Hepatobiliary

Question 1

Negative prognostic indicators for acute liver failure (4)

Answer 1

• PT> 100 s
• very old or very young animals
• marked ↑bilirubin
• Viral or idiosyncratic drug reaction as the cause

Question 2

List 5 toxins that cause direct destructive hepatotoxicity:

Answer 2

1. cycad palm
2. blue green algae
3. amanita
4. aflatoxins
5. xylitol

Question 3

List 5 indirect hepatotoxins (disrupts function):

Answer 3

1. acetominophen
2. sulphonamides
3. carprofen
4. xylitol
5. zonasamide
6. benzodiazepine

Question 4

Pathogenesis of portal hypertension:

Answer 4

1. Increased resistance: damage to hepatocytes and non-parenchymal cells -> change in hepatic architecture
   a. sinusoidal endothelial cells - overproduction of vasoconstrictors
   b. hepatic stellate cells differentiate into contractile myofibroblasts
2. Increase in portal blood flow:
   - splanchnic vasculature vasodilation -> decrease MAP and ECF
   - RAAS activation: Na and water retention
   - bacteria translocation stimulates hepatic kupffer cells + further HSC activation

Question 5

How does acute liver failure affect coagulopathy?

Answer 5

Mostly hypocoagulable with hyperfibrinolysis, however small portion hypercoagulable:
- primary: theombocytopenia (reduced thrombopoietin production) + thrombocytopathia (increased platelet inhibitors, NO, prostacyclin)
- secondary: decreased coag factor synthesis
- increased factor utilisation
- Vit K deficiency due to decrease bile flow altering K absorption from GI
- dysfibrinogenemia
- increased production of anticoagulants

Question 6

How to manage ascites?

Answer 6

1. Na restirction (diet < 0.05g/110kcal of Na)
2. Natriuresis with diuretics: spironolactone primary (takes time)
3. Abdominal paracentesis: remove 20-50% of volume to improve renal blood flow, splanchnic venous return and respiration

Question 7

Intrahepatic shunts are more common in?

Answer 7

Large dogs

Question 8

Extrahepatic shunts are more common in?

Answer 8

Small dogs and cats (better outcomes)

Question 9

List the 3 major post-op complications for PSS attenuation:

Answer 9

1. Portal hypertension
2. Coagulopathy
3. Post attenuation neurologic signs (PANS)

Question 10

The incompletely understood pathogenesis for primary hepatic lipidosis:

Answer 10

• obese cats with concurrent appetite disturbances
• excess peripheral lipid mobilisation to the liver
• difficiency of dietary proteins and other nutrients that would usually allow fat metabolism + transport out of the liver
• fat accumulates in hepatocytes, disrupting function

Question 11

Important dietary proteins in cats:

Answer 11

• methionine: precursor to glutathione
• carnitine: important in FA transport through the mitochondrial membranes
• taurine: conjugation of bile acids to bile salts
• arginine deficiency: contribute to HE caused by decreased urea cycle activity

Question 12

Ideal diet for hepatic lipidosis cats:

Answer 12

Protein 30-40% ME
Fat 50% ME
Low Carb 20% or lower (glucose intolerance & hyperglycemia common)