Astroglial dysfunction in hepatic encephalopathy

While the pathogenesis of hepatic encephalopathy (HE) remains elusive, there is considerable evidence pointing to a key role of ammonia-induced dysfunction of astrocytes in this condition. Deficits in the ability of astrocytes to take up glutamate from the extracellular space may lead to abnormal glutamatergic neurotransmission. Furthermore, excessive stimulation of neuronal and glial glutamate receptors by elevated extracellular levels of glutamate may lead to excitotoxicity and greater glial dysfunction. Ammonia also causes upregulation of astroglial peripheral-type benzodiazepine receptors (PBRs) which is associated with increased production of neurosteroids. These neurosteroids have potent positive modulatory effects on the neuronal GABA(A) receptor which, combined with an ammonia-induced astroglial defect in GABA uptake, may result in enhanced GABAergic tone. Brain edema, associated with fulminant hepatic failure, may also result from astroglial abnormalities as the edema appears to be principally caused by swelling of these cells. Increased amounts of glutamine in astrocytes resulting from elevated brain ammonia levels may be a factor in this swelling. Other osmolytes such as glutathione may also be involved. Glial swelling may also result from NH4+ - and K+ -mediated membrane depolarization as well as by the actions of PBR agonists and neurosteroids. These findings show that an ammonia-induced gliopathy is a major factor in the pathogenesis of HE.

[[Emergency pediatric EEG in mental confusion, behavioral disorders and vigilance disorders: a retrospective study]

Recording of electroencephalogram (EEG) is of value to estimate vigilance states in children as in adults. In order to determine the diagnostic and prognostic value of emergency EEG in case of mental confusion, behavioral disorders and vigilance disorders in childhood, we conducted a retrospective study in 397 children (aged 2 months to 16 years). EEG was recorded less than 24 hours after an emergency consultation for acute confusion or acute behavioral disorder (n = 106) or after admission to the intensive care unit for comatose stage (n = 291). EEG gave diagnostic indications mainly in case of convulsive pathology or hepatic encephalopathy. In comatose children, we established a 4-stage EEG scale of increasing severity. This classification was compared to EEG scales already published in the literature and appeared very similar to that from Pampiglione and Harden, established in 150 children after cardiac arrest. A highly poor prognostic value was associated with burst-suppression post-anoxic patterns and with isoelectric records signaling brain death. Our classification of emergency EEG patterns is mainly helpful in these two situations, but does not exclude strict and repeated clinical and EEG follow-up in other cases, as a relatively preserved initial EEG may later deteriorate.

Portosystemic hepatic encephalopathy after transjugular intrahepatic portosystemic shunt in patients with cirrhosis: clinical, laboratory, psychometric, and electroencephalographic investigations

A prospective study of hepatic encephalopathy (HE) including neuropsychiatric and psychometric evaluation, electroencephalography, and determination of arterial ammonia levels was performed in 55 cirrhotic patients treated consecutively by transjugular intrahepatic portosystemic shunt (TIPS). The cumulative HE rate increased from 23.6% within the 3-month interval before TIPS to 50. 9% within the first 3-month interval post-TIPS (P = .003). Significant and independent predictors of HE post-TIPS were the presence of HE pre-TIPS and reduced liver function. The cumulative HE rate declined in the second 3-month interval post-TIPS and reached the pre-TIPS level. Chronic forms of HE exceeding grade I were not observed. In a subgroup of 22 nonencephalopathic TIPS patients, the prevalence of subclinical HE did not change after TIPS. Among individual psychometric tests, the block design test gave the highest proportion of pathological results (about 50%), whereas selective reminding gave the lowest (10%-25%). Electroencephalography (EEG) showed a temporary increase of pathological results at 1 month after TIPS, when patients with overt HE (grade I) were included (proportion of 21.1% before vs. 57.1%, P = .005). Arterial ammonia concentration increased from a mean of 94 +/- 26 microgram/dL to 140 +/- 28 microgram/dL at 3 months after TIPS (P < .001). Elevated ammonia levels persisted. TIPS led to a temporary increase of HE incidence within 3 months. The decline of the HE rate beyond 3 months despite a sustained increase of arterial ammonia levels could not entirely be explained by reduction of shunt flow, nor by alteration of liver function. Instead, cerebral adaptation to gut-derived neurotoxins might be anticipated.

