urine specimen types, collection, preservation

left off on slide 18

what is urine

ultrafiltrate of plasma

what is the ideal test specimen for substances that require concentration or incubation for detection

first morning specimen

what specimen type is used to confirm postural (orthostatic) proteinuria

first morning specimen

what is a first morning specimen

urine sample collected first thing in the morning

what kind of urine are cells and casts most stable in

concentrated acidic urine

what can happen to high concentrations of salts in first morning specimens when left to cool at room temp

the salt may crystalize

what is a random urine sample

a urine sample collected at any time

what urine sample is most commonly used for routine screening in detecting abnormalities that may indicate disease

random urine specimen

what are the two types of timed collection urine specimen

predeterminesd length of time between samples; collection at a specific time

what kind of urine sample is used to screen for rmicroalbuminuria

predetermined length of time specimen

what urine sample is used to monitor urobilinogen

urine collection at a specific time

what time is the max amount of urobilinogen usually excreted in people

1400-1600

what are the four types of urine speciemsn

first morning, random, predetermined length of time, collection at specific time

what are the five urine collection techniques

routine void, midstream clean catch, catheterized specimen, suprapubic aspirations, pediatric collection

is a routine void sample appropriate for a urine culture

no it is not an optimal specimen

when are routine void samples used

routine urinalysis

what is the best specimen for routine analysis and urine culture

midstream clean catch

why is the midstream clean catch a ‘better’ specimen for cultures than routine

this technique prevents urethral washings from entering the specimen, eliminating any contamination

what is a urinary system issue common with catheterized patients

increased risk of UTI

what is a catheterized specimen

sterile catheter is insterted through urethra into the bladder or from the catheter bag

what collection technique is able to collect urine directly from each ureter of the kidney

catheterized specimen

what is a urine sample collected directly out of the ureter used to determine

this is to determine if one or both of the kidenys are involved in a disease process

what collection technique is principally for bacterial cultures especially for anaerobic microbe and in infants

suprapubic aspirations

why are urine samples from infants taken via suprapubic aspirations

this avoids specimen contamination when otherwise it would be unavoidable

what is a pediatric collection

plastic collector bags used for newborns, infants, and other pediatric patients who can’t urinate voluntarily

how is a pediatric collection done

the skin in the patient’s perineal area is cleansed and dried before the bag

is placed onto the skin with a hypoallergenic skin adhesive (over the penis for

males and around the vagina, excluding the anus, for females). The patient is

checked every fifteen minutes to see if there is specimen

what are five possible reasons for urine specimen rejection

unlabeled container, mislabeled container, inappropriately preserved specimen, visible contamination, quality not sufficient for testing

what is the most common urine preservation

refrigeration

what can refrigerated specimens be used for

culture and urinalysis

how long is refrigerated urine stable for

24 hrs

what is the gray top tube

BD vacutainer and contains buffered boric acid

how long is a gray top sample stable for at room temp

48 hours

what is a gray top sample used for

cultures only

what can happen to refrigerated urine

amophus urates/phosphares can precipitate as crystals

When should a sample be refrigerated

only if the sample can’t be analyzed within 2 hours of collection

what happens to the color of unpreserved urine and why

darkens or changes; oxidation or reduction of solutes (ex urobilinogen, bilirubin)

what happens to the clarity of unpreserved urine and why

it decreases due to crystal precipitation and bacterial proliferation

what happens to the odor of unpreserved urine and why

it increases in ammonia due to bac conversion of urea to ammonia and bacterial proliferation can cause a foul smell

what happens to the pH of unpreserved urine and why

it increases due to the bacterial conversion of urea to ammonia and the loss of CO2

what happens to the glucose of unpreserved urine and why

it decreases as it is consumbed by cells and/or bacteria

what happens to the ketones of unpreserved urine and why

it decreases due to volatizatin and bacterial conversion