a specific effect based on the established mechanisms of a disease. However, there are a few examples in which investigation of a pharmacological action has led to a previously unknown mechanism, i. e. the drug effect was observed initially before its mechanism became known. For example, the opiates had been in use for their analgesic effect for centuries before the question of endogenous substances that might explain the presence of opiate binding sites in the central nervous system (CNS) was raised, leading to the discovery of the opioids. A somewhat analogous development has occurred in another investigative arena, the observation that the administration of the benzodiazepine antagonist, flumazenil, has reversed the encephalopathy of hepatic failure. This has refocused research to discover whether one or more endogenous substances that bind to the benzodiazepine receptor in the CNS are responsible for the inhibition of CNS function of advanced liver failure. The investigative impetus was initiated by observations that patients with liver failure were highly vulnerable to benzodiazepines; therapeutic dosages precipitated coma or near-coma, and this effect was prolonged. The question was raised whether any given patient presenting with a coma-like state associated with advanced liver dysfunction might have received a benzodiazepine in the recent past, under circumstances overlooked or not recorded, that might be a contributing factor to the patient's condition. This led to testing the effects of the antagonist, with transitory success in arousing patients or improving their level of stupor. Further inquiry revealed that this improvement in mental function occurred in the absence of prior exposure to benzodiazepines. There followed a search for endogenous substances capable of binding to the benzodiazepine receptor, with CNS inhibitory effects. These investigations have resulted in the identification of several substances that may play a role in encephalopathy and can be displaced from the CNS receptor by properly designed antagonists-an ongoing investigative effort.

Long-term follow-up of auxiliary orthotopic liver transplantation for the treatment of fulminant hepatic failure

BACKGROUND

Auxiliary orthotopic liver transplantation (AOLT) was investigated as a bridge to native liver recovery in patients with fulminant hepatic failure (FHF).

METHODS

In the last 5 years seven patients with FHF were treated with AOLT at our institution. Five patients underwent resection of the native left lobe and orthotopic replacement with a donor left lobe (n = 3) or left lateral segment (n = 2). Two patients underwent left trisegmentectomy and whole liver auxiliary grafting. Conventional immunosuppression was used in all patients.

RESULTS

One patient had poor initial graft function and required retransplantation. Native liver function returned to normal in the six other patients. Immunosuppression was gradually tapered and completely discontinued in three patients, allowing for atrophy of the allograft. The allograft was removed in the other four patients. Despite evidence of native liver regeneration, two patients with aplastic anemia died after allograft removal. Four patients are alive at a mean follow-up of 3.5 years.

CONCLUSIONS

AOLT is technically feasible, rapidly restores liver function, and should be considered an important alternative to standard orthotopic liver transplantation (OLT) in the treatment of FHF. AOLT has the advantage that patients transplanted for FHF are not committed to lifelong immunosuppression with its attendant risks.