An open-label randomized controlled trial of lactulose and probiotics in the treatment of minimal hepatic encephalopathy

Secondary prophylaxis of hepatic encephalopathy in cirrhosis: an open-label, randomized controlled trial of lactulose, probiotics, and no therapy

OBJECTIVES

Lactulose is effective in secondary prophylaxis of hepatic encephalopathy (HE). Probiotics improves minimal hepatic encephalopathy (MHE), which predisposes to HE. No study has been conducted on the secondary prophylaxis of HE using probiotics. Our objective was to study the effects of lactulose and probiotics for secondary prophylaxis of HE.

METHODS

Consecutive cirrhotic patients who had recovered from HE were randomized to receive lactulose (Gp-L, 30 ml three times per day), three capsules of probiotics (Gp-P) per day containing 112.5 billion viable lyophilized bacteria per capsule, or no therapy (Gp-N). All patients were assessed by psychometry (number connection test (NCT-A, B), figure connection test if illiterate (FCT-A, B), digit symbol test (DST), and block design test (BDT)), critical flicker frequency (CFF) test, and arterial ammonia at inclusion. The patients were followed up monthly. The primary end point was development of overt HE according to West Haven criteria or a follow-up of 12 months.

RESULTS

Of 360 patients who recovered, 235 (65.2%) met the inclusion criteria (Gp-L, n=80; Gp-P, n=77; and Gp-N, n=78). In all, 38 patients (16.1%) were lost to follow-up and 77 patients developed HE (Gp-L, n=18; Gp-P, n=22; and Gp-N, n=37). There was a significant difference between Gp-L and Gp-N (P=0.001) and between Gp-P and Gp-N (P=0.02) but no difference between the Gp-L and Gp-P groups (P=0.349). The rate of readmission for causes other than HE (Gp-L, Gp-P, and Gp-N, 19:21:28; P=0.134) and deaths (Gp-L:Gp-P:Gp-N=13:11:16; P=0.56) in all three groups were similar. There was a high prevalence of abnormal psychometry test results (NCT-A, 71.5%; NCT-B, 69.2%; DST, 76.9%; and BDT, 85.2%), and FCT-A and -B were abnormal in 35 of 48 patients (72.7%). CFF was <38 Hz in 118 patients (50.2%). Upon multivariate analysis, recurrence of overt HE was significantly associated with two or more abnormal psychometric tests and arterial ammonia after the recovery of an episode of HE.

CONCLUSIONS

Lactulose and probiotics are effective for secondary prophylaxis of HE in patients with cirrhosis.

Treatment options for hepatic encephalopathy

Few formal treatment guidelines exist for managing hepatic encephalopathy. The nonabsorbable disaccharide, lactulose, is considered the first-line therapeutic agent for treating hepatic encephalopathy. Acidification of the gastrointestinal tract is the principal mechanism by which the drug inhibits production of ammonia by coliform bacteria. Elevated ammonia levels are seen in more than 80% of patients with hepatic encephalopathy. Systemic antibiotics, primarily neomycin, have also been employed to reduce bacterial production of ammonia, but associated adverse events limit their use in patients with hepatic encephalopathy. The semisynthetic, nonsystemic antibiotic, rifaximin, was approved in March 2010 by the United States Food and Drug Administration for the treatment of overt hepatic encephalopathy. Rifaximin decreases intestinal production and absorption of ammonia by altering gastrointestinal flora and is almost completely excreted unchanged in the feces. Rifaximin has been effective in improving behavioral, laboratory, mental, and intellectual abnormalities in patients with hepatic encephalopathy. The drug was compared with lactulose in well-designed clinical studies in patients with hepatic encephalopathy. Rifaximin was generally found to be equal or superior to lactulose in these studies. Although dosages have varied, most medical centers use a dosage of rifaximin 400 mg 3 times/day for hepatic encephalopathy. Recent clinical trials have used 550 mg twice/day in order to improve patient compliance. Additional clinical trials are being undertaken to further define the efficacy and safety of rifaximin in hepatic encephalopathy.

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

Hepatic encephalopathy (HE) is a serious and potentially fatal complication in patients with cirrhotic liver disease. It is a spectrum ranging from minimal hepatic encephalopathy (MHE) without recognizable clinical symptoms or signs, to overt HE with risk of cerebral edema and death. HE results in diminished quality of life and survival. The broad range of neuropsychiatric manifestations reflects the range of pathophysiological mechanisms and impairment in neurotransmission that are purported to cause HE including hyperammonemia, astrocyte swelling, intra-astrocytic glutamine, upregulation of 18-kDa translocator protein (TSPO) (formerly known as peripheral benzodiazepine receptor or PBTR), and manganese. There is a myriad of diagnostic tools including simple bedside clinical assessment, and more complex neuropsychological batteries and neurophysiological tests available today. Current treatment strategies are directed at reducing ammonia, with newer agents showing some early promise. This paper describes the pathophysiology of the disease and summarises current diagnostic and treatment therapies available.

