Liver Enzyme Elevation Flashcards
T/F: it is common to incidentally find liver enzyme elevation during pre-anesthetic bloodwork or routine health screening
true
What are the 2 ways to categorize liver enzyme elevation?
- hepatocellular injury (ALT and AST)
- Cholestasis/enzyme induction (ALP and GGT)
What are the 6 indicators of impaired liver function?
- bilirubin increased
- albumin decreased
- glucose decreased
- cholesterol variable
- BUN decreased
- clotting factors prolonged
The half life of ALT is very short (~2.5 days). How can we use this information to determine if true, continued hepatocellular injury is occurring?
Persistent increases in ALT
T/F: the magnitude of ALT or AST increase indicates the number of hepatocytes that are injured/affected.
true
Which surface enzymes can be induced with cholestasis (decreased bile flow)?
ALP
GGT
What are some sources of ALP elevation?
- liver
- corticosteroids (dogs, cushings)
- bone (young, growing dogs)
- phenobarbital
- hepatic lipidosis (cats)
what is the half life of ALP (short or long)?
70 hours (long) in dogs
6 hours in cats
if a patient has a low albumin, what do you need to rule out BEFORE attributing this to significant liver dysfuncton?
loss of albumin through kidneys or GI tract! (PLE, PLN)
T/F: glucose decreases when 25% of the liver function is lost
false – >75%
Besides chronic liver disease, what else liver-related can cause an elevated BUN?
portosystemic shunt (PSS)
what is the MOST sensitive liver function test in small animal?
bile acids
this is indicated in patients to screen for loss of hepatic function (>25-30) and/or PSS (>50)
what is a contraindication for performing a bile acids test?
hyperbilirubinemic or jaundiced patients.
T/F: the most common cause of abnormal liver enzymes is secondary to non-hepatic disease
true
this includes:
1. drugs (NSAIDs, acetaminophen, anticonvulsants, CBD antifungals, antibiotics-TMS, azathioprine, and methimazole)
2. toxins
3. endocrine disorders
4. dental disease
5. GI issues (IBD, pancreatitis)
6. metastatic neoplasia
7. nutritional abnormalities
8. cardiovascular disease (hypoxia, hypotension)
9. sepsis / infection
which 8 drugs can cause elevated liver enzymes?
NSAIDs, acetaminophen, anticonvulsants, CBD antifungals, antibiotics-TMS, azathioprine, and methimazole
what 4 endocrine diseases can cause elevated liver enzymes?
diabetes mellitus
hypothyroidism
hyperthyroidism
hyperadrenocorticism
there would be other symptoms present most likely: Pu/Pd, hyperactivity, weight loss, excess panting, hair loss, v/d, inappetance, cough/difficulty breathing
If you incidentally find elevated liver enzymes on routine blood work, but the patient does not have any clinical indication of liver disease or non-hepatic causes at that time, what is your plan?
recheck liver enzymes soon, do not start expensive or invasive testing prior to rechecking FIRST.
If you have a patient with elevated liver enzymes, what are specific indications to investigate further?
- ALT is greater than twice the normal for > 6-8 months
- unexplained liver enzymes elevation persisting over 6-8 weeks (esp. ALT)
- non-hepatic causes have been ruled out
What are the differentials for primary liver disease that causes liver enzyme elevation?
- idiopathic inflammatory hepatopathy (chronic hepatitis, cholangitis)
- copper-associated hepatopathy
- infectious hepatopathy (bacterial, lepto, viral)
- biliary tract disorders (choleliths, mucoceoles)
- hepatic vacuolar disorders
- benign hepatic nodular hyperplasia
- hepatic neoplasia
- portal vein hypoplasia
which breeds are more commonly associated with chronic idiopathic hepatitis?
- labs
- cocker spaniels
- dobermans
- west highland white terriers
which breeds are commonly assoc with copper-associated hepatitis?
- labs
- dalmations
- skye terries
- dobermans
- west highland white terriers
- bedlington terriers
what is your diagnostic plan in a patient that has persistent liver enzyme elevation?
- abdominal ultrasound (r/o inflammation, neoplasia, bile duct obstructions, mucoceles)
- +/- bile acids
- +/- FNA (focal lesions, lymphoma, mast cell tumors, hepatic lipidosis)
- biopsy (cu-hepatopathy, neoplasia)
What if an owner did not want to or was unable to pursue diagnostics to work-up liver enzyme elevation?
You can provide spectrum of care
- denamarin
- ursodiol
- vitamin E
- antibiotics - clavamox
what 3 therapies should you AVOID doing without getting a diagnosis in a case of liver enzyme elevation?
- penicillamine
- prednisone
- liver diet (protein-restricted)
what 2 things do you need to do prior to doing a liver biopsy?
BMBT
PT/PTT
what is the tx for copper hepatopathy?
D-penicillamine
liver diet with protein
prednisone
in what instance would you seriously recommend a liver biopsy?
if ALT continues increasing despite tx or if markers of liver function decrease
