hepatic encephalopathy

Question 1

What is hepatic encephalopathy?

Answer 1

Hepatic encephalopathy is brain dysfunction caused by advanced liver insufficiency

Question 2

Causes and risk factors for this:

Answer 2

• Cirrhosis
• liver cancer
• Hepatitis,
• Intestinal Bleed

Question 3

Pathophysiology of hepatic encephalopathy

Answer 3

Decreased Liver function → build up of toxic metabolites (NH3) → Astrocyte ion channels activated, increased production of cytokines and stimulation of osmotic pumps → swelling of astrocytes → contributes to cerebral oedema =
NEUROLOGICAL CHANGES

Question 4

Presentation of hepatic encephalopathy?

Answer 4

Mood Disturbances – Depression Sleep Disturbances – Insomnia
Motor Disturbances – Ataxia, Muscle Rigidity, Bradykinesia
Confusion
Liver Symptoms too – ascites, jaundice, peripheral oedema

Question 5

Diagnosis and investigations

Answer 5

FBC and Basal Metabolic Panel
Blood Alcohol
Blood ammonia – raised

Question 6

1st line treatment

Answer 6

1st Line: Lactulose

Question 7

2nd line treatment

Answer 7

Rifaximin – reduces number of ammonia producing intestinal bacteria
Liver transplant

Question 8

Complications of hepatic encephalopathy

Answer 8

Cerebral Oedema
Aspiration Pneumonia

Question 9

What is it caused by

Answer 9

build up of toxins that affect the brain.

Question 10

Which toxin predominantly affects the brain in HE?

Answer 10

Ammonia - produced by intestinal bacteria when they break down proteins and is absorbed in the gut

Question 11

2 reasons ammonia builds up in blood in patients with cirrhosis

Answer 11

1. functional impairment of the liver cells prevents them metabolising the ammonia into harmless waste products.
2. collateral vessels between the portal and systemic circulation mean that the ammonia bypasses liver altogether and enters the systemic system directly.

Question 12

How do we manage HE?

Answer 12

Laxatives (i.e. lactulose) promote the excretion of ammonia. The aim is 2-3 soft motions daily. They may require enemas initially. help clear the ammonia from the gut before it is absorbed and by giving antibiotics we reduce the number of bacteria in the gut producing ammonia.

Antibiotics (i.e. rifaximin) reduces the number of intestinal bacteria producing ammonia. Rifaximin is useful as it is poorly absorbed and so stays in the GI tract.

Nutritional support. They may need nasogastric feeding.

Question 13

Precipitating factors

Answer 13

Constipation
Electrolyte disturbance
Infection
GI bleed
High protein diet
Medications (particularly sedative medications)