Lactulose for minimal hepatic encephalopathy in patients with extrahepatic portal vein obstruction

BACKGROUND/AIMS

Minimal hepatic encephalopathy (MHE) is common in patients with extrahepatic portal vein obstruction (EHPVO). There is no study on the treatment of MHE using lactulose in patients with EHPVO.

PATIENTS AND METHODS

Consecutive EHPVO patients were assessed by psychometric (number connection test (NCT-A and B), digit symbol test (DST), serial dot test (SDT), line tracing test (LTT)), and critical flicker frequency (CFF) at inclusion. Patients diagnosed as MHE were treated with lactulose and psychometric tests, CFF, and were reassessed after 3 months.

RESULTS

Of the 70 patients screened, the prevalence of abnormal psychometric test was as follows: NCT-A (41%), NCT-B (53%), DST (38%), SDT (40%), and LTT (44%). Thirty patients (43%) had two or more than two abnormal (>2 SD) psychometry tests. Lactulose improved MHE in 16/30 (53%) of patients after 3 months of treatment. Arterial ammonia decreased after lactulose treatment compared to baseline (83.7±19.1 vs. 65.1±19.3 μmol/l, P=0.001). A total of 9 (75%) of 12 patients with large spontaneous shunt and 7 (39%) of 18 patients without spontaneous shunt improved with lactulose (P=0.07). CFF in patients with MHE (n=30) was significantly lower than those without MHE (n=40) (38.1±2.4 vs. 41.5±3.1 Hz, P=0.01). CFF was less than 38 Hz in 21 (70%) of 30 patients before treatment and in 10 (33%) patients after lactulose therapy in MHE patients. All patients could tolerate lactulose without any significant side effects. Four patients (13%) developed transient diarrhea in whom dose needed reduction, 3 (10%) did not like its taste but have continued, and 2 (6%) developed abdominal bloating sensation.

CONCLUSIONS

Lactulose is effective in the treatment of MHE in patients with EHPVO.

Probiotics for patients with hepatic encephalopathy

BACKGROUND

Hepatic encephalopathy is a disorder of brain function as a result of liver failure and/or portosystemic shunt. 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 health care resources. Probiotics are live microorganisms, which when administered in adequate amounts may confer a health benefit on the host.

OBJECTIVES

To quantify the beneficial and harmful effects of any probiotic in any dosage, compared with placebo or no intervention, or with any other treatment for patients with any grade of acute or chronic hepatic encephalopathy as assessed from randomised trials.

SEARCH METHODS

We searched the The Cochrane Hepato-Biliary Group Controlled Trials Register, The Cochrane Central Register of Controlled Trials (CENTRAL) in The Cochrane Library, MEDLINE, EMBASE, Science Citation Index Expanded, conference proceedings, reference lists of included trials and the WHO international clinical trials registry until April 2011 registry platform to identify new and ongoing trials.

SELECTION CRITERIA

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

DATA COLLECTION AND ANALYSIS

Three authors independently assessed the risk of bias of the included trials and extracted data on relevant outcomes, with differences resolved by consensus. We conducted random-effects model meta-analysis due to obvious heterogeneity of patients and interventions. A P value of 0.05 or less was defined as significant. Dichotomous outcomes are expressed as risk ratio (RR) and continuous outcomes as mean difference (MD) with 95% confidence intervals (CI).

MAIN RESULTS

We included seven trials of which 550 participants were randomised. Four of the seven trials compared a probiotic with placebo or no treatment in 245 participants, another trial compared a probiotic with lactulose in 40 participants , and the remaining two trials compared a probiotic with both placebo and lactulose in 265 participants. Each trial used different types of probiotics. Duration of administration of the experimental intervention varied from 10 days to 180 days. Two trials were industry funded, and five were unclear about origin of funding. All trials had high risk of bias. When probiotics were compared with no treatment, there was no significant difference in all-cause mortality (2 trials, 105 participants; 1/57 (2%) versus 1/48 (2%): RR 0.72; 95% CI 0.08 to 6.60), lack of recovery (4 trials, 206 participants; 54/107 (50%) versus 68/99 (69%): RR 0.72; 95% CI 0.49 to 1.05), adverse events (3 trials, 145 participants; 2/77 (3%) versus 6/68 (9%): RR 0.34; 95% CI 0.08 to 1.42), quality of life (1 trial, 20 participants contributed to the physical quality of life measurement, 20 participants contributed to the mental quality of life: MD Physical 0.00; 95% CI -5.47 to 5.47; MD Mental 4.00; 95% CI -1.82 to 9.82), or change of/or withdrawal from treatment (3 trials, 175 participants; 11/92 (12%) versus 7/83 (8%): RR 1.28; 95% CI 0.52 to 3.19). No trial reported sepsis or duration of hospital stay as an outcome. Plasma ammonia concentration was significantly lower for participants treated with probiotic at one month (3 trials, 226 participants: MD -2.99 μmol/L; 95% CI -5.70 to -0.29) but not at two months (3 trials, 181 participants: MD -1.82 μmol/L; 95% CI -14.04 to 10.41). Plasma ammonia decreased the most in the participants treated with probiotic at three months (1 trial, 73 participants: MD -6.79 μmol/L; 95% CI -10.39 to -3.19). When probiotics were compared with lactulose no trial reported all-cause mortality, quality of life, duration of hospital stay, or septicaemia. There were no significant differences in lack of recovery (3 trials, 173 participants; 47/87 (54%) versus 44/86 (51%): RR 1.05; 95% CI 0.75 to 1.47), adverse events (2 trials, 111 participants; 3/56 (5%) versus 6/55 (11%): RR 0.57; 95% CI 0.06 to 5.74), change of/or withdrawal from treatment at one month (3 trials, 190 participants; 8/95 (8%) versus 7/95 (7%): RR 1.10; 95% CI 0.40 to 3.03), plasma ammonia concentration (2 trials, 93 participants: MD -6.61 μmol/L; 95% CI -30.05 to 16.84), or change in plasma ammonia concentration (1 trial, 77 participants: MD 1.16 μmol/L; 95% CI -1.96 to 4.28).

