Labs of Gastroenterology (Schoenwald) Flashcards
What labs are liver tests on a CMP?
Protein, total, serum Albumin, serum Globulin, total A/G ratio Bilirubin, total Alkaline phosphatase, serum AST (SGOT) ALT (SGPT)
What are the functional cells in the liver called?
Hepatocytes
What are the functions of the liver?
Produces bilirubin
Amino acid and carbohydrate metabolism
Produces coagulation factors (Vit K dependent) and albumin
Lipid metabolism- cholesterol production
Metabolizes must drugs and hormones
Liver enzymes show…
Inflammation in the liver
What are the liver function tests?
Albumin
Prealbumin
Prothrombin
What is the normal range for albumin?
3.5-5 g/dl
What is the main function of albumin?
Maintain plasma oncotic pressure (holds fluid where it is supposed to be)
Why is albumin called a “carrier protein”?
Because albumin is the main carrier of hormones, drugs, anions, and fatty acids
How does albumin indicate liver function?
With severe damage, such as in cirrhosis, albumin will decrease
Low albumin causes…
Third spacing, fluid leaking into the interstitium (edema)
Low concentration of albumin in the setting of liver disease indicates
Poor prognosis
What are some non hepatic causes of hypoalbuminemia?
Malnutrition Malabsorption Protein loss from kidney or gut Increased volume of distribution (ascites or over hydration) Pregnancy Burns Trauma Alcohol use
Albumin has to be ______ to be associated with symptoms
Extremely low
What are the symptoms of low albumin?
Peripheral edema, ascites, or pulmonary edema (third spacing)
How does low albumin cause edema?
Albumin maintains oncotic pressure, if low, fluid leaks from intravascular space into interstitial spaces of tissue or into body cavities
What other value do low levels of albumin affect?
Interpretation of calcium levels- calcium could come up as low but once corrected for low albumin levels, really is not low
What is the normal range for prealbumin?
16-40 mg/dl
Prealbumin has a smaller/larger body pool compared to albumin
Smaller
Is prealbumin more sensitive to dietary protein intake than albumin?
Yes, prealbumin is more sensitive to dietary protein intake than albumin is
Is prealbumin affected by hydration state as albumin is?
No, prealbumin is not affected by hydration state as albumin is
Prealbumin is a good tool to assess _______ status
Nutritional
Total protein measures. _____ + _______
Albumin + globulin
What is globulin?
Total immunoglobulins in serum
NOT synthesized by the liver
Usually calculated, not measured
What is the normal range of total protein?
5.5-8.3 g/dl
Since total protein is of little value in assessing liver disease if albumin is known , what is total protein useful for?
Total protein is useful in assessing immune or hematologic dysfunction
What is prothrombin produced by?
The liver
What is the normal range of prothrombin time? (PT)
Normal range is 10-13 seconds, INR 1-2
What does prothrombin time measure?
Extrinsic coagulation pathway
Factors II, V, VII, X
What are the vitamin K dependent factors?
II, VII, IX, X
Coumadin therapy can be monitored by which lab value?
Prothrombin Time (PT)
There will be a ______ PT in liver disease
Prolonged PT
If it is substantial, this indicates >80% loss of liver function
Other than liver disease, what causes a prolonged PT?
Vitamin K deficiency.
Clotting factor deficiency
Autoimmune disease such as lupus
What is the normal value for aPTT (activated partial thromboplastin time)?
Normal varies between 30-40 seconds
What does aPTT measure?
Measures the intrinsic pathway-
Factors II, V, VIII, IX, X, XI
What lab value is used for monitoring heparin therapy?
APTT
Is aPTT dependent on liver function?
No, but PT is :)
What are the five liver enzymes?
Alkaline phosphatase (ALP) Gamma glutamyl transpeptidase (GGT) Aspartame aminotransferase (AST) Alanine aminotransferase (ALT) Lactate dehydrogenase (LDH)
What is the normal range of ALP?
The normal range varies, is depends on what methodology that the lab uses
What is the exact function of ALP?
Exact function is unknown
Where is ALP found?
