13 Diagnostic Tests for Hepatobiliary Disease

Icterus

What is the BIGGEST finding on clinical exam with hepatic disease?

CBC, Chem, UA

What is a "minimum database"

Microcytosis (from impaired transport of iron)

What type of RBC changes occur with hepatobiliary disease from portosystemic shunts?

Iron deficiency anemia, portosystemic shunting (NO anemia), GI bleed

What 3 things cause microcytosis?

Hemolytic anemia

What might cause regenerative MACROCYTIC anemia if the patient is jaundice?

Poiklocytes, acanthocytes

What SHAPE might RBC be in animals with portosystemic shunts or hepatobiliary disease?

ALT, AST

What are the two Chem. markers that measure hepatocellular membrane damage/leakage?

SAP (ALP), GGT

What are the two Chem. markers that measure the biliary tract and cholestasis?

Hepatocytes (fairly specific for liver cell injury)

WHERE is ALT normally found?

Extent of hepatic injury

The magnitude of ALT elevation on chem. tells you extent of hepatic injury OR prognosis/reversibility?

Cats

note: this is because it is also found in muscle especially in the dog, making it less specific than ALT

AST is more reliable predictor of hepatocellular damage in dogs or cats?

Steroids/phenobarb, bone (esp. puppies), and liver

ALP has isoenzymes where, especially for dogs?

Cats

note: meaning any elevation of ALP at ALL is significant, and this is not the same for dogs

Which animal has smaller stores and shorter half lives of ALP, cats or dogs?

GGT

What is the best specific enzyme for cholestasis in dogs and cats?

Liver function synthetic parameters

note: when bilirubin is elevated, it will elevate in bloodstream before you see it in mucous membranes, and there are 3 differentials: prehepatic hemolytic anemia, intrahepatic functional problems, or posthepatic

Bilirubin is used as a marker for WHAT?

Glucose, cholesterol, albumin, BUN

note: this is because the liver has a large role in making these

What are the 4 tests that ESTIMATE hepatic function?

Cats

Which animals have Heinz bodies (oxidized, denatured hemoglobin) with liver disease (hepatic lipidosis)?

Oxidative stress events: unregulated diabetes, unregulated hyperthyroidism, lymphoma

Besides hepatic lipidosis, what would be some differentials for a cat with heinz bodies?

CATS

Bilirubinuria is ALWAYS abnormal in which animal, even if it is trace amounts?

Serum bile acids, ammonia

What are more sensitive ways to assess liver function?

From cholesterol in liver

Where are bile acids made?

Bile acids will be increased

note: bile acids are made from cholesterol in the liver. So, if the liver is not working properly (cholestasis), they cannot be excreted into the intestines and will instead back up into liver cells and the blood stream

If the liver is not functioning, what will this do to bile acids?

Collect pre fasted bile acids, Fast patient, give small amount of food with fat, 2 hrs later collect post sample

How do you do a bile acid stimulation test?

Urine bile acids

What reflects the average blood level of serum bile acids during the interval of the urine formation?

Hepatobiliary disease/PSS

Urine bile acids tend to elevate well with hepatobiliary disease/PSS OR hepatic neoplasia?

Proteins in amino acids

Where do you mainly get ammonia naturally produced in your body?

Urea

What does the liver turn ammonia to to make it safer?

Ionized

When ammonia is ionized or nonionized, it becomes trapped in the gut and cannot reenter enterohepatic circulation, so it must be pooped out, called "ammonia trapping", good for treating hepatic encephalopathy

Ammonia

What is the biggest thing during liver disease that can cause hepatic encephalopathy

Bile acids (more stable)

Which is tested more often for liver disease, bile acids or ammonia testing?

Buccal mucosal bleeding test, thrombocytopenia and platelet function testing, PT, and APTT

You need to be careful with liver disease because it is so important for normal hemostasis. What coagulation tests can you do to see how these pathways are functioning?

PT

Which coagulation test looks at the extrinsic pathway of coagulation (very importantly, factor VII)?

APTT

Which coagulation test looks at intrinsic pathway of coagulation?

70-80% = NONSENSITIVE MARKER

How many clotting factors need to be nonfunctional for the PT/APTT to go up in liver disease?

Buccal mucosal bleeding

What is the only cage side test available to practitioners as a coagulation test?

Caudal shift

What will happen to the gastric axis with hepatomegaly?

Cranial shift

What will happen to the gastric axis with microhepatica?

Structure

Ultrasound looks at structure or function

Portosystemic shunts and 3D rendering

What hepatic abnormality is computed tomography best at imaging?

Scintigraphy

What imaging technique utilizes uptake of Technetium 99m and radioactive isotopes taken up by the tissue?

Post

When testing bile acids, should post or pre be higher?

Bile acids

Which test relies on intact enterohepatic circulation, ammonia or bile acids?

Cholestatic

(because a lot of factors are made by vitamin K, and if there is a decreased flow of bile, the coag. factors may not work)

With which type of liver disease should you be MOST worried about your coag. factors not working?

1. explain hepatomegaly

2. stage neoplasia

3. assess response to treatment

4. evaluate progression of disease

5. explain abnormal test results

6. determine hepatic involvement in systemic disease

Why do you want to do a cytology/biopsy of the liver?

Cytology (FNA)

Which sampling of the liver is minimally invasive and better for cells that suck up into your needle and exfoliate, where you don't need to look at tissue architecture

For neoplasia

Where is Tru-Cut biopsies best, what is it best to look at?

Abnormal = vessels are MASSIVE and congested

What is going on here? Is this normal or abnormal?

Abnormal = mucocele in the gallbladder

What is going on here? Is this normal or abnormal?

Abnormal = Hyperechoic areas are lipoma lesions in the liver

What is going on here? Is this normal or abnormal?

This is normal liver listed at 1, abnormal ascites going on at 2

What is going on here? Is this normal or abnormal?

Abnormal = small irregularly marginated liver at L and ascites at A = chronic hepatitis and scar tissue present

What is going on here? Is this normal or abnormal?

CT

What form of imaging is this?

Nuclear scintigraphy

What form of imaging is this?