l-ornithine-l-aspartate for hepatic encephalopathy in patients with cirrhosis: a meta-analysis of randomized controlled trials

Intravenous versus oral 'L-ornithine-L-aspartate' in overt hepatic encephalopathy: a randomized comparative study

Hepatic encephalopathy (HE), a morbid ordeal affecting chronic liver disease patients always insists for the search of a rational, superior & infallible agent beyond the time-proven standards i.e., Lactulose & Rifaximin. In this RCT, we compared the efficacy of intravenous (IV) L-ornithine-L-aspartate(LOLA) versus Oral LOLA in patients with chronic liver disease(CLD) enduring overt Hepatic Encephalopathy(OHE). 40 CLD patients with OHE were randomly assigned IV or oral LOLA in a 1:1 ratio. Patients were graded for HE and monitored for serum ammonia levels from day 1 to day 5. The aim was to compare IV versus oral LOLA efficacy in HE grades improvement and its correlation with ammonia levels. The study was registered with clinical trials registry-India, CTRI/2020/12/029943. Baseline characteristics of patients in both groups were similar. The mean difference in ammonia levels from day 1 to day 5 was 55.4 ± 32.58 µmol/L in the IV LOLA group and 60.75 ± 13.82 µmol/L in the oral LOLA group (p = 0.511). Significant reductions in ammonia levels were observed from day 1 to day 5 within each group (p < 0.001). HE grade & ammonia correlated positively in both groups. LOLA, regardless of administration route, has demonstrated efficacy in OHE.

Efficacy of L-ornithine L-aspartate for minimal hepatic encephalopathy in patients with cirrhosis: A meta-analysis of randomized controlled trials

BACKGROUND AND STUDY AIMS

Minimal hepatic encephalopathy (MHE) is an early stage of hepatic encephalopathy (HE) and is highly prevalent. The efficacy of L-ornithine L-aspartate (LOLA) for the treatment of HE is well known but its role in MHE remains uncertain. The objectives of the current study were to evaluate the efficacy of LOLA for the treatment of MHE in patients with cirrhosis.

METHODS

The Cochrane Library, PubMed, EMBASE, Web of Science and Ovid databases were searched. Only randomized controlled trials (RCTs) that compared the efficacy of LOLA with placebo or no intervention for the treatment of MHE in patients with cirrhosis were included from inception to January 2023. The primary outcomes were reversal of MHE and development of overt hepatic encephalopathy (OHE).

RESULTS

Overall, six RCTs comprising 292 patients were included. Compared with placebo or no intervention, LOLA was more effective in reversing MHE (RR = 2.264, 95 % CI = 1.528, 3.352, P = 0.000, I2 = 0.0 %) and preventing progression of OHE (RR = 0.220, 95 % CI = 0.076, 0.637, P = 0.005, I2 = 0.0 %). Based on subgroup analyses, oral LOLA treatment appeared more likely to reverse MHE (RR = 2.648, 95 % CI = 1.593, 4.402, P = 0.000, I2 = 0.0 %), intravenous LOLA treatment yielded a similar probability of reversing MHE (RR = 1.669, 95 % CI = 0.904, 3.084, P = 0.102, I2 = 0.0 %). LOLA did not show a superior possibility in reducing mortality (RR = 0.422, 95 % CI = 0.064, 2.768, P = 0.368, I2 = 0.0 %) and ammonia levels (SMD = 0.044, 95 % CI = -0.290, 0.379, P = 0.795, I2 = 0.0 %) compared with placebo or no intervention.

CONCLUSIONS

LOLA has significant beneficial effects on reversal of MHE and prevention of OHE in patients with cirrhosis compared with placebo or no intervention.

Efficacy and Safety of Variable Treatment Options in the Prevention of Hepatic Encephalopathy: A Systematic Review and Network Meta-Analysis

There are no guidelines for the most effective medication to reduce hepatic encephalopathy (HE) or the associated mortality. The purpose of this study is to determine the most effective possible treatment among the single treatment options or the combined treatment options for decreasing the morbidity and mortality of HE. We evaluated the outcomes by various parameters such as the quality of life, reduction in ammonia, all causes of mortality, adverse events, reversal of minimal HE, and development of overt HE. We systematically searched PubMed, Cochrane, Web of Science, and Scopus till the 19th of January 2023 for studies that assess various treatment options for HE. Data were extracted from eligible studies and pooled in a frequentist network meta-analysis as standardized mean difference (SMD) and their 95% confidence interval (CI) using the MetaInsight web-based tool. The Cochrane Tool was used to assess the randomized controlled trials' quality (RCT), while the NIH tool was used to assess the quality of the included cohort studies. Utilizing the R software, the network meta-analysis was conducted. In addition to a significant variation in cases of (Lactulose and Rifaximin) compared with Rifaximin (RR= 0.39, 95% CI [0.17; 0.89]), the results demonstrated a significantly lower incidence of overt HE in (Lactulose and Rifaximin) compared with placebo (RR=0.19, 95% CI [0.09; 0.40]). Most arms demonstrated a statistically significant reduction in the incidence of overt HE compared to albumin and placebo. The results also demonstrated a significant reduction in ammonia between L-ornithine-L-aspartate (LOLA) and probiotics (MD= -19.17, 95% CI [-38.01; -0.32]), as well as a significant difference in the incidence of LOLA compared to placebo (MD= -22.62, 95% CI [-39.16; -6.07]). This network meta-analysis has significant data for managing subclinical HE in people without a history of overt HE. Our analysis showed that (Lactulose and Rifaximin), followed by (Rifaximin and L-carnitine), followed by (Lactulose and Rifaximin with zinc) were the best combinations regarding overt HE. LOLA reduced ammonia best, followed by Nitazoxanide and finally Lactulose. (Lactulose and Nitazoxanide) have the least adverse effects, followed by (Rifaximin and L-carnitine), then Probiotics. Yet, all mortality outcomes and quality of life changes yielded no useful findings. Future studies like RCTs must be done to compare our therapies directly.

