MLS Clinical Procedures & Protocols 3

Question 1

Which quality control rule is violated when two consecutive QC values fall more than 2 standard deviations from the mean on the same side?

Accepted Answer

Westgard 2-2s rule

Answer

Westgard 1-3s rule

Answer

Westgard R-4s rule

Answer

Westgard 1-2s warning rule

Question 2

A lab receives a request for a STAT troponin on a patient in the ED. The tube arrives unlabeled. What should the MLS do?

Accepted Answer

Reject the specimen and document per policy

Answer

Label it using the requisition and process immediately

Answer

Call the ED to verify and relabel, then process if confirmed

Answer

Process the test and document the discrepancy afterward

Question 3

What does a corrected reticulocyte count (reticulocyte production index, RPI) below 2 indicate?

Accepted Answer

Hypoproliferative or ineffective erythropoiesis

Answer

Adequate bone marrow response to anemia

Answer

Hemolytic process with increased RBC destruction

Answer

Polycythemia vera with erythroid hyperplasia

Question 4

When performing a Gram stain, decolorization with acetone-alcohol is the most critical step. Over-decolorization will cause:

Accepted Answer

Gram-positive organisms to appear pink/red

Answer

Gram-positive organisms to appear purple

Answer

Gram-negative organisms to appear purple

Answer

No change because the safranin counterstain corrects this

Question 5

A 24-hour urine is received for creatinine clearance. The volume is 850 mL. The serum creatinine is 1.2 mg/dL and the urine creatinine is 90 mg/dL. The patient weighs 70 kg and is 175 cm tall (BSA 1.8 m²). What should the MLS check FIRST before calculating clearance?

Accepted Answer

Confirm the collection start and end times are documented

Answer

Verify the specimen was kept refrigerated during collection

Answer

Repeat the serum creatinine on a new specimen

Answer

Check if the patient took any nephrotoxic drugs

Question 6

Which blood component is stored at 20–24°C with continuous agitation?

Accepted Answer

Platelets

Answer

Packed red blood cells

Answer

Fresh frozen plasma

Answer

Cryoprecipitate

Question 7

A cerebrospinal fluid specimen arrives with three tubes numbered 1, 2, and 3. Which tube should be sent to microbiology for culture?

Accepted Answer

Tube 3, because it is least likely to be contaminated with skin flora from the tap

Answer

Tube 1, because it has the freshest sample

Answer

Tube 2, because it is the cleanest for cell counts

Answer

Any tube, because all CSF tubes are equivalent for culture