Question

which of the following clinical laboratory tests requires the collection of urine for 24 hours?
a clean catch specimen
b creatinine clearance
c blood urea nitrogen
d culture and sensitivity

Explanation:

• A clean - catch specimen is a mid - stream urine sample collected at a single time point, not over 24 hours.
• Creatinine clearance measures the rate at which creatinine is cleared from the blood by the kidneys. To accurately calculate this, urine is collected over a 24 - hour period.
• Blood urea nitrogen (BUN) is a blood test, not a urine test that requires 24 - hour urine collection.
• Culture and sensitivity of urine is usually done on a single urine sample (not a 24 - hour collection) to identify bacteria in the urine and determine which antibiotics are effective against them.

Answer:

B. creatinine clearance