Hepatic Flashcards
Breed predispositions to PVH without PH
Maltese
Cairn
Yorkies
What type of cPSS is most often seen in cats?
Extra-hepatic
What degrees of hyperbilirubinaemia are expected for:
- Seeing icteric plasma
- Seeing icteric MM
- 8 - 18umol/L
- > 50 - 85umol/L
Which type of portal hypertension is a high protein (rather than low protein) ascitic fluid expected in?
Lower protein is expected in pre-sinusoidal portal hypertension
Which amino acid is of particular importance in the urea cycle and therefore deficiencies of this can result in hepatic encephalopathy?
Arginine - cats with cysteine stones can therefore be hyperammonaemic due to arginie loss through COLA transporters
ALT:
- T 1/2 in the dog
- T 1/2 in the cat
- Alternative source from the liver
Dog: 48 - 60h
Cat: 6h
Muscle is the other main source
AST
- T 1/2 in the dog
- T 1/2 in the cat
- Alternative sources
- Dog: 22h
- Cat: 77 minutes
- Sources: muscle, RBC
ALP
- T 1/2 in the dog
- T 1/2 in the cat
- Alternative sources
Dog 70h
Cat: 6h
Sources: intestinal mucosa, renal cortex, placenta, liver, bone
In dogs can be induced by steroids
GGT
- T 1/2 in the dog
- T 1/2 in the cat
- Alternative sources
T 1/2 is unknown
Sources: Kidney>pancreas>liver>GB>intestine>spleen>heart>lungs>skeletal muscle>RBCs
CK
- T 1/2 and kinetics with muscle injury
Peak concentration occurs within 6 - 12 hours of muscle injury and will decline within 24 - 48 hours.
Degree of reduction in hepatic mass to result in hypoglycaemia
75%
Degree of loss of liver mass required for hypoalbuminaemia
70%
Which globulins are produced by the liver?
Alpha and beta globulins, although hypoglobulinaemia is rare in hepatic disease
What are the potential causes for increased pre-prandial rather than post-prandial bile acids?
Inter-digestive gallbladder contraction
Variations in gastric emptying and intestinal transit times
Varied responses to CCK
What is the indication for performing and ammonia tolerance test? how is this test performed?
- 2ml/kg of 5% ammonium hydrochloride administered 10 - 20cm into the rectum via a catheter
- Take basal, 20m and 40m sample
- Normal response is minimal increase in ammonia
Which coagulation factors are not produced by the liver?
vWF and a subtype of factor VIII
What is the indication for measurement of protein C and the clinical cut off of activity?
To help differentiate PSS from PVH. Activity <70% is indicative of PSS
What percentage of dogs with PSS may have ammonium biurate crystals?
50%
What conditions is a hypoechoic liver parenchyma associated with?
Acute hepatitis
Amyloidosis
Lymphoma
Cholangitis/Cholangiohepatitis
I.e. it is still non-specific
What is a normal CBD diameter in dogs and cats?
3mm dogs and up to 4mm in cats
Where in the abdomen is MAPSS more likely to be identified using AUS, what other findings can suggest MAPSS?
Left dorsal perirenal area
Reduced portal blood flow (<10m/s)
Hepatofugal flow
Enlarged PV and dilated left gonadal vein
What are the three weird and wonderful methods of evaluating for a PSS?
Portal scintigraphy with Tc99m-sulfur-colloid
Pre-rectal portal scintigraphy
Trans-Splenic Portal Scintigraphy
Outline the basis of and interpretation of Tc99m-Sulfur-Colloid scintigraphy
- Small colloidal particles that localise to the reticuloendothelial system
- In normal animals it should mostly be present in the liver
- In PSS a large amount may occur in the lungs
However, this can also occur with other causes of liver insufficiency in dogs and occurs normally in cats.
Outline the basis and interpretatino of pre-rectal portal scintigraphy
- Administration of a radionucleotide into the colon (usually sodium pertechnetate)
- In normal patients it should first be seen in the liver and then in the heart.
- In PSS it will be seen in the heart first. However, with small shunts it could reach both at the same time.
Computer programming can calculate a shunt fraction
What are the disadvantages to this technique?
○ Can have poor uptake from the colon –> non-diagnostic study
○ Poor anatomic detail, so determining the type and anatomy of the shunt can be challenging
○ False negatives if infused too high into the rectum
○ Need for isolation post procedure
Outline the basis of and interpretation of trans-splenic portal scintigraphy
- Ultrasound-guided injection of radiopharmaceutical (sodium pertechnetate) into the splenic parenchyma.
- In the normal animal this should be absorbed into the splenic vein which will then flow into the left gastric vein and then the main portal vein.
- Can miss shunts that enter the portal vein caudal to the splenic vein
Small shunts may be missed as well.
Which liver disease does FNA have the best PPV for?
Hepatocellular carcinoma followed by non-hepatocellular carcinomas and round cell tuours
Which hepatoprotectant has evidence for use in acute amanita phalloides toxicity?
Intravenous silmaryn
In hepatic disease which version of pred (prednisone vs. prednisolone) is more appropriate and why?
Prednisone needs to be converted to prednisolone to the liver so prednisolone is probably a better choice
What are the two chelating agents available for the treatment of copper hepatopathy?
D-penicillamine
Trientine
What is the mechanism by which Zinc reduced hepatic copper accumulation?
It results in ncreased synthesis of metallothionein by enterocytes which binds copper in enterocytes preventing its movement into the circulation and liver.
What are the four WSAVA classifications of cholangitis?
Neutrophilic
Lymphocytic
Destructive
Chronic associate with liver fluke
Infectious causes of acute canine hepatitis
Toxic causes of acute canine hepatitis
Drugs that may result in acute canine hepatitis
What clinical sign of hepatic disease is not expected with acute liver injury?
Ascites
What clinical signs outside of hepatic and general systemic signs may be seen with CAV-1 infections?
- Bronchopneumonia
- Conjunctivitis
- Photophobia
- Corneal opacity from anterior uveitis
Which leptospirosis spp. are zoonotic?
L. interrogans and kircheri
What specific treatment should be given to dogs with blue-green algae toxicity?
Cholestyramine - this blocks re-absorption of bile acids and may therefore prevent microcytins being absorbed. Otherwise the treatment is all supportive.
What does the COMMD1 mutation result in?
Failure of hepatocytes to be able to excrete copper into bile
What is the histologic localisation of copper when primary vs. secondary?
Zone 3 (centrilobular) = primary
Zone 1 (periportal) = secondary
I guess this makes sense as the liver is trying to move it to the bile in primary cases but in secondary cases it can’t move?
What stain is used to evaluate for hepatic copper?
Rubenaeic acid/rhonadine
What is the histopathologic distinction between cholangitis and cholangiohepatitis?
Cholangitis is limited to inflammtory changes within the bile duct luen and between biliary epithelial cells. It inflammation extends beyong the limiting plate (layer of hepatocytes that border the portal tract)
What percentage of cats with neutrophilic cholangitis are icteric vs. hyperbilirubinaemic?
34% icteric, 66% hyperbilirubinaemic
What percentage of bile and liver samples will culture positive in cases of neutrophilic cholangitis?
36% bile samples and 14% liver samples
How long should antibiotics for hepatic abcesses be given for?
Minimum of 6 weeks and should consider surgical or percutaneous drainage