AUTHORS' CONCLUSIONS

The trials we located suffered from a high risk of systematic errors ('bias') and high risk of random errors ('play of chance'). While probiotics appear to reduce plasma ammonia concentration when compared with placebo or no intervention, we are unable to conclude that probiotics are efficacious in altering clinically relevant outcomes. Demonstration of unequivocal efficacy is needed before probiotics can be endorsed as effective therapy for hepatic encephalopathy. Further randomised clinical trials are needed.

Clinical efficacy and safety of lactulose for minimal hepatic encephalopathy: a meta-analysis

OBJECTIVE

To evaluate the clinical efficacy of lactulose in patients with minimal hepatic encephalopathy (MHE).

METHODS

Randomized controlled trials (RCTs) comparing lactulose with placebo or with no intervention in the management of MHE that were conducted from January 1990 to July 2011 were searched from MEDLINE, EMBASE, SCI, Cochrane Controlled Trials Register, and China Biological Medicine Database. Studies with a Jadad score higher than 3 were included in the meta-analysis and evaluated using RevMan5.0 software for relative risk (RR) or weighted mean difference (WMD) with 95% confidence intervals (95% CI). Sensitivity analysis was performed on the ethnical differences and quality of the trials. Publication bias was observed using an inverted funnel plot.

RESULTS

Nine studies with 434 patients were included in the meta-analysis. Compared with placebo or no intervention, lactulose significantly reduced the risk of no improvement in neuropsychological tests (RR: 0.52, 95% CI: 0.44-0.62, P<0.00001), the time required for the completion of the number connection test-A (WMD: -26.95, 95% CI: -37.81 to -16.10, P<0.00001), and the mean number of abnormal neuropsychological tests (WMD: -1.76, 95% CI: -1.96 to -1.56, P<0.00001). Furthermore, the meta-analysis also showed that lactulose prevented the progression to overt hepatic encephalopathy (RR: 0.17, 95% CI: 0.06-0.52, P=0.002), reduced blood ammonia levels (WMD: -9.89 µmol/l, 95% CI: -11.01 to -8.77 µmol/l, P<0.00001), and improve health-related quality of life (WMD: -6.05, 95% CI: -6.30 to -5.20, P<0.00001). However, no significant difference was observed in the mortality of patients with MHE (RR: 0.75, 95% CI: 0.21-2.72, P=0.66), and lactulose significantly increased the incidence of diarrhea (RR: 4.38, 95% CI: 1.35-14.25, P=0.01).

CONCLUSION

Lactulose has significant beneficial effects for patients with MHE compared with placebo or no intervention.

Efficacy of probiotics in the treatment of minimal hepatic encephalopathy: a metaanalysis

AIM: To evaluate the efficacy of probiotics in the treatment of minimal hepatic encephalopathy.

METHODS: PUBMED, EMBASE, Web of Science, The Cochrane Central Register of Controlled Trials, Chinese Journals Full-text Database, Chinese Biomedical Database and Wan Fang Digital Journal Full-text database were searched to retrieve randomized controlled trials evaluating the efficacy of probiotics in the treatment of minimal hepatic encephalopathy. Statistical analysis was performed using Review Manager 4.3.

RESULTS: Nine randomized controlled trials were included. Compared to the control group, probiotics significantly decreased serum ammonia (SMD = 0.98, 95%CI: 0.25-1.71, P = 0.008), endotoxin (SMD = 1.03, 95%CI: 0.65-1.42, P < 0.00001) and ALT (WMD = 11.72, 95%CI: 5.57-17.88, P = 0.0002), shortened the time of number connection test (NCT) (WMD = 13.60, 95%CI: 1.53-25.66, P = 0.03), and reduced morbidity of clinical hepatic encephalopathy (RR = 0.15, 95%CI: 0.05-0.41, P = 0.0002).

CONCLUSION: Probiotics can significantly improve some clinical and biochemical parameters in patients with minimal hepatic encephalopathy, decrease the morbidity of clinical hepatic encephalopathy and may become a new choice for the treatment of minimal hepatic encephalopathy.