The assessment of the potential hepatotoxicity of new drugs by in vitro metabolomics

Drug hepatotoxicity assessment is a relevant issue both in the course of drug development as well as in the post marketing phase. The use of human relevant in vitro models in combination with powerful analytical methods (metabolomic analysis) is a promising approach to anticipate, as well as to understand and investigate the effects and mechanisms of drug hepatotoxicity in man. The metabolic profile analysis of biological liver models treated with hepatotoxins, as compared to that of those treated with non-hepatotoxic compounds, provides useful information for identifying disturbed cellular metabolic reactions, pathways, and networks. This can later be used to anticipate, as well to assess, the potential hepatotoxicity of new compounds. However, the applicability of the metabolomic analysis to assess the hepatotoxicity of drugs is complex and requires careful and systematic work, precise controls, wise data preprocessing and appropriate biological interpretation to make meaningful interpretations and/or predictions of drug hepatotoxicity. This review provides an updated look at recent in vitro studies which used principally mass spectrometry-based metabolomics to evaluate the hepatotoxicity of drugs. It also analyzes the principal drawbacks that still limit its general applicability in safety assessment screenings. We discuss the analytical workflow, essential factors that need to be considered and suggestions to overcome these drawbacks, as well as recent advancements made in this rapidly growing field of research.

Evidence-based approach to management of hepatic encephalopathy in adults

Hepatic encephalopathy (HE) is a reversible syndrome of impaired brain function and represents one of the many complications of portal hypertension and decompensated liver disease. Although ammonia is clearly implicated in the pathogenesis of HE, the pathogenesis of HE is multifactorial with numerous mechanisms that results in functional impairment of neuronal cells. The initial management of HE focuses on supportive care and stabilization which includes providing appropriate nutritional support. Thereafter, focus should be on identifying and treating the precipitating factors. There are many therapeutic agents available for the management of HE, most of which are directed towards lowering the gut nitrogen load and thus the serum ammonia level. This review aims to provide an update on the conventional and emerging treatment options for HE.

Recurrence of Hepatic Encephalopathy after TIPS: Effective Prophylaxis with Combination of Lactulose and Rifaximin

BACKGROUND

Transjugular intrahepatic portosystemic shunt (TIPS) implantation is an established procedure to treat portal hypertension with hepatic encephalopathy (HE) as a common complication. There is lack of evidence concerning HE prophylaxis after TIPS.

METHODS

N = 233 patients receiving TIPS between 2011 and 2018 at a German tertiary care center were included. Of them, 21% (n = 49) had a history of HE. The follow-up period was 12 months. The risk factors of post-TIPS HE were analyzed via multivariate analysis. The efficacy of prophylactic medication regimens was studied. The results show that 35.6% (n = 83) received no medication (NM), 36.5% (n = 85) received lactulose monoprophylaxis (LM), 2.6% (n = 6) rifaximin monoprophylaxis (RM) and 25.3% (n = 59) lactulose and rifaximin (LR) of which 64.4% received l-ornithin-l-aspartate (LOLA) additionally (LR + LOLA) and 36.6% did not (LRonly).

RESULTS

Multivariate analysis revealed higher age (p = 0.003) and HE episodes prior to TIPS (p = 0.004) as risk factors for HE after TIPS. LM has no prophylactic effect. LR prevents HE recurrence at 1, 3 and 12 months after TIPS (p = 0.003, p = 0.003, p = 0.006) but does not prevent HE in patients with no history of HE (p = 0.234, p = 0.483, p = 0.121). LR prevents HE recurrence compared with LM/NM (25.0% vs. 64.7%, p = 0.007) within 12 months after TIPS, whereas de novo occurrence is unaffected (p = 0.098). The additional administration of LOLA to LR has no benefit (LRonly: 25.0%, LR + LOLA: 29.7%, p = 0.780).

CONCLUSIONS

Higher age and previous HE are risk factors post-TIPS HE. In patients with HE prior to TIPS, effective prophylaxis of HE is feasible via combination of lactulose and rifaximin with no additional benefit from LOLA.

New Therapies of Liver Diseases: Hepatic Encephalopathy

Hepatic encephalopathy (HE) is a common complication of advanced liver disease which has profound implications in terms of the patients’ ability to fulfil their family and social roles, to drive and to provide for themselves. Recurrent and persistent HE is still a serious management challenge, translating into a significant burden for patients and their families, health services and society at large. The past few years have been characterized by significantly more attention towards HE and its implications; its definition has been refined and a small number of new drugs/alternative management strategies have become available, while others are underway. In this narrative review we summarize them in a pragmatic and hopefully useful fashion.

