Hepatic encephalopathy after transjugular intrahepatic portosystemic shunts: incidence and risk factors

OBJECTIVES

The aim of this study was to determine the incidence of new or worsened hepatic encephalopathy after transjugular intrahepatic portosystemic shunts (TIPS) and to ascertain which clinical characteristics are associated with this complication.

METHODS

At the University of California, San Francisco, over 22 months, TIPS were placed successfully in 108 adults. Seventy-seven patients in whom it was possible to assess the development of encephalopathy comprised the study population. Clinically significant encephalopathy was assessed at protocol clinic follow-up and, in some cases, by phone contact with the patient and the referring physician. Post-TIPS encephalopathy was defined as new onset of clinical encephalopathy requiring treatment or worsening of preexisting encephalopathy within 1 yr of TIPS.

RESULTS

The overall incidence of new or worsened encephalopathy was 23% (18/77). Post-TIPS encephalopathy was well controlled with lactulose in 78% of cases and was progressive in 22%. Multivariate analysis showed that an increased risk of encephalopathy was associated with an etiology of liver disease other than alcohol [relative risk (RR) 9.2, p = 0.0052], female gender (RR 3.0, p = 0.029), and hypoalbuminemia (RR 2.2 for each 1 g/dl decrease, p = 0.044).

CONCLUSIONS

Hepatic encephalopathy is a common complication of TIPS that can be controlled medically in most patients. The identification of clinical variables associated with an increased risk of encephalopathy may be useful in the selection of appropriate candidates for this procedure.

Marked deterioration in glycemic control with change in brand of lactulose syrup

Lactulose is a poorly absorbed synthetic disaccharide frequently used in the treatment of portasystemic encephalopathy. Because lactulose syrup contains small amounts of absorbable sugars, it may cause hyperglycemia in diabetic individuals, but is usually well tolerated. We report the case of a patient with diet-controlled diabetes and cirrhosis who experienced a marked deterioration in glycemic control, requiring insulin use, when he began using a different brand of lactulose syrup. The hyperglycemia resolved and insulin was discontinued after use of the original brand of lactulose syrup was resumed.

Rifaximin. A review of its antibacterial activity, pharmacokinetic properties and therapeutic potential in conditions mediated by gastrointestinal bacteria

Rifaximin is a derivative of rifamycin which acts by inhibiting bacterial ribonucleic acid (RNA) synthesis. It is virtually unabsorbed after oral administration; thus it is used primarily to treat local conditions within the gastrointestinal tract. In vitro data indicate rifaximin possesses good activity against species of Staphylococcus, Streptococcus and Enterococcus but lesser activity against species of Enterobacteriaceae. Bacterial resistance during exposure to rifaximin has been reported but its clinical importance remains to be fully defined. Results of comparative trials demonstrate that rifaximin is similar in efficacy to neomycin and lactulose in patients with hepatic encephalopathy and appears to be better tolerated. In 1 study, cyclical administration of rifaximin for 15 days per month was associated with progressive improvement over a 3-month period. In patients with infectious diarrhoea, rifaximin induces more rapid improvement in stool consistency and decreased frequency of faecal evacuations when compared with placebo, and is similar in efficacy to neomycin. Available data suggest rifaximin may be of some use in acute diverticulitis, but its use for the prevention of inflammatory complications or for control of common symptoms of diverticulosis requires further study. Preoperative treatment with rifaximin as antibacterial prophylaxis in colorectal surgery shows some potential but should be further investigated. Overall, rifaximin may be useful as an alternative therapy in hepatic encephalopathy but more data are needed to better define its clinical potential in infectious diarrhoea, diverticular disease and as antibacterial prophylaxis prior to colorectal surgery.

Flumazenil in the treatment of hepatic encephalopathy in children with fulminant liver failure

OBJECTIVE

To evaluate the effect of flumazenil on hepatic encephalopathy complicating fulminant liver failure in children.

DESIGN

Uncontrolled prospective study.

SETTING

Pediatric Intensive Care Unit, tertiary care center.

