Urine Specimen Collection and Physical Exam of Urine

Random urine collection:

1. pateint prep

2. how to collect

3. what testing can be done

4. minimal/optimal volume

1. clear directions and proper cleansing

2. done at any time, avoid fluid intake and exercise, drink normal amount

3. routine screening

4. 25-50mLs (udeally 50)

First morning urine collection:

1. pateint prep

2. how to collect

3. what testing can be done

4. minimal/optimal volume

1. clear directions and proper cleansing

2. collect first thing in the morning, patient should empty bladder prior to bed night before

3. routine analysis (preferred b/c it’s most conc.)

4. 25-50 mLs (50 preferred)

timed urine collection

1. pateint prep

2. how to collect

3. what testing can be done

4. minimal/optimal volume

1. clear directions

2. collected for a specific predetermined time (usually 24 hours), patient should arise and discard first sample, then collect throughout the next 24 hours, the next day, arise at same time as the first day and keep sample

3. measuring chemicals

4. N/A

routine voided specimens (random or first morning):

1. pateint prep

2. how to collect

3. what testing can be done

4. minimal/optimal volume

1. clear instructions and proper cleansing

2. have pateint void into appropriate container

3. routine analysis

4. 25-50 mLs (ideally 50)

what is included in a routine analysis

chemical and physical

clean-catch midstream urine specimen:

1. patient prep

2. how to collect

3. what testing can be done

4. minimal/optimal volume

1. cleanse hands and urinary opening

2. urinate about 1/3 into the toilet then collect midstream until sterile container is half way to ¾ of the way full then urinate last portion into toilet

3. routine analysis, miroscopic analysis, and bacterial cultures

4. 25-50 mLs (ideally 50 mL)

what method prevents contamination from normal bacterial flora near the urethral opening

clean-catch midstream urine specimens

catheterized specimens:

1. pateint prep

2. how to collect

3. what testing can be done

1. sterile catheter is enserted through urethra into bladder

2. specimen can be collected at any time from the bag by medical personnel

3. routine analysis, microscopic analysis, and culture

suprapubic aspirations:

1. pateint prep

2. how to collect

3. what testing can be done

1. the abdominal wall and distended bladder is punctured using a needle and syringe

2. collected by medical personnel via syringe

3. anaerobic cultures (normally for infants), routine analysis, and microscopic analysis

how long can an unpresevered urine specimen sit until it must be analyzed

2 hours

what can happen to urine if it is not preserved within 2 hours of collection

1. alteration of solutes (some may metabolize to different forms causing false (+) and (-)

2. bacterial growth (bacteria multiply quickly esp. if there’s glucose)

3. solute precipitation (causes turbidity and seeing sediments under microscope becomes hard)

4. prevent degradation of formed elements in urine (they can dissolve overtime)

5. temperature changes and light

four most common types of urine preservatives

refridgeration, boric acid, formalin, and thymol

refridgeration advanatages and disadvantages

advantages: most common, easiest, preserves for 24 hours at 4-8 C, can do physical, chemical, microscopic, and culture, inhibits bacteria growth

disadvantages: change in temp causes crystals to precipitate out, increase in amorphus crystal formation

boric acid advanatages and disadvantages

advantages: good for 24-72 hours, can do physical, chemical, microscopic, and culture, amount used depends on how much urine you have

disadvantages: can’t do the pH portion of chemical because it decreases the pH

formalin advanatages and disadvantages

advantages: preserves for microscopic analysis

disadvantages: it is a reducing agent so it interferes with the chemical analysis

thymol advanatages and disadvantages

advantages: used for microscopic analysis

disadvantages: inhibits yeast and bacteria, interfere’s with protein precipitation

when should urine be rejected

unlabeled/mislabeled

wrong collection technique for test ordered

mismatch of specimen name/ID #

imrpoper specimen preservation

contamination

QNS (quanity not sufficient)

pigment responsible for color of urine

urochrome

normla range of colors of urine in a healthy person

light yellow → yellow → dark yellow

pink (or wine) urine is caused by

hgb in RBCs or porphyrin products (breakdown of heme)

red urine is caused by

a lot of hgb, myoglobin, dye in foods/candy, menstruation, fresh bleed

dark amber urine is caused by

increased amounts of bilirubin or biliverdin

brown urine is caused by

hgb in RBCs or myoglobin that have been oxidized from an old wound

black urine is caused by

decomposing RBCs, the conversion of hgb → methgb, alkaptonuria (genetic disease where body can’t breakdown homogenistic acid from the breakdown of amino acids because of missing enzyme), and increased levels of melanin (esp in melanoma)

yellow-green urine is caused by

biliverdin, chlorophyll, and certain UTI’s from Pseudomonas

orange-yellow urine is caused by

urobilin (product of bilirubin metabolism) and phenoazopyrudine (AZO)

other (blue, wine, etc) urine is caused by

food dyes

purpose of the foam test

to see if there’s an increased amount of protein in the urine (if the foam stays then there’s a lot of protein in the urine)

why do we assess urine clarity

can help in diagnosis of different diseases/conditions

normal range of clarity for healthy individual

clear → hazy

what can cuase cloudy/turbid urine specimens

bacteria (UTIs)

cells, casts, and crystals

mucus (protein strands)

yeast

sperm

precipitation of solutes (chemicals)

vaginal, fecal, or skin contamination

medications and x-ray contrast media

what should a normal urine smell like in a healthy individual

faintly aromatic

why would a urine smell like ammonia

due to bacteria (converts urea → ammonia) usually because it’s been unpreserved but can be due to UTI

why would a urine smell sweet or fruity

because of ketones (lipid metabolism converts fats → keto acids) due to diabetes, a keto diet, or starvation

why would a urine smell foul

because of a bad UTI

why would a urine smell like bleach

because it has bleach in it (lol)

why would a urine smell musty

because a perosn has phenylketonuria (PKU) where they lack the enzyme that breaks down phenylalanine so it accumulates and spills into the blood

why would a urine smell like maple syrup

because a person has maple syrup urine disease where a person is missing enzymes needed to break down three amino acids so they accumulate and spill into the urine

why would a urine smell rancid or like rotting fish

because a person has triethylaminuria where they lack the enzymes- needed to breakdown four amino acids so they accumulate and spill into the urine

why would a urine smell like cabbage or sweaty feet

lots of perspiration causing dehydration

why would a urine smell like onion, asparagus, or garlic

due to eating these foods

osmolality vs specific gravity

osmolality measures the number of particles only

specific gravity measures the number of particles and their weight (expression of density)

normal range of speecific gravity in normal healthy individuals

1.002 to 1.035

principle of preforming specific gravity with a refractometer

it is an indirect measurement of a refractive index of light

as light bends and speeds up/slows it is measured

a greater concentration has what angle, velocity, and SG

decreased angle

decreased velocity

increased specific gravity

a diluted concentration has what angle, velocity, and SG

increased angle

increased velocity

decreased specific gravity

what effects the refractive index of a solution

temperature (automatically corrects, 15-30C)

wavelength (automatically set, 589nm)

conc of the solution