Update on pharmacotherapy of hepatic encephalopathy

Hepatic encephalopathy (HE) is a central nervous system disease caused by serious liver diseases or various portal vein systemic circulation abnormalities. The pathogenesis and pathophysiology of HE have not been fully elucidated yet, and among others, the most important is still the theory of ammonia intoxication proposed in the 1930s. Therefore, reducing blood ammonia is currently the main therapeutic strategy for HE, along with improving nervous system function. Thanks to the clarification of the mechanism underlying ammonia-induced brain cell injury in recent years, researchers have proposed some novel therapeutic targets and related drugs. This work will make a brief summary regarding the update of HE drugs with regard to ammonia reduction, nervous system improvement, and intervention of ammonia toxicity targets.

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.

Recent advances in understanding and managing hepatic encephalopathy in chronic liver disease

Hepatic encephalopathy (HE) is a common, severe complication of advanced chronic liver disease (CLD) and has a devastating impact on the patient’s quality of life and prognosis. The neurotoxin ammonia and the presence of systemic and neurological inflammation are considered the key drivers of this neuropsychiatric syndrome. Treatment options available in routine clinical practice are limited, and the development of novel therapies is hampered owing to the complexity and heterogeneity of HE. This review article aims to outline the current understanding of the pathomechanisms of HE and the recent advances in the identification and development of novel therapeutic targets.

Persistent or incident hyperammonemia is associated with poor outcomes in acute decompensation and acute-on-chronic liver failure

Background and Aim

The effect of elevated ammonia on organ failures (OF), apart from hepatic encephalopathy, in patients with acute decompensation (AD) of cirrhosis and acute‐on‐chronic liver failure (ACLF) is unclear. We aimed to assess the effect of persistent or incident hyperammonemia on OF and outcomes in patients with AD and ACLF.

Methods

A total of 229 patients with ACLF and 83 with AD were included. Arterial ammonia was measured on day 1 and day 3 of admission. Persistent or incident hyperammonemia was defined as a level of ≥79.5 μmol/L on day 3. The changes in ammonia levels during the first 3 days were analyzed with respect to the complications and outcomes.

Results

At admission, the median level of arterial ammonia was higher in ACLF compared to AD patients (103 vs 86 μmol/L, P < 0.001). Persistent or incident hyperammonemia was noted in 206 (66.0%) patients and was more frequent in ACLF compared to AD patients (70.7 vs 53.0%, P = 0.013). Patients with persistent or incident hyperammonemia, compared to those without it, developed a higher proportion of new‐onset OF during hospitalization involving liver (P = 0.018), kidney (P = 0.001), brain (P = 0.005), coagulation (P = 0.036), circulation (P = 0.002), and respiratory (P = 0.003) issues and had higher 28‐day mortality (log‐rank test, P < 0.001). After adjustment for chronic liver failure consortium ACLF score, persistent or incident hyperammonemia (hazard ratio, 3.174) was independently associated with 28‐day mortality. The presence of infection was an independent predictor of persistent or incident hyperammonemia.

Conclusion

Persistent or incident hyperammonemia during first 3 days of hospitalization in patients with AD or ACLF is associated with increased risk of OF and death.

Efficacy of rifaximin in the different clinical scenarios of hepatic encephalopathy

Hepatic encephalopathy is a frequent complication in patients with cirrhosis of the liver and is associated with a high mortality rate. Costs attributed to the management of patients with cirrhosis are especially high due to complications, such as hepatic encephalopathy, given that they increase the number of days of hospital stay. Different drugs are currently used to treat hepatic encephalopathy, and the main ones are lactulose, L-ornithine L-aspartate (LOLA), and certain antibiotics, especially rifaximin-α (RFX). Even though many of them have been shown to be effective to greater or lesser degrees, it is important to understand the differences between them, so that every patient receives individualized treatment and the best option is chosen, in accordance with the different clinical scenarios. Thus, the aim of the present study was to analyze the evidence on the advantages and disadvantages of the individual or combined use of the 3 main treatments for hepatic encephalopathy, specifically taking into consideration their different degrees of efficacy, their impact on quality of life, prophylaxis, and cost reduction.

Co-expression analysis and ceRNA network reveal eight novel potential lncRNA biomarkers in hepatocellular carcinoma

BACKGROUND

Hepatocellular carcinoma (HCC) is the most common primary liver cancer in the world, with a high degree of malignancy and recurrence. The influence of the ceRNA network in tumor on the biological function of liver cancer is very important, It has been reported that many lncRNA play a key role in liver cancer development. In our study, integrated data analysis revealed potential eight novel lncRNA biomarkers in hepatocellular carcinoma.

METHODS

Transcriptome data and clinical data were downloaded from the The Cancer Genome Atlas (TCGA) data portal. Weighted gene co-expression network analysis was performed to identify the expression pattern of genes in liver cancer. Then, the ceRNA network was constructed using transcriptome data.