PATIENTS

9 children with fulminant liver failure and hepatic encephalopathy awaiting emergency liver transplantation.

INTERVENTIONS

Changes in hepatic encephalopathy grade and in electroencephalogram were recorded during the injection of a bolus of flumazenil (0.01 mg/kg/i.v. bolus) followed by a continuous infusion of flumazenil (0.01 mg/kg/h).

MEASUREMENTS AND MAIN RESULTS

Before flumazenil, 7 children had grade 2 and 2 had grade 3 hepatic encephalopathy. Flumazenile injection mediated an arousal effect in 1 child in whom encephalopathy improved from grade 3 to grade 2. This effect lasted 30 min. No clinical response was observed in other children. An improvement of EEG anomalies was observed lasting 3 min in one child. Despite continuous infusion of flumazenil, encephalopathy worsened in all children.

CONCLUSION

The effect of intravenous administration of flumazenil on hepatic encephalopathy in children with fulminant liver failure is inconsistent. Its efficacy is transient. The therapeutic value of flumazenil in children with fulminant liver failure awaiting a liver graft is minimal at this dosage.

[Effect of lactitol (NS-4) on the increase in blood and brain ammonia concentration and on coma in newly developed rat models of hepatic coma]

Encephalopathy caused by hepatic cirrhosis is often associated with portasystemic shunt and hepatic parenchymal injury. Together, these are known as a combined-type symptom. Two experimental hepatic comatose models with combined-type symptom were developed in rats. Both of these models involve the administration of ammonium acetate (500 mg/kg) into the cecum in portacaval shunted (PCS) rats. In addition, hepatic injury was induced in one model by carbontetrachloride (CCl4) and in the other by dimethylnitrosamine (DMNA). These model rats showed a higher increase in the concentration of ammonia in the blood and a higher incidence of coma as determined by the loss of the righting reflex than did rats subjected to a shunt only (PCS operation + ammonia loading) or hepatic parenchymal injury only (CCl4 treatment + ammonia loading). The effect of lactitol, administered orally for 7.5 days, on the experimental hepatic coma was compared with that of lactulose. Lactitol significantly inhibited the increase in blood and brain ammonia concentration at doses of 3 and 6 g/kg/day and also reduced the incidence of coma. The effects of lactitol were similar to those of lactulose, a therapeutic agent for hepatic encephalopathy. Therefore, lactitol should be useful in the clinical treatment of hyperammonemia or hepatic encephalopathy.

[Lactitol suppresses the disturbance of consciousness caused by experimentally induced hepatic encephalopathy in rats: an EEG study]

Electroencephalographic (EEG) studies were conducted to demonstrate the ameliorating effects of lactitol and its reference drug lactulose on the disturbance of consciousness caused by severe hepatic encephalopathy in rats permanently implanted with cortical electrodes. A novel experimental animal model of combined-type human hepatic encephalopathy was prepared by portacaval shunting followed by a single treatment with dimethylnitrosamine (30 mg/kg, i.p.). Lactitol or lactulose was orally administered twice a day for seven days and once on the morning of the eighth day. Ammonium acetate (500 mg/kg) was injected into the cecum 4 hr after the final administration of the drug. In control animals not treated with either drug, but in which hepatic encephalopathy had been induced, ammonium acetate induced a comatose state defined by a loss of the righting reflex accompanied by slowing or flattening of the cortical EEG. In control animals, significant increases in delta (1-3 Hz)-activity and significant decreases in beta (13-25 Hz)-activity during coma were detected by means of EEG power spectral analysis. Lactitol at doses of 3 g/kg/day or higher or lactulose at 6 g/kg/day significantly suppressed these EEG changes. Both drugs also suppressed in a dose-dependent manner the loss of the righting reflex. Lactitol may therefore be useful for ameliorating the disturbance of consciousness in patients with hepatic encephalopathy.