A randomized controlled trial comparing lactulose, probiotics, and L-ornithine L-aspartate in treatment of minimal hepatic encephalopathy

BACKGROUND

Minimal hepatic encephalopathy (MHE) impairs daily functioning and health-related quality of life (HRQoL). The modalities of treatment of MHE have not been adequately studied.

AIMS

To compare lactulose, probiotics, and L-ornithine L-aspartate (LOLA) in treatment of MHE and effect on HRQoL by Sickness Impact Profile questionnaire.

METHODS

Consecutive patients with cirrhosis were screened for MHE. MHE was diagnosed by two or more abnormal psychometric tests (number/figure connection tests A and B, block design test, picture completion test). Patients were randomized to no treatment (GpA), lactulose 30-60 ml/twice per day (GpB), probiotics 110 billion colony forming units twice in a day (GpC), LOLA 6 g three times per day (GpD) for 3 months. Arterial ammonia and HRQoL assessment using SIP questionnaire was done at baseline and at 3 months.

RESULTS

One hundred and sixty (49.69%) of 322 patients with cirrhosis had MHE. After 3 months, MHE recovered in GpA four (10%), GpB 19 (47.5%), GpC 14 (35%), and GpD 14 (35%). MHE improved significantly in all three treatment groups (GpB, GpC, GpD) compared with no treatment (GpA) (P=0.006). Overt hepatic encephalopathy developed in nine (5.6%) of 160 patients; GpA four (10%), GpB one (2.5%), GpC two (5%), and GpD two (5%), respectively. There was significant improvement in SIP score in GpB (6.98±4.1), GpC (6.24±3.4), and GpD (7.33±3.8) versus GpA (1.05±2.6), P value of less than 0.001. The decrease in SIP score correlated with an improvement in MHE on multivariate analysis but there was no correlation with the type of intervention offered. There was no significant change in arterial ammonia level after therapy in GpA (-0.52±7.8 μmol/l). Arterial ammonia level in GpB (-8.47±5.8 μmol/l), GpC (-7.31±7.9 μmol/l), and GpD (-9.61±9.3 μmol/l) were significantly more than GpA (P<0.0001).

CONCLUSION

Lactulose, probiotics, and LOLA significantly improve MHE and HRQoL in patients with chronic liver disease.

Rifaximin: new therapeutic indication and future directions

BACKGROUND

Rifaximin is a nonabsorbable oral antibiotic that acts locally in the gastrointestinal tract with minimal systemic adverse effects. Rifaximin received new labeling for reduction in the risk of the recurrence of overt hepatic encephalopathy (HE) in patients with advanced liver disease in March of 2010.

OBJECTIVE

This article reviews the pharmacology, pharmacokinetics, and pharmacodynamics of rifaximin. The efficacy and safety of rifaximin in reducing the risk of the recurrence of overt HE in patients with advanced liver disease, the new US Food and Drug Administration-approved indication, is the focus of this review. Emerging data on the use of rifaximin in irritable bowel syndrome (IBS) and Clostridium difficile infection (CDI) are also evaluated.

METHODS

MEDLINE and International Pharmaceutical Abstracts from 1983 to January 31, 2011, were searched using the key terms rifaximin, L/105, secondary hepatic encephalopathy, irritable bowel syndrome, and Clostridium difficile. Ongoing trials were identified using the clinicaltrials.gov Web site. Abstracts from the annual meetings of the American College of Gastroenterology and Digestive Disease Week from 2004 to 2010 and references from relevant articles were reviewed. Only trials examining use of rifaximin in secondary prophylaxis of HE were included. Studies on the efficacy and safety of rifaximin in the treatment of acute episodes of HE have been recently summarized elsewhere and are not reviewed here.

RESULTS

Literature search identified one trial on rifaximin use in secondary prevention of HE, six trials in patients with IBS, and six small studies and case reports in patients with CDI. In a trial of 299 patients, use of rifaximin 550 mg by mouth twice daily for 6 months for prevention of recurrent HE was associated with significantly fewer breakthrough HE episodes compared with placebo (rifaximin 22%, placebo 46%; P < 0.001), with a hazard ratio of 0.42 (95% CI, 0.28-0.64). The rifaximin group also had fewer hospitalizations involving HE compared with placebo (rifaximin 13.6%, placebo 22.6%; P = 0.01), with a hazard ratio of 0.50 (95% CI, 0.29-0.87). Rifaximin improved IBS symptom management in ∼9% more patients than placebo in 2 prospective, randomized, double-blind, placebo-controlled trials of 1260 patients (in the rifaximin group, 40.8% patients reported IBS symptom improvement compared with 31.7% in the placebo group; P < 0.001). The efficacy of rifaximin has been reported for the treatment of refractory or recurrent CDI in small studies, case series, and a case report. Optimal dosing, duration, and role of rifaximin for CDI management is unclear. In clinical trials of rifaximin for prevention of recurrent HE and for nonconstipated IBS, its safety profile was comparable to placebo. In the trial of rifaximin for prevention of recurrent HE, the most common adverse events occurring in 10% to 15% of patients were ascites, dizziness, fatigue, and peripheral edema. Most common adverse effects in IBS trials included abdominal pain, diarrhea, bad taste, headache, and upper respiratory tract infection, occurring in <10% of patients.

