Labs of GI - Schoenwald Exam 3 Flashcards
What are the Vitamin K dependent coagulation factors? Where are they produced?
Factors II, VII, IX, and X. Produced in the liver
What is measured on a standard liver function test (LFT)? (3 things produced by the liver)
- Albumin
- Prealbumin
- Prothrombin
What is the normal range for albumin?
3.5 - 5 g/dl
What is the main function of albumin?
Maintains plasma oncotic pressure. Main carrier of hormones, drugs, anions and fatty acids. “Carrier protein”
A patient with severe damage to the liver (such as in cirrhosis) would have an (increased/decreased) albumin level
Decreased albumin
What are some non-hepatic causes of hypoalbuminemia?
- malnutrition
- malabsorption
- protein loss from kidney or gut
- increased volume of distribution (ascites or overhydration)
- pregnancy
- burns
- trauma
- alcohol use
A patient’s labs come back with mildly decreased albumin levels. Would you expect them to be symptomatic? What kind of symptoms can you expect from hypoalbuminemia?
No symptoms until albumin levels are very low.
Symptoms you may see with significantly low albumin levels: peripheral edema, ascites, pulmonary edema
*remember albumin maintains oncotic pressure. If low, fluid leaks into interstitial spaces
What other lab value on a CMP may be affected with low albumin levels?
Calcium levels
*you need to correct for low albumin to get an accurate calcium level (unless it is an ionized calcium lab)
What is the normal range for prealbumin?
Prealbumin: 16-40 mg/dl
(really hoping we don’t actually have to memorize these, but just in case!)
Which hepatic protein is more sensitive to dietary protein intake, albumin or prealbumin? Is it affected by hydration state, too?
Prealbumin is more sensitive to dietary protein intake. It is not affected by hydration status.
*not used by nutritionists much anymore, but can be useful in a patient who was found down and unable to give a good history. (low prealbumin = they haven’t eaten in a while)
Which of these is not synthesized by the liver?
A) prealbumin
B) prothrombin
C) globulin
D) albumin
C) globulin
How do you calculate globulin levels?
Total protein - albumin = globulin
(Globulin levels are not given on a CMP. TP and albumin are)
What is globulin a measure of?
Total immunoglobulins in serum (antibodies)
What is the total protein level useful in assessing for? What is a normal range for TP?
Immune or hematological dysfunction. TP is of little value in assessing liver disease (if the albumin is known)
nl range: 5.5-8.3 g/dl (again hopefully we don’t need to memorize these, but just in case)
What are the normal ranges for prothrombin time and INR?
Prothrombin time: 10-13 seconds
INR 1-2
Prothrombin time measures the (extrinsic/intrinsic) coagulation pathway. Which clotting factors?
Extrinsic
Factors II, V, VII, and X
Would you expect to see a prolonged or shortened prothrombin time in a patient with liver disease?
Prolonged
-other causes of prolonged PT: Coumadin therapy, Vit K deficiency, clotting factor deficiency, and autoimmine diseases (lupus)
Activated partial thromboplastin time (aPTT) is (longer/shorter) than PTT and measures the (extrinsic/intrinsic) clotting pathway. What clotting factors are measured?
Activated partial thromboplastin time (aPTT) is longer (30-40sec) than PTT and measures the intrinsic clotting pathway.
Factors II, V, VII, IX, X, and XI
True or False:
aPTT is not dependent on liver function
True
_______ is useful in monitoring heparin therapy, while ______ is used to monitor coumadin therapy.
aPTT is useful in monitoring heparin therapy, while PT is used to monitor coumadin therapy.
Which liver enzyme when elevated over 4x its normal range is suggestive of cholestasis?
Alkaline phosphatase (ALP)
From what two organs does most alkaline phosphatase come from? Where else can ALP come from?
Liver and bone (elevated in Paget’s disease, ‘member?)
Can also come from placenta, small intestine, kidneys, and leukocytes
When would you order a GGT lab?
To monitor for alcohol abuse (used with an alcohol abstinence plan to monitor for adherence) GGT decreases by ~50% in 2 weeks with abstinence
A patient’s labs come back with elevated ALP and elevated GGT. Is this likely a hepatic or nonhepatic issue?
Hepatic
An elevated ALP with normal GGT would likely indicate nonhepatic issue
What are AST and ALT used to assess?
Assess for cellular damage. AST/ALT released into serum due to leaky or necrotic hepatocytes
An elevated AST without ALT elevation suggests a _____ source.
An elevated AST without ALT elevation suggests a cardiac source.
A patient’s AST/ALT labs are as follows. Is this more likely an alcoholic liver disease or viral hepatitis?
AST: 700
ALT: 720
Viral Hepatitis
AST/ALT ratio <1
A patient’s AST/ALT labs are as follows. Is this more likely an alcoholic liver disease or viral hepatitis?
AST: 300
ALT: 100
Alcoholic liver disease
AST/ALT ratio >1
LDH is typically elevated in liver disease. Is LDH specific for liver disease or is it found in other organs?
LDH: nonspecific. Also found in heart, liver, blood, brain, skeletal mm, and lungs
What is the normal total bilirubin range?
Total bili: 0.3-1 mg/dl
What is the hallmark sign of elevated bilirubin?
Jaundice
Gilbert’s syndrome is a benign trait that shows intermittent elevations of what lab value that’s typically relevant to liver function?
unconjugated bilirubin (nonhepatic source)
*don’t forget to pronounce Gilbert like the name of a fancy French restaurant and not like your uncle from Texas
Hepatic encephalopathy is caused by elevated ______ levels.
Hepatic encephalopathy is caused by elevated ammonia levels.
Where does the majority of ammonia originate from?
Intestinal bacteria catabolism
Normal ammonia range:
Ammonia: 30-70 ug/dl
What tumor marker is elevated in 70-80% of hepatocellular carcinoma patients?
alpha fetoprotein (normal 10-20 ng/ml)
What are the exocrine and endocrine enzymes of the pancreas?
Exocrine: Trypsin, chymotrypsin, amylase, and lipase
Endocrine: insulin and glucagon
Which enzymes are most useful in assessing for pancreatitis?
Amylase and lipase
Pancreatic enzymes: _______ breaks down starch and _____ aids in fat digestion
Pancreatic enzymes: amylase breaks down starch and lipase aids in fat digestion
Which pancreatic enzyme rises faster upon onset of acute pacreatitis: Lipase or Amylase? When does it peak?
Amylase: rises within 2-6 hrs of onset, peaks at 20-30 hrs
Lipase rises and declines slower
What is the tumor marker measured to monitor treatment of colorectal carcinoma and pacreatic cancer?
Carcinoembryonic antigen (CEA)
used to monitor progress of treatment, not diagnosis