Hepatic disorders. Features and appropriate management

The spectrum of liver disease is extremely wide, with many of the underlying disorders having acute and chronic presentations. Most of the underlying pathogenetic mechanisms are accounted for by autoimmune disease, viral infection and toxic insult. The management strategy of any liver disease is a combination of treating the symptoms and complications that arise, as well as drug therapies relevant to the specific underlying diagnosis. Encephalopathy, ascites, spontaneous bacterial peritonitis, variceal bleeding and pruritus are the main complications at which drug therapy is directed, although in some cases it represents only 1 aspect of the overall management. Drug therapy per se is largely ineffective in acute liver failure with the possible exception of acetylcysteine, but many drugs are used in the management of the constituent components of this complex medical emergency. Treatments for specific liver conditions are expanding, especially in the areas of autoimmune and viral disease. The increasing availability and success of liver transplantation has tended to change the emphasis of management, and it is often not appropriate to exhaust the treatment options before referring the patient for transplantation. A comprehensive review of all liver disease is beyond the scope of this article, but hopefully the important principles of management and commonly occurring clinical decisions are discussed.

Rifaximin in the treatment of chronic hepatic encephalopathy

A study was performed to assess the efficacy and tolerability of rifaximin in the treatment of encephalopathy during cirrhosis of the liver. Fifty-five patients suffering from grade 1, 2 and 3 portosystemic encephalopathy, with a mean age of 58.9 years (range 30 to 86 years) were evaluated. The patients were treated for 15 consecutive days with rifaximin, an antibiotic which is not absorbed by the intestinal wall, at a dosage of 1200 mg/day in association with sufficient lactulose to induce 2 or 3 evacuations per day. Combined use of the 2 drugs proved an efficient means of controlling the majority of signs and symptoms. After just a few days, an improvement in the signs of encephalopathy was noted in all patients. The treatment was well tolerated and the patients completed the trial without any drug-related side-effects. The results of our trial, although in the context of an open assessment, confirm the clinical efficacy of rifaximin in association with a non-absorbable disaccharide such as lactulose. The 2 compounds have a synergetic effect in reducing ammonia-producing flora. Its efficacy and good tolerability make rifaximin a valid alternative to the use of aminoglycoside antibiotics associated with disaccharides in the treatment of patients with liver disease, particularly in the case of prolonged therapy.

Treatment of porto-systemic encephalopathy with lactitol verus lactulose: a randomized controlled study

BACKGROUND

Lactitol (beta-galactosido-sorbitol), a novel disaccharide analogue of lactulose, has been suggested as an alternative to lactulose in the treatment of portosystemic encephalopathy (PSE) in Western country. In order to assess its therapeutic effect and adverse reaction in PSE in the Chinese, we conducted this study.

METHODS

Forty-one patients with PSE were enrolled in this study. Patients were randomly divided into 2 groups to receive lactitol (n = 21) or lactulose (n = 20) for 5 days. The doses of both drugs were adjusted to keep daily bowel movement of 2 to 3 times. The PSE index (mental state, EEG, asterixis, number connection test [NCT], and ammonia) was evaluated in each patient before and after treatment. Daily doses of lactitol and lactulose, stool frequency, and side effect were recorded.

RESULTS

The mean dose of lactitol used was 66.3 +/- 36.4 gm and that of lactulose was 56.9 +/- 32.1 ml of lactulose. The majority of patients (37/41) gained clear consciousness after 5 days' treatment. In the lactitol group, blood ammonia, EEG, NCT, asterixis, mental status and PSE index before treatment were 208 +/- 62 micrograms/ml, 2.9 +/- 0.8, 4.0 +/- 0.0, 2.7 +/- 1.5, 2.9 +/- 0.7 and 77.1 +/- 10.5, respectively. All parameters decreased significantly after 5 days' treatment (119 +/- 50 micrograms/ml, 1.1 +/- 1.0, 2.9 +/- 1.2, 1.7 +/- 1.1, 0.7 +/- 0.7, and 34.4 +/- 16.0, p < 0.05). The lactulose group had the similar results. However, the improvement of PSE index after therapy in the lactitol group was significantly higher than that in the lactulose group (42.7 +/- 19.3 vs 31.1 +/- 13.7, p < 0.05). In addition, more patients in the lactitol group than in the lactulose group (67% vs 20%, p = 0.003) favored the taste of their assigned drugs. No patient who received lactitol experienced any side effects; however, six patients treated with lactulose complained of meteorism and flatulence, and four complained of nausea.

