Liver Function Tests Lecture Powerpoint

Question 1

No liver # on an LFT is a true reflection of…

Answer 1

….liver function

Question 2

Liver enzyme panel components and normal ranges (5)

Answer 2

• albumin NL 3.5
• AST/ALT NL 50 (measure of hepatocellular injuries, ALT correlates with abdominal adipose and is more specific to liver injury or death, AST correlates with skeletal muscle injury)
• Alk phos NL 120 (liver and bones)
• total bilirubin NL 1.8
• direct bilirubin NL 1.0

Question 3

ALT/AST measures

Answer 3

Slight elevations indicate low grade inflammation, high elevations indicate acute liver injury/necrosis, but normal does not mean no inflammation

Question 4

Alkaline phosphatase measures

Answer 4

Indicator of bile duct inflammation (obstruction, autoimmune, infection, etc.), can be elevated secondarily in pregnancy

Question 5

Bilirubin/alk phos measures

Answer 5

Prehpatic jaundice is due to elevated unconjugated bilirubin, hepatic is both conjugaed and unconjugated elevated, post hepatic is elevated conjugated bilirubin in serum

Question 6

Albumin measures

Answer 6

Non specific, somewhat related to liver function but also related to nutritional status, can lead astray (usually suggests chronic disease such as cancer or cirrhosis)

Question 7

ALT/AST elevated out of proportion to alk phos think ___, vise versa think ___

Answer 7

liver inflammation, obstruction (cholestatic pattern)

Question 8

Isolated hyperbilirubinemia should indicate the first test to order to be…

Answer 8

….fractionate it to determine amount of conjugated vs unconjugated

Question 9

Isolated hyperbilirubinemia primarily conjugated think ____ or ____. Unconjugated think ____ or ____

Answer 9

Dubin Johnson, Rotor syndrome

Gilbert’s syndrome, Crigler Najjar syndrome

Question 10

Most important test to evaluate liver function

Answer 10

INR (coumadin will mess it up) (INR that does not correct with parenteral vit K is suspicious for severe hepatocellular injury)

Question 11

____ may be the first sign of liver disease even years before liver disease is diagnosed

Answer 11

Low platelet count

Question 12

Extraneous labs to order in initial lab eval (acute) of liver patient (3)

Answer 12

• tox screen
• tylenol level
• acute viral hep panel

Question 13

Acute liver failure definition

Answer 13

Acute hepatocellular injury, hepatic encephalopathy (confusion), and prolonged PT (elevated INR), LFT’s typically >10x upper limits of normal, may need transplant if INR continues to rise

Question 14

Most common cause of drug induced liver injury + 2 others

Answer 14

• Acetaminophen (hepatocellular pattern)
• augmentin (cholestatic pattern)
• ionazid

Question 15

Initial first line study for suspected liver disease

Answer 15

Right upper quadrant ultrasound (can do with doppler)

Question 16

CT of liver/biliary tract

Answer 16

2nd line study behind ultrasound to assess liver damage, more expensive, limited due to contrast requires kidney functioning, but not limited by obesity, ascites, or overlying bowel gas

Question 17

MRI of liver/biliary tract

Answer 17

Useful for noninvasively visualizing hepatobiliary tree without having to use endoscopy, but very dependent on patient compliance

Question 18

Liver biopsy

Answer 18

Either ultrasound or CT guided most often percutaneous, indicated in diagnosis, staging, prognosis, and treatment options of liver dz, risks include pain (most common), bleeding, infection

Question 19

Transjugular liver biopsy

Answer 19

Access to the liverr thru the superior vena cava and the hepatic vein, does not traverse liver capsule so limits risk of intraperitoneal hemorrhage but allows for measurement of hepatic venous pressure gradient at same time (check for portal hypertension)

Question 20

General liver disease advice (5)

Answer 20

• no alcohol
• vaccinate hepA/B
• limit acetaminophen no more than 2 grams a day
• avoid raw seafood
• control weight, cholesterol, diabetes