A current review of the diagnostic and treatment strategies of hepatic encephalopathy

Effects of shunt embolization on hepatic encephalopathy recurrence in patients with major portosystemic shunts: A systematic review and meta‑analysis

This study addresses the effects of shunt embolization on the recurrence of hepatic encephalopathy (HE) in patients with major portosystemic shunts. MEDLINE via PubMed, Google Scholar, and Scopus was searched to find the relevant full-text articles published from inception until August 2024. The primary outcome was the degree of HE or mental state change determined by the West-Heaven classification system. Dichotomous data were compared using odds ratios (OR). 95% confidence (CI) intervals were provided for each outcome in the report. The random-effects model was used to analyze the data. Trim and fill, Egger's regression and funnel plot were employed to evaluate publication bias in this body of literature. A total of 7 articles and 254 patients were included in the present meta-analysis. It was found that shunt embolization significantly reduced the recurrence of HE in patients with portosystemic shunts due to liver cirrhosis. Overall analysis showed that the pooled OR was 0.253 and the overall heterogeneity of the data was substantial (95% CI: 0.117-0.550, I 2=60.52% and P=0.001). The funnel plot was reasonably symmetrical and no study was trimmed to either side of the mean. Begg's (P=0.229) and Egger's tests (P=0.273) showed no significant risk of publication bias. Quality assessment showed that the majority of the included studies were of low quality. In conclusion, the present meta-analysis indicates that shunt embolization after portosystemic shunt significantly reduces the recurrence of HE in patients with liver cirrhosis. However, the findings should be interpreted with caution due to the low quality and low number of the included studies. Future research should prioritize higher-quality trials to validate these results and explore long-term outcomes.

Rifaximin discontinuation during broad-spectrum antibiotic treatment in critically ill patients with hepatic encephalopathy

Hepatic encephalopathy (HE) is one of the main complications of cirrhosis, characterized by a wide spectrum of neuropsychiatric alterations that lead to an increase in mortality, morbidity and recurrent hospitalizations. Due to the central role in HE pathogenesis of ammonia and other neurotoxins primarily produced by the gut microbiota, the main therapeutic approaches for the treatment of HE are based on the modulation of the gut microbiota. Rifaximin is a non-absorbable broad-spectrum antibiotic, that is effective against ammonia-producing gram-positive, gram-negative, and anaerobic species, approved for the treatment of HE in secondary prophylaxis. The chronic administration of rifaximin in this setting is associated with a lower risk of HE recurrence and mortality, while the role of rifaximin for the treatment of an overt-HE episode in inpatients is still unclear. Limited data exist about the coadministration of rifaximin and broad-spectrum antibiotics commonly used to treat concomitant infections, as patients receiving or recently treated with antibiotics were frequently excluded from clinical trials. In this editorial we comment on the article by Ward et al published in the recent issue of the World Journal of Hepatology. It is a single center, retrospective, quasi-experimental, pharmacist-driven protocol, with the aim to evaluate the feasibility and safety of rifaximin discontinuation in critically ill patients with HE and chronic liver disease receiving broad-spectrum antibiotic therapies in intensive care units. The study revealed no differences between the protocol and control group in terms of primary outcome (days alive and free of delirium and coma to day 14) and secondary outcomes which include: Intensive care mortality, intensive care length of stay, intravenous vasopressor requirement changes and adverse effects rate. Therefore, rifaximin discontinuation during broad-spectrum antibiotic therapy does not appear to negatively impact the clinical status of critically ill liver patients, with a similar safety profile and significant cost savings, as compared to the coadministration of rifaximin and broad-spectrum antibiotics. In agreement with Ward et al, a recently published double-blind, randomized controlled trial provided additional evidence to support the feasibility of withholding rifaximin during broad-spectrum antibiotic therapy in critically ill cirrhotic patients. However, given the limitations of these studies, further multicentric and prospective clinical trials, enrolling a larger sample of non-critically ill patients, are needed to better establish the role of rifaximin in this setting.

Nontraditional Treatment of Hepatic Encephalopathy

The pathophysiology of hepatic encephalopathy (HE) is complex, with hyperammonemia playing a central role in its development. Traditional therapies for HE have targeted ammonia and include medications such as lactulose and rifaximin. Although these agents are considered standard of care, nontraditional treatments seek to affect other factors in the pathogenesis of HE. Finally, procedural therapies include albumin dialysis, shunt closure, and the ultimate cure for HE, which is liver transplant. The treatments discussed provide alternative options for patients who have failed standard of care. However, more high-quality studies are needed to routinely recommend many of these agents.

Low-dose ketamine improves animals' locomotor activity and decreases brain oxidative stress and inflammation in ammonia-induced neurotoxicity

Ammonium ion (NH4 + ) is the major suspected molecule responsible for neurological complications of hepatic encephalopathy (HE). No specific pharmacological action for NH4 + -induced brain injury exists so far. Excitotoxicity is a well-known phenomenon in the brain of hyperammonemic cases. The hyperactivation of the N-Methyl- d-aspartate (NMDA) receptors by agents such as glutamate, an NH4 + metabolite, could cause excitotoxicity. Excitotoxicity is connected with events such as oxidative stress and neuroinflammation. Hence, utilizing NMDA receptor antagonists could prevent neurological complications of NH4 + neurotoxicity. In the current study, C57BL6/J mice received acetaminophen (APAP; 800 mg/kg, i.p) to induce HE. Hyperammonemic animals were treated with ketamine (0.25, 0.5, and 1 mg/kg, s.c) as an NMDA receptor antagonist. Animals' brain and plasma levels of NH4 + were dramatically high, and animals' locomotor activities were disturbed. Moreover, several markers of oxidative stress were significantly increased in the brain. A significant increase in brain tissue levels of TNF-α, IL-6, and IL-1β was also detected in hyperammonemic animals. It was found that ketamine significantly normalized animals' locomotor activity, improved biomarkers of oxidative stress, and decreased proinflammatory cytokines. The effects of ketamine on oxidative stress biomarkers and inflammation seem to play a key role in its neuroprotective mechanisms in the current study.