CONCLUSIONS

Both lactitol and lactulose are effective in the treatment of PSE, though the effect of lactitol seems slightly superior to that of lactulose in our study. Lactitol is more acceptable to our patients due to better palatability and less side effects. Lactitol is another good alternative in the treatment of PSE.

Effects of an infusion of branched-chain amino acids on neurophysiological and psychometric testings in cirrhotic patients with mild hepatic encephalopathy

Psychotropic action of a branched-chain-enriched amino acid solution (Aminoleban) was quantitatively and visually examined in six cirrhotic patients with mild hepatic encephalopathy (grades I and II) using electrophysiological and psychometric methods. Neurophysiological effects of the amino acid solution were observed by comparing topographic spectrum analyses of electroencephalography (EEG) before and immediately after an intravenous 3 h infusion of the solution. The delta wave in the frontal region diminished from 61 +/- 13 to 12 +/- 4% (P < 0.01) and the alpha wave in the occipital region increased from 11 +/- 3 to 51 +/- 11% (P < 0.01). Latencies of the P3 wave in visual evoked potentials, which were topographically recorded in the occipital region, shortened from 220 +/- 32 to 148 +/- 19 ms (P < 0.01). Latencies of the P300 wave in event-related potentials, which were topographically recorded in the centro-temporal region, shortened from 493 +/- 81 to 360 +/- 93 ms (P < 0.05). Topographic reaction pattern of P300 was irregular toward the occipital or parietal region in cirrhotic patients. The EEG frequency power spectrum, illustrated by the colour density spectral array of computer-aided polysomnography analysis, clearly showed a gradual increase of the alpha wave spectrum and a gradual decrease of the delta wave spectrum after initiation of the infusion. These immediate neurophysiological changes were confirmed by improvement of quantitative psychometric tests including number connection test, reaction time to sound, and digit symbol and block design tests of Wechsler Adult Intelligence Scale.(ABSTRACT TRUNCATED AT 250 WORDS)

Fulminant hepatic failure associated with status epilepticus in children: three cases and a review of potential mechanisms

Fulminant hepatic failure is a rare complication of status epilepticus. Although many of the anticonvulsants used to treat the seizures are known to have hepatotoxic properties, the exact mechanism leading to massive destruction of the liver following a prolonged seizure remains unclear. Three children are presented who developed fulminant hepatic failure following status epilepticus and subsequently died of multiple organ failure. The literature is reviewed with particular attention to the possible interaction between the anticonvulsants and the metabolic consequences of status epilepticus. We postulate that it is a combination of hypoxia and ischemia that occurs during a prolonged seizure with altered metabolism of free radicals secondary to the anticonvulsant drugs which leads to widespread hepatocyte membrane damage.

Reversal of behavioral changes in rats subjected to portacaval shunt with oral neomycin therapy

The portacaval shunt rat is often used as a model of human portal-systemic encephalopathy, but its relevance to human portal-systemic encephalopathy remains uncertain. Specifically, it has not been demonstrated that the behavioral changes seen in this model respond to measures known to improve portal-systemic encephalopathy in human subjects. Accordingly, the aim of this study was to establish whether neomycin (an effective treatment for portal-systemic encephalopathy in human beings) added to the drinking water of rats subjected to portacaval shunt reversed or ameliorated the reduction in spontaneous motor activity, which represents a measure of encephalopathy in this animal model. A randomized, placebo-controlled crossover design was used, with each animal serving as its own control. After establishment of baseline activities, 12 rats with portacaval shunt and 12 sham-operated rats were divided into two equal groups: Group A animals received neomycin for 1 wk; this was followed by 1 wk off neomycin; in group B rats, the sequence was reversed. Spontaneous intake of neomycin for 7 days at doses comparable to human usage (0.1 to 0.2 gm/kg/day) was associated with a significant increase in spontaneous motor activity in rats subjected to portacaval shunt (26.4% in group A, 66.3% in group B; p < 0.01 for each protocol) with no significant effect in sham-operated animals. Withdrawal of neomycin resulted in reversal of this effect in group A rats subjected to portacaval shunt. Similar significant improvements for exploratory activity as measured on the basis of nose-hole pokes was also seen in rats subjected to portacaval shunt and given neomycin.(ABSTRACT TRUNCATED AT 250 WORDS)

