Hepatic Encephalopathy Flashcards
Definition
Neuropsychiatric syndrome due to liver disease
Incidence of HE in cirrhotic patient
50-70%
Survival rate of HE
42% 1 year survival
Survival rate of HE
1 year survival of 42%
3 years survival of 23%
Precipitating factors of HE
Drugs (especially sedatives, antidepressants)
Dehydration (including diuretics, paracentesis)
Portosystemic shunting
Infection
Hypokalaemia
Constipation
Increased Protein load (including gastrointestinal bleeding)
Main neurotoxin involved in HE
Ammonia
Why is there accumulation of ammonia in cirrhosis
Normally ammonia is metabolized by liver hepatocytes for excretion
In cirrhosis, there are less hepatocytes so there is accumulation of ammonia in the blood
Only cells in the brain that can metabolized ammonia
Astrocytes
 pathophysiology of ammonia in HE
elevated ammonia -> increased glutamate -> excitatory changes -( agitation, confusion, seizures, coma )
Elevated ammonia -> AStrocytes metabolize it -> glutamine accumulation -> AStrocytes swelling swelling -> brain edema
Clinical presentation in low HE form
Deficit of Attention , working memory , psychomotor speed and visuospatiala ctivity
Clinical presentation of HE as it progresses
 personality changes
Apathy
irritability
disinhibition
sleep wake cycle
progressive disorientation to tim and space
Inappropriate behavior
acute confusional state
agitation
Somnolence
Stupor
Coma
What is flapping tremor or asterixis
Not a tremor but a negative myoclonus with loss of postural tone
Investigations
EEG - diffuse slowing of alpha waves , delta waves visible
arterial ammonia levle
Management of HE
Remove precipitating factors
Lactulose for bowel movement to limit colonic ammonia absorption
Rifaximin to reduce bacteria to prevent overproduction of ammonia
Liver transplantation in chronic or refractory encephalopathy
