Fecal Analysis Flashcards
(109 cards)
1
Q
a specimen that contains bacteria, cellulose, undigested foodstuffs, GI secretions, bile pigments, cells from the intestinal walls, electrolytes, and water
A
Fecal Specimen
2
Q
how much feal specimen is excreted in a 24-hour period
A
100 to 200 g
3
Q
resistant to digestion pass through the upper intestine unchanged but are metabolized by bacteria in the lower intestine, producing large amounts of flatus
A
Oligosaccharides
4
Q
site where digestion of ingested proteins, carbohydrates, and fats takes place
A
- Alimentary Tract
5
Q
primary site for the final breakdown and reabsorption of compounds
A
Small Intestine
6
Q
aid in the digestion of fats
A
Bile salts
7
Q
how much fluid is excreted in the feces
A
150 mL
8
Q
When the amount of water reaching the large intestine exceeds this amount, it is excreted with the solid fecal material, producing
A
diarrhea
9
Q
- provides time for additional water to be reabsorbed from the fecal material, producing small, hard stools
A
Constipation
10
Q
it is increase in daily stool weight above 200 g, increased liquidity of stools, and frequency of more than three times per day
A
Diarrhea
11
Q
diarrhea lasting less than 4 weeks
A
Acute Diarrhea
12
Q
diarrhea persisting for more than 4 weeks
A
Chronic Diarrhea
13
Q
major mechanisms of diarrhea
A
secretory, osmotic, and intestinal hypermotility
14
Q
laboratory test use to differentiate major mechanism of diarrhea
A
fecal electrolytes (fecal sodium, fecal potassium), fecal osmolality, and stool pH
15
Q
Normal Total Fecal Osmolarity
A
290 mOsm/kg
16
Q
Normal Fecal Sodium
A
30 mmol/L
17
Q
Normal Fecal Potassium
A
75 mmol/L
18
Q
formula on how to calculate fecal osmotic gap
A
osmotic gap = 290 - [2 (fecal Na + K)]
19
Q
A fecal fluid pH of less than 5.6 indicates a
A
malabsorption of sugars
20
Q
A fecal fluid pH of less than 5.6 indicates a malabsorption of sugars, causing an
A
osmotic diarrhea
21
Q
caused by increased secretion of water
A
Secretory Diarrhea
22
Q
what leads to secretory diarrhea
A
Bacterial, viral, and protozoan infections –> increased secretion of water and electrolytes –> override the reabsorptive ability of the large intestine –> leading to secretory diarrhea
23
Q
osmotic gap of osmotic diarrhea vs secretory diarrhea
A
osmotic diarrhea = greater than 50 mOsm/kg
secretory diarrhea = less than 50 mOsm/kg
24
Q
caused by poor absorption that exerts osmotic pressure across the intestinal mucosa – results in excessive watery stool
A
Osmotic diarrhea
25
impaired food digestion
Maldigestion
26
impaired nutrient absorption by the intestine
Malabsorption
27
it is when an unabsorbable solute increases the stool osmolality and the concentration of electrolytes is lower
Osmotic gap
28
when the specimen is stored for hours, there is markedly increased osmolality. why?
