Labs of gastroenterology-schoenwald-exam 3 Flashcards
Anion gap Calculation=
Sodium- (Cl- and CO2)=
GI labs included in the CMP:
- protein
- Albumin
- A/G ratio= albumin/globulin
- Bilirubin
- Alk phos
- AST
- ALT
- GFR
Liver contains ______
hepatocytes
List the 5 functions of the liver
liver is complex!
- Produces bilirubin
- Amino acid and carbohydrate metabolism
- Produces coagulation factors (Vit K dependent) and albumin
- Lipid metabolism
- cholesterol production
- Metabolizes most drugs and hormones
LFT= (what does this include)
=liver function tests Includes: -albumin -prealbumin -prothrombin
(if these are all normal the liver is fine)
ALbumin= normal range?
3.5-5 g/dl
albumin- main fx?
to maintain plasma oncotic pressure
albumin: other functions?
-Main carrier of hormones, drugs, anions and fatty acids-”carrier protein”
- Indicates liver function
- with severe damage, albumin decreases (ex cirrhosis)
Low concentrations of albumin in the setting of liver disease=
poor prognosis
Nonhepatic causes of hypoablbuminemia (list ex’s)
-Malnutrition
-Malabsorption
-Protein loss from kidney or gut
-Increased volume of distribution (ascites or overhydration)
-Pregnancy
-Burns
Trauma
Alcohol use
Hypoalbumin is not associated with Sx until _______
extremely low
Sx associated with low albumin levels
peripheral edema, ascites or pulmonary edema
Remember*** albumin maintains ______ ______, if low, fluid leaks form intravascular space into interstitial spaces of tissue or into body cavities
oncotic pressure**
Low levels of albumin effect interpretation of _____ levels
Calcium levels
(most Ca 2+ is bound to albumin) ionized Ca 2+ is NOT bound to albumin
Prealbumin:
- normal range?
- similar to?
16-40 mg/dl
-Similar to albumin- in that it’s synthesized by liver
Prealbumin: has a _____ body pool than albumin
Smaller body pool than albumin AND more sensitive to protein intake (dietary) than albumin
T/F: prealbumin is not affected by hydration state
true
T/F: prealbumin is a good tool to assess nutritional status
true
Total protein= albumin + _____
globulin
Globulin=
== total immunoglobulins in serum
- *Not synthesized by liver
- *Usually calculated, not measured
Normal Range of total protein=
5.5-8.3 g/dl
TP (total protein) is _____ value in assessing liver disease if albumin is known
little value
albumin is MUCh more important
TP is useful in assessing..
immune or hematologic dysfunction
Prothrombin Time (PT):
- Prothrombin is produced by the ____
- normal range=
- liver
- 10-13 seconds, INR 1-2
Prothrombin Time (PT) measures..
extrinsic coagulation pathway
PT measures the Vitamin K clotting factors which are..
2, 7, 9 , and 10
Coagulation Factors in the extrinsic pathway
II,V,VII, and X
PT is used to monitor _____ therapy ?
Coumadin therapy
In liver disease, what can happen to the PT?
Prolonged PT in liver disease (substantial, >80% loss of function) but is not specific
Other causes of prolonged PT:
- Vit K deficiency
- Clotting factor deficiency
- Autoimmune diseases-lupus
Activated partial thromboplastin time (aPTT):
- how long?
- Measures the ______ pathway
- factors?
-Normal varies (30-40-seconds)
-Measures intrinsic pathway
-Factors II,V,VIII,IX,X,XI (2,5,8,9,10,11)
-Used for monitoring heparin therapy
NOT dependent on liver function
Activated partial thromboplastin time (aPTT): is used for monitoring ______ therapy
heparin!
-aPTT is NOT dependent on liver function *
You can use PT and /or ____ to monitor liver disease
INR
Liver enzymes: (list 5)
- Alkaline Phosphatase (ALP)
- Gamma glutamyl transpeptidase (GGT)
- Aspartate aminotransferase (AST)
- Alanine aminotransferase (ALT)
- Lactate dehydrogenase (LDH)
Alkaline Phosphatase=
- normal?
