M2U1: URINE SPECIMEN TYPES, COLLECTION AND PRESERVATION

Question 1

For urine preservatives what is the use of refrigeration ?

Answer 1

Storage before and after testing

Question 2

For urine preservatives what is the use of commercial transport tubes ?

Answer 2

Urine transport from off-site to laboratory

Question 3

For urine preservatives what is the use of boric acid ?

Answer 3

• Keeps pH at 6
• Bacteriostatic at 18 g/L
• Culture transport

Question 4

For urine preservatives what is the use of Thymol ?

Answer 4

Sediment preservation

Question 5

For urine preservatives what is the use of formalin ?

Answer 5

Cytology

Question 6

For urine preservatives what is the use of saccomanno’s fixative ?

Answer 6

Cytology

Question 7

For urine preservatives what is the use of acids ?

Answer 7

Quantitative analysis of steroids, hormones, and other solutes

Question 8

For urine preservatives what is the use of sodium carbonate ?

Answer 8

Quantitative analysis of porphyrins, porphobilinogen

Question 9

Change observed in unpreserved urine: Colour

Answer 9

darken - oxidation of reduction of solutes (urobilinogen, bilirubin)

Question 10

Change observed in unpreserved urine: Clarity

Answer 10

decreases - crystal precipitation; bacterial proliferation

Question 11

Change observed in unpreserved urine: Odor

Answer 11

ammoniacal - bacterial conversion of urea to ammonia; bacterial proliferation

Question 12

Change observed in unpreserved urine: pH

Answer 12

increase - bacterial conversion of urea to ammonia; loss of CO2

Question 13

Change observed in unpreserved urine: glucose

Answer 13

decrease - bacterial and cellular consumption

Question 14

Change observed in unpreserved urine: ketones

Answer 14

decrease - volatilization and bacterial conversion

Question 15

Change observed in unpreserved urine: bilirubin

Answer 15

decrease - photo-oxidiation to biliverdin

Question 16

Change observed in unpreserved urine: urobilinogen

Answer 16

decrease - oxidation to urobilin

Question 17

Change observed in unpreserved urine: nitrite

Answer 17

increase - bacterial conversion to nitrates

Question 18

Change observed in unpreserved urine: blood cells

Answer 18

decrease - lysis and disintegration

Question 19

Change observed in unpreserved urine: casts

Answer 19

decrease - lysis and disintegration

Question 20

Change observed in unpreserved urine: bacteria

Answer 20

increase - proliferation

Question 21

Change observed in unpreserved urine: trichomonads

Answer 21

decrease - loss of motility; death

Question 22

urine specimen should be delivered to the lab immediately within ___ hour

Answer 22

1 hour

Question 23

Refrigeration of the sample at __C to __C is commonly suitable for the majority of specimens

Answer 23

2C - 8C degrees

Question 24

why is refrigeration of routine urinalysis specimen not recommended if they will be analyzed within 2 hours ?

Answer 24

• it can induce precipitation oof amorphous urate and phosphate crystals and other non-pathologic crystals
• increase specific gravity

Question 25

what may be a reason to a patient’s urine specific gravity becomes greater than 1.040 ?

Answer 25

• recent injection of radiographic contrast media (x-ray dye)
• recent mannitol infusion

Question 26

What are the factors to make an ideal first morning urine specimen ?

Answer 26

• stored in the bladder for a minimum of 4 hours

- sleeping with an empty bladder

Question 27

which specimen type is characterized by hyperglycemia ?

Answer 27

second morning (fasting) specimen

Question 28

What time of the day is best to collect a timed urine for determination of urinary urobilinogen ?

Answer 28

2pm - 4pm

Question 29

What to do if the concentration of a particular substance remains constant in timed urine specimens ?

Answer 29

• they may be collected over a shorter period

- care must be taken to keep the patient hydrated