MLS Diagnostic Procedures & Reporting 2

Question 1

A critical value for serum potassium is reported to the nurse. The nurse is unavailable. What is the correct next step?

Accepted Answer

Contact the charge nurse or covering physician and document

Answer

Critical values must be communicated to a responsible caregiver immediately; if the primary nurse is unavailable, the charge nurse or covering provider must be notified and all attempts documented.

Question 2

Which analyte requires a timed 24-hour urine collection for the most clinically meaningful result?

Accepted Answer

Creatinine clearance

Answer

Creatinine clearance requires a 24-hour urine collection to calculate glomerular filtration rate accurately by accounting for diurnal variation in excretion.

Question 3

A laboratory receives a blood culture bottle that has been incubating for 5 days with no growth signal. What is the standard reporting outcome?

Accepted Answer

Report 'No growth at 5 days' and discard

Answer

Standard blood culture incubation is 5 days; bottles with no instrument signal at that point are reported as 'No growth at 5 days' and discarded per protocol.

Question 4

Which of the following urine findings is most consistent with nephrotic syndrome?

Accepted Answer

3+ proteinuria with fatty casts and oval fat bodies

Answer

Nephrotic syndrome is characterized by massive proteinuria, hypoalbuminemia, and lipiduria, producing fatty casts and oval fat bodies (Maltese cross pattern) on urinalysis.

Question 5

A hemoglobin electrophoresis at alkaline pH shows a band migrating to the S position. Which confirmatory test best differentiates HbS from HbD?

Accepted Answer

Acid electrophoresis (pH 6.2)

Answer

Acid electrophoresis separates HbS from HbD because HbD migrates with HbA at acid pH while HbS remains in the S position, confirming the identity of the variant.

(MLS) Medical Laboratory Scientist Practice Test

(MLS) Medical Laboratory Scientist Practice Test

MLS Diagnostic Procedures & Reporting 2