- Exact function?
- where is it found?
- Normal varies
- Exact function unknown
- Found in liver, bone, placenta, small intestine, kidneys and leukocytes
Alk phosphatase MC comes from from?
liver and bone
Alkaline Phosphatase: elevations ____x normal are suggestive of cholestasis
4x normal
Cholestasis=
obstruction of large bile duct
GGT(Gamma glutamyl transpeptidase (GGT):
- normal range?
- Can be helpful in assessing?
- Normal range varies
- Can be helpful in assessing if increased ALP due to hepatic source (increased ALP with normal GGT most likely nonhepatic)
GGT is elevated in ____ ____ Pts
alcohol abuse
Abstinence from alcohol, often decreases GGT by ___% in 2 weeks
50%
AST/ALT:
-assess?
-cellular damage
AST/ALT is released into serum due to ____
leaky cell or necrosis of cell
Higher concentrations of AST/ALT do not necessarily correlate with ..
poorer prognosis
AST elevations WITHOUT ALT elevations suggests _____ source
cardiac
AST is generally _____ than ALT in alcohol abuse
- HIGHER
- *AST/ALT ratio >1 in alcoholic liver disease
AST/ALT ratio <1 in _____ Pts
hepatitis
Lactate dehydrogenase (LDH)
- found in?
- elevations occur in?
- Nonspecific- found in heart, liver, blood, brain, skeletal mm, lung
- **Elevations occur in liver disease
Bilirubin:
- total bilirubin normally is _____
- = the sum of ?
-0.3-1 mg/dl
=Sum of conjugated and unconjugated bili
Bilirubin elevations can be due to ..
obstruction vs liver damage
____ is hallmark sign of elevated bilirubin
**JAUNDICE
Gilbert’s syndrome=
=benign trait with intermittent elevations in unconjugated(non hepatic source) bilirubin
Ammonia:
- normal range?
- majority originates from?
- Normal 30-70ug/dl
- from intestinal bacterial catabolism
Ammonia is absorbed and processed by ____
liver
If the liver is damaged, ammonia levels will be _____
increased
Elevations in ammonia result in _______ _______
**hepatic encephalopathy-altered mental status
Hepatitis serologies:
- which ones are fecal to oral spread?
- which ones are blood borne?
- Serologies for Hep A,B,C,D and E
- -Hepatitis A and E fecal to oral spread
- -Hepatitis B, C and D blood borne
Alpha fetoprotein:
- normal range?
- marker for?
- 10-20 ng/ml
- Tumor marker for hepatocellular carcinoma (HCC)
Alpha fetoprotein is elevated in ____% of HCC cases
70-80%
Pancreas:
- exocrine fx?
- endocrine fx?
Exocrine(secrete into ducts) and endocrine(secrete into circulation) functions
Pancreas:
exocrine enzymes? (list)
trypsin, chymotrypsin, amylase and lipase-digestive enzymes
Pancreas:
-endocrine enzymes? (list)
hormones insulin and glucagon
Pancreatitis=
inflammation of the pancreas
Pancreatitis:
-assessed by measuring?
amylase and lipase
Pancreatitis: sx?
-what are the main causes? (2)
sx: Nausea, vomiting, severe abdominal pain with radiation to the back
- Alcohol abuse and gallstones =main causes
Amylase:
- normal range?
- fx?
- 44-128 IU/L
- Breaks starch into individual glucose molecules
Amylase is secreted by pancreas and _____
salivary glands
Amylase concentrations rise within ____hrs of onset of acute pancreatitis and peak at ______hrs
- 2-6 hrs
- peak @ 20-30 hrs
Lipase:
- normal range?
- aids in _____
Normal <1.5 U/ml
–Aids in fat digestion
T/F: Lipase declines faster than amylase
FALSE! Lipase declines slower than amylase
Carcinoembryonic Antigen (CEA)=
- marker for?
- used for monitoring progress of _____
=Tumor marker for colorectal carcinomas
–Used for monitoring progress of treatment, NOT diagnosis**