there is increased degradation of carbohydrates
29
describes conditions of enhanced motility (hypermotility) or slow motility (constipation)
Altered Motility
30
functional disorder in which the nerves and muscles of the bowel are extra sensitive, causing cramping, bloating, flatus, diarrhea, and constipation
Irritable Bowel Syndrome (IBS)
31
excessive movement of intestinal contents through the GI tract that can cause diarrhea
Intestinal hypermotility
32
describes hyper motility of the stomach and the shortened gastric emptying half-time, which causes the small intestine to fill too quickly with undigested food from the stomach
Rapid Gastric Emptying (RGE) dumping syndrome
33
hallmark of early dumping syndrome (EDS)
Rapid Gastric Emptying (RGE) dumping syndrome
34
gastric emptying time of Rapid Gastric Emptying (RGE) dumping syndrome
< 35 mins
35
Symptoms begin 10 to 30 minutes following meal ingestion
Early Dumping Syndrome (EDS)
36
occurs 2 to 3 hours after a meal and is characterized by weakness, sweating, and dizziness
Late Dumping Syndrome (LDS)
37
useful in diagnosing pancreatic insufficiency and small-bowel disorders that cause malabsorption
Steatorrhea (fecal fat)
38
when there Absence of bile salts that assist pancreatic lipase in the breakdown and subsequent reabsorption of dietary fat (primarily triglycerides)
Steatorrhea (fecal fat)
39
what decrease the production of pancreatic enzymes
cystic fibrosis, chronic pancreatitis, and carcinoma
40
a sugar that does not need to be digested but does need to be absorbed to be present in the urine
D-xylose
41
what happens if D-xylose is low
resulting steatorrhea indicates a malabsorption condition
42
what indicates a normal D-xylose test
pancreatitis
43
increase results seen in steatorrhea
1 to 8 µm is considered slightly increased, and 100 droplets measuring 6 to 75 µm
44
normal results in steatorrhea
100 small droplets, less than 4 µm in diameter, per high-power field
45
what specimen may signify a blockage of the bile duct
pale (acholic stools)
46
what specimen indicates intestinal oxidation of stercobilinogen to urobilin
Brown Feces
47
specimen color with - Upper GI
black, dark red, tarry stool
48
what produces the black, tarry stool
when there is degradation of hemoglobin during the time when - Blood that originates from the esophagus, stomach, or duodenum takes approximately 3 days to appear in the stool
49
stool color with lower GI
red stool
50
what makes the stool red
blood has less time to be reabsorbed
51
stool of patients taking oral antibiotics, because of the oxidation of fecal bilirubin to biliverdin
- Green stools
52
primary neutrophil that affect the intestinal mucosa
Leukocytes
53
stains use for fecal leukocytes
1. wet preparations stained with methylene blue
2. dried smears stained with Wright’s or Gram stain
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faster procedure for feal leukocytes but may be more difficult to interpret
- Methylene Blue
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provide permanent slides for evaluation
- Dried Preparations
56
finding of any neutrophils has ap proximately 70% sensitivity for the presence of invasive bacteria
oil immersion
57
detects fecal leukocytes and remains sensitive in refrigerated and frozen specimens
- Lactoferrin Latex Agglutination Test
58
what indicates an invasive bacterial pathogen
- presence of lactoferrin
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- frequently ordered in conjunction with microscopic examinations for fecal fats
- Pancreatic Insufficiency
60
what enhances the muscle fiber striations
- emulsifying a small amount of stool in 10% alcoholic eosin
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muscle striations in only one direction
- Partially Digested Fibers
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no visible striations of muscle fibers
Digested Fibers
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the only muscle fiber that are counted
undigested fibers
64
stains used for neutral fats (triglycerides), fatty acid salts (soaps), fatty acids, and cholesterol.
Sudan III, Sudan IV, or oil red O
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most frequently used stain in fecal fats
Sudan III
66
appearance of neutral fats when stained by Sudan III
Orange - red droplets
66
what does not directly stain with sudan III
- Soaps and fatty acids
67
- most frequently performed fecal analysis
Occult blood
67
necessary when there is no visible bleeding present despite the excess bleeding of 2.5mL/150g of stool
- fecal occult blood testing (FOBT)
68
- has a high positive predictive value for detecting colorectal cancer in the early stages
occult blood
68
- most frequently used screening test for occult blood
Guaiac-Based Fecal Occult Blood Tests
69
- reaction uses the pseudoperoxidase activity of hemoglobin reacting with hydrogen peroxide to oxidize a colorless compound to a colored compound
Guaiac-Based Fecal Occult Blood Tests
70
it is based on detecting the pseudoperoxidase activity of hemoglobin
Guaiac-Based Fecal Occult Blood Tests
71
- Prevent False-positive reaction
1. test sensitivity must be decreased, which can be accomplished by varying the amount and purity of the guaiac reagent used in the test
2. Obtaining samples from the center of the stool avoids false-positive reactions
3. specimens mailed to the laboratory should not be rehydrated before adding the hydrogen peroxide unless specifically instructed by the kit manufacturer
4. Specimens applied to the paper in the laboratory should be allowed to dry before testing.
5. specimens should be tested within 6 days of collection
6. Two samples from three different stools should be tested before a negative result is confirmed
71
what do you instuct to the patient instructTo prevent the presence of dietary pseudoperoxidases in the stool,
patients should be in structed to avoid eating red meats, horseradish, melons, raw broccoli, cauliflower, radishes, and turnips for 3 days before specimen collection.