Metabolomics profiles in acute-on-chronic liver failure: Unveiling pathogenesis and predicting progression

Acute-on-chronic liver failure (ACLF) usually develops based on acute decompensation (AD) of cirrhosis and is characterized by intense systemic inflammation, multiple organ failure, and high short-term mortality. Validated biomarkers for the diagnosis and prognosis of ACLF remain to be clarified. Metabolomics is an emerging method used to measure low-molecular-weight metabolites and is currently frequently implemented to understand pathophysiological processes involved in disease progression, as well as to search for new diagnostic or prognostic biomarkers of various disorders. The characterization of metabolites in ACLF has recently been described via metabolomics. The role of metabolites in the pathogenesis of ACLF deserves further investigation and improvement and could be the basis for the development of new diagnostic and therapeutic strategies. In this review, we focused on the contributions of metabolomics on uncovering metabolic profiles in patients with ACLF, the key metabolic pathways that are involved in the progression of ACLF, and the potential metabolite-associated therapeutic targets for ACLF.

Inadequate practices for hepatic encephalopathy management in the inpatient setting

Hepatic encephalopathy (HE) is an important complication of decompensated liver disease. Hospital admission for episodes of HE are very common, with these patients being managed by the hospitalists. These admissions are costly and burdensome to the health-care system. Diagnosis of HE at times is not straightforward, particularly in patients who are altered and unable to provide any history. Precipitants leading to episodes of HE, should be actively sought and effectively tackled along with the overall management. This mandates timely diagnostics, appropriate initiation of pharmacological treatment, and supportive care. Infections are the most important precipitants leading to HE and should be aggressively managed. Lactulose is the front-line medication for primary treatment of HE episodes and for prevention of subsequent recurrence. However, careful titration in the hospital setting along with the appropriate route of administration should be established and supervised by the hospitalist. Rifaximin has established its role as an add-on medication, in those cases where lactulose alone is not working. Overall effective management of HE calls for attention to guideline-directed nutritional requirements, functional assessment, medication reconciliation, patient education/counseling, and proper discharge planning. This will potentially help to reduce readmissions, which are all too common for HE patients. Early specialty consultation may be warranted in certain conditions. Numerous challenges exist to optimal care of hospitalized OHE patients. However, hospitalists if equipped with knowledge about a systematic approach to taking care of these frail patients are in an ideal position to ensure good inpatient and transition of care outcomes.

Organ and brain crosstalk: The liver-brain axis in gastrointestinal, liver, and pancreatic diseases

The liver is the largest organ in the human body and is responsible for the metabolism and storage of the three principal nutrients: carbohydrates, fats, and proteins. In addition, the liver contributes to the breakdown and excretion of alcohol, medicinal agents, and toxic substances and the production and secretion of bile. In addition to its role as a metabolic centre, the liver has recently attracted attention for its function in the liver-brain axis, which interacts closely with the central nervous system via the autonomic nervous system, including the vagus nerve. The liver-brain axis influences the control of eating behaviour in the central nervous system through stimuli from the liver. Conversely, neural signals from the central nervous system influence glucose, lipid, and protein metabolism in the liver. The liver also receives a constant influx of nutrients and hormones from the intestinal tract and compounds of bacterial origin via the portal system. As a result, the intestinal tract and liver are involved in various immunological interactions. A good example is the co-occurrence of primary sclerosing cholangitis and ulcerative colitis. These heterogeneous roles of the liver-brain axis are mediated via the vagus nerve in an asymmetrical manner. In this review, we provide an overview of these interactions, mainly with the liver but also with the brain and gut.

Acute-on-Chronic Liver Failure: Pathophysiological Mechanisms and Management

Acute-on-chronic liver failure (ACLF) is a multifaceted condition with poor treatment options and high short-term mortality. ACLF can develop in patients with or without liver cirrhosis, where patients with decompensated cirrhosis display a higher risk of short-term mortality. Pathophysiological mechanisms include systemic inflammation due to bacterial and fungal infections and acute hepatic insult with drug, alcohol, and viral hepatitis. Cryptogenic factors also contribute to the development of ACLF. The clinical outcome of patients with ACLF gets further complicated by the occurrence of variceal hemorrhage, hepatorenal syndrome, hepatic encephalopathy, and systemic immune dysfunction. Regardless of the better understanding of pathophysiological mechanisms, no specific and definitive treatment is available except for liver transplantation. The recent approach of regenerative medicine using mesenchymal stem cells (MSCs) could be advantageous for the treatment of ACLF as these cells can downregulate inflammatory response by inducing antiinflammatory events and prevent hepatic damage and fibrosis by inhibiting hepatic stellate cell activation and collagen synthesis. Moreover, MSCs are involved in tissue repair by the process of liver regeneration. Considering the broad therapeutic potential of MSCs, it can serve as an alternative treatment to liver transplant in the near future, if promising results are achieved.

Therapeutic Applications of Resveratrol in Hepatic Encephalopathy through Its Regulation of the Microbiota, Brain Edema, and Inflammation

Hepatic encephalopathy is a common complication in patients with liver cirrhosis and portosystemic shunting. Patients with hepatic encephalopathy present a variety of clinical features, including neuropsychiatric manifestations, cognitive dysfunction, impaired gut barrier function, hyperammonemia, and chronic neuroinflammation. These pathogeneses have been linked to various factors, including ammonia-induced oxidative stress, neuronal cell death, alterations in the gut microbiome, astrocyte swelling, and blood-brain barrier disruptions. Many researchers have focused on identifying novel therapeutics and prebiotics in the hope of improving the treatment of these conditions. Resveratrol is a natural polyphenic compound and is known to exert several pharmacological effects, including antioxidant, anti-inflammatory, and neuroprotective activities. Recent studies suggest that resveratrol contributes to improving the neuropathogenic effects of liver failure. Here, we review the current evidence describing resveratrol's effects in neuropathogenesis and its impact on the gut-liver axis relating to hepatic encephalopathy. We highlight the hypothesis that resveratrol exerts diverse effects in hepatic encephalopathy and suggest that these effects are likely mediated by changes to the gut microbiota, brain edema, and neuroinflammation.