RESULTS

The integrated analysis of miRNA and RNAseq in the database show eight novel lncRNAs that may be involved in important biological pathways, including TNM and disease development in liver cancer. We performed function enrichment analysis of mRNAs affected by these lncRNAs.

CONCLUSIONS

By identifying the ceRNA network and the lncRNAs that affect liver cancer, we showed that eight novel lncRNAs play an important role in the development and progress of liver cancer.

Hepatic Encephalopathy Challenges, Burden, and Diagnostic and Therapeutic Approach

Hepatic encephalopathy (HE) is an important cause of morbidity and mortality in patients with cirrhosis. The impact of HE on the health care system is similarly profound. The number of hospital admissions for HE has increased in the last 10-year period. HE is a huge burden to the patients, care givers, and the health care system. HE represents a "revolving door" with readmission, severely affects care givers, and has effects on cognition that can persists after liver transplant. This article reviews the current literature to discuss the challenges and diagnostic and therapeutic approaches to HE.

Chinese guidelines on management of hepatic encephalopathy in cirrhosis

The Chinese Society of Hepatology developed the current guidelines on the management of hepatic encephalopathy in cirrhosis based on the published evidence and the panelists' consensus. The guidelines provided recommendations for the diagnosis and management of hepatic encephalopathy (HE) including minimal hepatic encephalopathy (MHE) and overt hepatic encephalopathy, emphasizing the importance on screening MHE in patients with end-stage liver diseases. The guidelines emphasized that early identification and timely treatment are the key to improve the prognosis of HE. The principles of treatment include prompt removal of the cause, recovery of acute neuropsychiatric abnormalities to baseline status, primary prevention, and secondary prevention as soon as possible.

Apatinib-induced hyperammonemic encephalopathy

Apatinib is an orally administered small-molecule vascular endothelial growth factor receptor-2 inhibitor that has demonstrated encouraging anticancer activity across a broad range of malignancies, including gastric cancer, non-small-cell lung cancer, breast cancer, and hepatocellular carcinoma. We report a case of probable apatinib-induced hyperammonemic encephalopathy in a 69-year-old male. The patient received apatinib as targeted therapy for hepatocellular carcinoma and presented with acute confusion and hypersomnolence after four days of medication initiation. He showed improvement on drug withdrawal; then he resumed apatinib with a half dose and had a recurrence. Possible underlying mechanisms that include direct neuronal effect and antiangiogenic properties are discussed. We would like to draw attention to the potential risk of vascular endothelial growth factor receptor-tyrosine kinase inhibitors induced hyperammonemic encephalopathy even with a low dosage. Clinicians should be aware of any unexplained neurological syndrome after the initiation of apatinib in patients with hepatocellular carcinoma.

Pathophysiology of hepatic encephalopathy and future treatment options

Understanding of the pathophysiology of hepatic encephalopathy has conditioned new treatment options. Ammonia detoxification in hepatic encephalopathy is regulated by two enzymes: glutaminase or glutamine synthetase. The first produces ammonia and the second detoxifies the ammonia, which is why treatments are aimed at glutaminase inhibition or glutamine synthetase activation. At present, we know that both enzymes are found not only in the liver, but also in the muscle, intestine, kidney, and brain. Therefore, current treatments can be directed at each enzyme at different sites. Awareness of those potential treatment sites makes different options of approach possible in the patient with hepatic encephalopathy, and each approach should be personalized.

Current and future pharmacological therapies for managing cirrhosis and its complications

Due to the restrictions of liver transplantation, complication-guided pharmacological therapy has become the mainstay of long-term management of cirrhosis. This article aims to provide a complete overview of pharmacotherapy options that may be commenced in the outpatient setting which are available for managing cirrhosis and its complications, together with discussion of current controversies and potential future directions. PubMed/Medline/Cochrane Library were electronically searched up to December 2018 to identify studies evaluating safety, efficacy and therapeutic mechanisms of pharmacological agents in cirrhotic adults and animal models of cirrhosis. Non-selective beta-blockers effectively reduce variceal re-bleeding risk in cirrhotic patients with moderate/large varices, but appear ineffective for primary prevention of variceal development and may compromise renal function and haemodynamic stability in advanced decompensation. Recent observational studies suggest protective, haemodynamically-independent effects of beta-blockers relating to reduced bacterial translocation. The gut-selective antibiotic rifaximin is effective for secondary prophylaxis of hepatic encephalopathy; recent small trials also indicate its potential superiority to norfloxacin for secondary prevention of spontaneous bacterial peritonitis. Diuretics remain the mainstay of uncomplicated ascites treatment, and early trials suggest alpha-adrenergic receptor agonists may improve diuretic response in refractory ascites. Vaptans have not demonstrated clinical effectiveness in treating refractory ascites and may cause detrimental complications. Despite initial hepatotoxicity concerns, safety of statin administration has been demonstrated in compensated cirrhosis. Furthermore, statins are suggested to have protective effects upon fibrosis progression, decompensation and mortality. Evidence as to whether proton pump inhibitors cause gut-liver-brain axis dysfunction is conflicting. Emerging evidence indicates that anticoagulation therapy reduces incidence and increases recanalisation rates of non-malignant portal vein thrombosis, and may impede hepatic fibrogenesis and decompensation. Pharmacotherapy for cirrhosis should be implemented in accordance with up-to-date guidelines and in conjunction with aetiology management, nutritional optimisation and patient education.