CONCLUSIONS

Rifaximin can be an effective option for reduction in the risk of the recurrence of HE in patients with advanced liver disease. Studies suggest that rifaximin provides relief of global symptoms of diarrhea-predominant IBS and bloating. Use of rifaximin in CDI requires further study.

The gut microbiota and human health with an emphasis on the use of microencapsulated bacterial cells

The gut microbiota plays a crucial role in maintaining health. Alterations of the gut bacterial population have been associated with a number of diseases. Past and recent studies suggest that one can positively modify the contents of the gut microbiota by introducing prebiotics, probiotics, synbiotics, and other therapeutics. This paper focuses on probiotic modulation of the gut microbiota by their delivery to the lower gastrointestinal tract (GIT). There are numerous obstacles to overcome before microorganisms can be utilized as therapeutics. One important limitation is the delivery of viable cells to the lower GIT without a significant loss of cell viability and metabolic features through the harsh conditions of the upper GIT. Microencapsulation has been shown to overcome this, with various types of microcapsules available for resolving this limitation. This paper discusses the gut microbiota and its role in disease, with a focus on microencapsulated probiotics and their potentials and limitations.

Diet and cognition in chronic liver disease

PURPOSE OF REVIEW

The spectrum of neurocognitive impairment in cirrhosis spans a continuum of minimal hepatic encephalopathy (MHE) to overt hepatic encephalopathy (OHE), the pathophysiology of which remains incompletely understood. The current available evidence, however, suggests that nutrition plays an important role in its development and points to the fact that malnutrition increases the morbidity and mortality of patients with cirrhosis. This review incorporates recent findings published in the last 2 years within the evolution of evidence regarding the role dietary manipulation can play in the comprehensive management of patients with cirrhosis and cognitive dysfunction.

RECENT FINDINGS

In patients with cirrhosis it is important to prevent starvation physiology which occurs after few hours of caloric deprivation as compared to 3 days in noncirrhotics. This can be accomplished by making sure that cirrhotic patients have daily breakfast and a late evening snack. In addition, probiotics and symbiotics are well tolerated and improve cognitive function in patients with MHE.

SUMMARY

The long-time held belief that protein restriction is needed to improve encephalopathy has no scientific basis but remains widely practiced. Branched-chain amino acids supplement may be helpful in patients who continue to suffer from OHE despite treatment of precipitating events and pharmacologic treatment with lactulose and rifaximin. Preventing starvation physiology and supplementing the diet with prebiotics and symbiotics are helpful in patients with MHE.

Rifaximin improves psychometric performance and health-related quality of life in patients with minimal hepatic encephalopathy (the RIME Trial)

OBJECTIVES

Cirrhotics with minimal hepatic encephalopathy (MHE) have a poor health-related quality of life (HRQOL). Treatment of MHE is still evolving. The aim of this double-blind randomized pilot study was to assess the efficacy of rifaximin in improving neuropsychometric (NP) test performance and HRQOL in patients with MHE.

METHODS

MHE was diagnosed if any two NP tests (number and figure connection tests, picture completion, digit symbol, and block design tests) were deranged beyond 2 s.d. of normal. HRQOL was assessed using the sickness impact profile (SIP) questionnaire.

RESULTS

A total of 486 patients with cirrhosis were screened and 284 were found eligible. Out of these 115 (40.9%) had MHE, of which 21 refused consent and 94 were randomized to receive placebo (n=45) and rifaximin (n=49; 1200 mg/day) for 8 weeks. At the end of treatment, significantly more number of patients in rifaximin group showed reversal of MHE (75.5% (37/49) vs. 20% (9/45) in placebo group; P<0.0001). Rifaximin group also showed significant reduction in mean number of abnormal NP tests (baseline, 2.35 (95% confidence interval (CI), 2.17-2.53); 2 weeks, 1.29 (95% CI, 1.02-1.56), P=0.002; 8 weeks, 0.81 (95% CI, 0.61-1.02), P=0.000), compared with placebo group (baseline, 2.31 (95% CI, 2.03-2.59); 2 weeks, 2.03 (95% CI, 1.74-2.31); 8 weeks, 1.97 (95% CI, 1.69-2.25), P>0.05). The mean total SIP score also improved significantly in rifaximin group (baseline, 11.67 (95% CI, 10.31-13.03); 8 weeks, 6.45 (95% CI, 5.59-7.30); P=0.000) compared with placebo group (baseline, 9.86 (95% CI, 8.66-11.06); 8 weeks, 8.51 (95% CI, 7.35-9.67); P=0.82). Improvement in HRQOL correlated with improvement in NP tests. Rifaximin was well tolerated.

CONCLUSIONS

Rifaximin significantly improves both cognitive functions and HRQOL in patients with MHE.