Pathophysiology of decompensated cirrhosis: Portal hypertension, circulatory dysfunction, inflammation, metabolism and mitochondrial dysfunction

Patients with acutely decompensated cirrhosis have a dismal prognosis and frequently progress to acute-on-chronic liver failure, which is characterised by hepatic and extrahepatic organ failure(s). The pathomechanisms involved in decompensation and disease progression are still not well understood, and as specific disease-modifying treatments do not exist, research to identify novel therapeutic targets is of the utmost importance. This review amalgamates the latest knowledge on disease mechanisms that lead to tissue injury and extrahepatic organ failure - such as systemic inflammation, mitochondrial dysfunction, oxidative stress and metabolic changes - and marries these with the classical paradigms of acute decompensation to form a single paradigm. With this detailed breakdown of pathomechanisms, we identify areas for future research. Novel disease-modifying strategies that break the vicious cycle are urgently required to improve patient outcomes.

The impact of acute kidney injury on mortality and clinical outcomes in patients with alcoholic cirrhosis in the USA

INTRODUCTION

Acute kidney injury (AKI) is associated with increased morbidity and mortality in patients with chronic liver disease. Although the impact of AKI on patients with liver disease has been established, its impact on alcoholic cirrhosis has not been studied.

METHODS

Our study utilized data from the National Inpatient Sample for the year 2016 for all patients with a diagnosis of alcoholic cirrhosis and AKI. Primary outcomes were mortality, length of stay (LOS) and hospitalization cost were compared. Secondary outcomes were complications of cirrhosis and its impact on mortality. Multivariate logistic regression analysis and propensity-score matching were used to compare the two groups.

RESULTS

A total of 29 906 patients were included and 6733 (22.5%) had AKI. Propensity-matched multivariate analysis demonstrates that AKI was associated with a significant increase risk of mortality [odds ratio (OR): 8.09; 95% confidence interval (CI), 6.68-9.79; P < 0.0001]. AKI prolonged the hospital stay by 3.68 days (95% CI, 3.42-3.93; P < 0.0001) and increased total hospital charges by $50 284 (95% CI, 45 829-54 739; P < 0.0001). AKI increased the risk of complications of cirrhosis, including hepatorenal syndrome (OR: 19.15; 95% CI, 16.1-22.76), ascites (OR: 2.27; 95% CI, 2.11-2.44), hepatic encephalopathy (OR: 2.54; 95% CI, 1.87-3.47) and portal hypertension (OR: 1.08; 95% CI, 1.01-1.16).

CONCLUSION

AKI in alcoholic cirrhosis significantly increases the risk of mortality, hospitalizations costs and LOS. Further studies are needed on addressing renal failure and treatment options for patients with alcoholic cirrhosis.

The Association between Hepatic Encephalopathy and Diabetic Encephalopathy: The Brain-Liver Axis

Hepatic encephalopathy (HE) is one of the main consequences of liver disease and is observed in severe liver failure and cirrhosis. Recent studies have provided significant evidence that HE shows several neurological symptoms including depressive mood, cognitive dysfunction, impaired circadian rhythm, and attention deficits as well as motor disturbance. Liver disease is also a risk factor for the development of diabetes mellitus. Diabetic encephalopathy (DE) is characterized by cognitive dysfunction and motor impairment. Recent research investigated the relationship between metabolic changes and the pathogenesis of neurological disease, indicating the importance between metabolic organs and the brain. Given that a diverse number of metabolites and changes in the brain contribute to neurologic dysfunction, HE and DE are emerging types of neurologic disease. Here, we review significant evidence of the association between HE and DE, and summarise the common risk factors. This review may provide promising therapeutic information and help to design a future metabolic organ-related study in relation to HE and DE.

Non-Lactulose Medication Therapies for the Management of Hepatic Encephalopathy: A Literature Review

OBJECTIVE

The most appropriate medication regimen to mitigate the consequences hepatic encephalopathy remains inconclusive. This review seeks to serve as a reference for clinicians to help guide therapy decisions with regard to hepatic encephalopathy.

METHODS

A comprehensive literature review between August 2018 and April 2019 was accomplished with the assistance of a medical librarian. Sources of literature review include PubMed, MEDLINE, SCOPUS, ProQuest Central, CINAHL, and ProQuest Dissertations. The authors selected randomized clinical and double-blind cross-over trials evaluating probiotics, zinc, polyethylene glycol, rifaximin, and flumazenil. Sixteen clinical trials are discussed in this review. Pertinent safety, efficacy, and statistical and clinical outcomes are summarized by the authors.

CONCLUSIONS

The most appropriate regimen to mitigate the consequences of hepatic encephalopathy remains elusive; however, the agents discussed within this review offer alternative options for patients unresponsive to or intolerant of traditional lactulose therapy. This review seeks to serve as a repository for relevant clinical trials, and as a reference for clinicians to help guide therapy decisions.

Retrograde Transvenous Obliteration (RTO): A New Treatment Option for Hepatic Encephalopathy

Hepatic Encephalopathy (HE) is a complication of liver disease, consisting of brain dysfunction often due to portosystemic shunting of blood flow in the liver. HE can range from minimal HE, presenting with normal neurological function, to overt HE, with neurological and neuropsychiatric abnormalities. Various clinical grading systems are used to differentiate HE to provide the appropriate treatments. Traditional treatment of HE aims to identify and resolve precipitating factors through targeting hyperammonemia and administering antibiotics or probiotics. While retrograde transvenous obliteration (RTO), including balloon-occluded retrograde transvenous obliteration, coil-assisted retrograde transvenous obliteration or plug-assisted retrograde tranvenous obliteration, is an established procedure to manage gastric varices, little is known about its potential to treat HE. RTO is a procedure to occlude a spontaneous portosystemic shunt, minimizing shunting of portal blood to systemic circulation. Though there is not a large study with HE patients who have undergone RTO; the results appear promising in reducing HE. Side effects, however, should be considered in the treatment of HE such as the transient worsening of portal hypertension and the formation of additional shunts. While additional studies are needed to assess the long-term success, RTO appears to be an effective alternative method to alleviate clinical symptoms of HE when pharmacological therapies and other conservative medical managements have failed.

