MLS Treatment Planning & Management 3 — Questions and Answers
Question 1: A patient with type 2 diabetes has an HbA1c of 9.8%. After 3 months of metformin therapy, repeat HbA1c is 9.1%. This result MOST likely indicates:
- Treatment failure requiring insulin initiation
- Partial response; consider adding a second agent (Correct answer)
- Adequate glycemic control achieved
- Hemoglobin variant interfering with the assay
Correct answer: Partial response; consider adding a second agent
A 0.7% reduction with HbA1c still well above the 7% target suggests a partial response, supporting addition of a second antidiabetic agent.
Question 2: Which laboratory test is used to MONITOR patients receiving thiopurine therapy (azathioprine or 6-mercaptopurine) for inflammatory bowel disease?
- Serum drug level by immunoassay
- Thiopurine methyltransferase (TPMT) activity and thiopurine metabolite levels (Correct answer)
- CBC and liver function tests only
- Erythrocyte sedimentation rate
Correct answer: Thiopurine methyltransferase (TPMT) activity and thiopurine metabolite levels
TPMT genotype/phenotype guides dosing, while 6-TGN and 6-MMP metabolite levels help optimize efficacy and identify toxicity or non-adherence.
Question 3: A post-cardiac surgery patient has a heparin-induced thrombocytopenia (HIT) score of 6 (high probability). The CORRECT immediate management is to:
- Switch to low molecular weight heparin (LMWH)
- Stop all heparin and start a direct thrombin inhibitor (Correct answer)
- Transfuse platelets to prevent bleeding
- Reduce heparin dose and monitor platelet count daily
Correct answer: Stop all heparin and start a direct thrombin inhibitor
HIT is an immune-mediated thrombotic disorder; all heparin must be discontinued immediately and replaced with a non-heparin anticoagulant such as argatroban or bivalirudin.
Question 4: A patient's serum lithium level is 2.4 mEq/L. Which clinical scenario would explain why toxicity symptoms are ABSENT despite a supratherapeutic level?
- The sample was drawn in the distribution phase shortly after a dose (Correct answer)
- The patient has renal impairment causing accumulation
- The specimen was collected in a sodium-containing tube
- The patient metabolized lithium faster than expected
Correct answer: The sample was drawn in the distribution phase shortly after a dose
Lithium levels drawn within 1–2 hours of a dose reflect the distribution phase and are falsely elevated; trough levels at 12 hours post-dose are standard.
Question 5: Which platelet function test is used to guide antiplatelet therapy selection (aspirin vs. P2Y12 inhibitor) in high-risk cardiovascular patients?
- Platelet aggregometry (LTA) (Correct answer)
- Bleeding time
- D-dimer assay
- Thromboelastography (TEG)
Correct answer: Platelet aggregometry (LTA)
Light transmission aggregometry using ADP and arachidonic acid agonists assesses P2Y12 and COX-1 pathway inhibition to evaluate aspirin and P2Y12 inhibitor response.
Question 6: A patient with B12 deficiency is started on intramuscular cyanocobalamin injections. Which CBC change is expected FIRST after initiating therapy?
- Normalization of MCV
- Rise in reticulocyte count at 5–7 days (Correct answer)
- Correction of hypersegmented neutrophils
- Normalization of hemoglobin at 4 weeks
Correct answer: Rise in reticulocyte count at 5–7 days
Reticulocytosis peaks at 5–7 days post-B12 injection, confirming bone marrow response before macrocytosis or hemoglobin normalize.
Question 7: A neonate with hyperbilirubinemia has a total bilirubin of 22 mg/dL at 72 hours of life. The MOST appropriate laboratory-guided intervention is:
- Increase oral feeding frequency only
- Initiate phototherapy and obtain DAT and blood type (Correct answer)
- Perform exchange transfusion immediately
- Repeat bilirubin in 24 hours without intervention
Correct answer: Initiate phototherapy and obtain DAT and blood type
Total bilirubin at this level in a 3-day-old neonate meets phototherapy threshold; DAT and blood typing identify hemolytic causes requiring escalated management.
MLS Treatment Planning & Management 3
A patient with type 2 diabetes has an HbA1c of 9.8%.
After 3 months of metformin therapy, repeat HbA1c is 9.1%.
This result MOST likely indicates: