Specimen Collection and Procurement Questions and Answers Flashcards
6 cards from real MLPAO practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 6 Specimen Collection and Procurement Questions and Answers flashcards as text
What is the significance of a yellow-grey (gold) top SST (serum separator tube) in blood collection?
Answer: It contains a clot activator and gel separator that migrates between clot and serum during centrifugation to produce serum
SST tubes contain silica particles that activate clotting and a polymer gel that forms a stable barrier between serum and the clot after centrifugation, providing a stable serum sample.
Which of the following is the most appropriate site for capillary blood collection in a premature neonate?
Answer: Medial or lateral plantar surface of the heel
The medial or lateral plantar surface of the heel is the approved capillary collection site for neonates and premature infants. Fingertips must never be used in neonates due to risk of bone injury.
In patients receiving intravenous (IV) infusions, what is the correct approach when drawing blood specimens from the same arm?
Answer: Stop the infusion, wait at least 2 minutes, collect distal to the IV site, and note the location on the requisition
Blood should not be collected from the same arm as an IV infusion. If unavoidable, stop the infusion for at least 2 minutes, collect below (distal to) the IV site, and note the IV fluid and collection site on the requisition.
What is a common cause of falsely elevated potassium in a venous blood specimen?
Answer: Delayed centrifugation in a tube without anticoagulant causing cell lysis
Delayed centrifugation of serum tubes allows continued glycolysis by RBCs and release of intracellular potassium (K+) into serum, falsely elevating potassium results — a common pre-analytical error.
What is the recommended maximum number of venipuncture attempts per phlebotomist during a single patient encounter?
Answer: Two attempts, then escalate to a more experienced collector
Most clinical laboratory standards recommend a maximum of two venipuncture attempts per phlebotomist. After two failed attempts, a more experienced collector should be requested to minimize patient discomfort and anxiety.
When is it necessary to collect a trough level for therapeutic drug monitoring (TDM) of vancomycin?
Answer: Immediately before the next scheduled vancomycin dose
Vancomycin trough levels are collected immediately before the next scheduled dose (at the lowest point in the dosing interval) to assess drug accumulation, dosing adequacy, and risk of toxicity.