Current and emerging strategies for treating hepatic encephalopathy

Hepatic encephalopathy (HE) is caused by liver impairment and has a multitude of symptoms in affected patients, including change in level of consciousness, intellectual function, and neuromuscular function. Pharmacologic therapy includes use of nonabsorbable disaccharides (lactulose and lactitol), and antibiotics such as neomycin, paromycin, metronidazole, and rifaximin. Probiotics, acarbose, and drugs such as L-carnitine and flumazenil, may also be helpful in treating HE.

Rifaximin for the treatment of hepatic encephalopathy

Hepatic encephalopathy (HE) is a complication of cirrhosis, the severity of which can range from subtle, neurocognitive dysfunction (minimal HE) to more apparent and severe cognitive and motor manifestations with increasing grades of the condition (overt HE). Current treatment options are targeted at reducing the levels of ammonia and other gut-derived toxins, the purported culprits behind the pathogenesis of HE. One of these therapeutic options, the nonsystemic antibiotic rifaximin, is efficacious for the treatment of minimal and overt HE. However, HE may be a cyclic condition in which patients with overt HE enter remission following treatment and then relapse. Thus, safe, effective and well-tolerated treatments are needed to maintain HE remission. Rifaximin maintained HE remission more effectively than placebo in a large, randomized controlled trial. Rifaximin is safe and well-tolerated for the treatment of minimal and overt HE and for the maintenance of HE remission.

The impact of nutrition on cirrhotic patients awaiting liver transplantation

PURPOSE OF REVIEW

To review the most recent aspects of nutrition therapy of cirrhotic patients on the waiting list for liver transplantation.

RECENT FINDINGS

Undernutrition has been widely reported among these patients, despite the lack of consensus on the best nutritional assessment tools in this population. Nutrition therapy has been marked by controversy. Nonetheless, recent findings have pointed out to the important role of the nutrition status and of some specific nutrients on the outcome of these patients.

SUMMARY

We report the latest findings on nutrition care of patients with end-stage liver disease on the waiting list for liver transplantation such as the impact of the nutritional status on outcome, probiotic and branched-chain amino acid supplementation, as well as the use of immunomodulating formula. Another important strategy that has been shown to improve these patients' nutritional care is the offering of nocturnal meals and micronutrient supplementation.

Pharmacotherapy of hepatic encephalopathy in cirrhosis

IMPORTANCE OF THE FIELD

Hepatic encephalopathy (HE) is a major complication encountered in nearly half of the patients with liver cirrhosis.

AREAS COVERED IN THIS REVIEW

A review of the safety and efficacy of current therapies for HE that seek to pre-empt ammonia production and/or to increase its elimination, reducing inflammation, blocking benzodiazepine-like compound production, and supporting systemic hemodynamics.

WHAT THE READER WILL GAIN

Insight into some recent advances in the management of HE that could modify our therapeutic approach to end-stage liver disease. Cirrhotic individuals during an overt HE episode require careful management, focusing on precipitant factors as well as metabolic and hemodynamic derangements.

TAKE HOME MESSAGE

Intestinal ammoniagenesis requires flora modification by antibiotics, prebiotics and probiotics; glutaminase inhibition as well as antibiotics to pre-empt systemic inflammation. Hemodynamic/fluid support is essential. Nutritional support is crucial and hypoproteinemic diets should be avoided. Blocking benzodiazepine-like compounds by the use of flumazenil could be useful in patients with severe, benzodiazepine-induced HE. Long-term rifaximin is well tolerated, does not promote resistance and could decrease overt HE bouts in patients with previous episodes of overt HE. Lactulose is better than no treatment in improving quality of life in patients with minimal HE; it also acts as secondary prophylaxis following overt HE.

Predictors of minimal hepatic encephalopathy in patients with cirrhosis

BACKGROUND/AIM

Minimal hepatic encephalopathy (MHE) impairs patient's daily functioning of life. Predictors of MHE in cirrhotic patients have not been evaluated.

PATIENTS AND METHODS

A total of 200 cirrhotic patients (Child A, 74 [37%]; Child B, 72 [36%]; Child C, 54 [27%]) were evaluated by psychometry, P300 auditory event-related potential (P300ERP) and critical flicker frequency (CFF). MHE was diagnosed by abnormal psychometry (>2 S.D.) and P300ERP (>2.5 S.D.). Univariate and multivariate logistic regression analyses were performed to determine the predictors of MHE.