Sarcopenia: Ammonia metabolism and hepatic encephalopathy

Sarcopenia (loss of muscle mass and/or strength) frequently complicates liver cirrhosis and adversely affects the quality of life; cirrhosis related liver decompensation and significantly decreases wait-list and post-liver transplantation survival. The main therapeutic strategies to improve or reverse sarcopenia include dietary interventions (supplemental calorie and protein intake), increased physical activity (supervised resistance and endurance exercises), hormonal therapy (testosterone), and ammonia lowering agents (L-ornithine L-aspartate, branch chain amino acids) as well as mechanistic approaches that target underlying molecular and metabolic abnormalities. Besides other factors, hyperammonemia has recently gained attention and increase sarcopenia by various mechanisms including increased expression of myostatin, increased phosphorylation of eukaryotic initiation factor 2a, cataplerosis of α ketoglutarate, mitochondrial dysfunction, increased reactive oxygen species that decrease protein synthesis and increased autophagy-mediated proteolysis. Sarcopenia contributes to frailty and increases the risk of minimal and overt hepatic encephalopathy.

Update on the Therapeutic Management of Hepatic Encephalopathy

PURPOSE OF REVIEW

Hepatic encephalopathy (HE) is a common and devastating complication to chronic liver disease. In this paper, we summarize the latest research and evidence of both conventional and up-coming treatments.

RECENT FINDINGS

Meta-analyses report beneficial effects of lactulose, branched-chain amino acids, rifaximin, and to some degree L-ornithine L-aspartate on the manifestations of HE in patients with cirrhosis, and generally the numbers needed to treat are low. Recent studies on newer HE treatments including ornithine phenylacetate, spherical carbon, and fecal microbiota transplant also report potentially beneficial effects on HE manifestations. The conventional treatments benefit patients with HE. Newer treatments are under study and more research is needed for their validation.

Hepatic encephalopathy: current challenges and future prospects

Hepatic encephalopathy (HE) is a common complication of liver dysfunction, including acute liver failure and liver cirrhosis. HE presents as a spectrum of neuropsychiatric symptoms ranging from subtle fluctuating cognitive impairment to coma. It is a significant contributor of morbidity in patients with liver disease. HE is observed in acute liver failure, liver bypass procedures, for example, shunt surgry and transjugular intrahepatic portosystemic shunt, and cirrhosis. These are classified as Type A, B and C HE, respectively. HE can also be classified according to whether its presence is overt or covert. The pathogenesis is linked with ammonia and glutamine production, and treatment is based on mechanisms to reduce the formation and/or removal of these compounds. There is no specific diagnostic test for HE, and diagnosis is based on clinical suspicion, excluding other causes and use of clinical tests that may support its diagnosis. Many tests are used in trials and experimentally, but have not yet gained universal acceptance. This review focuses on the definitions, pathogenesis and treatment of HE. Consideration will be given to existing treatment, including avoidance of precipitating factors and novel therapies such as prebiotics, probiotics, antibiotics, laxatives, branched-chain amino acids, shunt embolization and the importance of considering liver transplant in appropriate cases.

Hepatic encephalopathy: a critical current review

Hepatic encephalopathy (HE) is a serious neuropsychiatric complication of cirrhosis and/or porto-systemic shunting. The clinical symptoms are widely variable, extending from subtle impairment in mental state to coma. The utility of categorizing the severity of HE accurately and efficiently serves not only to provide practical functional information about the current clinical status of the patient but also gives valuable prognostic information. In the past 20–30 years, there has been rapid progress in understanding the pathophysiological basis of HE; however, the lack of direct correlation between pathogenic factors and the severity of HE make it difficult to select appropriate therapy for HE patients. In this review, we will discuss the classification system and its limitations, the neuropsychometric assessments and their challenges, as well as the present knowledge on the pathophysiological mechanisms. Despite the many prevalent hypotheses around the pathogenesis of the disease, most treatments focus on targeting and lowering the accumulation of ammonia as well as inflammation. However, treatment of minimal HE remains a huge unmet need and a big concerted effort is needed to better define this condition to allow the development of new therapies. We review the currently available therapies and future approaches to treat HE as well as the scientific and clinical data that support their effectiveness.

Evaluation and Management of Hepatic Encephalopathy: Current Status and Future Directions

Hepatic encephalopathy is a spectrum of neurocognitive manifestations often seen in patients with liver injury or rarely in patients with portosystemic shunting without liver injury. It can be divided into minimal (covert) hepatic encephalopathy and overt hepatic encephalopathy, depending on the severity. Patients with hepatic encephalopathy have compromised clinical outcomes, decreased quality of life, and increased healthcare utilization, often resulting in a heavy financial and personal burden on caregivers. The diagnosis remains largely clinical, with the exclusion of possible other causes for the altered mental status. Current treatment strategies include nonabsorbable disaccharides and antibiotics. This review will focus on the diagnosis, management and clinical impact of hepatic encephalopathy.

The Effects of Probiotics and Symbiotics on Risk Factors for Hepatic Encephalopathy: A Systematic Review

Alterations in the levels of intestinal microbiota, endotoxemia, and inflammation are novel areas of interest in the pathogenesis of hepatic encephalopathy (HE). Probiotics and symbiotics are a promising treatment option for HE due to possible beneficial effects in modulating gut microflora and might be better tolerated and more cost-effective than the traditional treatment with lactulose, rifaximin or L-ornithine-L-aspartate. A systematic search of the electronic databases PubMed, ISI Web of Science, EMBASE, and Cochrane Library was conducted for randomized controlled clinical trials in adult patients with cirrhosis, evaluating the effect of probiotics and symbiotics in changes on intestinal microflora, reduction of endotoxemia, inflammation, and ammonia, reversal of minimal hepatic encephalopathy (MHE), prevention of overt hepatic encephalopathy (OHE), and improvement of quality of life. Nineteen trials met the inclusion criteria. Probiotics and symbiotics increased beneficial microflora and decreased pathogenic bacteria and endotoxemia compared with placebo/no treatment, but no effect was observed on inflammation. Probiotics significantly reversed MHE [risk ratio, 1.53; 95% confidence interval (CI): 1.14, 2.05; P=0.005] and reduced OHE development (risk ratio, 0.62; 95% CI: 0.48, 0.80; P=0.0002) compared with placebo/no treatment. Symbiotics significantly decreased ammonia levels compared with placebo (15.24; 95% CI: -26.01, -4.47; P=0.006). Probiotics did not show any additional benefit on reversal of MHE and prevention of OHE development when compared with lactulose, rifaximin, and L-ornithine-L-aspartate. Only 5 trials considered tolerance with minimal side effects reported. Although further research is warranted, probiotics and symbiotics should be considered as an alternative therapy for the treatment and management of HE given the results reported in this systematic review.