[Effects of neomycin on intestinal digestion, absorption and fermentation of carbohydrates in patients with liver cirrhosis: evidence for an alternative therapeutic mechanism in hepatic encephalopathy]

BACKGROUND

Despite non absorbable antibiotics and neomycin may have antagonistic effects on intestinal bacterial environment, both have synergistic effects in the treatment of hepatic encephalopathy. This could be due to their action on different enteric flora or a neomycin induced carbohydrate malabsorption.

AIM

To investigate the effects of neomycin on intestinal digestion, absorption and fermentation of carbohydrates in patients with liver cirrhosis.

PATIENTS AND METHODS

Thirty eight Child B or C cirrhotic patients separated in three groups; subjects within each group were randomized to receive neomycin (2/g/day for 10 days, n = 8) or placebo (n = 4). Absorption of lactose and d-xylose and fermentation of d-xylose, lactose and lactulose (measured using hydrogen breath tests) were studied before and after the treatment period.

RESULTS

Neomycin did not change lactose fermentation but reduced plasma glucose rise after lactose ingestion (38.8 +/- mg/dl to 22 +/- 6 mg/dl p < 0.05). Plasma d-xylose levels at 30 min and its 5 h urinary excretion were reduced by neomycin from 19 +/- 3 to 9 +/- 2 mg/dl and from 4.9 +/- 0, 8 to 2.6 +/- 0.3 g/5h respectively (p < 0.05). Fermentation of d-xylose, lactose and lactulose was not reduced by neomycin. No significant changes were observed after placebo treatment.

CONCLUSIONS

Neomycin therapy is associated with a reduction of intestinal digestion and absorption of carbohydrates, preserving bacterial fermentation capacity, probably increasing the non absorbable carbohydrate load reaching the colon.

Effect of prostaglandin E1 on experimental acute hepatic failure in rabbits: prostaglandin E1 prevents the development of multiple-organ failure

Acute hepatic failure was induced in 50 male rabbits by D-galactosamine HCl (1 g per kg bw), and the effects of prostaglandin E1 on this model were investigated. Twelve hours after the administration of D-galactosamine HCl, a continuous infusion of prostaglandin E1 (2 micrograms.kg-1.h-1 or 20 micrograms.kg-1.h-1) was started. Ten animals in each group were observed until the time of death and mean survival times were compared between the groups. Five animals in each group were used for the determination of regional blood flows and brain water content. After the injections of D-galactosamine HCl, serum aspartate transaminase and alanine transaminase activity rose markedly and prothrombin time was prolonged. The administration of prostaglandin E1 did not affect these levels. However, the survival time in the prostaglandin E1 20 micrograms.kg-1.h-1 group (48.2 +/- 10.4 h) was significantly longer (p < 0.005, p < 0.01) than those in the untreated group (24.9 +/- 5.0 h) and the prostaglandin E1 2 micrograms.kg-1.h-1 group (28.1 +/- 5.8 h). Prostaglandin E1 20 micrograms.kg-1.h-1 inhibited elevations of blood urea nitrogen and creatinine and significantly inhibited the decrease of urine volume and urinary sodium excretion.(ABSTRACT TRUNCATED AT 250 WORDS)

Hepatic encephalopathy with increased cerebral blood flow in SPECT and MRI abnormalities in the basal ganglia

A case of hepatic encephalopathy with increased cerebral blood flow in single-photon emission computed tomography (SPECT) and abnormalities upon magnetic resonance imaging (MRI) is reported. SPECT showed increased blood flow exceeding 70 ml/100 g/min in the cerebellum, basal ganglia and cerebral cortex, with hyperammonemia and abnormal electroencephalographic signs showing severe generalized slowing. SPECT data and MRI might reflect abnormal metabolism and neuropathological changes in hepatic encephalopathy.