RESULTS

Eighty-two (41%) patients were diagnosed to have MHE - 26/74 (35%) in Child A, 26/72 (36%) in Child B and 30/54 (56%) in Child C. Ninety-seven (48.5%) patients had abnormal psychometric tests, and 96 (48%) had prolonged P300ERP (>358 ms). Sixteen (16.5%) patients with abnormal psychometry had P300ERP < 358 ms, and 15 (14.5%) patients with normal psychometry results had P300ERP > 358 ms. One hundred and three patients had CFF value < 39 Hz with specificity of 86.6% and sensitivity of 72.9% for MHE. Model for end-stage liver disease (MELD) (17.9 +/- 5.7 vs. 13.4 +/- 4.2, P = 0.005), Child-Turcotte-Pugh (CTP) score (8.4 +/- 2.5 vs. 7.7 +/- 2.2, P = 0.02), ammonia (104.8 +/- 37.9 vs. 72.5 +/- 45.2 micromol/L, P = 0.001) and CFF (37.0 +/- 2.8 vs. 41.0 +/- 3.4 Hz, P = 0.001) were significantly higher in MHE as compared to non-MHE patients. Ninety-one (45.5%) patients had MELD > 15.5, 115 (57.5%) had CTP score > 7.5, while 93 (46.5%) had venous ammonia > 84.5 micromol/L. On univariate analysis, MELD (8.52 [95% CI, 4.46-16.26; P = 0.001]), CFF (17.34 [95% CI, 8.16-36.85; P = 0.001]) and venous ammonia (7.80 [95% CI, 4.11-14.81; P = 0.003]) were associated with MHE; while CTP score (1.51 [95% CI, 0.85-2.69; P = 0.30]) was not significant. On multivariate analysis, MELD, CFF and venous ammonia were predictive of MHE.

CONCLUSION

Prevalence of MHE in this study was 41%; and MELD > 15.5, CFF < 39 Hz and venous ammonia > 84.5 micromol/L were predictive of MHE.

Minimal hepatic encephalopathy: consensus statement of a working party of the Indian National Association for Study of the Liver

Hepatic encephalopathy (HE) is a major complication that develops in some form and at some stage in a majority of patients with liver cirrhosis. Overt HE occurs in approximately 30-45% of cirrhotic patients. Minimal HE (MHE), the mildest form of HE, is characterized by subtle motor and cognitive deficits and impairs health-related quality of life. The Indian National Association for Study of the Liver (INASL) set up a Working Party on MHE in 2008 with a mandate to develop consensus guidelines on various aspects of MHE relevant to clinical practice. Questions related to the definition of MHE, its prevalence, diagnosis, clinical characteristics, pathogenesis, natural history and treatment were addressed by the members of the Working Party.

Current concepts in the assessment and treatment of hepatic encephalopathy

Hepatic encephalopathy (HE) is defined as a metabolically induced, potentially reversible, functional disturbance of the brain that may occur in acute or chronic liver disease. Standardized nomenclature has been proposed but a standardized approach to the treatment, particularly of persistent, episodic and recurrent encephalopathy associated with liver cirrhosis has not been proposed. This review focuses on the pathogenesis and treatment of HE in patients with cirrhosis. The pathogenesis and treatment of hepatic encephalopathy in fulminant hepatic failure is quite different and is reviewed elsewhere.

Predictors of nonresponse to lactulose for minimal hepatic encephalopathy in patients with cirrhosis

BACKGROUND/AIMS

Minimal hepatic encephalopathy (MHE) impairs health-related quality of life and predicts overt hepatic encephalopathy (HE) in cirrhotic patients. Lactulose is effective in the treatment of MHE. However, not all patients respond to lactulose. We evaluated predictors of nonresponse to lactulose.

PATIENTS AND METHODS

Consecutive 110 cirrhotic patients without HE were evaluated for MHE by psychometry, P300 auditory event-related potential (P300ERP), venous ammonia and critical flicker frequency (CFF). MHE was diagnosed by abnormal psychometry and P300ERP (>2 SD). MHE patients were treated with lactulose for 1 month. Response was defined by normalization of the abnormal test parameters (both psychometric tests and P300ERP).

RESULTS

Sixty patients (54.5%) were diagnosed as having MHE: 17/39 (44%) in Child's A, 21/42 (50%) Child's B and 22/29 (76%) in Child's C. There was a significant difference between Child's C's vs Child's A's and B's (P<0.05). Abnormal psychometric tests and abnormal P300ERP were seen in 74 (67%) and 74 (67%) patients respectively. Of 60 patients with MHE, after treatment, psychometry remained abnormal in 22 (36.6%) and P300ERP in 21 (35%) patients. CFF was<38 Hz in 34 (57%) and 11 (18%) patients, respectively, before and after treatment in MHE patients. There was a significant difference between the baseline serum sodium level (134.7+/-2.6 vs 131.1+/-2.2 mmol/L, P=0.001) and the venous ammonia level (76.6+/-20.7 vs 113.4+/-22.8 micromol/L, P=0.001) between responders vs nonresponders. Receiver operating characteristic analysis was performed to identify the cutoff for venous ammonia [cutoff 93.5 mmol/L, area under the curve (AUC) 0.892 (0.814-0.970)] and for the serum sodium level [cutoff 132.5 mmol/L, AUC 0.874 (0.779-0.998)]. Taking a cutoff of 93.5 mmol/L for ammonia patient had a sensitivity of 88.5% and a specificity of 79.4%, respectively, and a cutoff of 132.5 mmol/L for serum sodium patient had a sensitivity of 76.5% and a specificity of 88.5% for nonresponse to lactulose. On univariate analysis and multivariate analysis, serum sodium and venous ammonia were the only two parameters associated with nonresponse to lactulose.