Probiotics for people with hepatic encephalopathy

BACKGROUND

Hepatic encephalopathy is a disorder of brain function as a result of liver failure or portosystemic shunt or both. Both hepatic encephalopathy (clinically overt) and minimal hepatic encephalopathy (not clinically overt) significantly impair patient's quality of life and daily functioning, and represent a significant burden on healthcare resources. Probiotics are live micro-organisms, which when administered in adequate amounts, may confer a health benefit on the host.

OBJECTIVES

To determine the beneficial and harmful effects of probiotics in any dosage, compared with placebo or no intervention, or with any other treatment for people with any grade of acute or chronic hepatic encephalopathy. This review did not consider the primary prophylaxis of hepatic encephalopathy.

SEARCH METHODS

We searched The Cochrane Hepato-Biliary Group Controlled Trials Register, CENTRAL, MEDLINE, Embase, Science Citation Index Expanded, conference proceedings, reference lists of included trials, and the World Health Organization International Clinical Trials Registry Platform until June 2016.

SELECTION CRITERIA

We included randomised clinical trials that compared probiotics in any dosage with placebo or no intervention, or with any other treatment in people with hepatic encephalopathy.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures expected by The Cochrane Collaboration. We conducted random-effects model meta-analysis due to obvious heterogeneity of participants and interventions. We defined a P value of 0.05 or less as significant. We expressed dichotomous outcomes as risk ratio (RR) and continuous outcomes as mean difference (MD) with 95% confidence intervals (CI).

MAIN RESULTS

We included 21 trials with 1420 participants, of these, 14 were new trials. Fourteen trials compared a probiotic with placebo or no treatment, and seven trials compared a probiotic with lactulose. The trials used a variety of probiotics; the most commonly used group of probiotic was VSL#3, a proprietary name for a group of eight probiotics. Duration of administration ranged from 10 days to 180 days. Eight trials declared their funding source, of which six were independently funded and two were industry funded. The remaining 13 trials did not disclose their funding source. We classified 19 of the 21 trials at high risk of bias.We found no effect on all-cause mortality when probiotics were compared with placebo or no treatment (7 trials; 404 participants; RR 0.58, 95% CI 0.23 to 1.44; low-quality evidence). No-recovery (as measured by incomplete resolution of symptoms) was lower for participants treated with probiotic (10 trials; 574 participants; RR 0.67, 95% CI 0.56 to 0.79; moderate-quality evidence). Adverse events were lower for participants treated with probiotic than with no intervention when considering the development of overt hepatic encephalopathy (10 trials; 585 participants; RR 0.29, 95% CI 0.16 to 0.51; low-quality evidence), but effects on hospitalisation and change of/or withdrawal from treatment were uncertain (hospitalisation: 3 trials, 163 participants; RR 0.67, 95% CI 0.11 to 4.00; very low-quality evidence; change of/or withdrawal from treatment: 9 trials, 551 participants; RR 0.70, 95% CI 0.46 to 1.07; very low-quality evidence). Probiotics may slightly improve quality of life compared with no intervention (3 trials; 115 participants; results not meta-analysed; low-quality evidence). Plasma ammonia concentration was lower for participants treated with probiotic (10 trials; 705 participants; MD -8.29 μmol/L, 95% CI -13.17 to -3.41; low-quality evidence). There were no reports of septicaemia attributable to probiotic in any trial.When probiotics were compared with lactulose, the effects on all-cause mortality were uncertain (2 trials; 200 participants; RR 5.00, 95% CI 0.25 to 102.00; very low-quality evidence); lack of recovery (7 trials; 430 participants; RR 1.01, 95% CI 0.85 to 1.21; very low-quality evidence); adverse events considering the development of overt hepatic encephalopathy (6 trials; 420 participants; RR 1.17, 95% CI 0.63 to 2.17; very low-quality evidence); hospitalisation (1 trial; 80 participants; RR 0.33, 95% CI 0.04 to 3.07; very low-quality evidence); intolerance leading to discontinuation (3 trials; 220 participants; RR 0.35, 95% CI 0.08 to 1.43; very low-quality evidence); change of/or withdrawal from treatment (7 trials; 490 participants; RR 1.27, 95% CI 0.88 to 1.82; very low-quality evidence); quality of life (results not meta-analysed; 1 trial; 69 participants); and plasma ammonia concentration overall (6 trials; 325 participants; MD -2.93 μmol/L, 95% CI -9.36 to 3.50; very low-quality evidence). There were no reports of septicaemia attributable to probiotic in any trial.

AUTHORS' CONCLUSIONS

The majority of included trials suffered from a high risk of systematic error ('bias') and a high risk of random error ('play of chance'). Accordingly, we consider the evidence to be of low quality. Compared with placebo or no intervention, probiotics probably improve recovery and may lead to improvements in the development of overt hepatic encephalopathy, quality of life, and plasma ammonia concentrations, but probiotics may lead to little or no difference in mortality. Whether probiotics are better than lactulose for hepatic encephalopathy is uncertain because the quality of the available evidence is very low. High-quality randomised clinical trials with standardised outcome collection and data reporting are needed to further clarify the true efficacy of probiotics.

Cerebrospinal fluid metabolomics highlights dysregulation of energy metabolism in overt hepatic encephalopathy

BACKGROUND & AIMS

Hepatic encephalopathy (HE) is a neurological complication observed in patients with liver disease and/or porto-systemic shunt. The proportion of cirrhotic patients developing overt HE is about 20%, and 60-80% of cirrhotic patients exhibit mild cognitive impairment potentially related to minimal HE. However, the pathophysiological mechanisms of HE remain poorly understood. In this context, metabolomics was used to highlight dysfunction of metabolic pathways in cerebrospinal fluid (CSF) samples of patients suffering from HE.