[Pathogenesis and treatment of hepatic encephalopathy]

Cirrhotic patients with hepatic encephalopathy show a variety of neuropsychiatric abnormalities. The pathogenesis appears to be ascribable to an increase in gut-derived neurotoxic substances and to functional alteration in inhibitory and excitatory neurotransmission in the brain. On the basis of the potential pathogenesis, therapies are designed by reducing the production and absorption of gut-derived neurotoxins and/or by modifying the balance of central neurotransmission. In this review, the current concept of the pathogenesis and treatment of hepatic encephalopathy is described.

Hepatic disease and psychiatric illness: relationships and treatment

A relationship between hepatic diseases and psychiatric symptoms has long been speculated. While liver detoxication makes the exogenous substances harmless for the body, there are occasions where the liver may convert a harmless substance into a more toxic substance. With such an important role, the liver protects all the organs of the body. When liver is malfunctioning, toxic metabolites injurious to the brain may be produced. As the brain receives a high blood supply, a large amount of metabolites reach this organ. Hence, the metabolic function of the liver keeps a delicate reciprocal relationship between the two organs. In addition, a number of psychiatric medications affect liver functions. Another perplexing clinical problem is the difficulty in treating psychiatric symptoms in patients with liver disease. For example, benzodiazepines which do not affect the liver function in physically healthy psychiatric patients, may induce hepatic coma in patients with liver disease. Benzodiazepine antagonists produce dramatic and temporary improvement in patients with hepatic coma. Clinically, many psychoactive drugs produce hepatic complications. The very same drugs which produce hepatic side effects are required for the treatment of psychiatric symptoms in patients with hepatic disorders. To appropriately handle these situations, a thorough knowledge of the side effects of these drugs is necessary.

Flumazenil in cirrhotic patients in hepatic coma: a randomized double-blind placebo-controlled crossover trial

Previous reports have suggested that "endogenous" benzodiazepines could contribute to neural inhibition in hepatic encephalopathy. RO 15-1788 (flumazenil), a specific antagonist of brain benzodiazepine receptors, could thus reverse the neurological symptoms of hepatic encephalopathy. To test this possibility, we conducted a double-blind, placebo-controlled crossover trial of the efficacy of flumazenil in cirrhotic patients in hepatic coma. Seventy-seven cirrhotic patients in hepatic coma were evaluated. Fifty-six were excluded from the trial because of multiorgan failure or because coma was precipitated by prior use of benzodiazepines, and 21 patients were randomly assigned to the flumazenil group (11 patients) or the placebo group (10 patients). Treatment was administered intravenously as a 20-ml solution (placebo or 2 mg flumazenil); seven patients were crossed over. Clinical status was assessed blindly by two observers, using a modified Glasgow scale, every 15 min for 6 hr. Electroencephalogram tracings obtained before and after drug administration were evaluated blindly by two independent observers. Serum concentrations of benzodiazepines before treatment were measured by means of a fluorescence polarization immunoassay. Improvement in neurological symptoms was observed in six patients treated with flumazenil, whereas none in the placebo group showed improvement (p < 0.05; Fisher's exact test). Improvements in electroencephalogram tracings were demonstrated in four patients treated with flumazenil, compared with two patients in the placebo group (p = NS). Benzodiazepines were found in the serum of four patients treated with flumazenil (two responders and two nonresponders); all of these patients had received pharmaceutical benzodiazepines 4 to 6 days before the trial.(ABSTRACT TRUNCATED AT 250 WORDS)