Flashcards in Physical Examination Deck (27)
A patient with uncontrolled diabetes mellitus will most likely have:
A. pale urine with a high specific gravity
B. concentrated urine with a high specific gravity
C. pale urine with a low specific gravity
D. dark urine with a high specific gravity
A- pale urine with a high specific gravity. The high specific gravity is due to the glucose in the urine. Diabetes mellitus have polyuria, so that the volume of the urine dilutes the urochrome (color), making the urine pale.
While performing an analysis of a baby's urine, the technologist notices the specimen has a "mousy" odor. Of the following substances that may be excreted in urine, the one that MOST characteristically produces this odor is:
A. phenylpyruvic acid
C. coliform bacilli
A- phenylpyruvic acid. Phenylketonuria is a genetic disorder that results in a urine with a "mousy" odor. Acetone has a fruity odor. Bacteria can produce an ammonia odor. Porphyrin has no odor, but a characteristic red color.
An ammonia-like odor is characteristically associated with urine from patients who:
A. are diabetic
B. have hepatitis
C. have an infection with Proteus sp
D. have a yeast infection
C- have an infection with Proteus sp. Ammonia is the byproduct of urea breakdown. Proteus is urease positive.
Urine that develops a port wine color after standing may contain:
B- porphyrins. Porphyrin is port wine red. Melanin would be black, and bilirubin would be amber to brown.
Acid urine that contains hemoglobin will darken on standing due to the formation of:
D. red blood cells
C- methemoglobin. Hemoglobin may be converted to methemoglobin in an acid urine. This will cause the sample to darken on standing.
Urine from a 50-year-old man was noted to turn dark red on standing. This change is caused by:
B- porphyrins. The 2 pigments are porphyrin and urochrome. Urochrome is "urine color" or yellow. Porphyrin is red.
The clarity of a urine sample should be determined:
A. using glass tubes only; never plastic
B. following thorough mixing of the specimen
C. after addition of sulfosalicylic acid
D. after the specimen cools to room temp
B- following thorough mixing of the specimen. Clarity or haziness is due to solids and cells in the solution. These settle to the bottom of the tube; therefore the sample should be well mixed.
A is false, you don't use glass tubes in urinalysis.
C is false, adding SSA will precipitate urines with positive protein.
D is false, allowing the specimen to cool to room temp may cause amorphous crystals to form.
Milky urine form a 24-year-old woman would most likely contain:
B. many white blood cells
C. red blood cells
B- many white blood cells. The 2 items listed that produce a white color are white blood cells and semen. It is more likely that a woman would have a UTI with many WBCs than enough post coital sperm contamination to make the urine white.
A brown-black urine would most likely contain:
A. bile pigment
D. blood cells
C- melanin. Melanin is black.
Bile is green/brown.
Porphrins are red.
Blood cells are red or white.
The yellow color of urine is primarily due to:
A. urochrome pigment
D. homogenistic acid
A- urochrome pigment.
The only normal pigment/substance listed here is urochrome.
Red urine may be due to:
B. excess urobilin
D. homogenistic acid
C- Myoglobin is red, like hemoglobin.
Homogenistic acid would produce a dark urine on standing.
Bilirubin is amber.
A urine specimen collected on an apparently healthy -year-old man shortly after he finished eating lunch was cloudy but showed normal results on a multiple reagent strip analysis. The most likely cause of the turbidity is:
B. white blood cells
Since the patient is healthy, assume the turbidity is caused by something nonpathologic. After meals, urine is more alkaline; this is referred to as the alkaline tide. Due to this pH, amorphous phosphates may be found.
In which of the following metabolic diseases will urine turn dark brown to black upon standing?
C. maple syrup disease
B- In alkaptonuria, the acid urine will turn black on standing.
Urine osmolality is related to:
C. specific gravity
C- specific gravity.
Both osmolality and specific gravity measure solutes in a solution.
Urine specific gravity is an index of the ability of the kidney to:
A. filter the plasma
B. concentrate the urine
C. alter the hydrogen ion concentration
D. reabsorb sodium ions
B- concentrate the urine.
Specific gravity gives the concentration for the sample relative to water. It does not give specific info about H+ or Na+ ions.
Osmolality is a measure of:
A. dissolved particles, including ions
B. undissociated molecules only
C. total salt concentration
D. molecule size
A- dissolved particles, including ions.
Salts will dissociate into ions, and each ion contributes to the osmolality.
A patient urine sample has an increased protein and a high specific gravity. Which of the following would be a more accurate measure of urine concentration?
C. refractive index
Only 2 of the answers, osmolality and refractive index, measure urine concentration. Refractive index is disproportionately affected by protein, so osmolality is the correct answer.
To prepare a solution appropriate for quality control of the refractometer, a technician should use:
A. urea with a specific gravity of 1.040
B. water with a specific gravity of 1.005
C. sodium chloride with a specific gravity of 1.022
D. calcium chloride with an osmolarity of 460
C- sodium chloride with a specific gravity of 1.022.
An easy to make control for urinalysis is 6.5% NaCl which has a specific gravity of 1.022.
A urine's specific gravity is directly proportional to its:
B. dissolved solids
C. salt content
D. sugar content
B. dissolved solids.
Dissolved solids, including salt, sugar, urea, etc contribute to specific gravity. Turbidity is caused by cells and crystals, which do not dissolve, and do not contribute to specific gravity.
Isosthenuria is associated with a specific gravity which is usually:
A. variable between 1.001 and 1.008
B. variable between 1.015 and 1.022
C. fixed around 1.010
D. fixed around 1.020
C- Isosthenuric urine has a specific gravity of 1.010.
A specific gravity less than that is termed hyposthenuric, and one greater that that is hypersthenuric.
The fluid leaving the glomerulus normally has a specific gravity of:
Fluid leaving the glomerulus is isosthenuric.
An antidiuretic hormone deficiency is associated with a:
A. specific gravity around 1.031
B. low specific gravity
C. high specific gravity
D. variable specific gravity
B- low specific gravity.
Diuretics cause people to lose water as urine. Antidiuretic hormone has the opposite effect, that of retaining water. A deficiency of ADH results in a loss of water in the urine. The amount of solutes (salts and sugars) is not altered, but they are diluted, resulting in a low specific gravity.
Use of a refractometer over a urinometer is preferred due to the fact that the refractometer uses:
A. large volume of urine and compensates for temp
B. small volume of urine and compensates for glucose
C. small volume of urine and compensates for temp
D. small volume of urine and compensates for protein
C- refractometers use small volumes of urine (1 drop) and compensate for temp.
A pitfall of refractometers is that they are disproportionately affected by glucose and protein.
Calibration of refractometers is done by measuring the specific gravity of distilled water and:
C. sodium chloride
C- sodium chloride.
Distilled water is used to calibrate the refractometer. Since protein and glucose cause refractometer error, these should not be used as calibrators. Urea is susceptible to urease from bacterial contamination. NaCl is cheap and reliable.
The method of choice for performing a specific gravity measurement of urine following administration of x-ray contrast dyes is:
A. reagent strip
A- reagent strip.
The reagent strip is not affected by contrast dye.
The refractometer reads the darker solution as density. A densitometer is a chem instrument, not a urinalysis instrument. A urinometer is not generally used in the modern lab.
Which of the following urinary parameters are measured during the course of concentration and dilution tests to assess renal tubular function?
A. urea, nitrogen and creatinine
B. osmolality and specific gravity
C. sodium and chloride
D. sodium and osmolality
B- osmolality and specific gravity.