**5. Diagnosis**

Checking for Elevated Blood ammonia levels is the most commonly used parameter for assessment, but they may also be elevated due to other possible causes (i-e tourniquet use, delayed processing and cooling of sample, disorders related to ammonia and proline metabolism). In acute liver failure, arterial ammonia levels >150 mg/dl may be predictive of brain edema and herniation. However, measurement of arterial ammonia over venous ammonia offers no advantage in Chronic liver disease.(3, 44)

Hepatic Encephalopathy 501

Many treatment options are available for the treatment of HE with the mainstay to eliminate the underlying factors that precipitate HE. It is recommended that all patients should receive the empiric therapy (Box C) for HE, based on the principle of reducing the production and absorption of ammonia. Some strategies that are commonly applied to stop

1. in patients with HE induced by gastrointestinal hemorrhage, stop the bleeding with vasoactive drugs, an endoscopic therapy or an angiographic shunt (TIPS), correct the anemia with a blood transfusion and use a nasogastric tube to facilitate upper

3. Resolve constipation by cathartic and/or bowel enema, electrolyte abnormalities by

4. Correct deterioration of renal function by stopping diuretics, treating dehydration and

5. if HE is precipitated by the administration of exogenous sedatives, discontinue

Nonadsorable disaccharides (Lacutlose and Lactitol) especially Lactulose are considered the first line therapy for HE despite lack of well-designed randomized controlled trial. They are metabolized by the colonic bacteria and form by products that reduce the colonic PH, hence interfering with mucosal uptake of glutamine and reducing the synthesis and absorption of ammonia. There are other proposed mechanism of lactulose in HE such as lactulose modifies the colonic flora which in turn results in shift of urease containing bacteria with lactobacillus, fourfold increased fecal nitrogen excretion due to increase stool volume and it

Management of precipitating factors,

Reduction of ammonia

Modulation intestinal flora

precipitating events are the following:

gastrointestinal cleansing;

discontinuing nephrotoxic drugs

 Lactulose (15-30ml orally, twice daily) Rifaximin (550mg orally, twice daily) Neomycin (500mg orally, four times daily) Metronidazole (250mg orally, four times daily) Vancomycin (250mg orally, four times daily) Sodium Benzoate(5 mg orally, twice daily)

Flumazenil (1-3 mg IV)

**7.1 Nonadsorable disaccharides** 

2. Promptly start Antibiotics therapy for infections;

benzodiazepines and start flumazenil.(49)

Box C. Empiric Treatment for Hepatic encephalopathy(48)

**7. Reduction of ammonia and modulation of neurotransmission** 

discontinuing diuretics and correct hypo- or hyperkalemia;

Modulation of neurotransmission Correction of nutritional deficiencies Reduction of inflammation/infection


Table 1. West Haven classification for grading of HE(1)

Neuropsychometric evaluation usually is done via 'paper and pencil tests' and 'computerized tests'. The routinely used paper and pencil tests include psychometric HE scores (PHES) and The Repeatable Battery for the Assessment of neurological status (RBANS). PHES has been endorsed as a 'gold standard' for diagnosis of MHE and is used to diagnose the cognitive changes that characterize MHE. RBANS in addition to diagnosing the cognitive issues, also scores patient's memory.(45) Some computerized psychometric tests like 'The inhibitory control test' and 'CDR computerized assessment system' are gaining popularity as promising diagnostic tests due to their effectiveness and convenience(46). However, the value of these psychometric tests is limited by methodological problems, training and education, demographic dependence and lack of standardization.(43)

Neurophysiological assessment is done via Electroencephalography (EEG) and the Critical flicker frequency test (CFF). EEG is associated with decreased electrical activity and shows diffuse slowing of alpha waves with eventual development of delta waves.(47) CCF, a light based test, is used for a rapid and reliable quantification of HE. Based on the principle of hepatic retinopathy, it represents the frequency at which discrete light pulses are first perceived by the patient. A CCF of below 39 Hz is diagnostic for MHE and the test results are not dependent on sex, occupation and education level.(48)

Imaging Modalities include different Magnetic resonance techniques( T1-weighted imaging, proton spectroscopy, magnetic transfer ratio, T2- weighted FLAIR sequence and diffusion weighted imaging) to measure cerebral edema, changes in brain activity and concentration of different substances( i-e glutamine, choline). A CT scan can be used to exclude subdural hematoma or other cerebrovascular events that may mimic HE.(48)
