OBJECTIVES: Hepatic encephalopathy (HE) is a neuropsychiatric syndrome associated with fulminant hepatic failure and chronic liver disease. Its pathogenesis is unclear. One of the factors implicated is enhanced GABA-ergic tone, which is probably related to increased concentrations of cerebral benzodiazepine (BNZ). In the present study, we tested flumazenil, a cerebral BNZ antagonist, in cirrhosis patients with hepatic encephalopathy.
METHODS: Out of 47 patients, 7 were excluded prior to randomization for various reasons. Twenty patients were included in the flumazenil group and 20 in the placebo group in a prospective, randomized, double-blind, placebo-controlled study. Patients were given flumazenil (1 mg/h, continuous IV infusion) or an equal volume of saline solution for 5 hours. Before and after treatment, portosystemic encephalopathy (PSE) stage and number connection test (NCT) scores were checked every half hour for 5 hours. EEG was recorded 15 minutes before and 1 hour after treatment.
RESULTS: While significant improvements were determined in PSE stage and NCT score in the flumazenil group, there were no such improvements in the placebo group. There was no statistically significant difference between pre- and post-treatment EEGs in either group.
CONCLUSION: It was concluded that continuous IV infusion of flumazenil had beneficial and safe effects in the treatment of hepatic encephalopathy patients.
The P300 complex was derived from the electroencephalogram (EEG) as subjects mentally counted infrequent large checkerboard visual stimuli, presented randomly among frequent small checkerboard stimuli. Use of low contrast (10%) stimuli and four midline scalp electrodes, facilitated separation of cognitive and sensory components and enabled the P300 complex to be resolved into three distinct components--N200, P3a, and P3b. In 20 healthy adult subjects normative data were established and the P3a and P3b components were shown to depend on cognitive function. In 19 age-matched cirrhotic patients without overt hepatic encephalopathy (HE) the EEG and visual evoked potentials (VEPs) were normal, but latencies of P3a and/or P3b were prolonged in 9. Prolonged latencies were not associated with an abnormal number connection test. Ten additional age-matched cirrhotic patients without overt HE, who were alcohol, drug, and caffeine free, were randomized to receive flumazenil (1 mg) and placebo intravenously, double-blind. After flumazenil or placebo, latencies of P3a and P3b and psychometric test results did not change significantly. These findings suggest that in cirrhotic patients without overt HE (i) impaired cognitive sensory function may occur in the absence of abnormalities of a standard psychometric test, the EEG, or VEPs, and (ii) increased latencies of P3a and P3b may constitute a component of subclinical HE, which is not mediated by increased brain levels of central benzodiazepine receptor agonist ligands.
Journal»Digestive and liver disease : official journal of the Italian Society of Gastroenterology and the Italian Association for the Study of the Liver
AIMS: The aim of this study was to evaluate the effects of flumazenil on hepatic encephalopathy in patients with liver cirrhosis.
PATIENTS AND METHODS: . In the double blind randomized, placebo controlled study, 54 patients with hepatic encephalopathy grade III-IV were randomly assigned to receive either flumazenil 2 mg iv (group A) or placebo (group B); conventional treatment with branched-chain amino acid, saline, glucose, and lactulose was administered in both groups. A 24-hour observation period was established. Clinical improvement was defined as a 3 point decrease in the Glasgow coma score at any time within 24 hours.
RESULTS: Clinical improvement was obtained in 22/28 patients in group A and in 14/26 in group B (p<0.05); improvement was observed within the first six hours in 21/22 patients in group A and only in 3/14 in group B. Mortality rate was not different between group A and B; however, all 6 non-responders in group A and only 5 out of 12 in group B died within 24 hours. Among patients with post-bleeding encephalopathy, 11 out of 17 in group A and only 2 out of 14 in group B improved (p<0.001).
CONCLUSIONS: Flumazenil may exert a beneficial effect in a subset of patients with acute hepatic encephalopathy; encephalopathy associated with bleeding is more likely to respond to flumazenil; responders to the treatment usually improve within the first 6 hours while lack of response usually represents a bad prognostic sign.