Acute pancreatitis and fulminant hepatic failure

BACKGROUND

The association of acute pancreatitis with fulminant hepatic failure (FHF) was first recognized in 1973. Since then, few studies have described the clinical profile of the FHF patient with acute pancreatitis. Identification of the distinguishing attributes of pancreatitis in combination with FHF will provide a more sound basis for clinical management. The purposes of this study were to identify distinguishing clinical characteristics of acute pancreatitis in FHF and to compare outcomes with those of patients with acutely decompensated chronic liver disease and acute pancreatitis (DECOMP).

STUDY DESIGN

This was a retrospective survey of 30 patients with FHF and 30 with DECOMP admitted during the period July 1995 to July 1997.

RESULTS

The prevalence of acute pancreatitis in FHF and DECOMP was 33% and 23%, respectively. Acute pancreatitis was associated with severe hepatocellular synthetic dysfunction, renal insufficiency, requirement for endotracheal intubation, increased acuity of illness at the time of ICU admission, more rapid decompensation during the disease, and significantly greater mortality in both the FHF and DECOMP groups.

CONCLUSIONS

In both FHF and DECOMP, acute pancreatitis increases disease acuity and mortality. Acute pancreatitis does not occur with significantly greater frequency in FHF. Implementation of orthotopic liver transplantation may not be warranted in this setting.

Acute hemolytic crisis with fulminant hepatic failure as the first manifestation of Wilson's disease: a case report

We report a 27-year-old woman who developed Coombs' negative hemolytic anemia and fulminant hepatic failure as the initial manifestation of Wilson's disease. Unmeasurably low level of serum alkaline phosphatase provided a clue to the diagnosis of Wilson's disease. The diagnosis was established with the presence of Kayser-Fleischer ring, decreased serum ceruloplasmin level, and elevated urine and serum copper levels. In spite of repeated plasmapheresis, she died of multiorgan failure on the fifth hospital day.

Subclinical hepatic encephalopathy impairs daily functioning

Subclinical hepatic encephalopathy (SHE) is assumed to have a negative effect on patients' daily functioning; therefore, treatment is recommended. However, no studies have been performed that document the clinical relevance of SHE. We performed a study in which the prevalence of SHE was determined in 179 outpatients with cirrhosis using two psychometric tests (Number Connection Test Part A [NCT-A] and the Digit Symbol Test [DGT]) and automated analysis of the electroencephalogram (EEG). SHE was defined by the presence of at least one abnormal psychometric test and/or abnormal slowing of the EEG. The influence of cirrhosis and SHE on patients' daily functioning was assessed using the Sickness Impact Profile (SIP) questionnaire. The distribution of SIP scores of the patients with cirrhosis differed from the reference scores of the general population. Patients with cirrhosis and SHE (n = 48) reported significantly more impairment in all 12 scales of the SIP, in the psychosocial subscore, the physical subscore, as well as in the total SIP score, compared with cirrhotic patients without SHE (n = 131). Multivariate analysis taking into account severity of liver disease (Child-Pugh score), presence of varices, and alcoholic etiology, showed that SHE independently was related to a diminished total SIP score. The reproducibility of the SIP was high when the test was repeated after a 3-month period. We conclude that SHE implies impaired daily functioning and warrants attempts at treatment.