In the liver, bone, placenta, small intestine, kidneys, and leukocytes
What are some conditions that ALP is elevated in?
Pregnancy Bone Mets (cancer)
Where does most of the ALP come from?
The liver and the bone
What do elevations of >4 times the normal of ALP suggest?
Cholestasis- obstruction of the large bile duct
What is the normal range of GGT?
The normal range of GGT varies
What can GGT be helpful in assessing?
If an increased ALP is from a hepatic source
Increased ALP, normal GGT= most like non hepatic
What level can you check to see if a patient is being compliant with not drinking?
GGT- elevated in alcohol abuse
With abstinence from alcohol, GGT can decrease by ___% in 2 weeks
50%
AST/ALT is used to assess….
Cellular damage
What causes ALT/AST to be released into the serum?
Released due to a leaky cell or necrosis of a cell
Do higher concentrations of ALT/AST correlate with poorer prognosis?
No
AST elevations without ALT elevations suggest a ____ source
Cardiac
This measure has been replaced by troponin
AST is usually higher/lower than ALT in alcohol abuse
Higher
AST/ALT ratio in alcoholic liver disease
Ratio >1
AST/ALT ratio in hepatitis
Ratio <1
LDH is specific/nonspecific
Nonspecific- found in the heart, liver, blood, brain, skeletal muscle, lung
LDH increases/decreases in liver disease
Increases, but not only in liver disease
What is the normal range of total bilirubin?
0.3-1 mg/dl
Total bilirubin is the sum of ____ and _____
Conjugated and unconjugated bilirubin
Elevations of bilirubin can be due to…
Obstructions vs liver damage
What is the hallmark sign of elevated bilirubin?
Jaundice
What syndrome is classified as a benign trait with intermittent elevations in unconjugated (non hepatic sources) of bilirubin?
Gilbert’s syndrome, causes mild elevations in total bilirubin
What is the normal range of ammonia?
30-70 ug/dl
What does the majority of ammonia originate from?
Intestinal bacterial catabolism
Ammonia is absorbed and processed by the….
Liver
If the liver is damaged, ammonia is decreased/increased?
Increased
Elevations of what level result in hepatic encephalopathy and therefore altered mental status?
Elevations in ammonia
What are the serologies for hepatitis?
Hep A, B, C, D, E
What strains of hepatitis are fecal to oral spread?
A, E fecal to oral spread
What strains of hepatitis are blood borne?
B C D
What is the normal range for Alpha fetoprotein?
10-20 ng/ml
What does alpha fetoprotein indicate?
Tumor marker for hepatocellular carcinoma (HCC)
Alpha fetoprotein is elevated in ____% of HCC cases
70-80%
What organ is both an exocrine and endocrine gland?
The pancreas
What does exocrine secrete into?
Ducts
What does endocrine secrete into?
Circulation
What are the exocrine enzymes of the pancreas?
Trypsin
Chymotrypsin
Amylase
Lipase
Amylase and lipase are _____ enzymes
Digestive enzymes
What are the endocrine hormones of the pancreas
Insulin and glucagon (glucose metabolism)
What is pancreatitis?
Inflammation of the pancreas
How is pancreatitis measured?
By measuring amylase and Lipase
What are the clinical sxs of pancreatitis?
Nausea, vomiting, severe abdominal pain with radiation to the back
What are the main causes of pancreatitis?
Alcohol abuse and gallstones
What are the normal levels of amylase?
44-128 IU/L
What is the function of amylase?
Breaks starch into individual glucose molecules
What is amylase secreted by?
Pancreas and salivary glands
Concentrations of amylase rise within ___ hours of onset of acute pancreatitis and peak at ____ hours
2-6
20-30
What is the normal range for lipase?
<1.5 U/ml
What enzyme aids in the digestion of fats?
Lipase
Lipase declines slower/faster than amylase
Slower
What is carcinoembryonic Antigen (CEA) a tumor marker for?
Colorectal carcinomas
What is CEA used for?
Monitoring progress of treatment of colorectal carcinoma not diagnosis