Hepatic encephalopathy 2018: A clinical practice guideline by the Italian Association for the Study of the Liver (AISF)

Hepatic encephalopathy (HE) is a common, worrisome and sometimes difficult to manage complication of end-stage liver disease. HE is often recurrent, requiring multiple hospital admissions. It can have serious implications in terms of a patient's ability to perform complex tasks (for example driving), their earning capacity, their social and family roles. This guideline reviews current knowledge on HE definition, pathophysiology, diagnosis and treatment, both by general principles and by way of a summary of available drugs and treatment strategies. The quality of the published, pertinent evidence is graded, and practical recommendations are made. Where possible, these are placed within the Italian health service context, with reference to local diagnosis and management experience.

L-Ornithine L-Aspartate (LOLA) for Hepatic Encephalopathy in Cirrhosis: Results of Randomized Controlled Trials and Meta-Analyses

This manuscript represents an appraisal of the evidence in support of L-ornithine-L-aspartate (LOLA) for the management and treatment of hepatic encephalopathy (HE) in cirrhosis. Meta-analyses of randomized controlled trials (RCTs) conducted over the last two decades generally reveal evidence of benefit of LOLA in a range of clinical presentations. This included improvement of mental state grade in overt HE (OHE) assessed by West Haven criteria as well as in minimal HE (MHE) assessed by psychometric testing where the oral formulation of LOLA was determined to be particularly effective. However, concerns over study quality were noted in one meta-analysis. Nevertheless, the concomitant lowering of fasting blood ammonia was reported in all RCTs using this endpoint. Network meta-analyses showed that LOLA appears to be comparable (or superior) in efficacy to non-absorbable disaccharides or probiotics. Emerging evidence from single RCTs show efficacy of LOLA for the treatment of post-transjugular intrahepatic portosystemic shunt (TIPSS) HE as well as for secondary HE prophylaxis. These findings provide support for the use of LOLA in the treatment of HE and future trials should focus on the use of LOLA for prophylaxis.

Mechanistic insight, diagnosis, and treatment of ammonia-induced hepatic encephalopathy

Hepatic encephalopathy is a neuropsychological syndrome due to biochemical disturbance of brain function in advanced liver disease patients. Diagnosis and treatment of the condition is very demanding and has negative toll on finances with increased healthcare utilization. The pathophysiology is not completely understood; however, there is evidence that ammonia plays an important role in the etiology. Conventional methods of solely relying on blood ammonia level to diagnose hepatic encephalopathy did not help much; likewise, the use of lactulose alone in treating hepatic encephalopathy has also been discouraged. This paper analyzed the current knowledge regarding the mechanism of how ammonia disrupts the normal brain function as well as the use of latest diagnosing tools including those under development to evaluate the neuropsychiatric state of patients and their quality of life. The efficacies of lactulose and rifaximin combination for short-term and long-term treatment in addition to nutritional interventions and other drugs undergoing clinical trials were also reviewed.

Why and when to measure ammonemia in cirrhosis?

Hyperammonemia plays a key role in the pathophysiology of hepatic encephalopathy (HE) and most HE treatments are ammonia-lowering drugs. However, the usefulness of measuring ammonemia in routine practice remains controversial and not recommended systematically even when neurological symptoms are present. First, ammonemia measurement should be carefully performed in order to avoid a falsely elevated result. When performed, a normal ammonemia in a cirrhotic patient with neurological symptoms should lead to reconsider the diagnosis of HE. Indeed, literature data show that most cirrhotic patients with HE have an elevated ammonemia, which is however individually poorly correlated with the severity of symptoms. Nevertheless, elevated ammonemia seems to be a factor of bad prognosis in cirrhosis. A decrease in ammonemia after treatments is well proven but it is not determined whether it is associated with clinical efficacy. Repeated measurements could be useful in this context, especially in non-responders, to help differentiating other causes of encephalopathy, such as drug induced. In acute liver failure, the prognostic value of hyperammonemia is well described and could help an early recognition the most severe forms of this disease. We will also discuss how integrating ammonemia into the diagnostic work-up of liver failure and/or encephalopathy. Ammonemia is also essential to diagnose urea cycle disorders or drug toxicity that both need specific interventions.

Efficacy of l-Ornithine l-Aspartate for the Treatment of Hepatic Encephalopathy and Hyperammonemia in Cirrhosis: Systematic Review and Meta-Analysis of Randomized Controlled Trials

BACKGROUND/OBJECTIVES

l-Ornithine l-Aspartate (LOLA) is a mixture of two endogenous amino acids with the capacity to fix ammonia in the form of urea and/or glutamine. Its' efficacy for the treatment of Hepatic Encephalopathy (HE), a known hyperammonemic disorder, remains the subject of debate. This study quantitatively analyzed the efficacy of LOLA in patients with cirrhosis and HE.