CONCLUSION

The prevalence of MHE was 55% and MHE improved in 57% patients with lactulose. Baseline low serum sodium and high venous ammonia were highly predictive of nonresponse to lactulose therapy.

Secondary prophylaxis of hepatic encephalopathy: an open-label randomized controlled trial of lactulose versus placebo

BACKGROUND & AIMS

Hepatic encephalopathy (HE) is associated with a poor prognosis. Lactulose is used for the treatment of HE. There is no study on the prevention of recurrence of HE using lactulose.

METHODS

Consecutive cirrhotic patients who recovered from HE were randomized to receive lactulose (HE-L group) or placebo (HE-NL group). All patients were assessed by psychometry (number connection test [NCT-A and B], figure connection test if illiterate [FCT-A and B], digit symbol test [DST], and object assembly test [OAT]), critical flicker frequency test, and blood ammonia at inclusion. Primary end point was development of overt HE.

RESULTS

Of 300 patients with HE who recovered, 140 (46.6%) met the inclusion criteria and were included. There was a high prevalence of abnormal psychometry test results (NCT-A, 67.5%; NCT-B, 62.5%; DST, 70%; and OAT, 80%), and FCT-A and B were abnormal in 10 of 14 patients. Critical flicker frequency was <38 Hz in 77 patients (55%). Twelve (19.6%) of 61 patients in the HE-L group and 30 (46.8%) of 64 in the HE-NL group (P = .001) developed HE over a median follow-up of 14 months (range, 1-20 months). Readmission rate due to causes other than HE (HE-L vs HE-NL, 9:6; P = NS) and deaths (HE-L vs HE-NL, 5:11; P = .18) in 2 groups were similar. Recurrence of overt HE was significantly associated with 2 or more abnormal psychometric tests after the recovery of an episode of HE (r = 0.369, P = .02).

CONCLUSIONS

Lactulose is effective for prevention of recurrence of HE in patients with cirrhosis.

Minimal hepatic encephalopathy

Minimal hepatic encephalopathy (MHE) is the mildest form of spectrum of hepatic encephalopathy (HE). Patients with MHE have no recognizable clinical symptoms of HE but have mild cognitive and psychomotor deficits. The prevalence of MHE is high in patients with cirrhosis of liver and varies between 30% and 84%; it is higher in patients with poor liver function. The diagnostic criteria for MHE have not been standardized but rest on careful patient history and physical examination, normal mental status examination, demonstration of abnormalities in cognition and/or neurophysiological function, and exclusion of concomitant neurological disorders. MHE is associated with impaired health-related quality of life, predicts the development of overt HE and is associated with poor survival. Hence, screening all patients with cirrhosis for MHE using psychometric tests, and treatment of those patients diagnosed to have MHE has been recommended. Ammonia plays a key role in the pathogenesis of MHE, which is thought to be similar to that of overt HE. Thus, ammonia-lowering agents such as lactulose and probiotics have been tried. These agents have been shown to improve cognitive and psychometric deficits, and have good safety profile. Future studies will better define the role of other drugs, such as rifaximin, acetyl L-carnitine and L-ornithine L-aspartate.

Effects of probiotics and commensals on intestinal epithelial physiology: implications for nutrient handling

Eukaryotes and prokaryotes have developed mutually beneficial relationships over millennia of evolutionary adaptation. Bacteria in our gut rely on our diet and the protected environment of our bodies just as our health depends on byproducts of microbial metabolism. Microorganisms of the gut microbiota ferment carbohydrates into short-chain fatty acids, convert dietary and endogenous nitrogenous compounds into ammonia and microbial protein, and synthesize and activate B vitamins and vitamin K. The benefit from their activity is multiplex and translates into increased energy for the gut epithelial cells, balanced absorption of salt and water, nitrogen recycling, breakdown of complex lipids and cholesterol, and detoxification of waste compounds.

Management options for minimal hepatic encephalopathy

Minimal hepatic encephalopathy (MHE) is a neurocognitive dysfunction that is present in the majority of patients with cirrhosis. MHE has a characteristic cognitive profile that cannot be diagnosed clinically. This cognitive dysfunction is independent of sleep dysfunction or problems with overall intelligence. MHE has a significant impact on quality of life, the ability to function in daily life and progression to overt hepatic encephalopathy. Driving ability can be impaired in MHE and this may be a significant factor behind motor vehicle accidents. A crucial aspect of the clinical care of MHE patients is their driving history, which is often ignored during routine care and can add a vital dimension to the overall disease assessment. Driving history should be an integral part of the care of patients with MHE. The preserved communication skills and lack of specific signs and insight make MHE difficult to diagnose. The predominant strategies for MHE diagnosis are psychometric or neurophysiological testing. These are usually limited by financial, normative or time constraints. Studies into inhibitory control, cognitive drug research and critical flicker frequency tests are encouraging. These tests do not require a psychologist for administration and interpretation. Lactulose and probiotics have been studied for their potential use as therapies for MHE, but these are not standard-of-care practices at this time. Therapy can improve the quality of life in MHE patients but the natural history, specific diagnostic strategies and treatment options are still being investigated.