Pancreatic function Flashcards
List endocrine tests
- Gastrin
- Insulin
- Glucose
List exocrine pancreatic function tests
Amylase and lipase
List indirect tests
- Qualitative fecal fat analysis
- Fecal elastase
- Fecal chymotrypsin
- Bilirubin
Which pancreatic function test is the most sensitive, uses actual pancreatic secretions, endoscopy/Dreiling tube method after stimulation with secretin and/or cholecystokinin (CCK)?
Direct
CCK
- Hormone secreted by intestinal mucosal cells
- Causes acinar cells to secrete enzymes and bile
CCK test measures
- pH
- Secretory rate
- Enzyme activity
- Bicarb
How does pancreatic obstruction affect pancreatic flow and enzymes?
- Decreased pancreatic flow
- Increased enzymes
Which diseases show reduced bicarb and enzymes
- CF
- Chronic pancreatitis
- Pancreatic cysts
- Calcification
- Edema of pancreas
4 sources of fecal lipids
- Unabsorbed ingested lipids
- Lipids excrete into intestine
- Cells shed into the intestine
- Metabolism of intestinal bacteria
Normal fecal lipid composition
- 60% fatty acids
- 30% sterols, higher alcohols, and carotenoids
- 10% triglycerides
- small amounts of cholesterol and phospholipids
Increased fecal fat can be caused by
Biliary obstruction
Severe steatorrhea associated with
Exocrine pancreatic insufficiency or disease of small intestine
Fecal fat qualitative screening test uses which fat soluble stains?
- Sudan III
- Sudan IV
- Oil Red O
- Nile blue sulfate
Is technical skill important in Fecal fat qualitative screening test?
Yes
How do fat soluble stains work?
Dissolve in and color lipid droplets
Sudan staining colors which fats? Which colors?
- Neutral fats (triglycerides) and other lipids
- Yellow-orange to red with Sudan III
Which type of fat stain requires heating?
Sudan
Steatorrhea features how many lipid droplets?
> 100 small/large may be present
Definitive test for steatorrhea
Quantitative fecal fat analysis
How many hr stool specimen for Quantitative fecal fat analysis?
72 hr
Diet for Quantitative fecal fat analysis
Lipid-rich diet for at least 2 days
Quantitative fecal fat analysis measures which fats?
Only saponifiable fatty acids
Gravimetric method for fecal fat determination
- Emulsify entire fecal sample in water
- Fatty acid soaps (Ca and Mg salts of fatty acids) are converted to free fatty acids
- Extract lipids into organic solvent
How much exocrine pancreatic function is lost before a 72 hr fecal fat test becomes positive?
90%
Fecal elastase-1 is what type of indicator?
Non-invasive indirect indicator of moderate and severe exocrine pancreatic dysfunction (secreted by pancreas)
Fecal elastase-1 is similar to which proteolytic enzyme?
Chymotrypsin
Fecal fat and fecal enzyme levels in exocrine pancreatic insufficiency
- Fecal fat increased
- Fecal enzymes decreased
Fecal chymotrypsin sensitivity/specificity and what affects it
- Less sensitive and less specific
- Can be affected by supplements
Patients with which disease have reduced ability to reabsorb Cl- from sweat and why?
Cystic fibrosis because chloride transporter (CFTR gene product) not functioning
Sweat chloride testing level of difficulty to perform
High difficulty
How to diagnose CF in kids
2-5x increase in sweat Na and Cl
Can sweat chloride testing differ btwn heterozygous and homozygous carriers?
NO
Almost exclusively pancreatic test that is more sensitive, specific, and accurate
Lipase