METHODS

Efficacy was defined as the extent of lowering of blood ammonia and improvement of mental state assessed in clinically overt HE (OHE) by Westhaven criteria or psychometric testing for assessment of Minimal HE (MHE). Appropriate keywords were used for electronic and/or manual searches of databases to identify RCTs for inclusion. Study quality and risk of bias were assessed using the Jadad Composite Scale together with The Cochrane Scoring Tool. Random Effects Models were used to express pooled Risk Ratio (RR) or Mean Difference (MD) with associated 95% Confidence Intervals (CI).

RESULTS

10 RCTs (884 patients) were included. Regression analysis showed no evidence of publication bias or other small study effects. Eight RCTs had low risk of bias by Jadad/Cochrane criteria. Comparison with placebo/no intervention controls revealed that LOLA was significantly more effective for improvement of mental state in all types of HE (RR 1.36 (95% CI 1.10-1.69), p = 0.005), OHE (RR: 1.19, 95% CI of 1.01-1.39, test for overall effect: Z = 2.14, p = 0.03), MHE (RR: 2.15 (1.48-3.14), p < 0.0001) and for lowering of blood ammonia (MD: -17.50 μmol/l (-27.73 to (-7.26)), p = 0.0008). Improvement of mental state was greater in trials with low risk of bias. Heterogeneity was reduced in trials from Europe or with >100 participants. Oral LOLA appeared particularly effective for the treatment of MHE.

CONCLUSION

LOLA appears to improve mental state and lower ammonia in patients with HE or MHE. Further studies are required in some subgroups of HE and in the era of HE reclassification.

L-ornithine L-aspartate for prevention and treatment of hepatic encephalopathy in people with cirrhosis

BACKGROUND

Hepatic encephalopathy is a common complication of cirrhosis and has high associated morbidity and mortality. The condition is classified as overt if it is clinically apparent or minimal if only evident though psychometric testing. The exact pathogenesis of this syndrome is unknown although ammonia is thought to play a key role. L-ornithine L-aspartate has ammonia-lowering properties and may, therefore, benefit people with cirrhosis and hepatic encephalopathy.

OBJECTIVES

To evaluate the beneficial and harmful effects of L-ornithine L-aspartate versus placebo, no intervention, or other active interventions in people with cirrhosis and hepatic encephalopathy.

SEARCH METHODS

We undertook electronic searches of The Cochrane Hepato-Biliary Group Controlled Trials Register, CENTRAL, MEDLINE, Embase, LILACS and Science Citation Index Expanded to December 2017 and manual searches of meetings and conference proceedings; checks of bibliographies; and corresponded with investigators and pharmaceutical companies.

SELECTION CRITERIA

We included randomised clinical trials, irrespective of publication status, language, or blinding. We included participants with cirrhosis who had minimal or overt hepatic encephalopathy or who were at risk for developing hepatic encephalopathy. We compared: L-ornithine L-aspartate versus placebo or no intervention; and L-ornithine L-aspartate versus other active agents such as non-absorbable disaccharides, antibiotics, probiotics, or branched-chain amino acids.

DATA COLLECTION AND ANALYSIS

Two review authors, working independently, retrieved data from published reports and correspondence with investigators and pharmaceutical companies. The primary outcomes were mortality, hepatic encephalopathy, and serious adverse events. We undertook meta-analyses and presented the results as risk ratios (RR) and mean differences (MD) with 95% confidence intervals (CI). We assessed bias control using the Cochrane Hepato-Biliary Group domains; we evaluated the risk of publication bias and other small trial effects in regression analyses; conducted subgroup and sensitivity analyses; and performed Trial Sequential Analyses. We determined the quality of the evidence using GRADE.

MAIN RESULTS

We identified 36 randomised clinical trials, involving at least 2377 registered participants, which fulfilled our inclusion criteria including 10 unpublished randomised clinical trials. However, we were only able to access outcome data from 29 trials involving 1891 participants. Five of the included trials assessed prevention, while 31 trials assessed treatment. Five trials were at low risk of bias in the overall assessment of mortality; one trial was at low risk of bias in the assessment of the remaining outcomes.L-ornithine L-aspartate had a beneficial effect on mortality compared with placebo or no intervention when including all trials (RR 0.42, 95% CI 0.24 to 0.72; I² = 0%; 19 trials; 1489 participants; very low quality evidence), but not when the analysis was restricted to the trials at low risk of bias (RR 0.47, 95% CI 0.06 to 3.58; 4 trials; 244 participants). It had a beneficial effect on hepatic encephalopathy compared with placebo or no intervention when including all trials (RR 0.70, 95% CI 0.59 to 0.83; 22 trials; 1375 participants; I² = 62%; very low quality evidence), but not in the one trial at low risk of bias (RR 0.96, 95% CI 0.85 to 1.07; 63 participants). The analysis of serious adverse events showed a potential benefit of L-ornithine L-aspartate when including all randomised clinical trials (RR 0.63, 95% CI 0.45 to 0.90; 1 trial; 1489 participants; I² = 0%; very low quality evidence), but not in the one trial at low risk of bias for this outcome (RR 0.83, 95% CI 0.15 to 4.65; 63 participants). The Trial Sequential Analyses of mortality, hepatic encephalopathy, and serious adverse events found insufficient evidence to support or refute beneficial effects. Subgroup analyses showed no difference in outcomes in the trials evaluating evaluating the prevention or treatment of either overt or minimal hepatic encephalopathy or trials evaluating oral versus intravenous administration We were unable to undertake a meta-analysis of the three trials involving 288 participants evaluating health-related quality of life. Overall, we found no difference between L-ornithine L-aspartate and placebo or no intervention in non-serious adverse events (RR 1.15, 95% CI 0.75 to 1.77; 14 trials; 1076 participants; I² = 40%). In comparison with lactulose, L-ornithine L-aspartate had no effect on mortality (RR 0.68, 95% CI 0.11 to 4.17; 4 trials; 175 participants; I² = 0%); hepatic encephalopathy (RR 1.13, 95% CI 0.81 to 1.57); serious adverse events (RR 0.69, 95% CI 0.22 to 2.11); or non-serious adverse events (RR 0.05, 95% CI 0.01 to 0.18). In comparison with probiotics, L-ornithine L-aspartate had no effect on mortality (RR 1.01, 95% CI 0.11 to 9.51); serious adverse events (RR 1.07, 95% CI 0.23 to 4.88); or changes in blood ammonia concentrations from baseline (RR -2.30 95% CI -6.08 to 1.48), but it had a possible beneficial effect on hepatic encephalopathy (RR 0.71, 95% CI 0.56 to 0.90). Finally, in comparison with rifaximin, L-ornithine L-aspartate had no effect on mortality (RR 0.33, 95% CI 0.04 to 3.03; 2 trials; 105 participants); hepatic encephalopathy (RR 1.06, 95% CI 0.57 to 1.96); serious adverse events (RR 0.32, 95% CI 0.01 to 7.42), or non-serious adverse events (RR 0.32, 95% CI 0.01 to 7.42).