Cerebral changes in hepatic encephalopathy

Hepatic encephalopathy (HE) accompanied by an impairment of consciousness from orientation disorder (grade II) to coma (grade IV) is considered to be overt HE and is treated as an emergency. However, subclinical hepatic encephalopathy (SHE) can be detected by sensitive and quantitative neuropsychological examinations in cirrhotic patients without overt HE. The introduction of the SHE concept is clinically important for preventing the deterioration of SHE (grades 0 and I) to overt HE (grade II and more severe), prolonging the compensated state of cirrhosis without its deterioration to hepatic failure, and the continuation of patient treatment at home. We developed a new diagnostic method for SHE using a quantitative neuropsychological test, with the computerization of all operations. Evaluations of cerebral function and morphology are useful for the determination of the pathophysiology of HE, and assist the diagnosis of SHE. The latencies of the P3 wave in the visually evoked potential and the P300 wave in the event-related potential are prolonged in cirrhotic patients with SHE and are well expressed in three-dimensional coloured topograms (brain mapping). Automated polysomnographic analysis is useful for continuous-monitoring electroencephalograms (EEG) and for the detection of the sleep disturbance observed in cirrhotic patients with SHE. Brain atrophy in computed tomography (CT), magnetic resonance imaging (MRI) and high signals in the basal ganglia in the MR-T1-weighted images have frequently been observed in patients with SHE. The reduction of regional cerebral blood flow (rCBF) by 99mtechnetium-1, 1-ethylcysteinate dimer (99mTc-ECD)-single photon emission computed tomography (SPECT) and the choline/N-acetylaspartic acid ratio by proton-magnetic resonance spectroscopy (1H-MRS) were observed in the hippocampus in patients with SHE. These approaches (cerebral function tests and imaging diagnoses of the brain) can also be used to evaluate the effectiveness of treatments for HE; for example, branched-chain amino acid (BCAA) was shown by automated continuous polysomnographic analysis to be a psychotropic drug which acts directly on the central nervous system and the clinical significance of choline administration to HE patients is now being evaluated by 1H-MRS and neuropsychological tests.

Pathogenesis of acute hepatic encephalopathy

Hepatic encephalopathy (HE) is a major neuropsychiatric complication of chronic liver disease. Depending upon the duration and severity of the liver disorder and of the presence of precipitating factors, HE may present as one of two major types. Portal-systemic encephalopathy (PSE) results from portal-systemic shunting of venous blood that arises either spontaneously or due to surgical portacaval anastomosis or transjugular intrahepatic shunts (TIPS) aimed at reducing portal hypertension.

Pathogenesis and treatment of chronic hepatic encephalopathy

Although there is general agreement that hepatic encephalopathy (HE) is functional in nature, its pathogenesis has not yet been elucidated. A variety of mechanisms have been implicated such as the action of ammonia and other neurotoxins, disturbances of the blood-brain barrier and alterations of various neurotransmitter systems and their receptors [for reviews, see 1–3]. Further, manganese deposition in the basal ganglia and zinc deficiency have been discussed. Undoubtedly, ammonia plays a decisive role and pathogenetic models of HE have to explain why HE in chronic liver disease is precipitated by quite different factors, such as bleeding, infections, sedatives, diuretics, electrolyte disturbances and trauma. This brief article focuses on some new aspects on the pathogenesis of HE and its treatment.

Visual attention in cirrhotic patients: a study on covert visual attention orienting

Attentional dysfunction, which influences overall cognitive productivity, is not well characterized in cirrhotic patients. The aim of this study was to clarify the features of covert visual attention orienting in cirrhotics without overt hepatic encephalopathy. One hundred consecutive cirrhotic patients and 40 controls were enrolled. Visual covert attention orienting was assessed by the Posner test, which evaluates the effect of a cue on visual reaction times. Patients were characterized by the number connection test (NCT) and electroencephalographic (EEG) spectral analysis. The severity of liver disease was graded using standard laboratory parameters and the Child-Pugh's classification. Fifty-five psychometric and EEG evaluations were performed in the follow-up of 17 patients to assess the relationship between the variations of psychometric and neurophysiological findings. NCT and quantified-EEG parameters (altered in 19% and 40% of cirrhotic patients, respectively) were linked to each other and to the severity of liver disease. The Posner test showed a delay of visual reaction times in class B-C cirrhotic patients. Reaction times were correlated with ammonia and EEG parameters. The effect of the cue was higher in cirrhotic patients than in controls, particularly in the invalid position. This study suggests that cirrhotic patients have a reduced activity rate and reduced capacity to disengage attention previously focused on a cue. Such alterations are linked to NCT and EEG findings.