72
during collection why do you advice patient to not take aspirin and NSAIDs 7 days before the collection
to prevent possible GI irritation
72
why vitamine C avoided 3 days before collection
- because ascorbic acid is a strong reducing agent that interferes with the peroxidase reaction, causing a false-negative result
73
true or false:
Failure to allow stool samples to soak into the filter paper slide for 3 to 5 minutes before adding developer may result in a false-negative result
true
74
- is specific for the globin portion of human hemoglobin and uses polyclonal anti-human hemoglobin antibodies
Immunochemical Fecal Occult Blood Test
75
a FOBT that is more sensitive to lower GI bleeding that could be an indicator of colon cancer or other GI disease and can be used for patients who are taking aspirin and other anti-inflammatory medications
Immunochemical Fecal Occult Blood Test
75
- offers a porphyrin-based FOBT fluorometric test for hemoglobin based on the conversion of heme to fluorescent porphyrins
- HemoQuant of Porphyrin-Based Fecal Occult Blood Test
75
- measures both intact hemoglobin and the hemoglobin that has been converted to porphyrins
HemoQuant (Porphyrin-Based Fecal Occult Blood Test)
76
- confirmatory test for steatorrhea
Quantitative Fecal Fat Testing
76
what makes HemoQuant (Porphyrin-Based Fecal Occult Blood Test) false - positive
non-human sources of blood (red meat) are present such as red meat
77
a Fecal fat test that - requires the collection of at least a 3-day specimen
Quantitative Fecal Fat Testing
- - The patient must maintain a regulated intake of fat (100 g/d) before and during the collection period.
78
- rapid (5 minutes) and safe procedure for analyzing quantitative fecal fat
- Hydrogen Nuclear Magnetic Resonance Spectroscopy (1H NMR)
78
method routinely used and is the gold standard for fecal fat
- Van de Kamer titration
79
what is the reference base of Hydrogen Nuclear Magnetic Resonance Spectroscopy (1H NMR)
100 g/d intake are 1 to 6 g/d or a coefficient of fat retention of at least 95%.
80
a rapid test to estimate the amount of fat excretion
- Acid Steatocrit
81
- distinguish between the presence of fetal blood or maternal blood in an infant’s stool and vomits
APT Test (Fetal Hemoglobin)
82
- distinguishes not only between HbA and HbF but also between maternal hemoglobins AS, CS, and SS
APT Test (Fetal Hemoglobin)
83
results of alkali-resistant fetal hemoglobin during APT test
solution remains pink (HbF) after standing for 2 minutes
84
is capable of gelatin hydrolysis but is most frequently measured by spectrophotometric methods
- Chymotrypsin
84
- denaturation of the maternal hemoglobin (HbA) during APT test
yellow-brown super natant after standing for 2 minutes
85
is more resistant to intestinal degradation and is a more sensitive indicator of less severe cases of pancreatic insufficiency
- Fecal chymotrypsin
85
what causes high concentration of HbF
the presence of maternal thalassemia major producing erroneous results
86
an isoenzyme of the enzyme elastase and is the enzyme form produced by the pancreas
- is pancreas specific and its concentration is about five times higher than in pancreatic juice
- Elastase I
87
Elastase I is measured by
ELISA kit
88
ELISA kit for Elastase I provides
provides a very sensitive indicator of exocrine pancreatic insufficiency
89
it causes osmotic diarrhea from the osmotic
pressure of the unabsorbed sugar in the intestine drawing in fluid
and electrolytes
Increase carbohydrates
90
- test is specific in differentiating pancreatic from nonpancreatic causes in patients with steatorrhea
Elastase I
91
a result of intestinal inability to
reabsorb carbohydrates, as is seen in celiac disease, or lack of
digestive enzymes
presence of carbohydrates in CSF
92
detects congenital disaccharidase deficiencies as well as
enzyme deficiencies due to nonspecific mucosal injury
Copper Reduction Test
92
normal stool pH
7 and 8
93
distinguish between diarrhea caused by abnormal
excretion of reducing sugars and those caused by various
viruses and parasites
Clinitest tablet
93
carbohydrate intolerance reference range
0.5 g/dL
94
most common test for malabsorption of carbohydrate
D-xylose
95
test for maldigestion of carbohydrate
lactose intolerance
96