METHODS

CSF samples were collected in 27 control patients without any proven neurological disease and 14 patients with symptoms of HE. Plasma samples were obtained from control patients, and from cirrhotic patients with and without HE. Metabolomic analysis was performed using liquid chromatography coupled to high-resolution mass spectrometry.

RESULTS

Concentrations of 73 CSF metabolites, including amino acids, acylcarnitines, bile acids and nucleosides, were altered in HE patients. Accumulation of acetylated compounds, which could be due to a defect of the Krebs cycle in HE patients, is reported for the first time. Furthermore, analysis of plasma samples showed that concentrations of metabolites involved in ammonia, amino-acid and energy metabolism are specifically and significantly increased in CSF samples of HE patients. Lastly, several drugs were detected in CSF samples and could partially explain worsening of neurological symptoms for some patients.

CONCLUSION

By enabling the simultaneous monitoring of a large set of metabolites in HE patients, CSF metabolomics highlighted alterations of metabolic pathways linked to energy metabolism that were not observed in plasma samples.

LAY SUMMARY

CSF metabolomics provides a global picture of altered metabolic pathways in CSF samples of HE patients and highlights alterations of metabolic pathways linked to energy metabolism that are not observed in plasma samples.

Limonene in exhaled breath is elevated in hepatic encephalopathy

Breath samples were taken from 31 patients with liver disease and 30 controls in a clinical setting and proton transfer reaction quadrupole mass spectrometry (PTR-Quad-MS) used to measure the concentration of volatile organic compounds (VOCs). All patients had cirrhosis of various etiologies, with some also suffering from hepatocellular cancer (HCC) and/or hepatic encephalopathy (HE). Breath limonene was higher in patients with No-HCC than with HCC, median (lower/upper quartile) 14.2 (7.2/60.1) versus 3.6 (2.0/13.7) and 1.5 (1.1/2.3) nmol mol^-1 in controls. This may reflect disease severity, as those with No-HCC had significantly higher UKELD (United Kingdom model for End stage Liver Disease) scores. Patients with HE were categorized as having HE symptoms presently, having a history but no current symptoms and having neither history nor current symptoms. Breath limonene in these groups was median (lower/upper quartile) 46.0 (14.0/103), 4.2 (2.6/6.4) and 7.2 (2.0/19.1) nmol mol^-1, respectively. The higher concentration of limonene in those with current symptoms of HE than with a history but no current symptoms cannot be explained by disease severity as their UKELD scores were not significantly different. Longitudinal data from two patients admitted to hospital with HE show a large intra-subject variation in breath limonene, median (range) 18 (10-44) and 42 (32-58) nmol mol^-1.

Effect of undifferentiated versus hepatogenic partially differentiated mesenchymal stem cells on hepatic and cognitive functions in liver cirrhosis

Liver cirrhosis is the outcome of chronic liver injury. The current study aimed to investigate the therapeutic effect of undifferentiated mesenchymal stem cells versus in vitro partially differentiated mesenchymal stem cells on liver cirrhosis and hepatic encephalopathy. 50 adult male albino rats constituted the animal model and were divided into the following groups: control, thioacetamide, undifferentiated mesenchymal stem cells and hepatocyte growth factor-differentiated mesenchymal stem cells groups. Cognitive assessment was achieved by open field test and Y-maze task. We measured serum alanine aminotransferase, albumin and transforming growth factor-beta1, gene expression of α-smooth muscle actin, matrix metalloprotein-2, its tissue inhibitor and apoptotic markers: Bax and Bcl2, brain glial fibrillary acidic protein, synaptophysin, and dopaminergic receptors.

Model-guided identification of a therapeutic strategy to reduce hyperammonemia in liver diseases

BACKGROUND & AIMS

Recently, spatial-temporal/metabolic mathematical models have been established that allow the simulation of metabolic processes in tissues. We applied these models to decipher ammonia detoxification mechanisms in the liver.

METHODS

An integrated metabolic-spatial-temporal model was used to generate hypotheses of ammonia metabolism. Predicted mechanisms were validated using time-resolved analyses of nitrogen metabolism, activity analyses, immunostaining and gene expression after induction of liver damage in mice. Moreover, blood from the portal vein, liver vein and mixed venous blood was analyzed in a time dependent manner.

RESULTS

Modeling revealed an underestimation of ammonia consumption after liver damage when only the currently established mechanisms of ammonia detoxification were simulated. By iterative cycles of modeling and experiments, the reductive amidation of alpha-ketoglutarate (α-KG) via glutamate dehydrogenase (GDH) was identified as the lacking component. GDH is released from damaged hepatocytes into the blood where it consumes ammonia to generate glutamate, thereby providing systemic protection against hyperammonemia. This mechanism was exploited therapeutically in a mouse model of hyperammonemia by injecting GDH together with optimized doses of cofactors. Intravenous injection of GDH (720 U/kg), α-KG (280 mg/kg) and NADPH (180 mg/kg) reduced the elevated blood ammonia concentrations (>200 μM) to levels close to normal within only 15 min.

CONCLUSION

If successfully translated to patients the GDH-based therapy might provide a less aggressive therapeutic alternative for patients with severe hyperammonemia.

