Hepatic encephalopathy occurs when the liver fails to detoxify toxic substances, such as ammonia, which are then able to pass into the brain. This causes neurological symptoms ranging from mild confusion to coma. Precipitating factors include gastrointestinal bleeding, infections, and certain drugs. Treatment focuses on reducing ammonia production in the gut through lactulose, antibiotics, and low-protein diets. Correcting electrolyte imbalances and removing precipitating medications or infections are also important for management of hepatic encephalopathy.
2. Definition
It is a state of disordered CNS function, resulting from
failure of liver to detoxify toxic agents because of hepatic
insufficiency and porto-systemic shunt.
It represents a reversible decrease in neurologic function.
It occurs most often in patients with cirrhosis but also
occur in acute hepatic failure.
3. Pathogenesis
Ammonia formed by protein breakdown in GIT
Liver liver dysfunction (abnormal) NH3 Passes
BBB Hepatic encephalopathy.
Other factors:
Increase sensitivity to glutamine & GABA (inhibitory
neurotransmitter)
Increase circulating levels of endogenous
benzodiazepines.
4. Pathogenesis (acute & chronic )
The basic cause is same in both forms but the mechanism is somewhat
different
Diminished detoxification of toxic intestinal nitrogenous compounds
Increased in blood
NH3 etc
Toxic effect on
brain
Appearance of
abnormal amines in
systemic circulation
Interference with
neurotransmission
5. Endotoxins
Ammonia.
Mercaptans (degradation of methionine in the gut)
Phenols.
Free fatty acids.
Gamma amino butyric acid(GABA)
Octopamine.
10. Clinical Features
A Disturbance in consciousness
Disturbances in sleep rhythm.
Impaired memory/ apraxia.
Mental confusion.
Apathy.
Drowsiness / Somnolence.
Coma.
11. B. Changes Personality
Childish behavior.
May be aggressive out burst.
Euphoric.
Foetor hepaticus Foulsmelling breath associated
with liver disease due to mercaptans.
12. C Neurological signs:
Flapping tremor / Asterixis (in pre coma).
Exaggerated tendon reflex.
Extensor plantar reflex.
18. Management
Supportive Treatment.
Specific Treatment aims at:
Decreasing ammonia production in colon
Elimination or treatment of precipitating factors.
20. TREATMENT
Hospitalize the patient.
Maintain ABC.
Identify and remove the precipitating factors.
Iv fluid dextrose ,saline.
Stop Diuretic Therapy.
Correct any electrolyte imbalance.
Ryle tube feeding & bladder catheterization.
Reduce the ammonia (NH3) Load.
Diet Restriction of protein diet.
High glucose diet.
Treat Constipation by Laxatives.
21. Lactulose
Lactulose 15-30ml X 3 4 times a day- result aims at 2-4
stools/day.
Rectal use is indicated when patient is unable to take
orally.
300ml of lactulose in 700ml of saline or sorbitol as a
retention enema for 30 60 min.
May be repeated 4 6 hours.
22. Mechanism of action of Lactulose
A non-absorbable disaccharide.
It produces osmosis of water- Diarrhea.
It reduces pH of colonic content & thereby prevents
absorption of NH3.
It converts NH3- NH4 that can be excreted.
23. Treat the GIT & other Infections
Antibiotics:
Rifaximin
Broad spectrum antibiotic, recently approved in humans
for HE.
Negligible systemic absorption.
Shown to decrease hospitalizations and length of stay as
compared to lactulose in humans.
DOSE: 550 mg orally B.I.D
24. Metronidazole : 250mg orally T.D.S
Neomycin : 0.5 1 g orally 6 or 12 hours for 7 days.
Side effects: Ototoxicity, nephrotoxicity.
Vancomycin : 1 g orally B.I.D
25. DIET
With held dietary protein during acute episode if patient
cannot eat.
Oral intake should be 60 80 g/day as tolerated.
Vagetable protein is better tolerated than meat protein.
G.I.T bleeding should be controlled
120ml of magnesium citrate by mouth or NG tube every 3
4 hours until stool free of blood.
26. Stimulation of metabolic ammonia
metabolism:
Sodium benzoate
5 g orally twice a day.
L-ornithine-L-aspartate
9 g orally thrice a day.
L-acyl-carnitine aspartate
4 g orally daily.
Zinc sulphate
600mg/day in divided doses.
27. Correct amino acid metabolic
imbalance
Infusion or oral administration of BCAA
(branched-chain amino acid)
Its use is unnecessary except in patient who are intolerant
of standard protein supplements.
GABA/BZ complex antagonist:
Flumazenil ( particularly if patient has been given
banzodiazepines )
Opiods & sedatives should be avoided.
28. Acarbose
留 glucosidase inhibitor.
Under study.
Other Therapies:
Prebiotics & probiotics.
Extracorporeal albumin dialysis ( MARS)
Liver transplant.
29. PROGNOSIS
Acute hepatic encephalopathy may be treatable.
Chronic forms of the disorder often keep getting worse or
continue to come back.
Both forms may result in irreversible coma and death.
Approximately 80% (8 out of 10 patients) die if they go
into a coma.
Recovery & the risk of the condition returning vary from
patient to patient
30. REFERENCES
Davidsons Principles & Practice of Medicine- 21st edition.
Harrisons Principles of internal Medicine-10th & 17th
edition.
Current Medical Diagnosis & Treatment 2014 edition.