AUTHORS' CONCLUSIONS

The results of this review suggest a possible beneficial effect of L-ornithine L-aspartate on mortality, hepatic encephalopathy, and serious adverse events in comparisons with placebo or no-intervention, but, because the quality of the evidence is very low, we are very uncertain about these findings. There was very low quality evidence of a possible beneficial effect of L-ornithine L-aspartate on hepatic encephalopathy, when compared with probiotics, but no other benefits were demonstrated in comparison with other active agents. Additional access to data from completed, but unpublished trials, and new randomised placebo-controlled, double-blind clinical trials are needed.

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.

The burden of minimal hepatic encephalopathy: from diagnosis to therapeutic strategies

Minimal hepatic encephalopathy (MHE) is the mildest form of hepatic encephalopathy (HE). It affects the performance of psychometric tests focused on attention, working memory, psychomotor speed, and visuospatial ability, as well as electrophysiological and other functional brain measures. MHE is a frequent complication of liver disease, affecting up to 80% of tested patients. By being related to falls, an impairment in fitness to drive and the development of overt HE, MHE severely affects the lives of patients and caregivers by altering their quality of life and their socioeconomic status. MHE is detected in clinically asymptomatic patients using appropriate psychometric tests and neurophysiological methods that highlight neuropsychological alterations, such as video-spatial orientation deficits, attention disorders, memory, reaction times, electroencephalogram slowing, prolongation of latency-evoked cognitive potentials, and reduction in the critical flicker frequency. Several treatments have been proposed for MHE treatment, including non-absorbable disaccharides, poorly absorbable antibiotics such as rifaximin, probiotics and branched-chain amino acids. However, because of the multiple diagnosis methods, the various endpoints of treatment trials and the variety of agents used in trials, the treatment of MHE is not currently recommended as routine, but only on a case-by-case basis.

L-ornithine L-aspartate in bouts of overt hepatic encephalopathy

High-quality data on the efficacy of L-ornithine L-aspartate (LOLA) in patients with cirrhosis and bouts of overt hepatic encephalopathy (OHE) are missing. We evaluated the efficacy of intravenous LOLA in the reversal of bouts of OHE in patients with cirrhosis. In this prospective, double-blind, randomized, placebo-controlled trial conducted at two tertiary care institutes in India, 370 patients with cirrhosis and bouts of OHE were screened. After exclusion, 193 (52.16%) patients were randomized to receive either intravenous infusions of LOLA (n = 98), 30 g daily, or placebo (n = 95) for 5 days. Standard of care treatment (including lactulose and ceftriaxone) was given in both groups. Randomization was done centrally (http://www.sealedenvelope.com/). All study personnel were blinded to the treatment assignment. Fasting venous ammonia levels were estimated daily from 0 to 5 days. Serum tumor necrosis factor-alpha, interleukins, hemogram, and liver and renal function tests were performed at days 0 and 5. Primary outcome was mental state grade at day 5 of treatment. The grade of OHE was significantly lower in the LOLA group (compared to placebo) on days 1-4 but not on day 5. The mean time taken for recovery was lower in the LOLA group compared to the placebo group (1.92 ± 0.93 versus 2.50 ± 1.03 days, P = 0.002; 95% confidence interval -0.852 to -0.202). Venous ammonia at day 5 and length of hospital stay were significantly lower in the LOLA group. No significant difference in interleukins was seen between the groups. Conclusion: In patients with bouts of OHE, intravenous LOLA (as an add-on therapy to lactulose and ceftriaxone) significantly improves the grade of OHE over days 1-4, but not on day 5, and decreases venous ammonia, time of recovery, and length of hospital stay. (Hepatology 2018;67:700-710).