The effects of flumazenil on the latencies and amplitudes of visual event-related potentials (ERPs), number-connection test (NCT) and visual and auditory reaction times (VRT and ART) were evaluated in ten patients with cirrhosis without clinically overt encephalopathy (HE). Delayed latencies of the ERP component P3a and/or P3b were found in three patients and the time to complete NCT was prolonged in two other patients. Changes in the latencies and amplitudes of the ERP components (N200, P3a and P3b) during 40 min following infusion of flumazenil (1 mg) and placebo were similar. Results of the three psychometric tests did not change significantly after either flumazenil or placebo infusion. Eight of the ten patients felt more alert for several minutes after the administration of flumazenil, whereas no patient experienced any change of perception after infusion of placebo. Prolongation of the latencies of P3a and P3b may be a component of the syndrome of subclinical HE. However, these neuro-electrophysiological abnormalities in cirrhotic patients may not be attributable to increased brain levels of natural benzodiazepines. Copyright (C) 1999 Elsevier Science Ireland Ltd.
The rationale for use of benzodiazepine receptor antagonists is based on the so-called benzodiazepine pathogenetic hypothesis of hepatic encephalopathy (HE). To assess the efficacy of flumazenil, a specific benzodiazepine receptor antagonist, in a large and selected population of cirrhotic patients with severe HE, we conducted a double-blind, placebo-controlled, cross-over trial on 527 cirrhotic patients with HE grade III and IVa admitted to Intensive Care Units over a 5-year period; among them, 265 (132 of grade III and 133 of grade IVa) received flumazenil, whereas 262 (130 of grade III and 132 of grade IVa) received placebo. Treatment was begun within 15 minutes of randomization; the response to treatment was assessed by neurological score and by continuous electroencephalographic (EEG) recordings. Improvement of the neurological score was documented in 17.5% of grade III patients treated with flumazenil and in 14.7% of grade IVa patients, compared, respectively, with 3.8% and 2.7% of the patients of both groups treated with placebo. Improvements in EEG tracings were observed in 27.8% of grade III patients and in 21.5% of grade IVa patients, compared, respectively, with 5% and 3.3% of the patients of both groups treated with placebo. Benzodiazepines were detected in the serum of 10 patients (4 in grade III group and 6 in grade IVa group). Flumazenil is beneficial only in a selected subset of cirrhotic patients with severe HE; the applicability of this treatment to unselected patients with severe HE still remains to be determined.
Several factors suggest that endogenous benzodiazepines and gamma-amino-butyric acid may be involved in pathophysiology of hepatic encephalopathy (HE). Contrasting opinions exist on the therapeutic efficacy of flumazenil in the treatment of HE. This study was planned to assess the efficacy of flumazenil by a double-blind, placebo-controlled, crossover design in a large and selected population of cirrhotic patients in stage 4a HE admitted to intensive care units over a 4-year period. Out of 236 patients selected for the study, 132 received flumazenil, whereas 131 patients received placebo. Improvement of the neurological score was documented in 31 patients (23%) of flumazenil group and in two patients (1.5%) of placebo group (p < 0.001) during the first study period, whereas during the crossover period, improvement of the neurological score was documented in seven patients (5.3%) of the flumazenil group and in none of the placebo group (p = 0.022). Improvements in EEG tracings were observed in 44 patients (33.3%) of flumazenil group and in five patients (3.8%) of placebo group (p < 0.001) during the first study period; during the crossover period, improvements in EEG tracings were observed in 10 patients (7.5%) of the flumazenil group and in two patients (1.5%) of the placebo group (p = 0.040). The presence of benzodiazepines was detected in the serum of three responders and in two non-responders. The presence of diazepam and NN-desmethyl diazepam was documented in two responders; prior intake of synthetic diazepam was later confirmed in these patients. The results of our study suggest that flumazenil is beneficial only in a selected subset of cirrhotic patients with severe HE; the applicability of this treatment to unselected patients with hepatic coma or to cirrhotic patients with less severe HE still remains to be determined.
It is not yet clear if benzodiazepine receptor ligands, implicated in the pathophysiology of hepatic coma, also have a role in subclinical cognitive or neurophysiological alterations in cirrhotic patients. Therefore, we carried out a double-blind, placebo-controlled study to evaluate the effectiveness of flumazenil, a benzodiazepine antagonist, on brainstem auditory evoked responses and on the number connection test in cirrhotic patients with subclinical neurophysiological or cognitive alterations. Thirteen cirrhotic subjects with subclinical neurophysiological or cognitive alterations were studied. A total of 3 mg of flumazenil or saline was infused intravenously. Before and after the infusion, the number connection test was administered and brainstem auditory evoked responses recorded. After 72 h, patients were crossed over. Flumazenil did not influence brainstem auditory evoked responses or the number connection test. A screening test for benzodiazepines was negative in all subjects. We conclude that benzodiazepine receptor ligands have a negligible role, if any, in the pathophysiology of subclinical neurophysiological or cognitive alterations of cirrhotic patients.