Prolonged Delirium With Catatonia Following Orthotopic Liver Transplant Responsive to Memantine

A 59-year-old man with nonalcoholic steatohepatitis cirrhosis underwent an orthotopic liver transplant and experienced a complicated postoperative course, including a prolonged delirium. After discharge to rehabilitation, he had 2 subsequent admissions for delirium. On the first readmission, the transplant team started the patient on risperidone and resumed treatment with sertraline. On his second readmission, neurology and psychiatry were consulted. On evaluation, the patient demonstrated signs of catatonia. On the basis of recommendations from psychiatry, the risperidone and sertraline were stopped, and the patient was started on mirtazapine. He failed to demonstrate improvement within the next 48 hours. Extensive work-up demonstrated a multifactorial etiology for his delirium, including calcineurin-related neuropsychiatric toxicity from tacrolimus leading to possible posterior reversible encephalopathy syndrome. However, after the initiation of memantine on hospital day 3-before the cessation of tacrolimus-the patient demonstrated marked improvement in mental status and motor symptoms. His magnetic resonance imaging, in addition to findings that raised concerns about posterior reversible encephalopathy syndrome, had demonstrated bilateral basal ganglia abnormalities on T1 imaging of uncertain origin. It is postulated that these findings served as predisposing factors for the patient's catatonic symptoms. Although it has been described in case reports following liver transplant, catatonia remains an underrecognized neuropsychiatric complication following liver transplant. This case demonstrates the effectiveness of memantine, an N-methyl-D-aspartic acid antagonist that decreases glutamine excitotoxicity, as a potential treatment for catatonia in postliver transplant patients.

Gradual improvement of hyperammonemic hepatic encephalopathy after the extirpation of a large uterine leiomyoma in a woman with constipation and liver cirrhosis resulting from autoimmune hepatitis

There have been few reports regarding the improvement of hyperammonemic hepatic encephalopathy after the extirpation of a large uterine leiomyoma. We present a case of a 53-year-old postmenopausal woman who experienced a clouding of consciousness. She had been suffering from mild hepatitis and a large uterine leiomyoma. On admission, she had experienced constipation for seven days and exhibited a high serum ammonia level (251 μg/dL). She was diagnosed with liver cirrhosis as a result of autoimmune hepatitis, combined with Sjögren's syndrome. A total hysterectomy was performed 29 days after admission. Severe diarrhea lasted for three days after surgery. By the sixth postoperative day, the patient's consciousness level had normalized and her serum ammonia level had fallen to 47 μg/dL. Although the true mechanism of hyperammonemia in this case is unclear, we speculate that organic constipation following chronic obstruction of the colon might have played a role in the development of the condition.

The Measurement of Ammonia in Human Breath and its Potential in Clinical Diagnostics

Ammonia is an important component of metabolism and is involved in many physiological processes. During normal physiology, levels of blood ammonia are between 11 and 50 µM. Elevated blood ammonia levels are associated with a variety of pathological conditions such as liver and kidney dysfunction, Reye's syndrome and a variety of inborn errors of metabolism including urea cycle disorders (UCD), organic acidaemias and hyperinsulinism/hyperammonaemia syndrome in which ammonia may reach levels in excess of 1 mM. It is highly neurotoxic and so effective measurement is critical for assessing and monitoring disease severity and treatment. Ammonia is also a potential biomarker in exercise physiology and studies of drug metabolism. Current ammonia testing is based on blood sampling, which is inconvenient and can be subject to significant analytical errors due to the quality of the sample draw, its handling and preparation for analysis. Blood ammonia is in gaseous equilibrium with the lungs. Recent research has demonstrated the potential use of breath ammonia as a non-invasive means of measuring systemic ammonia. This requires measurement of ammonia in real breath samples with associated temperature, humidity and gas characteristics at concentrations between 50 and several thousand parts per billion. This review explores the diagnostic applications of ammonia measurement and the impact that the move from blood to breath analysis could have on how these processes and diseases are studied and managed.

Current diagnosis and management of post-transjugular intrahepatic portosystemic shunt refractory hepatic encephalopathy

Transjugular intrahepatic portosystemic shunt has evolved into an important option for management of complications of portal hypertension. The use of polytetrafluoroethylene covered stents enhances shunt patency. Hepatic encephalopathy (HE) remains a significant problem after TIPS placement. The approach to management of patients with refractory hepatic encephalopathy typically requires collaboration between different specialties. Patient selection for TIPS requires careful evaluation of risk factors for HE. TIPS procedure-related technical factors like stent size, attention to portosystemic pressure gradient reduction and use of adjunctive variceal embolization maybe important. Conservative medical therapy in combination with endovascular therapies often results in resolution or substantial reduction of symptoms. Liver transplantation is, however, the ultimate treatment.

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.

Intermittent hyperammonemic encephalopathy after ureterosigmoidostomy: spontaneous onset in the absence of hepatic failure

Intermittent hyperammonemic encephalopathy after ureterosigmoidostomy is a rare, but if unrecognized, potentially lethal condition. Ureterosigmoidostomy was performed in a male patient with bladder extrophy. After 35 years, he developed hyperammonemic encephalopathy. Diagnostic procedures did not reveal hepatic nor metabolic disorders. Despite administration of preventive medical treatment, several episodes recurred. A durable prevention was finally achieved by conversion into an ileal conduit.

Intermittent hyperammonemic encephalopathy can occur decades after ureterosigmoidostomy. In the case of absence of metabolic disorders and resistance to medical treatment, conversion into a urinary diversion using an ileal segment constitutes an effective ultima ratio.

Diagnosis of reversible causes of coma

Because coma has many causes, physicians must develop a structured, algorithmic approach to diagnose and treat reversible causes rapidly. The three main mechanisms of coma are structural brain lesions, diffuse neuronal dysfunction, and, rarely, psychiatric causes. The first priority is to stabilise the patient by treatment of life-threatening conditions, then to use the history, physical examination, and laboratory findings to identify structural causes and diagnose treatable disorders. Some patients have a clear diagnosis. In those who do not, the first decision is whether brain imaging is needed. Imaging should be done in post-traumatic coma or when structural brain lesions are probable or possible causes. Patients who do not undergo imaging should be reassessed regularly. If CT is non-diagnostic, a checklist should be used use to indicate whether advanced imaging is needed or evidence is present of a treatable poisoning or infection, seizures including non-convulsive status epilepticus, endocrinopathy, or thiamine deficiency.

