3.5. Liver + Biliary Tree Disease - Portosystemic Encephalopathy

Question 1

What is Portosystemic Encephalopathy?

Answer 1

This is a neuropsychiatric condition

Question 2

What is Encephalopathy?

Answer 2

Irritation of the Brain

Question 3

What is Portosystemic Encephalopathy secondary to?

Answer 3

Liver Cirrhosis / Hepatic Failure

Question 4

What are the main predisposing factors to Portosystemic Encephalopathy?

Answer 4

1. Gastrointestinal Haemorrhage
2. Constipation
3. Infection
4. Drugs
5. Fluid/Electrolyte Disturbances
6. Surgical Procedures
7. Toxic Substances

Question 5

In which Group of people is Constipation a common source of Portosystemic Encephalopathy?

Answer 5

The Elderly

Question 6

What infections can cause Portosystemic Encephalopathy?

Answer 6

1. Urinary Tract Infections - These are the most common
2. Chest Infection (URTI/LRTI)
3. Spontaneous Bacterial Peritonitis - this must be rules out as a cause

Question 7

What type of drugs can lead to Portosystemic Encephalopathy?

Answer 7

Central Nervous System Depressants

Question 8

What can cause Fluid / Electrolyte Disturbances?

Answer 8

1. Diuretic Therapy

2. Paracentesis

Question 9

What Surgical Procedure, used in the Liver, can commonly lead to Portosystemic Encephalopathy?

Answer 9

Transjugular Intrahepatic Portocaval Shunt (TIPS)

Question 10

What Toxic substances, in high levels, may be a causative factor?

Answer 10

1. Ammonia
2. Free Fatty Acids
3. Thiols
4. False Neurotransmitters (e.g. Octopamine)
5. The activation of the Gamma-Aminobutyric Acid System (An inhibitory neurotransmitter)

Question 11

What is the Pathology of Portosystemic Encephalopathy?

Answer 11

1. The exact mechanism is unknown, but it is multifactorial
2. Due to the Aetiology, Toxins are not deal with properly by the Liver
3. These allow the Toxins to remain in the Blood which will irritate the Brain

Question 12

What are the Clinical Signs of Portosystemic Encephalopathy?

Answer 12

1. Asterixis (Hepatic Flap)
2. Fetor Hepaticus
3. Decreased Blood Pressure
4. Decreased Blood Glucose
5. Decrease Blood Urea
6. Decreased Mental Function
7. Confusion to Coma

Question 13

What is Asterixis?

Answer 13

A flapping tremor caused by Hepatic Failure

Question 14

What is Fetor Hepaticus?

Answer 14

Sweet Smelling Breath

Question 15

Why does Fetor Hepaticus occur in Portosystemic Encephalopathy?

Answer 15

Portosystemic Shunting allows Thiols into the Lungs

Question 16

Why might there be a Decrease in Blood Pressure / Urea?

Answer 16

If the patient goes into Renal Failure as a result of the Aetiology

Question 17

Why might there be a Decrease in Blood Glucose?

Answer 17

Due to the Liver being damaged, and so unable to release the Glucose stored in it

Question 18

How might the Decrease in Mental Function present?

Answer 18

1. Drowsiness
2. Constructional Apraxia
3. Hyperreflexia
4. Increased Tone

Question 19

What is Constructional Apraxia?

Answer 19

The patient being unable to write / draw

Question 20

What are Hyperreflexia and Increased Tone examples of?

Answer 20

Upper Motor Neuron Signs

Question 21

Why might Upper Motor Neuron Signs occur?

Answer 21

Due to the irritation and effect on the Central Nervous System and the Brain

Question 22

How is the Decreased Mental Function graded?

Answer 22

Grade 1 - Impaired Concentration
Grade 2 - Disorientation
Grade 3 - Confusion / Amnesia
Grade 4 - Coma

Question 23

What are the Symptoms of Portosystemic Encephalopathy?

Answer 23

1. Asymptomatic
2. Infectious Markers (Fever, Nausea/Vomiting…)
3. Psychogenic changes

Question 24

When would Infectious Markers be present?

Answer 24

If an infection was the cause

Question 25

What Psychogenic changed might occur?

Answer 25

1. Irritability 2. Confusion 3. Disorientation 4. Slow Slurred Speech

Question 26

What investigations are required for Portosystemic Encephalopathy?

Answer 26

1. Liver Function Test (and Biochemistry) 2. Electroencephalography (EEG) 3. Visually Evoked Responses 4. Arterial Blood Ammonia

Question 27

What are Liver Function Tests (and Biochemistry) Looking for?

Answer 27

Liver Function Test: 1. Prothrombin Time 2. Serum Albumin Liver Biochemistry: 1. Bilirubin 2. Alkaline Phosphatase 3. Gamma-Glutamyl Transpeptidase 4. Aminotranferases: a) Aspartate Aminotransferase b) Alanine Aminotransferase

Question 28

What is the purpose of the Liver Function Tests (and Biochemistry)?

Answer 28

To find the presence of Liver Disease

Question 29

What is the purpose of Electroencephalography (EEG)?

Answer 29

To view the damage to the Brain

Question 30

What will be shown on an Electroencephalography before a Coma occurs?

Answer 30

A decrease in the Frequency of Normal Alpha Waves

Question 31

What do Visually Evoked Responses detect?

Answer 31

Subclinical Encephalopathy

Question 32

What is the Purpose of Arterial Blood Ammonia?

Answer 32

To identify the cause of the irritation to the Brain

Question 33

What is the Treatment of Portosystemic Encephalopathy?

Answer 33

To treat the underlying cause

Question 34

How do you treat the underlying Infection?

Answer 34

Antibiotics

Question 35

How do you treat the underlying Constipation?

Answer 35

1. Laxatives (Dextrose / Lactulose) | 2. Enema

Question 36

How do you treat the underlying Electrolyte Disturbance?

Answer 36

Potassium Supplements

Question 37

How do you treat the underlying Renal Failure?

Answer 37

Dialysis - this can also be used for severe hepatic failure

Question 38

What general measures might be taken?

Answer 38

Nasogastric Tube - for medication

Question 39

If the patient enters into a Coma, what will be required?

Answer 39

1. Ventillation | 2. I.V. access - for medication and nutrition