Portal-systemic encephalopathy from a spontaneous gastrorenal shunt diagnosed by three-dimensional computed tomography and treated effectively by percutaneous vascular embolization

A 67-year-old man with a portal-systemic shunt confirmed by three-dimensional computed tomography (3D-CT) was successfully treated by percutaneous vascular embolization. The patient had aggravated loss of memory, disorientation, and hyperammonemia. A gastrorenal shunt 16 mm in diameter was found by 3D-CT reconstructed by helical computed tomography (CT). Embolization was performed only in the shunt percutaneously through the inferior vena cava. One year after the embolization, no recurrence of portal-systemic encephalopathy and no portal hypertension have appeared, and the clinical course has been good.

Use of balloon-occluded retrograde transvenous obliteration with ethanolamine oleate for the treatment of hepatic encephalopathy in a cirrhotic patient with a large spontaneous splenorenal shunt

We describe a technique for the treatment of hepatic encephalopathy in a cirrhotic patient with a large spontaneous splenorenal shunt. This large shunt was successfully occluded without severe complications by retrograde transrenal venous obliteration with ethanolamine oleate after balloon occlusion. This procedure may be an effective method to occlude a large spontaneous splenorenal shunt for the treatment of hepatic encephalopathy.

Effect of inhibition of ornithine decarboxylase activity in a model of acute hepatocellular necrosis

OBJECTIVE

The effect of blockade of the enzyme ornithine decarboxylase by difluoromethylornithine (DFMO) on hepatocellular necrosis and survival in rats treated with thioacetamide (TAA) was investigated.

DESIGN

In one experiment, the effect of DFMO on survival of rats with TAA-induced acute hepatocellular necrosis was determined. In another experiment, blood and liver specimens were obtained from DFMO or saline-treated rats 24 h after the administration of TAA for determinations of serum alanine aminotransferase (ALT) and liver content of polyamines and microsomal cytochrome P-450 and for assessment of hepatic histology.

METHODS

Liver polyamines were determined by reversed-phase HPLC and microsomal cytochrome P-450 content by dithionite-difference spectroscopy of CO-treated homogenates. The severity of hepatocellular necrosis was scored blindly.

RESULTS

TAA-treated rats that received DFMO survived longer than saline-treated controls (P < 0.01). Serum ALT and liver putrescine concentrations were lower and the histological severity of acute hepatocellular necrosis was less in DFMO-treated rats with TAA-induced hepatocellular necrosis than in saline-treated controls (P < 0.05, P < 0.01 and P < 0.05, respectively). Total cytochrome P-450 levels were similar in DFMO and saline-treated rats with TAA-induced hepatocellular necrosis.

CONCLUSIONS

DFMO increases survival in TAA-induced fulminant hepatic failure by decreasing the severity of acute hepatocellular necrosis. The beneficial effects of DFMO do not appear to be mediated by its effects on polyamine metabolism, but may be attributable to an effect of DFMO on thioacetamide metabolism or on an alternative pathway of ornithine metabolism.

Fulminant hepatic failure in acute acetaminophen overdose

Fulminant hepatic failure is a serious complication of acetaminophen overdose. The cascade of complications starts with an alert patient that can quickly result in hepatic coma and even death. The nurse completes a poisoning history, provides an antidote, and assesses the extent of hepatic failure from an overdose. This article uses a case study to describe the problems and nursing care for the patient with hepatic failure from acetaminophen overdose. Advanced assessment skills by the critical care nurse enable prompt recognition of postoverdose complications for early intervention and treatment. Acute care nurse practitioners, utilizing the same techniques, can develop protocols for emergency or intensive care units where these patients may be admitted and subsequently cared for.