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.

Hepatic Encephalopathy: An Update on the Pathophysiology and Therapeutic Options

Hepatic encephalopathy is a spectrum of reversible neuropsychiatric abnormalities, seen in patients with liver dysfunction and/or portosystemic shunting. One of the most debilitating complications of cirrhosis, encephalopathy affects 30-45% of cirrhotics. In addition to significantly affecting the lives of patients and their caregivers, it is also associated with increased morbidity and mortality as well as significant utilization of health care resources. In this paper, we provide an overview on the pathophysiology, diagnosis, management and newer therapies 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.

Minimal hepatic encephalopathy in cirrhosis- how long to treat?

INTRODUCTION

Minimal hepatic encephalopathy (MHE) can reverse after short-term treatment. However, relapse rate of MHE after stopping treatment has not been studied so far. We aimed to evaluate long-term (9 months) efficacy of a short-term (3 months) treatment of MHE with lactulose/rifaximin, for maintenance of remission from MHE.

MATERIAL AND METHODS

In this prospective study, consecutive patients with cirrhosis and MHE were treated with lactulose/rifaximin for 3 months. After treatment, they were followed up for 6 months. Psychometric testing for diagnosis of MHE was performed at baseline, 3 months and 9 months.

RESULTS

Of the 527 patients screened, 351 were found eligible and tested for MHE. Out of these, 112 (31.9%) patients had MHE (mean age 55.3 years; 75% males). They were randomized to receive Rifaximin (n = 57; 1,200 mg/day) or Lactulose (n = 55; 30-120 mL/day) for three months. At 3 months, 73.7% (42/57) patients in Rifaximin group experienced MHE reversal compared to 69.1% (38/55) in Lactulose group (p = 0.677). Six months after stopping treatment, 47.6% (20/42) in rifaximin group and 42.1% (16/38) patients in lactulose group experienced MHE relapse (p = 0.274). The overt hepatic encephalopathy development rate (7.1% vs. 7.9%) and mortality rate (0.23% vs. 0%) were similar in both groups. The Child-Turcotte-Pugh score and model for end stage liver disease (MELD) scores of patients who had MHE relapse were higher compared to those who didn't. On multivariate regression analysis, MELD score was an independent predictor of MHE relapse.

CONCLUSION

Of the patients who became MHE negative after short-term (3 months) treatment with rifaximin/lactulose, almost 50% had a relapse of MHE at 6 months follow-up.

Current state of knowledge of hepatic encephalopathy (Part V): clinical efficacy of L-ornithine-L-aspartate in the management of HE

In cirrhotic patients with portosystemic encephalopathy, OA has confirmed its efficacy both in uncontrolled clinical trials and more recently in placebo-controlled double-blind studies in patients with manifest hepatic encephalopathy and hyperammonemia. OA improved performance in Psyhometric Tests as well as mental state gradation. The therapy had little side effects, increasing with higher intravenously administered dosages, and was well tolerated after oral and parenteral administration.

L‐ornithine L‐aspartate for people with cirrhosis and hepatic encephalopathy

This is a protocol for a Cochrane Review (Intervention). The objectives are as follows:

To assess the beneficial and harmful effects of L‐ornithine L‐aspartate versus placebo, no intervention, or other active interventions for people with cirrhosis and hepatic encephalopathy.

Vigilance and wake EEG architecture in simulated hyperammonaemia: a pilot study on the effects of L-Ornithine-L-Aspartate (LOLA) and caffeine

Hyperammonaemia/mild hepatic encephalopathy (HE) can be simulated by the oral administration of a so-called amino acid challenge (AAC). This study sought to assess the effects of the AAC alone and in combination with either ammonia-lowering [L-ornithine-L-aspartate (LOLA)] or vigilance-enhancing medication (caffeine). Six patients with cirrhosis (5 males; 61.3 ± 9.2 years; 5 Child A, 1 Child B) and six healthy volunteers (5 males; 49.8 ± 10.6 years) were studied between 08:00 and 19:00 on Monday of three consecutive weeks. The following indices were obtained: hourly capillary ammonia, hourly subjective sleepiness, paper & pencil/computerized psychometry and wake electroencephalography (EEG) at 12:00, i.e. at the time of the maximum expected effect of the AAC.

RESULTS

On average, patients had worse neuropsychological performance and slower EEG than healthy volunteers in all conditions but differences did not reach significance. In healthy volunteers, the post-AAC increase in capillary ammonia levels was contained by both the administration of LOLA and of caffeine (significant differences between 10:00 and 14:00 h). The administration of caffeine also resulted in a reduction in subjective sleepiness and in the amplitude of the EEG on several frontal/temporal-occipital sites (p < 0.05; paired t-test). Changes in ammonia levels, subjective sleepiness and the EEG in the three conditions were less obvious in patients. In conclusion, both LOLA and caffeine contained the AAC-induced increase in capillary ammonia, especially in healthy volunteers. Caffeine also counteracted the AAC effects on sleepiness/EEG amplitude. The association of ammonia-lowering and vigilance-enhancing medication in the management of HE is worthy of further study.