Therapy for alcoholic liver disease

Alcoholism results in about 2.5 million deaths annually worldwide, representing 4% of all mortality. Although alcoholism is associated with more than 60 diseases, most mortality from alcoholism results from alcoholic liver disease (ALD). ALD includes alcoholic steatosis, alcoholic hepatitis, and alcoholic cirrhosis, in order of increasing severity. Important scoring systems of ALD severity include: Child-Pugh, a semi-quantitative scoring system useful to roughly characterize clinical severity; model for end-stage liver disease, a quantitative, objective scoring system used for prognostication and prioritization for liver transplantation; and discriminant function, used to determine whether to administer corticosteroids for alcoholic hepatitis. Abstinence is the cornerstone of ALD therapy. Psychotherapies, including twelve-step facilitation therapy, cognitive-behavioral therapy, and motivational enhancement therapy, help support abstinence. Disulfiram decreases alcohol consumption by causing unpleasant sensations after drinking alcohol from accumulation of acetaldehyde in serum, but disulfiram can be hepatotoxic. Adjunctive pharmacotherapies to reduce alcohol consumption include naltrexone, acamprosate, and baclofen. Nutritional therapy helps reverse muscle wasting, weight loss, vitamin deficiencies, and trace element deficiencies associated with ALD. Although reduced protein intake was previously recommended for advanced ALD to prevent hepatic encephalopathy, a diet containing 1.2-1.5 g of protein/kg per day is currently recommended to prevent muscle wasting. Corticosteroids are first-line therapy for severe alcoholic hepatitis (discriminant function ≥ 32), but proof of their efficacy in decreasing mortality remains elusive. Pentoxifylline is an alternative therapy. Complications of advanced ALD include ascites, spontaneous bacterial peritonitis, esophageal variceal bleeding, hepatic encephalopathy, hepatorenal syndrome, hepatopulmonary syndrome, and portopulmonary hypertension. Alcoholic cirrhotics have increased risk of developing hepatomas. Liver transplantation is the ultimate therapy for severe ALD, but generally requires 6 mo of proven abstinence for eligibility. Alcoholic cirrhotics who maintain abstinence generally have a relatively favorable prognosis after liver transplantation.

Diabetes mellitus and decompensated cirrhosis: risk of hepatic encephalopathy in different age groups

BACKGROUND

The aim of the present study was to examine the association of diabetes mellitus (DM) with the prevalence and severity of hepatic encephalopathy (HE) in patients with decompensated cirrhosis (DC) and determine the impact of age and gender on this relationship.

METHODS

West Haven criteria was used to prospectively evaluate 352 consecutive patients with DC for the presence of HE. Detailed clinicobiochemical profiling of patients was performed. Categorical data and ordered categorical variables were evaluated using the Chi-squared test for independence and trend, respectively. Continuous normal and non-parametric data were evaluated using the t-test and Mann-Whitney U-test, respectively.

RESULTS

At the time of admission, HE was present in 50.3% of patients. In all, 118 patients had DM (33.5%). Patients with DM had a significantly higher prevalence (58.5% vs 42.6%; P = 0.03) and severity of HE (P(trend) = 0.01) than patients without DM. However, there were no significant differences between the two groups in terms of Child-Pugh class, MELD scores, the presence of ascites and esophageal varices. Patients with DM had higher platelet counts than those without DM (P(trend) = 0.003). In age and gender subgroup analyses, older patients and men with DM had significantly greater evidence of HE (P = 0.02 and 0.03, respectively). Multivariate analysis showed that DM (P = 0.03) and older age (P = 0.006) were independently related to HE, whereas the association of gender was non-significant.

CONCLUSION

Both DM and older age are independently associated with HE in patients with cirrhosis.

Antibiotics for the treatment of hepatic encephalopathy

The treatment of hepatic encephalopathy (HE) is complex and therapeutic regimens vary according to the acuity of presentation and the goals of therapy. Most treatments for HE rely on manipulating the intestinal milieu and therefore antibiotics that act on the gut form a key treatment strategy. Prominent antibiotics studied in HE are neomycin, metronidazole, vancomycin and rifaximin. For the management of the acute episode, all antibiotics have been tested. However the limited numbers studied, adverse effects (neomycin oto- and nephrotoxicity, metronidazole neurotoxicity) and potential for resistance emergence (vancomycin-resistant enterococcus) has limited the use of most antibiotics, apart from rifaximin which has the greatest evidence base. Rifaximin has also demonstrated, in conjunction with lactulose, to prevent overt HE recurrence in a multi-center, randomized trial. Despite its cost in the US, rifaximin may prove cost-saving by preventing hospitalizations for overt HE. In minimal/covert HE, rifaximin is the only systematically studied antibiotic. Rifaximin showed improvement in cognition, inflammation, quality-of-life and driving simulator performance but cost-analysis does not favor its use at the current time. Antibiotics, especially rifaximin, have a definite role in the management across the spectrum of HE.

Rifaximin versus Nonabsorbable Disaccharides for the Treatment of Hepatic Encephalopathy: A Meta-Analysis

Background. Many studies have found that the antibiotic rifaximin is effective for the treatment of hepatic encephalopathy. However, there is no uniform view on the efficacy and safety of rifaximin. Methods. We performed a meta-analysis through electronic searches to evaluate the efficacy and safety of rifaximin in comparison with nonabsorbable disaccharides. Results. A total of 8 randomized controlled trials including 407 patients were included. The efficacy of rifaximin was equivalent to nonabsorbable disaccharides according to the statistical data (risk ratio (RR): 1.06, 95% CI: 0.94–1.19; P = 0.34). Analysis showed that patients treated with rifaximin had better results in serum ammonia levels (weighted mean difference (WMD): −10.63, 95% CI: −30.63–9.38; P = 0.30), mental status (WMD: −0.32, 95% CI: −0.67–0.03; P = 0.07), asterixis (WMD: −0.12, 95% CI: −0.31–0.08; P = 0.23), electroencephalogram response (WMD: −0.21, 95% CI: −0.34–−0.09; P = 0.0007), and grades of portosystemic encephalopathy (WMD: −2.30, 95% CI: −2.78–−1.82; P < 0.00001), but only the last ones had statistical significance. The safety of rifaximin was better than nonabsorbable disaccharides (RR: 0.19, 95% CI: 0.10–0.34; P < 0.00001). Conclusion. Rifaximin is at least as effective as nonabsorbable disaccharides, maybe better for the treatment of hepatic encephalopathy. And the safety of rifaximin is better.