Aortic stenosis with end-stage liver disease: prioritizing surgical and anesthetic therapies

A 48-year-old man with end-stage liver disease and aortic stenosis (AS), was being evaluated for liver transplantation. This report focuses on the question of which medical problem to correct first, the end-stage liver disease or the AS. Risk factors for surgical correction of AS and liver transplantation are reviewed and discussed, and the surgical and anesthetic management strategies for this patient are outlined.

Cerebral blood flow velocity in patients with subclinical portal-systemic encephalopathy

Alterations in cerebral blood flow (CBF) are implicated in the etiology of portal-systemic encephalopathy. We hypothesized that CO2 reactivity of the cerebral circulation may be impaired in subjects with chronic liver disease (CLD) who also had subclinical portal-systemic encephalopathy (SPSE). We compared the relationship between PETCO2 and cerebral blood flow velocity in 10 patients with CLD with those of 10 healthy control subjects. Middle cerebral artery mean blood flow velocity (MCAMFV) was measured using transcranial Doppler during rest, hyperventilation, and hypoventilation. The degree of SPSE was quantified by using psychometric testing. Patients with CLD had poorer psychometric test scores compared with control subjects. Patients with CLD had lower PETCO2, MCAMFV, and blood pressure values and higher heart rates, differing from control subjects in all ventilation states. However, CO2 reactivity, the rate of change in MCAMFV to changes in ventilation (expressed as percent change in CBF velocity per mm Hg change in PETCO2) was similar for both groups (4.6% +/- 0.6% vs 4.2% +/- 0.5% for patients with CLD versus control subjects, P = 0.15).

IMPLICATIONS

Psychometric test scores in patients with chronic liver disease revealed subclinical impairment compared with control subjects. Transcranial Doppler measurements of middle cerebral artery blood flow with varying PETCO2 were conducted, but the CO2 response of patients with liver disease was within the range of control subjects.

Experiences with novel techniques for reduction of stent flow in transjugular intrahepatic portosystemic shunts

The transjugular intrahepatic portosystemic shunt (TIPS) may deteriorate liver function and can cause encephalopathy in patients with cirrhosis of the liver. Then reduction of TIPS flow may be required. We here report several attempts to reduce shunt flow in TIPS-induced encephalopathy or liver function impairment with novel techniques. Three patients with cirrhosis of the liver were investigated: Two with severe recurrent encephalopathy and one with impaired liver function following TIPS insertion. Insertion of a reducing stent was ineffective to decrease shunt flow velocity in one patient with severe coagulopathy. Sufficient reduction of shunt flow was achieved by embolizing the space around the hourglass waist of the reducing stent with an occlusion emulsion. Insertion of a conventional stent within the preexisting TIPS with or without additional embolization reduced TIPS flow in the other patients. After reduction of shunt flow encephalopathy improved and liver function returned to the level before TIPS, respectively. During follow-up no occlusion of TIPS was observed. Thus, reduction of shunt flow velocity can be achieved by insertion of an additional stent into a curve-shaped TIPS. Embolization can be helpful to decrease TIPS flow, particularly in patients with severe coagulopathy. Reduction of TIPS flow can correct TIPS-induced complications.

Hepatic plasma flow estimated according to Fick's principle in patients with hepatic encephalopathy: evaluation of indocyanine green and D-sorbitol as test substances

The magnitude of hepatic plasma flow in patients with liver failure and hepatic encephalopathy (HE) is unknown because a reliable flow estimate has not been available. The purpose of this study was to estimate hepatic plasma flow in patients with HE and to evaluate indocyanine green (ICG) and sorbitol as test compounds. Fourteen patients with acute liver failure (ALF) and nine patients with chronic liver failure (CLF), all with HE grade II or more, were studied. After hepatic vein catheterization, hepatic plasma flow was estimated by use of constant infusion, simultaneous arterial and hepatic vein concentration measurements, and calculated according to Fick's principle. The hepatic extraction fraction of D-sorbitol 0.179+/-0.144 (mean+/-SD) was higher than the hepatic extraction fraction of ICG 0.054+/-0.085 (P < .001). The low hepatic extraction fraction of ICG rendered this compound unfit for estimation of hepatic plasma flow in these patients. In contrast, by using D-sorbitol the hepatic plasma flow could be estimated in 21 of 23 patients with a median SD of 8.4% (range, 2.6% to 29%). The D-sorbitol estimated hepatic plasma flow was 1.2+/-0.5 L/min (n = 12) in patients with ALF and 1.4+/-0.9 L/min (n = 9) in patients with CLF. These values are higher than what has been reported in normal subjects and in patients with cirrhosis without HE. An elevated hepatic flow should increase oxygen delivery and may enhance the failing liver's ability to remove substances from the blood. At the same time, hepatic first pass metabolism is reduced. We conclude that an elevated hepatic flow in these patients is of clinical importance.

Brain lactate by magnetic resonance spectroscopy during fulminant hepatic failure in the dog

A noninvasive test is needed to assess the severity of encephalopathy during fulminant hepatic failure. This feasibility study was designed to compare a noninvasive test, brain lactate measurement by magnetic resonance spectroscopy, with intracranial pressure monitoring in a large animal model of fulminant hepatic failure. Five dogs received an intraventricular catheter for intracranial pressure measurement. Liver injury was induced by intravenous bolus of D-galactosamine. Brain lactate concentrations were determined by magnetic resonance spectroscopy for up to 48 hours after D-galactosamine administration (t = 0 hour). A dose of D-galactosamine exceeding 1.5 g/kg resulted in fulminant hepatic failure. Brain lactate levels increased to > 10 mmol/L in the two dogs that developed severe intracranial hypertension of > 50 mm Hg and sustained cerebral perfusion pressures of < 40 mm Hg. Both dogs experienced brain death, 42 and 48 hours after the administration of D-galactosamine. Brain lactate concentrations determined by magnetic resonance spectroscopy were in agreement with brain tissue concentrations of lactate determined by high-performance liquid chromatography at necropsy. Plasma lactate concentrations were only mildly elevated (3.2 and 4.2 mmol/L) at the time of brain death. Elevated levels of brain lactate are associated with intracranial hypertension and poor neurological outcome during fulminant hepatic failure.

Hyperventilation restores cerebral blood flow autoregulation in patients with acute liver failure

BACKGROUND/AIMS

In patients with acute liver failure loss of cerebral blood flow autoregulation may result from cerebral vasodilatation. Since arterial hypocapnia induces cerebral vasoconstriction, we investigated whether cerebral blood flow autoregulation could be reestablished by mechanical hyperventilation.

METHODS

Seven consecutive patients (median age 45, range 30-50 years) with acute liver failure and hepatic encephalopathy stage IV entered the study. They were all maintained on mechanical ventilation. Cerebral blood flow autoregulation was evaluated by using transcranial Doppler sonography to assess mean flow velocity (Vmean) in the middle cerebral artery, during a rise in mean arterial pressure by norepinephrine infusion (0.5-10 microg/h). The patients were subsequently hyperventilated for 15 min before cerebral blood flow autoregulation was re-evaluated in the same mean arterial pressure range.

RESULTS

At baseline PaCO2 (4.0 (3.5-4.9)kPa), all patients had impaired cerebral blood flow autoregulation as Vmean increased from 47 (30-78) to 68 (49-107) cm x s(-1) (p<0.05), as MAP was raised from 82 (60-88) to 106 (89-123) mmHg. During hyperventilation, five of seven patients restored cerebral autoregulation as Vmean remained unchanged at 51 (45-70) cm x s(-1) during a rise in MAP from 84 (65-94) to 110 (89-130) mmHg. Cerebral blood flow autoregulation was not restored in two patients, but hyperventilation reduced the slope of the mean arterial pressure-Vmean correlation. These two patients had renal failure and were treated with intermittent hemodialysis.

CONCLUSIONS

Cerebral blood flow autoregulation was restored by hyperventilation in five of seven patients with acute liver failure, indicating that cerebral vasodilatation is of pathophysiological importance in dysregulation of cerebral circulation in acute liver failure.

What should we expect from a bioartificial liver in fulminant hepatic failure?

Fulminant hepatic failure is associated with high mortality. Liver transplantation is an effective therapy that improves survival, and because of donor organ shortage and urgency, a bioartificial liver could act as an effective bridge to liver transplantation in patients with fulminant hepatic failure. We discuss the place of the bioartificial liver in the treatment of other causes of liver failure.

Immediate and long-term portal hemodynamic consequences of small-diameter H-graft portacaval shunt

BACKGROUND

Effective hepatic blood flow is thought to play a critical role in outcome following portal decompressive procedures. We have shown previously that hepatic arterialization occurs soon after shunting, preserving nutrient flow, but the remote effects of shunting are unknown. The purpose of this study was to determine the effect of small-diameter prosthetic H-graft portacaval shunt (HGPCS) on effective hepatic blood flow (EHF) and portal pressures 1 year from shunt placement.

METHODS

Patients undergoing 8-mm HGPCS had effective hepatic blood flow determined using low-dose galactose clearance preoperatively, postoperatively, and at 1 year postshunt. Portal blood flow, pressures, and portal vein/inferior vena cava pressure gradients were determined intraoperatively before and after shunt placement and at 1 year.

RESULTS

Twenty patients undergoing shunting had flows measured. All patients had significant reductions in portal vein/inferior vena cava pressure gradients while effective hepatic flow was maintained immediately postoperatively. At 1 year following shunting, effective hepatic blood flow was significantly lower than both pre- and postoperative rates of flow while portal pressures and gradients were significantly increased. Albumin, cholesterol, and PT were improved at 1 year while total bilirubin was slightly worse. Nineteen of 20 patients are still alive with average follow-up of 26 +/- 10.3 months. Four patients were encephalopathic preop, 5 postop, and none chronically.

CONCLUSIONS

Recollateralization of varices and progression of cirrhosis may account for the observed reductions in EHF at 1 year. Regardless of the cause, diminution of EHF at 1 year is well compensated as demonstrated by minimal encephalopathy and ascites, improved hepatic function reflected in blood chemistry profiles, and good survival.

Behavioral and physiological sex differences observed in an animal model of fulminant hepatic encephalopathy in the rat

Hepatic encephalopathy is characterized by a number of neuropsychiatric and motor disturbances observed in patients with liver dysfunction. The purpose of this study is to fully characterize behavioral and physiological sex differences in an animal model of fulminant hepatic encephalopathy (FHE). Male and female rats were administered thioacetamide (600 mg/kg) via i.p. (intraperitoneal) injection at Hours 0 and 24 and allowed to progress into the four stages of FHE. Male rats reached all four stages of FHE significantly earlier than female rats (p < 0.05). The performance of the male rats deteriorated more quickly (p < 0.05) than that of the females in all of the sensory and motor behavioral tests. Sex differences were observed in the liver enzymes of the FHE rats. The levels of aspartate aminotransferase (AST), alanine aminotransferase (ALT), and alkaline phosphatase were significantly greater (p < 0.05) in male rats in all four stages of FHE. Significant increases were also observed in the levels of direct and total bilirubin (p < 0.05). Neuronal damage was observed in the CA1 and CA2 regions of the hippocampus. In the CA1 region, male rats displayed greater pathological changes in Stages III and IV (p < 0.05) than female rats. The damage in the CA2 region was only observed in Stage IV male rats. Our data indicate that observable behavioral and physiological sex differences occur in thioacetamide-induced FHE in the rat.